View source for CubeSat

{{Short description|Miniature satellite in 10 cm cube modules}}
[[File:Ncube2.jpg|thumb|[[nCube (satellite)|Ncube-2]], a Norwegian CubeSat ({{cvt|10|cm}} cube)]]
A '''CubeSat''' is a class of [[small satellite]] with a form factor of {{cvt|10|cm}} cubes.<ref>[https://static1.squarespace.com/static/5418c831e4b0fa4ecac1bacd/t/56e9b62337013b6c063a655a/1458157095454/cds_rev13_final2.pdf CubeSat Design Specification Rev. 13], The CubeSat Program, Cal Poly SLO</ref> CubeSats have a mass of no more than {{cvt|2|kg}} per unit,<ref name=":6">{{Cite book |url=https://static1.squarespace.com/static/5418c831e4b0fa4ecac1bacd/t/5f24997b6deea10cc52bb016/1596234122437/CDS+REV14+2020-07-31+DRAFT.pdf |title=Cubesat Design Specification |publisher=[[California Polytechnic State University, San Luis Obispo|Cal Poly SLO]] |year=2020 |location=[[San Luis Obispo]] |pages=12}}</ref> and often use [[commercial off-the-shelf]] (COTS) components for their [[electronics]] and structure. CubeSats are deployed into orbit from the [[International Space Station]], or launched as [[secondary payload]]s on a [[launch vehicle]].<ref name='database'/> {{As of|2023|December}}, more than 2,300 CubeSats have been launched.<ref name="auto">{{cite web |title=Nanosatellite & CubeSat Database |first=Erik |last=Kulu |date=28 August 2020 |url=https://www.nanosats.eu/ |access-date=5 January 2024}}</ref>
In 1999, [[California Polytechnic State University]] (Cal Poly) professor [[Jordi Puig-Suari]] and [[Bob Twiggs]], a professor at [[Stanford University]] Space Systems Development Laboratory, developed the CubeSat specifications to promote and develop the skills necessary for the design, manufacture, and testing of small satellites intended for [[low Earth orbit]] (LEO) that perform scientific research and explore new space technologies. Academia accounted for the majority of CubeSat launches until 2013, when more than half of launches were for non-academic purposes, and by 2014 most newly deployed CubeSats were for commercial or amateur projects.<ref name='database'/>
[[File:Nanosatellites yearly launches.svg|thumb|Yearly launched CubeSats as of December 2023<ref>{{Cite web| title = Nanosatellites by launch years | url = https://nanosats.eu| website = nanosats.eu| access-date = 2024-01-05}}</ref>]]
Functions typically involve experiments that can be miniaturized or serve purposes such as [[Earth observation]] or [[Amateur radio satellite|amateur radio]]. CubeSats are employed to demonstrate spacecraft technologies intended for small satellites or that present questionable feasibility and are unlikely to justify the cost of a larger satellite. Scientific experiments with unproven underlying theory may also find themselves aboard CubeSats because their low cost can justify higher risks. Biological research payloads have been flown on several missions, with more planned.<ref name=abio>{{Cite web|author=Prachi Patel |date=2010-07-12 |title=Tiny Satellites for Big Science |url=http://www.astrobio.net/news-exclusive/tiny-satellites-for-big-science/ |website=Astrobiology Magazine |access-date=2015-10-20 |archive-url=https://web.archive.org/web/20201120032126/http://www.astrobio.net/news-exclusive/tiny-satellites-for-big-science/ |archive-date=2020-11-20 |url-status=dead}}</ref> Several missions to the [[Moon]] and beyond are planning to use CubeSats.<ref>{{Cite web|title = Tiny Cubesats Set to Explore Deep Space|url = http://www.space.com/29306-cubesats-deep-space-exploration.html|website = Space.com| date=11 May 2015 |access-date = 2015-10-20}}</ref> The first CubeSats in deep space were flown in the [[Mars Cube One|MarCO]] mission, where two CubeSats were launched towards Mars in May 2018 alongside the successful ''[[InSight]]'' mission.<ref name="NYT-2010318">{{cite news |last=Stirone |first=Shannon |title=Space Is Very Big. Some of Its New Explorers Will Be Tiny. – The success of NASA's MarCO mission means that so-called cubesats likely will travel to distant reaches of our solar system. |url=https://www.nytimes.com/2019/03/18/science/cubesats-marco-mars.html |date=18 March 2019 |work=[[The New York Times]] |access-date=18 March 2019 }}</ref>
Some CubeSats have become [[Timeline of first artificial satellites by country|countries' first-ever satellites]], launched either by universities, state-owned, or private companies. The searchable Nanosatellite and CubeSat Database lists over 4,000 CubeSats that have been or are planned to be launched since 1998.<ref name="auto"/>
== History==
[[File:CubeSat in hand.jpg|thumb|1U CubeSat structure]]
Professors [[Jordi Puig-Suari]] of [[California Polytechnic State University]] and [[Bob Twiggs]] of [[Stanford University]] proposed the CubeSat [[reference design]] in 1999<ref name="Tiny">{{cite news |last= Messier |first= Douglas |url= http://www.space.com/29464-cubesats-space-science-missions.html |title= Tiny 'Cubesats' Gaining Bigger Role in Space |work= Space.com |date= 22 May 2015 |access-date= 2015-05-23 }}</ref><ref name=Helvajian2008>{{cite book|editor1-last= Helvajian|editor1-first= Henry|title= Small Satellites: Past, Present, and Future|year= 2008|publisher= Aerospace Press|location= El Segundo, Calif.|isbn= 978-1-884989-22-3|editor2-first= Siegfried W.|editor2-last= Janson}}</ref>{{rp|159}} with the aim of enabling [[graduate student]]s to design, build, test and operate in space a [[spacecraft]] with capabilities similar to that of the first spacecraft, [[Sputnik]]. The CubeSat, as initially proposed, did not set out to become a standard; rather, it became a standard over time by a process of [[emergence]]. The first CubeSats launched in June 2003 on a [[Russia]]n [[Eurockot]], and approximately 75 CubeSats had entered orbit by 2012.<ref name=sn20120813>{{cite news |title=Cubist Movement |newspaper= Space News |page= 30 | date = 2012-08-13 |quote= When professors [[Jordi Puig-Suari]] of [[California Polytechnic State University]] and [[Bob Twiggs]] of [[Stanford University]] invented the CubeSat, they never imagined that the tiny satellites would be adopted by universities, companies and government agencies around the world. They simply wanted to design a spacecraft with capabilities similar to [[Sputnik]] that graduate student could design, build, test and operate. For size, the professors settled on a ten-centimeter cube because it was large enough to accommodate a basic communications payload, [[Solar panels on spacecraft|solar panels]] and a battery. }}</ref>
The need for such a small-factor satellite became apparent in 1998 as a result of work done at Stanford University's Space System Development Laboratory. At SSDL, students had been working on the [[OPAL (Spacecraft)|OPAL]] (Orbiting Picosatellite Automatic Launcher) microsatellite since 1995. OPAL's mission to deploy daughter-ship "[[picosatellite]]s" had resulted in the development of a launcher system that was "hopelessly complicated" and could only be made to work "most of the time". With the project's delays mounting, Twiggs sought [[DARPA]] funding that resulted in the redesign of the launching mechanism into a simple pusher-plate concept with the satellites held in place by a spring-loaded door.<ref name="Helvajian2008" />{{rp|151–157}}
Desiring to shorten the development cycle experienced on OPAL and inspired by the picosatellites OPAL carried, Twiggs set out to find "how much could you reduce the size and still have a practical satellite". The picosatellites on OPAL were {{cvt|10.1|×|7.6|×|2.5|cm|0}}, a size that was not conducive to covering all sides of the spacecraft with solar cells. Inspired by a {{cvt|4|in|cm}} cubic plastic box used to display [[Beanie Babies]] in stores,<ref name=abio/> Twiggs first settled on the larger ten-centimeter cube as a guideline for the new CubeSat concept. A model of a launcher was developed for the new satellite using the same pusher-plate concept that had been used in the modified OPAL launcher. Twiggs presented the idea to Puig-Suari in the summer of 1999 and then at the Japan–U.S. Science, Technology and Space Applications Program (JUSTSAP) conference in November 1999.<ref name="Helvajian2008" />{{rp|157–159}}
The term "CubeSat" was coined to denote [[Miniaturized satellite#Nanosatellite|nanosatellites]] that adhere to the standards described in the CubeSat design specification. Cal Poly published the standard in an effort led by aerospace engineering professor Jordi Puig-Suari.<ref name="tiny">{{cite news | title = CubeSats: Tiny Spacecraft, Huge Payoffs | url = http://www.space.com/businesstechnology/cube_sats_040908.html | author = Leonard David | year = 2004 | work = [[Space.com]] | access-date = 2008-12-07 }}</ref> [[Bob Twiggs]], of the Department of Aeronautics & Astronautics at Stanford University, and currently a member of the space science faculty at Morehead State University in Kentucky, has contributed to the CubeSat community.<ref>{{cite news | url = http://spacefellowship.com/news/art14006/satellite-pioneer-joins-morehead-state-s-space-science-faculty.html | title = Satellite pioneer joins Morehead State's space science faculty | author = Rob Goldsmith | date = October 6, 2009 | work = [[Space Fellowship]] | access-date = 2010-09-20 | archive-url = https://web.archive.org/web/20131103070142/http://spacefellowship.com/news/art14006/satellite-pioneer-joins-morehead-state-s-space-science-faculty.html | archive-date = November 3, 2013 | url-status = dead }}</ref> His efforts have focused on CubeSats from educational institutions.<ref name="cnn">{{cite news | url = http://www.cnn.com/2006/TECH/space/08/30/cloudsat/index.html | title = CubeSat losses spur new development | author = Leonard David | year = 2006 | work = [[Space.com]] | access-date = 2008-12-11 }}</ref> The specification does not apply to other cube-like nanosatellites such as the NASA "MEPSI" nanosatellite, which is slightly larger than a CubeSat. GeneSat-1 was NASA's first fully automated, self-contained biological spaceflight experiment on a satellite of its size. It was also the first U.S.-launched CubeSat. This work, led by John Hines at NASA Ames Research, became the catalyst for the entire NASA CubeSat program.<ref>{{cite web
|url= https://www.nasa.gov/centers/ames/missions/2007/genesat1.html
|title= NASA – GeneSat-1
|access-date= 2017-02-11
|archive-date= 2021-11-14
|archive-url= https://web.archive.org/web/20211114005047/https://www.nasa.gov/centers/ames/missions/2007/genesat1.html
|url-status= dead
}}</ref>
In 2017, this standardization effort led to the publication of ISO 17770:2017 by the [[International Organization for Standardization]].<ref>{{Cite web |author=((Technical Committee ISO/TC 20/SC 14 (Space systems and operations) )) |date=June 2017 |title=ISO 17770:2017 |url=https://www.iso.org/standard/60496.html |access-date=2023-05-15 |website=[[International Organization for Standardization]]}}</ref> This standard defines specifications for CubeSats including their physical, mechanical, electrical, and operational requirements.<ref>{{Cite web |author=((Technical Committee ISO/TC 20/SC 14 (Space systems and operations) )) |date=June 2017 |title=ISO 17770:2017 Space systems — Cube satellites (CubeSats); Scope |url=https://www.iso.org/obp/ui/#iso:std:iso:17770:ed-1:v1:en |access-date=2023-05-15 |website=www.iso.org}}</ref> It also provides a specification for the interface between the CubeSat and its launch vehicle, which lists the capabilities required to survive the environmental conditions during and after launch and describes the standard deployment interface used to release the satellites. The development of standards shared by a large number of spacecraft contributes to a significant reduction in the development time and cost of CubeSat missions.
==Design==
The CubeSat specification accomplishes several high-level goals. The main reason for miniaturizing satellites is to reduce the cost of deployment: they are often suitable for launch in multiples, using the excess capacity of larger launch vehicles. The CubeSat design specifically minimizes risk to the rest of the launch vehicle and payloads. Encapsulation of the launcher–[[Payload (air and space craft)|payload]] interface takes away the amount of work that would previously be required for mating a piggyback satellite with its launcher. Unification among payloads and launchers enables quick exchanges of payloads and utilization of launch opportunities on short notice.
Standard CubeSats are made up of {{cvt|10x10x11.35|cm}} units designed to provide {{cvt|10x10x10|cm}} or {{cvt|1|L}} of useful volume, with each unit weighing no more than {{Cvt|2|kg|lb}}.<ref name=":6" /> The smallest standard size is 1U, consisting of a single unit, while the most common form factor was the 3U, which comprised over 40% of all nanosatellites launched to date.<ref>{{Cite web |last=Kulu |first=Erik |title=Cubesat types |url=https://www.nanosats.eu/#figures |access-date=2022-04-12 |website=Nanosats Database}}</ref><ref name='specs'>{{Cite web| url = https://static1.squarespace.com/static/5418c831e4b0fa4ecac1bacd/t/56e9b62337013b6c063a655a/1458157095454/cds_rev13_final2.pdf |title = CubeSat Design Specification| date = February 20, 2014| access-date = March 25, 2017|website = The CubeSat Program, CalPoly SLO|last = Mehrparvar|first = Arash}}</ref> Larger form factors, such as the 6U and 12U, are composed of 3Us stacked side by side.<ref name=":6" /> In 2014, two 6U [[Perseus-M]] CubeSats were launched for maritime surveillance, the largest yet at the time. The [[Mars Cube One]] (MarCO) mission in 2018 launched two 6U cubesats towards Mars.<ref>{{Cite web |title=MarCO: Planetary CubeSats Become Real |url=http://www.planetary.org/blogs/guest-blogs/van-kane/0708-marco-planetary-cubesats.html |access-date=2016-02-23 |website=www.planetary.org}}</ref><ref>{{Cite web |last=Clark |first=Stephen |title=Launch of NASA's next Mars mission delayed until at least 2018 {{!}} Spaceflight Now |url=http://spaceflightnow.com/2015/12/27/launch-of-nasas-next-mars-mission-delayed-until-at-least-2018/ |access-date=2016-02-23}}</ref>
Smaller, non-standard form factors also exist; [[The Aerospace Corporation]] has constructed and launched two smaller form CubeSats of 0.5U for radiation measurement and technological demonstration,<ref>{{Cite web|title = AeroCube 6A, 6B (CubeRad A, B)|url = http://space.skyrocket.de/doc_sdat/aerocube-6.htm|website = space.skyrocket.de| access-date = 2015-10-18}}</ref> while [[Swarm Technologies]] has built and deployed a constellation of over one hundred 0.25U CubeSats for [[Internet of things|IoT]] communication services.<ref>{{Cite web |title=SpaceBEE 10, ..., 180 |url=https://space.skyrocket.de/doc_sdat/spacebee-10.htm |access-date=2022-04-12 |website=Gunter's Space Page}}</ref><ref>{{Cite web |title=Swarm gets green light from FCC for its 150-satellite constellation |url=https://techcrunch.com/2019/10/17/swarm-gets-green-light-from-fcc-for-its-150-satellite-constellation/ |access-date=2022-04-12 |website=TechCrunch |date=18 October 2019}}</ref>
[[File:Scientist holding a CubeSat.jpg|thumb|Scientist holding a CubeSat chassis]]
Since nearly all CubeSats are {{cvt|10x10|cm}} (regardless of length) they can all be launched and deployed using a common deployment system called a Poly-PicoSatellite Orbital Deployer (P-POD), developed and built by Cal Poly.<ref name="esappod">{{cite web |title=Educational Payload on the Vega Maiden Flight – Call For CubeSat Proposals |url=http://esamultimedia.esa.int/docs/LEX-EC/CubeSat_CFP_issue_1_rev_1.pdf |year=2008 |publisher=[[European Space Agency]] |access-date=2008-12-07}}</ref>
No electronics [[Computer form factor|form factors]] or communications protocols are specified or required by the CubeSat Design Specification, but COTS hardware has consistently used certain features which many treat as standards in CubeSat electronics. Most COTS and custom designed electronics fit the form of [[PC/104]], which was not designed for CubeSats but presents a {{cvt|90x96|mm}} profile that allows most of the spacecraft's volume to be occupied. Technically, the PCI-104 form is the variant of PC/104 used<ref>{{Cite web|title = PCI/104-Express – PC/104 Consortium|url = http://pc104.org/hardware-specifications/pci104-express/|website = PC/104 Consortium|access-date = 2015-10-22}}</ref> and the actual [[pinout]] used does not reflect the pinout specified in the PCI-104 standard. Stackthrough connectors on the boards allow for simple assembly and electrical interfacing and most manufacturers of CubeSat electronics hardware hold to the same signal arrangement, but some products do not, so care must be taken to ensure consistent signal and power arrangements to prevent damage.<ref>{{Cite web| title=FAQ| url=http://www.cubesatshop.com/index.php?option=com_content&view=section&layout=blog&id=10&Itemid=82| website=www.cubesatshop.com| access-date=2015-10-22}}</ref>
Care must be taken in electronics selection to ensure the devices can tolerate the radiation present. For very [[low Earth orbit]]s (LEO) in which atmospheric reentry would occur in just days or weeks, [[radiation]] can largely be ignored and standard consumer grade electronics may be used. Consumer electronic devices can survive LEO radiation for that time as the chance of a [[single event upset]] (SEU) is very low. Spacecraft in a sustained low Earth orbit lasting months or years are at risk and only fly hardware designed for and tested in irradiated environments. Missions beyond low Earth orbit or which would remain in low Earth orbit for many years must use [[Radiation hardening|radiation-hardened]] devices.<ref>{{Cite web| title = Space Radiation Effects on Electronic Components in Low Earth Orbit| url = http://www.diyspaceexploration.com/space-radiation-effects-on-electronic-components-in-low-earth-orbit/| website = DIY Space Exploration| access-date = 2015-11-05| language = en-US| url-status = dead| archive-url = https://web.archive.org/web/20151027221637/http://www.diyspaceexploration.com/space-radiation-effects-on-electronic-components-in-low-earth-orbit/| archive-date = 2015-10-27}}</ref> Further considerations are made for operation in high vacuum due to the effects of [[Sublimation (phase transition)|sublimation]], [[outgassing]], and [[Whisker (metallurgy)|metal whiskers]], which may result in mission failure.<ref>{{Cite web| url = http://nepp.nasa.gov/whisker/failures/| title = Whisker Failures| access-date = 2015-11-05| date = 2009-08-09| publisher = NASA}}</ref>
===Structure===
The number of joined units classifies the size of CubeSats and according to the CubeSat Design Specification are [[Scalability|scalable]] along only one axis to fit the forms of 0.5U, 1U, 1.5U, 2U, or 3U. All the standard sizes of CubeSat have been built and launched, and represent the form factors for nearly all launched CubeSats as of 2015.<ref>{{Cite web| title = CubeSat| url = http://space.skyrocket.de/doc_sat/cubesat.htm| website = space.skyrocket.de| access-date = 2015-10-18}}</ref> Materials used in the structure must feature the same [[coefficient of thermal expansion]] as the deployer to prevent jamming. Specifically, allowed materials are four aluminum alloys: [[7075 aluminium alloy|7075]], [[6061 aluminium alloy|6061]], [[5005 aluminium alloy|5005]], and [[5052 aluminium alloy|5052]]. Aluminum used on the structure which contacts the P-POD must be [[anodize]]d to prevent [[cold welding]], and other materials may be used for the structure if a waiver is obtained.<ref name='specs'/> Beyond cold welding, further consideration is put into material selection as not all materials can be [[Materials for use in vacuum|used in vacuums]]. Structures often feature soft dampers at each end, typically made of rubber, to lessen the effects of impacting other CubeSats in the P-POD.
Protrusions beyond the maximum dimensions are allowed by the standard specification, to a maximum of {{cvt|6.5|mm}} beyond each side. Any protrusions may not interfere with the deployment rails and are typically occupied by antennas and solar panels. In Revision 13 of the CubeSat Design Specification an extra available volume was defined for use on 3U projects. The additional volume is made possible by space typically wasted in the P-POD Mk III's spring mechanism. 3U CubeSats which utilize the space are designated 3U+ and may place components in a cylindrical volume centered on one end of the CubeSat. The cylindrical space has a maximum diameter of {{cvt|6.4|cm}} and a height no greater than {{cvt|3.6|cm}} while not allowing for any increase in mass beyond the 3U's maximum of {{cvt|4|kg}}. Propulsion systems and antennas are the most common components that might require the additional volume, though the payload sometimes extends into this volume. Deviations from the dimension and mass requirements can be waived following application and negotiation with the [[launch service provider]].<ref name='specs'/>
CubeSat structures do not have all the same strength concerns as larger satellites do, as they have the added benefit of the deployer supporting them structurally during launch.<ref>{{Cite journal |last=Thomas |first=Daniel |date=2021-11-01 |title=Enhancing the electrical and mechanical properties of graphene nanoplatelet composites for 3D printed microsatellite structures |url=https://www.sciencedirect.com/science/article/pii/S2214860421003754 |journal=Additive Manufacturing |volume=47 |pages=102215 |doi=10.1016/j.addma.2021.102215 |issn=2214-8604}}</ref> Still, some CubeSats will undergo [[Structural dynamics|vibration analysis]] or [[structural analysis]] to ensure that components unsupported by the P-POD remain structurally sound throughout the launch.<ref>{{Cite journal| title = Stress and Thermal Analysis of CubeSat Structure | journal = Applied Mechanics and Materials| pages = 426–430| volume = 554| doi = 10.4028/www.scientific.net/amm.554.426| first1 = Nur| last1 = Athirah| first2 = Mohd| last2 = Afendi| first3 = Ku| last3 = Hafizan| first4 = N.A.M.| last4 = Amin| first5 = M.S. Abdul| last5 = Majid|year = 2014| s2cid = 110559952}}</ref> Despite rarely undergoing the analysis that larger satellites do, CubeSats rarely fail due to mechanical issues.<ref>{{Cite journal| url=http://web.csulb.edu/~hill/ee400d/Project%20Folder/CubeSat/The%20First%20One%20Hundred%20Cubesats.pdf| title=The First One Hundred CubeSats: A Statistical Look| last=Swartwout| first=Michael| date=December 2013| journal=Journal of Small Satellites| volume=2| issue=2| pages=213| bibcode=2013JSSat...2..213S| access-date=28 November 2015| archive-date=8 December 2015| archive-url=https://web.archive.org/web/20151208093346/http://web.csulb.edu/~hill/ee400d/Project%20Folder/CubeSat/The%20First%20One%20Hundred%20Cubesats.pdf| url-status=dead}}</ref>
===Computing===
Like larger satellites, CubeSats often feature multiple computers handling different tasks in [[Parallel computing|parallel]] including the [[Spacecraft attitude control|attitude control]] (orientation), power management, payload operation, and primary control tasks. COTS attitude-control systems typically include their own computer, as do the power management systems. Payloads must be able to interface with the primary computer to be useful, which sometimes requires the use of another small computer. This may be due to limitations in the primary computer's ability to control the payload with limited communication protocols, to prevent overloading the primary computer with raw data handling, or to ensure payload's operation continues uninterrupted by the spacecraft's other computing needs such as communication. Still, the primary computer may be used for payload related tasks, which might include [[image processing]], [[data analysis]], and [[data compression]]. Tasks which the primary computer typically handles include the delegation of tasks to the other computers, attitude control, calculations for [[orbital maneuver]]s, [[Scheduling (computing)|scheduling]], and activation of active thermal control components. CubeSat computers are highly susceptible to radiation and builders will take special steps to ensure proper operation in the high radiation of space, such as the use of [[ECC memory|ECC RAM]]. Some satellites may incorporate [[Redundancy (engineering)|redundancy]] by implementing multiple primary computers; this could be done on valuable missions to lessen the risk of mission failure. Consumer [[smartphone]]s have been used for computing in some CubeSats, such as NASA's [[PhoneSat]]s.
===Attitude control===
[[File:Near Earth Asteroid Scout.jpg|thumb|[[Near-Earth Asteroid Scout]] concept: a controllable [[solar sail]] CubeSat]]
[[Spacecraft attitude control|Attitude control]] (orientation) for CubeSats relies on miniaturizing technology without significant performance degradation. Tumbling typically occurs as soon as a CubeSat is deployed, due to asymmetric deployment forces and bumping with other CubeSats. Some CubeSats operate normally while tumbling, but those that require pointing in a certain direction or cannot operate safely while spinning, must be detumbled. Systems that perform attitude determination and control include [[reaction wheel]]s, [[magnetorquer]]s, thrusters, [[star tracker]]s, [[Sun sensor]]s, Earth sensors, [[angular rate sensor]]s, and [[GPS navigation device|GPS receivers and antennas]]. Combinations of these systems are typically seen in order to take each method's advantages and mitigate their shortcomings. [[Reaction wheels]] are commonly utilized for their ability to impart relatively large [[Moment (physics)|moments]] for any given energy input, but reaction wheel's utility is limited due to saturation, the point at which a wheel cannot spin faster. Examples of CubeSat reaction wheels include the Maryland Aerospace MAI-101<ref>{{Cite web| url = http://maiaero.com/products/s/mai-101/| title = Maryland Aerospace Reaction Wheels| access-date = September 4, 2015| url-status = dead| archive-url = https://web.archive.org/web/20150716161428/http://maiaero.com/products/s/mai-101/| archive-date = July 16, 2015}}</ref> and the Sinclair Interplanetary RW-0.03-4.<ref>{{Cite web| url = http://www.sinclairinterplanetary.com/reactionwheels| title = Sinclair Interplanetary Reaction Wheels| access-date = September 4, 2015| archive-date = September 24, 2015| archive-url = https://web.archive.org/web/20150924101944/http://www.sinclairinterplanetary.com/reactionwheels| url-status = dead}}</ref> Reaction wheels can be desaturated with the use of thrusters or magnetorquers. Thrusters can provide large moments by imparting a [[Couple (mechanics)|couple]] on the spacecraft but inefficiencies in small propulsion systems cause thrusters to run out of fuel rapidly. Commonly found on nearly all CubeSats are magnetorquers which run electricity through a coil to take advantage of Earth's magnetic field to produce a [[Moment (physics)|turning moment]]. Attitude-control modules and solar panels typically feature built-in magnetorquers. For CubeSats that only need to detumble, no attitude determination method beyond an [[angular rate sensor]] or electronic [[gyroscope]] is necessary.
Pointing in a specific direction is necessary for Earth observation, orbital maneuvers, maximizing solar power, and some scientific instruments. Directional pointing accuracy can be achieved by sensing Earth and its horizon, the Sun, or specific stars. Sinclair Interplanetary's SS-411 Sun sensor<ref>{{Cite web| url = http://www.sinclairinterplanetary.com/digitalsunsensors| title = Sinclair Interplanetary Sun Sensors| access-date = September 4, 2015| archive-date = November 17, 2015| archive-url = https://web.archive.org/web/20151117032733/http://www.sinclairinterplanetary.com/digitalsunsensors| url-status = dead}}</ref> and ST-16 star tracker<ref>{{Cite web| url = http://www.sinclairinterplanetary.com/startrackers| title = Sinclair Interplanetary Star Trackers| access-date = September 4, 2015| archive-date = September 24, 2015| archive-url = https://web.archive.org/web/20150924101946/http://www.sinclairinterplanetary.com/startrackers| url-status = dead}}</ref> both have applications for CubeSats and have flight heritage. Pumpkin's Colony I Bus uses an aerodynamic wing for passive attitude stabilization.<ref>{{Cite web| url = http://www.cubesatkit.com/docs/press/Pumpkin_GAINSTAM_2009.pdf| title = Pumkin's Colony I CubeSat Bus| date = 4 Nov 2009| access-date = September 4, 2015| last = Kalman| first = Andrew}}</ref> Determination of a CubeSat's location can be done through the use of on-board GPS, which is relatively expensive for a CubeSat, or by relaying radar tracking data to the craft from Earth-based tracking systems.
=== Propulsion ===
CubeSat propulsion has made rapid advancements in: [[Cold gas thruster|cold gas]], [[Rocket engine|chemical propulsion]], [[Electrically powered spacecraft propulsion|electric propulsion]], and [[solar sail]]s. The biggest challenge with CubeSat propulsion is preventing risk to the launch vehicle and its primary [[payload]] while still providing significant capability.<ref>{{Cite web| url = https://www.nasa.gov/sites/default/files/files/Small_Spacecraft_Technology_State_of_the_Art_2014.pdf| title = Small Spacecraft Technology State of the Art| date = February 2014| access-date = September 4, 2015| website = NASA| publisher = NASA Ames| last = Frost| first = Chad| url-status = dead| archive-url = https://web.archive.org/web/20150226081748/http://www.nasa.gov/sites/default/files/files/Small_Spacecraft_Technology_State_of_the_Art_2014.pdf| archive-date = February 26, 2015}}</ref> Components and methods that are commonly used in larger satellites are disallowed or limited, and the CubeSat Design Specification (CDS) requires a waiver for pressurization above {{cvt|1.2|atm}}, over 100 Wh of stored chemical energy, and hazardous materials.<ref name='specs'/> Those restrictions pose great challenges for CubeSat propulsion systems, as typical space propulsion systems utilize combinations of high pressures, high energy densities, and hazardous materials. Beyond the restrictions set forth by [[launch service provider]]s, various technical challenges further reduce the usefulness of CubeSat propulsion. [[Gimbaled thrust]] cannot be used in small engines due to the complexity of gimbaling mechanisms, thrust vectoring must instead be achieved by thrusting asymmetrically in multiple-nozzle propulsion systems or by changing the center of mass relative to the CubeSat's geometry with actuated components.<ref>{{Cite web| title = PowerCube| url = http://www.tethers.com/PowerCube.html| website = www.tethers.com| access-date = 2015-11-26}}</ref> Small motors may also not have room for [[Throttle|throttling]] methods that allow smaller than fully on thrust, which is important for precision maneuvers such as [[Space rendezvous|rendezvous]].<ref>{{Cite book| chapter = Liquid-Propellant Rocket Engine Throttling: A Comprehensive Review| publisher = American Institute of Aeronautics and Astronautics| doi = 10.2514/6.2009-5135| first1 = Matthew| last1 = Casiano| first2 = James| last2 = Hulka|author3-link=Vigor Yang| first3 = Vigor| last3 = Yang| title = 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit| year = 2009| isbn = 978-1-60086-972-3| hdl = 2060/20090037061| s2cid = 111415930}}</ref> CubeSats which require longer life also benefit from propulsion systems; when used for [[Orbital station-keeping|orbit keeping]] a propulsion system can slow [[orbital decay]].
==== Cold gas thrusters ====
A [[cold gas thruster]] typically stores [[inert gas]], such as [[nitrogen]], in a [[Pressure vessel|pressurized tank]] and releases the gas through a [[Rocket engine nozzle|nozzle]] to produce thrust. Operation is handled by just a single [[valve]] in most systems, which makes cold gas the simplest useful propulsion technology.<ref name=":1">{{Cite web|title=Spacecraft Propulsion – Chemical |url=http://www.sv.vt.edu/classes/ESM4714/Student_Proj/class03/stillwater/prj/background/sp_chemical.htm| website=www.sv.vt.edu| access-date=2015-11-26| archive-url=https://web.archive.org/web/20151004075951/http://www.sv.vt.edu/classes/ESM4714/Student_Proj/class03/stillwater/prj/background/sp_chemical.htm| archive-date=2015-10-04| url-status=dead}}</ref> Cold gas propulsion systems can be very safe since the gases used do not have to be volatile or [[Corrosive substance|corrosive]], though some systems opt to feature dangerous gases such as [[sulfur dioxide]].<ref>{{Cite web| title=Propulsion Unit for Cubesats (PUC)| url=http://www.cuaerospace.com/Products/SmallSatellitePropulsion/TabId/195/ArtMID/737/ArticleID/169/Propulsion-for-Cubesats-PUC-%E2%80%93-A-Smart-Robust-Propulsion-System-for-CubeSats.aspx| access-date=26 Nov 2015| publisher=CU Aerospace, LLC}}</ref> This ability to use inert gases is highly advantageous to CubeSats as they are usually restricted from hazardous materials. Only low performance can be achieved with them,<ref name=":1" /> preventing high impulse maneuvers even in low mass CubeSats. Due to this low performance, their use in CubeSats for main propulsion is limited and designers choose higher efficiency systems with only minor increases in complexity. Cold gas systems more often see use in CubeSat attitude control.
==== Chemical propulsion ====
[[Rocket engine|Chemical propulsion]] systems use a chemical reaction to produce a high-pressure, high-temperature gas that accelerates out of a [[Propelling nozzle|nozzle]]. Chemical propellant can be liquid, solid or a hybrid of both. Liquid propellants can be a [[Monopropellant rocket|monopropellant]] passed through a [[catalyst]], or [[Liquid-propellant rocket|bipropellant]] which [[Combustion|combusts]] an [[Oxidizing agent|oxidizer]] and a [[fuel]]. The benefits of [[Monopropellant rocket|monopropellants]] are relatively low-complexity/high-thrust output, low power requirements, and high reliability. Monopropellant motors tend to have high thrust while remaining comparatively simple, which also provides high reliability. These motors are practical for CubeSats due to their low power requirements and because their simplicity allows them to be very small. Small [[hydrazine]] fueled motors have been developed,<ref name=":0">{{Cite web| url=http://www.rocket.com/cubesat| title=Aerojet CubeSat Thrusters| access-date=September 4, 2015| website=Aerojet Rocketdyne| archive-url=https://web.archive.org/web/20150823030523/http://www.rocket.com/cubesat| archive-date=August 23, 2015| url-status=dead}}</ref> but may require a waiver to fly due to restrictions on hazardous chemicals set forth in the CubeSat Design Specification.<ref name="specs" /> Safer chemical propellants which would not require hazardous chemical waivers are being developed, such as AF-M315 ([[hydroxylammonium nitrate]]) for which motors are being or have been designed.<ref name=":0" /><ref>{{Cite web |url=http://busek.com/technologies__greenmonoprop.htm |title=Busek Green monopropellant thruster |access-date=September 4, 2015 |website=Busek Space Propulsion |publisher=Busek}}</ref> A "Water Electrolysis Thruster" is technically a chemical propulsion system, as it burns [[hydrogen]] and [[oxygen]] which it generates by on-orbit [[electrolysis of water]].<ref name="Tethers2015">{{cite web |url=http://www.tethers.com/HYDROS.html |title=HYDROS – Water Electrolysis Thruster |work=Tethers Unlimited, Inc. |date=2015 |access-date=2015-06-10}}</ref>
==== Electric propulsion ====
[[File:BIT-3 Iodine 60W with BHC-50E.jpg|thumb|The [[Busek]] BIT-3 [[gridded ion thruster]] will be used to propel the [[Lunar IceCube]] 6U CubeSat.]]
CubeSat [[Electrically powered spacecraft propulsion|electric propulsion]] typically uses electric energy to accelerate propellant to high speed, which results in high [[specific impulse]]. Many of these technologies can be made small enough for use in nanosatellites, and several methods are in development. Types of electric propulsion currently being designed for use in CubeSats include [[Hall-effect thruster]]s,<ref>{{Cite web| title = Busek Hall Effect Thrusters| url = http://www.busek.com/technologies__hall.htm| website = www.busek.com| access-date = 2015-11-27}}</ref> [[ion thruster]]s,<ref>{{Cite web| title = Busek Ion Thrusters| url = http://www.busek.com/technologies__ion.htm| website = www.busek.com| access-date = 2015-11-27}}</ref> [[pulsed plasma thruster]]s,<ref>{{Cite web| title = PPTCUP| url = http://www.mars-space.co.uk/projects/pptcup| website = www.mars-space.co.uk| access-date = 2015-11-27| archive-url = https://web.archive.org/web/20151208051408/http://www.mars-space.co.uk/projects/pptcup| archive-date = 2015-12-08| url-status = dead}}</ref> [[Colloid thruster|electrospray thrusters]],<ref>{{Cite web|title = Busek Electrospray Thrusters| url = http://www.busek.com/technologies__espray.htm| website = www.busek.com| access-date = 2015-11-27}}</ref> and [[Resistojet rocket|resistojets]].<ref>{{Cite web| title = Busek Electrothermal Thrusters| url = http://www.busek.com/technologies__therm.htm| website = www.busek.com| access-date = 2015-11-27| archive-date = 2015-12-08| archive-url = https://web.archive.org/web/20151208055749/http://www.busek.com/technologies__therm.htm| url-status = dead}}</ref> Several notable CubeSat missions plan to use electric propulsion, such as NASA's [[Lunar IceCube]].<ref name="LunarIceCube2015">{{cite web |url=http://www.nasa.gov/feature/goddard/lunar-icecube-to-take-on-big-mission-from-small-package |title=Lunar IceCube to Take on Big Mission from Small Package |work=NASA |date=2015 |access-date=2015-09-01 }}</ref> The high efficiency associated with electric propulsion could allow CubeSats to propel themselves to Mars.<ref name="Mars2015">{{cite news |url=http://www.thespacereview.com/article/2506/1 |title=Mars missions on the cheap |work=The Space Review |location=USA |date=5 May 2014 |access-date=2015-05-21 }}</ref> Electric propulsion systems are disadvantaged in their use of power, which requires the CubeSat to have larger solar cells, more complicated power distribution, and often larger batteries. Furthermore, many electric propulsion methods may still require pressurized tanks to store propellant, which is restricted by the CubeSat Design Specification.
The [[ESTCube-1]] used an [[Electric sail|electric solar-wind sail]], which relies on an electromagnetic field to act as a sail instead of a solid material. This technology used an [[electric field]] to deflect [[protons]] from [[solar wind]] to produce thrust. It is similar to an [[electrodynamic tether]] in that the craft only needs to supply electricity to operate.
==== Solar sail ====
[[Solar sail]]s&nbsp;(also called&nbsp;light sails&nbsp;or&nbsp;photon sails) are a form of&nbsp;spacecraft propulsion&nbsp;using the&nbsp;[[radiation pressure]]&nbsp;(also called solar pressure) from stars to push large ultra-thin mirrors to high speeds, requiring no propellant. Force from a solar sail scales with the sail's area, this makes sails well suited for use in CubeSats as their small mass results in the greater acceleration for a given solar sail's area. However, solar sails still need to be quite large compared to the satellite, which means useful solar sails must be  deployed, adding mechanical complexity and a potential source of failure. This propulsion method is the only one not plagued with restrictions set by the CubeSat Design Specification, as it does not require high pressures, hazardous materials, or significant chemical energy. A small number of CubeSats have employed a solar sail as its main propulsion and stability in deep space, including the 3U [[NanoSail-D2]] launched in 2010, and the [[LightSail-1]] in May 2015.
[[LightSail-2]] successfully deployed on a Falcon Heavy rocket in 2019,<ref name="Name change">{{cite news |last=Davis |first=Jason |url=http://www.planetary.org/blogs/jason-davis/2016/20160229-meet-lightsail-2.html |title=Meet LightSail 2, The Planetary Society's new solar sailing CubeSat |work=The Planetary Society |date=1 March 2016 |access-date=2016-03-01}}</ref><ref>{{Cite web |url=https://www.planetary.org/blogs/jason-davis/lightsail-2-successful-flight-by-light.html |title=LightSail 2 Spacecraft Successfully Demonstrates Flight by Light |website=www.planetary.org |access-date=2020-02-29}}</ref> while one CubeSat that was planned to launch on the [[Space Launch System]]'s first flight ([[Artemis 1]]) in November 2022 was set to use a solar sail: the [[Near-Earth Asteroid Scout]] (NEA Scout).<ref name="McNutt">{{cite web |last1=McNutt |first1=Leslie |last2=Castillo-Rogez |first2=Julie |date=2014 |title=Near-Earth Asteroid Scout |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140012882.pdf |access-date=2015-05-13 |work=NASA |publisher=American Institute of Aeronautics and Astronautics}}</ref> The CubeSat was declared lost when communications were not established within 2 days.<ref>{{Cite web |last=Dickinson |first=David |date=2022-12-06 |title=Status Update: Artemis 1's SmallSat Missions |url=https://skyandtelescope.org/astronomy-news/status-update-artemis-1s-smallsat-missions/ |access-date=2023-04-23 |website=Sky&Telescope}}</ref>
===Power===
[[File:Winglet Pumpkin Solar Pannels for CubeSat.png|thumb|Winglet solar panels increase surface area for power generation.]]
CubeSats use [[solar cell]]s to convert solar light to electricity that is then stored in rechargeable [[Lithium-ion battery|lithium-ion batteries]] that provide power during eclipse as well as during peak load times.<ref>{{cite web |url=http://www.diyspaceexploration.com/power-system-budget-analysis/ |title=CubeSats: Power System and Budget Analysis |work=DIY Space Exploration |date=2015 |access-date=2015-05-22 |url-status=dead |archive-url=https://web.archive.org/web/20150522113355/http://www.diyspaceexploration.com/power-system-budget-analysis/ |archive-date=2015-05-22 }}</ref> These satellites have a limited surface area on their external walls for solar cells assembly, and has to be effectively shared with other parts, such as antennas, optical sensors, camera lens, propulsion systems, and access ports. Lithium-ion batteries feature high energy-to-mass ratios, making them well suited to use on mass-restricted spacecraft. Battery charging and discharging is typically handled by a dedicated electrical power system (EPS). Batteries sometimes feature heaters<ref>{{Cite web| title = Batteries|url = http://cubesatcookbook.com/directory/batteries/ |website = The CubeSat Cookbook|date = 9 March 2010 | access-date = 2015-10-20}}</ref> to prevent the battery from reaching dangerously low temperatures which might cause battery and mission failure.<ref>{{Cite web|title = Lithium Battery Failures| url = http://www.mpoweruk.com/lithium_failures.htm| website = www.mpoweruk.com| access-date = 2015-10-20}}</ref>
The rate at which the batteries decay depends on the number of cycles for which they are charged and discharged, as well as the depth of each discharge: the greater the average depth of discharge, the faster a battery degrades. For LEO missions, the number of cycles of discharge can be expected to be on the order of several hundred.
Due to size and weight constraints, common CubeSats flying in LEO with body-mounted solar panels have generated less than 10 W.<ref>{{Cite journal|last1=Spangelo|first1=Sara|last2=Longmier|first2=Benjamin|date=2015-04-20|title=Optimization of CubeSat System-Level Design and Propulsion Systems for Earth-Escape Missions|journal=Journal of Spacecraft and Rockets|volume=52|issue=4|pages=1009–1020|doi=10.2514/1.A33136|bibcode=2015JSpRo..52.1009S|issn=0022-4650|hdl=2027.42/140416|url=https://deepblue.lib.umich.edu/bitstream/2027.42/140416/1/1.A33136.pdf|hdl-access=free}}</ref> Missions with higher power requirements can make use of [[Spacecraft attitude control|attitude control]] to ensure the solar panels remain in their most effective orientation toward the Sun, and further power needs can be met through the addition and orientation of deployable solar arrays, which can be unfolded to a substantially larger area on-orbit. Recent innovations include additional spring-loaded solar arrays that deploy as soon as the satellite is released, as well as arrays that feature [[thermal knife]] mechanisms that would deploy the panels when commanded. CubeSats may not be powered between launch and deployment, and must feature a [[remove before flight|remove-before-flight]] pin which cuts all power to prevent operation during loading into the P-POD. Additionally, a deployment switch is actuated while the craft is loaded into a P-POD, cutting power to the spacecraft and is deactivated after exiting the P-POD.<ref name="specs" />
===Telecommunications===
[[File:Secondary antennas4.gif|thumb|upright=0.8|Deployable high-gain mesh reflector antenna operating at Ka-band (27–40 GHz) for the radar in a CubeSat ([[RaInCube]])]]
The low cost of CubeSats has enabled unprecedented access to space for smaller institutions and organizations but, for most CubeSat forms, the range and available power is limited to about 2&nbsp;W for its communications antennae.<ref name="Grumman2014">{{cite news|last=Ochoa|first=Daniel |url=http://www.northropgrumman.com/BusinessVentures/AstroAerospace/Documents/pageDocs/tech_papers/SmallSat_DeployableHelical_ochoa_SSC14-IX-4.pdf |title=Deployable Helical Antenna for Nano-Satellite |work=Northrop Grumman Aerospace Systems |date=2014 |access-date=2015-05-21 |archive-date=2016-05-13 |archive-url=https://web.archive.org/web/20160513193738/http://www.northropgrumman.com/BusinessVentures/AstroAerospace/Documents/pageDocs/tech_papers/SmallSat_DeployableHelical_ochoa_SSC14-IX-4.pdf |url-status=dead }}</ref>
Because of tumbling and low power range, radio-communications are a challenge. Many CubeSats use an [[omnidirectional antenna|omnidirectional]] [[monopole antenna|monopole]] or [[dipole antenna]] built with commercial measuring tape. For more demanding needs, some companies offer [[high-gain antenna]]e for CubeSats, but their deployment and pointing systems are significantly more complex.<ref name="Grumman2014"/> For example, [[Massachusetts Institute of Technology|MIT]] and [[Jet Propulsion Laboratory|JPL]] are developing an inflatable dish antenna based on a [[mylar]] skin inflated with a [[sublimation (phase transition)|sublimating powder]], claiming a 7× boost in range—potentially able to reach the Moon—but questions linger concerning survivability after micrometeor impacts.<ref name="InflatableDish">{{cite news |last=Chu |first=Jennifer |url=http://newsoffice.mit.edu/2013/inflatable-antennae-could-give-cubesats-greater-reach-0906 |title=Inflatable antennae could give CubeSats greater reach |work=MIT News |location=USA |date=6 September 2015 |access-date=2015-05-21 }}</ref> JPL has successfully developed [[X band|X-band]] and [[Ka band|Ka-band]] high-gain antennas for [[Mars Cube One|MarCO]]<ref name=":3">{{Cite book |last1=Hodges |first1=R. E. |last2=Chahat |first2=N. E. |last3=Hoppe |first3=D. J. |last4=Vacchione |first4=J. D. |title=2016 IEEE International Symposium on Antennas and Propagation (APSURSI) |chapter=The Mars Cube One deployable high gain antenna |date=2016-06-01 |pages=1533–1534 |doi=10.1109/APS.2016.7696473 |isbn=978-1-5090-2886-3 |s2cid=27368017}}</ref><ref name=":4">{{Cite web |url=http://hackaday.com/2017/02/22/interview-nacer-chahat-designs-antennae-for-mars-cubesats/|title=Dr. Nacer Chahat Interview on High-gain deployable antennas for CubeSats|last=Chahat|first=Nacer|date=2017-02-22|website=Hackaday}}</ref> and Radar in a CubeSat ([[RaInCube]]) missions.<ref name=":4"/><ref>{{Cite journal |last1=Chahat |first1=N. |last2=Hodges |first2=R. E. |last3=Sauder |first3=J. |last4=Thomson |first4=M. |last5=Peral |first5=E. |last6=Rahmat-Samii |first6=Y. |date=2016-06-01 |title=CubeSat Deployable Ka-Band Mesh Reflector Antenna Development for Earth Science Missions |journal=IEEE Transactions on Antennas and Propagation |volume=64 |issue=6 |pages=2083–2093 |doi=10.1109/TAP.2016.2546306 |issn=0018-926X |bibcode=2016ITAP...64.2083C |s2cid=31730643}}</ref><ref>{{Cite web |url=http://www.jpl.nasa.gov/news/news.php?feature=6672|title=A Box of 'Black Magic' to Study Earth from Space |website=NASA/JPL |access-date=2017-01-22}}</ref>
==== Antennas ====
Traditionally, [[Low Earth orbit|Low Earth Orbit]] Cubesats use antennas for communication purpose at UHF and S-band. To venture farther in the solar system, larger antennas compatible with the [[NASA Deep Space Network|Deep Space Network]] (X-band and Ka-band) are required. [[Jet Propulsion Laboratory|JPL]]'s engineers developed several deployable high-gain antennas compatible with 6U-class CubeSats<ref>{{cite book |last=Chahat |first=Nacer |editor-first1=Nacer |editor-last1=Chahat |author-link= |date= 13 December 2020 |title=CubeSat Antenna Design |url= https://onlinelibrary.wiley.com/doi/book/10.1002/9781119692720 |location= |publisher=Wiley |page= |doi=10.1002/9781119692720 |isbn= 9781119692584 |s2cid=242921969 }}</ref> for MarCO<ref name=":3" /><ref name=":5">{{Cite web|url=http://hackaday.com/2017/02/22/interview-nacer-chahat-designs-antennae-for-mars-cubesats/|title=Interview: Nacer Chahat Designs Antennas for Mars CubeSats|last=By|website=Hackaday|access-date=2017-02-25|date=2017-02-22}}</ref> and [[Near-Earth Asteroid Scout]].<ref>{{Cite web|url=https://www.nasa.gov/content/nea-scout|title=NEA Scout mission|date=2015-10-30|website=NASA.gov}}</ref> JPL's engineers have also developed a {{cvt|0.5|m}} mesh reflector antenna operating at Ka-band and compatible with the DSN<ref name=":3" /><ref name=":5" /><ref>{{Cite journal|last1=Chahat|first1=N.|last2=Hodges|first2=R. E.|last3=Sauder|first3=J.|last4=Thomson|first4=M.|last5=Rahmat-Samii|first5=Y.|date=2017-01-01|title=Deep Space Network Telecommunication CubeSat Antenna: Using the deployable Ka-band mesh reflector antenna.|journal=IEEE Antennas and Propagation Magazine|volume=PP|issue=99|pages=31–38|doi=10.1109/MAP.2017.2655576|issn=1045-9243|bibcode=2017IAPM...59...31C|s2cid=25220479}}</ref> that folds in a 1.5U stowage volume. For MarCO, JPL's antenna engineers designed a Folded Panel Reflectarray (FPR)<ref>{{Cite journal|last1=Hodges|first1=R. E.|last2=Chahat|first2=N.|last3=Hoppe|first3=D. J.|last4=Vacchione|first4=J. D.|date=2017-01-01|title=A Deployable High-Gain Antenna Bound for Mars: Developing a new folded-panel reflectarray for the first CubeSat mission to Mars.|journal=IEEE Antennas and Propagation Magazine|volume=PP|issue=99|pages=39–49|doi=10.1109/MAP.2017.2655561|issn=1045-9243|bibcode=2017IAPM...59...39H|s2cid=35388830}}</ref> to fit on a 6U CubeSat bus and supports X-band Mars-to-Earth telecommunications at 8&nbsp;kbit/s at 1AU.
=== Thermal management ===
Different CubeSat components possess different acceptable temperature ranges, beyond which they may become temporarily or permanently inoperable. Satellites in orbit are heated by [[Thermal radiation|radiative heat]] emitted from the [[Sun]] directly and reflected off Earth, as well as heat generated by the craft's components. CubeSats must also [[Radiative cooling|cool by radiating heat]] either into space or into the cooler Earth's surface, if it is cooler than the spacecraft. All of these radiative heat sources and sinks are rather constant and very predictable, so long as the CubeSat's orbit and eclipse time are known.
Components used to ensure the temperature requirements are met in CubeSats include [[multi-layer insulation]] and [[Heating element|heaters]] for the battery. Other [[spacecraft thermal control]] techniques in small satellites include specific component placement based on expected thermal output of those components and, rarely, deployed thermal devices such as [[louver]]s. Analysis and simulation of the spacecraft's thermal model is an important determining factor in applying thermal management components and techniques. CubeSats with special thermal concerns, often associated with certain deployment mechanisms and payloads, may be tested in a [[thermal vacuum chamber]] before launch. Such testing provides a larger degree of assurance than full-sized satellites can receive, since CubeSats are small enough to fit inside of a thermal vacuum chamber in their entirety. [[Thermometer|Temperature sensor]]s are typically placed on different CubeSat components so that action may be taken to avoid dangerous temperature ranges, such as reorienting the craft in order to avoid or introduce direct thermal radiation to a specific part, thereby allowing it to cool or heat.
===Costs===
CubeSat forms a cost-effective independent means of getting a payload into orbit.<ref name="tiny"/> After delays from low-cost launchers such as [[Interorbital Systems]],<ref>As noted in the linked article, Interorbital promised its Neptune 45 – intended to carry ten CubeSats, among other cargo – would launch in 2011, but as of 2014 it had yet to do so.</ref> launch prices have been about $100,000 per unit,<ref>{{cite web | title = OSSI-1 Amateur Radio CubeSat launched | url = http://www.southgatearc.org/news/april2013/ossi_1_amateur_radio_cubesat_launched.htm | year = 2013 | publisher = Southgate Amateur Radio News | access-date = 2014-07-07 | archive-url = https://web.archive.org/web/20150924104046/http://www.southgatearc.org/news/april2013/ossi_1_amateur_radio_cubesat_launched.htm | archive-date = 2015-09-24 | url-status = dead }}</ref><ref>{{Cite web|title = Commercial Space Launch Schedule and Pricing|url = http://www.spaceflightindustries.com/schedule-pricing/|website = Spaceflight|access-date = 2015-10-18|url-status = dead|archive-url = https://web.archive.org/web/20151016001943/http://www.spaceflightindustries.com/schedule-pricing/|archive-date = 2015-10-16}}</ref> but newer operators are offering lower  pricing.<ref>[https://rocketlabusa.com/space-is-open-for-business-online/ "Space Is Open For Business, Online"], rocketlabusa.com</ref> A typical price to launch a 1U cubesat with a full service contract (including end-to-end integration, licensing, transportation etc.) was about $60,000 in 2021.
Some CubeSats have complicated components or instruments, such as [[LightSail-1]], that push their construction cost into the millions of dollars,<ref>{{Cite web| title = After letdown, solar-sail project rises again| url = http://www.nbcnews.com/id/33812469/ns/technology_and_science-space/#.ViPAwitRKVI| archive-url = https://web.archive.org/web/20150518095341/http://www.nbcnews.com/id/33812469/ns/technology_and_science-space/#.ViPAwitRKVI| url-status = dead| archive-date = May 18, 2015| website = msnbc.com| access-date = 2015-10-18| date = 2009-11-10}}</ref> but a basic 1U CubeSat can cost about $50,000 to construct.<ref>{{Cite web| title = Cubesats explained and why you should build one| url = http://www.diyspaceexploration.com/what-are-cubesats/| website = DIY Space Exploration| access-date = 2015-10-18| url-status = dead| archive-url = https://web.archive.org/web/20151013051317/http://www.diyspaceexploration.com/what-are-cubesats| archive-date = 2015-10-13}}</ref> This makes CubeSats a viable option for some schools, universities, and small businesses.
==Past missions==
{{main|List of CubeSats}}
[[File:NanoRacksCubeSatLaunch ISS038-E-056389.jpg|thumb|upright=1.15|left|[[NanoRacks]] CubeSats being launched from the [[NanoRacks CubeSat Deployer]] on the ISS on February 25, 2014]]
The ''Nanosatellite & Cubesat Database'' lists over 2,000 CubeSats that have been launched since 1998.<ref name="auto"/> One of the earliest CubeSat launches was on 30 June 2003 from Plesetsk, Russia, with [[Eurockot Launch Services]]'s ''Multiple Orbit Mission''. The CubeSats were injected into a [[Sun-synchronous orbit]] and included the Danish [[AAU CubeSat]] and DTUSat, the Japanese XI-IV and CUTE-1, the Canadian Can X-1, and the US [[Quakesat]].<ref>{{cite web |url=http://www.eurockot.com/alist.asp?cnt=20040706&main=5 |publisher=[[Eurockot Launch Services]] |title=EUROCKOT Successfully Launches MOM – Rockot hits different Orbits |access-date=2010-07-26 |archive-url=https://web.archive.org/web/20100303013451/http://www.eurockot.com/alist.asp?cnt=20040706&main=5 |archive-date=2010-03-03 |url-status=dead}}</ref>
On February 13, 2012, three P-POD deployers containing seven CubeSats were placed into orbit along with the [[LARES (satellite)|Lares]] satellite aboard a [[Vega (rocket)|Vega]] rocket launched from French Guiana. The CubeSats launched were [[e-st@r]] Space (Politecnico di Torino, Italy), Goliat (University of Bucharest, Romania), [[MaSat-1]] (Budapest University of Technology and Economics, Hungary), [[PW-Sat]] (Warsaw University of Technology, Poland), Robusta (University of Montpellier 2, France), [[UniCubeSat-GG]] (University of Rome La Sapienza, Italy), and [[Xatcobeo|XaTcobeo]] (University of Vigo and INTA, Spain). The CubeSats were launched in the framework of the "Vega Maiden Flight" opportunity of the European Space Agency.<ref>{{cite web |url=http://www.esa.int/Our_Activities/Launchers/Launch_vehicles/Vega3/CubeSats | title = Seven Cubesats launched on Vega's maiden flight |author=ESA |date=13 February 2012 |publisher=European Space Agency |access-date=February 3, 2014 |author-link=ESA |archive-url= https://web.archive.org/web/20131113012113/http://www.esa.int/Our_Activities/Launchers/Launch_vehicles/Vega3/CubeSats |archive-date=13 November 2013 |url-status=dead}}</ref>
On September 13, 2012, eleven CubeSats were launched from eight P-PODs, as part of the "OutSat" secondary payload aboard a [[United Launch Alliance]] [[Atlas V]] rocket.<ref>{{cite news |url=https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/csswe |title=Air Force Launches Secret Spy Satellite NROL-36 |date=Sep 2012 |work=[[Space.com]] |access-date=March 21, 2013}}</ref> This was the largest number of CubeSats (and largest volume of 24U) orbited on a single launch so far, made possible by the new NPS CubeSat Launcher system ([[NPSCuL]]) developed at the Naval Postgraduate School (NPS). The CubeSats were: SMDC-ONE 2.2 (Baker), SMDC-ONE 2.1 (Able), AeroCube 4.0(x3), Aeneas, [[CSSWE]], CP5, [[CXBN]], CINEMA, and Re (STARE).<ref>{{cite web |url=http://www.nro.gov/news/press/2012/2012-09.pdf |title=NROL-36 Features Auxiliary Payloads |author=NRO |date=June 2012 |publisher=National Reconnaissance Office |access-date=March 21, 2013 |archive-url=https://web.archive.org/web/20130217180351/http://www.nro.gov/news/press/2012/2012-09.pdf |archive-date=February 17, 2013 |url-status=dead}}</ref>
Five CubeSats ([[RAIKO (satellite)|Raiko]], [[Niwaka]], [[We-Wish]], [[TechEdSat]], [[F-1 (satellite)|F-1]]) were placed into orbit from the [[International Space Station]] on October 4, 2012, as a technology demonstration of small satellite deployment from the ISS. They were launched and delivered to ISS as a cargo of [[Kounotori 3]], and an ISS astronaut prepared the deployment mechanism attached to [[Japanese Experiment Module]]'s robotic arm.<ref>{{cite web |url= http://www.jaxa.jp/press/2011/03/20110302_sac_smallsat.pdf | title = 「きぼう」からの小型衛星放出に係る技術検証について |language=ja |trans-title=On Technical Verification of Releasing Small Satellites from "Kibo" | author = Kuniaki Shiraki | publisher = [[JAXA]] | date = March 2, 2011 | access-date = March 4, 2011 }}</ref><ref>{{cite web |url= http://www.jaxa.jp/press/2011/06/20110615_sac_smallsat.pdf | title = 「きぼう」からの小型衛星放出実証ミッションに係る搭載小型衛星の選定結果について | publisher = JAXA | author = Mitsumasa Takahashi | date = June 15, 2011 | access-date = June 18, 2011 }}</ref><ref>{{cite web |url=http://iss.jaxa.jp/kibo/about/jssod/ |title=「きぼう」日本実験棟からの小型衛星放出ミッション |language=ja |publisher=JAXA |date=October 5, 2012 |access-date=December 1, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20121113230512/http://iss.jaxa.jp/kibo/about/jssod/ |archive-date=November 13, 2012 }}</ref>
Four CubeSats were deployed from the [[Cygnus Mass Simulator]], which was launched April 21, 2013 on the maiden flight of Orbital Sciences' [[Antares (rocket)|Antares rocket]].<ref name=OSSlideBriefing>{{cite web |url=http://www.orbital.com/Antares-Cygnus/files/Pre-Launch-Guest-Briefing.pdf | title = Antares Test Launch "A-ONE Mission" Overview Briefing | date = 17 April 2013 | publisher = Orbital Sciences | access-date = 18 April 2013 }}</ref> Three of them are 1U [[PhoneSat]]s built by NASA's [[Ames Research Center]] to demonstrate the use of [[Smartphone|smart phones]] as [[avionics]] in CubeSats. The fourth was a 3U satellite, called Dove-1, built by [[Planet Labs]].
On April 26, 2013 [[NEE-01 Pegaso]] was launched and was the first CubeSat able to transmit live video from orbit, also the first 1U CubeSat to achieve more than 100 watts of power as installed capacity. Later in November same year [[NEE-02 Krysaor]] also transmitted live video from orbit. Both CubeSats were built by the [[Ecuadorian Space Agency]].
A total of thirty-three CubeSats were deployed from the ISS on February 11, 2014. Of those thirty-three, twenty-eight were part of the [[Flock-1]] constellation of Earth-imaging CubeSats. Of the other five, two are from other US-based companies, two from Lithuania, and one from Peru.<ref>{{cite web |url=http://www.spacenews.com/article/civil-space/39459planet-labs-cubesats-deployed-from-iss-with-many-more-to-follow |archive-url=https://archive.today/20140309044632/http://www.spacenews.com/article/civil-space/39459planet-labs-cubesats-deployed-from-iss-with-many-more-to-follow |url-status=dead |archive-date=March 9, 2014 |title=Planet Labs CubeSats Deployed from ISS with Many More To Follow |author=Debra Werner |date=February 11, 2014 |publisher=SpaceNews, Inc. |access-date=March 8, 2014}}</ref>
The [[LightSail-1]] is a 3U CubeSat prototype propelled by a [[solar sail]]. It was launched on 20 May 2015 from Florida. Its four sails are made of very thin [[Mylar]] and have a total area of {{cvt|32|m2}}. This test will allow a full checkout of the satellite's systems in advance of the main 2016 mission.<ref name=planetary20150126>{{cite web |url=http://www.planetary.org/blogs/jason-davis/2015/20150112-lightsail-test-flight.html |title=It's Official: LightSail Test Flight Scheduled for May 2015 |date=January 26, 2015 |last=Davis |first=Jason |work=[[The Planetary Society]]}}</ref>
On October 5, 2015, AAUSAT5 (Aalborg University, Denmark), was deployed from the ISS. launched in the framework of the "Fly Your Satellite!" programme of the European Space Agency.<ref>{{cite web |url=http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/AAUSAT5_CubeSat_starts_its_space_mission |title=AAUSAT5 CubeSat starts its space mission |author=ESA |date=9 October 2015 |publisher=European Space Agency |access-date=September 28, 2016 |author-link=ESA}}</ref>
The [[Miniature X-ray Solar Spectrometer CubeSat]] is a 3U launched to the [[International Space Station]] on 6 December 2015 from where it was deployed on 16 May 2016. It is the first mission launched in the [[NASA]] Science Mission Directorate CubeSat Integration Panel,<ref>[http://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_166651.pdf NASA Briefing to Committee on Achieving Science Goals with CubeSats]</ref> which is focused on doing science with CubeSats. As of 12 July 2016, the minimum mission success criterion (one month of science observations) has been met, but the spacecraft continues to perform nominally and observations continue.<ref>{{cite web|url=http://lasp.colorado.edu/home/minxss/2016/07/12/minimum-mission-success-criteria-met/|title=The Miniature X-ray Solar Spectrometer (MinXSS) » Minimum mission success criteria met|date=12 July 2016 }}</ref>
Three CubeSats were launched on April 25, 2016, together with Sentinel-1B on a Soyuz rocket VS14 launched from Kourou, French Guiana. The satellites were: AAUSAT4 (Aalborg University, Denmark), e-st@r-II (Politecnico di Torino, Italy) and OUFTI-1 (Université de Liège, Belgium). The CubeSats were launched in the framework of the "Fly Your Satellite!" programme of the European Space Agency.<ref>{{cite web |url=http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/Student_satellites_fly_freely_on_their_orbit_in_space |title=Student satellites fly freely on their orbit in_space |author=ESA |date=26 April 2016 |publisher=European Space Agency |access-date=April 26, 2016 |author-link=ESA}}</ref>
On February 15, 2017, Indian Space Research Organisation ([[ISRO]]) set a record with the launch of 104 satellites on a single rocket. The launch of [[PSLV-C37]] in a single payload, including the Cartosat-2 series and 103 co-passenger satellites, together weighed over {{cvt|650|kg}}. Of the 104 satellites, all but three were CubeSats. Of the 101 nano satellites, 96 were from the United States and one each from Israel, Kazakhstan, the Netherlands, Switzerland and the United Arab Emirates.<ref>{{cite web |url=https://www.reuters.com/article/us-space-launch-satellites-india-idUSKBN15U0EI |title=India launches record 104 satellites at one go |date=15 February 2017 |publisher=[[Reuters]] |access-date=February 15, 2017}}</ref><ref>{{cite web |url=http://spacenews.com/india-sets-record-with-launch-of-104-satellites-on-a-single-rocket/ |title=India sets record with launch of 104 satellites on a single rocket |date=15 February 2017 |access-date=February 15, 2017 }}</ref>
===2018 InSight mission: MarCO CubeSats===
[[File:PIA19388-Mars-InSight-MarCO-CubeSats-20150612.jpg|thumb|An artist's rendering of [[Mars Cube One|MarCO]] A and B during the descent of [[InSight]]]]
The May 2018 launch of the ''[[InSight]]'' stationary Mars lander included two CubeSats to fly by Mars to provide additional relay communications from ''InSight'' to Earth during entry and landing.<ref name=":2">{{Cite news |url=https://www.nytimes.com/2016/03/10/science/nasa-reschedules-mars-insight-mission-for-may-2018.html|title=NASA Reschedules Mars InSight Mission for May 2018|last=Chang|first=Kenneth|date=2016-03-09|newspaper=The New York Times|issn=0362-4331|access-date=2016-04-28}}</ref> This is the first flight of CubeSats outside of the Earth's direct orbit. The mission CubeSat technology is called [[Mars Cube One]] (MarCO); each one is a six-unit CubeSat, {{cvt|14.4x9.5x4.6|in|cm}}. MarCO is an experiment, but not necessary for the ''InSight'' mission, to add relay communications to space missions in important time durations, in this case from the time of ''InSight'' atmospheric entry to its landing.
MarCO launched in May 2018 with the ''InSight'' lander, separated after launch and then traveled in their own trajectories to Mars. After separation, both MarCO spacecraft deployed two radio antennas and two solar panels. The high-gain, [[X band]] antenna is a flat panel to direct radio waves. MarCO navigated to Mars independently from the ''InSight'' lander, making their own course adjustments on the flight.
During ''InSight''{{'s}} entry, descent and landing (EDL) in November 2018,<ref name=":2" /> the lander transmitted telemetry in the [[UHF]] radio band to NASA's [[Mars Reconnaissance Orbiter]] (MRO) flying overhead. MRO forwarded EDL information to Earth using a radio frequency in the X band, but cannot simultaneously receive information in one band if transmitting on another. Confirmation of a successful landing could be received on Earth several hours after, so MarCO was a technology demonstration of real-time telemetry during the landing.<ref>{{Cite web|title=NASA Prepares for First Interplanetary CubeSat Mission| date=12 June 2015 |url=http://www.nasa.gov/press-release/nasa-prepares-for-first-interplanetary-cubesats-on-agency-s-next-mission-to-mars |access-date=2015-06-12}}</ref><ref>{{Cite web |title=NASA Prepares for First Interplanetary CubeSats |url=http://www.jpl.nasa.gov/news/news.php?feature=4622 |website=www.jpl.nasa.gov |date=12 June 2015 |access-date=2015-06-12 |url-status=live |archive-url= https://web.archive.org/web/20150717042851/http://www.jpl.nasa.gov/news/news.php?feature=4622 |archive-date=2015-07-17}}</ref><ref>{{Cite web|title=InSight Mars Lander|date=23 February 2015|publisher=NASA|url=http://www.nasa.gov/mission_pages/insight/main/index.html|access-date=2015-06-12|archive-date=2015-06-13|archive-url=https://web.archive.org/web/20150613223152/http://www.nasa.gov/mission_pages/insight/main/index.html|url-status=dead}}</ref>
{{multiple image |total_width=630|header=Views from MarCO |align=center|caption_align=center|image1=PIA22830 Two Days Till Mars for MarCO, Annotated version.jpg |caption1=Mars (24 November 2018) |image2=PIA22742-FirstImageFromA-CubeSAT-MarCO-Mars-20181002.jpg |caption2=Mars (2 October 2018) |image3=PIA22323 First Image from MarCO-B, Annotated Version.jpg|caption3=Earth and Moon (9 May 2018)}}
{{clear}}
==Programs ==
[[File:NanoRacks CubeSat Deployer deploying SHARC.jpg|thumb|NanoRacks]]
===CubeSat Launch Initiative===
NASA's CubeSat Launch Initiative created in 2010,<ref>{{cite web |title=NASA's CubeSat Launch Initiative |website=[[NASA]] |archive-url=https://web.archive.org/web/20230627024112/https://www.nasa.gov/directorates/heo/home/CubeSats_initiative/ |archive-date=2023-06-27 |url-status=live |url=http://www.nasa.gov/directorates/heo/home/CubeSats_initiative}}</ref> provides CubeSat launch opportunities to educational institutions, non-profit organizations and NASA Centers. {{asof|2016}} the CubeSat Launch Initiative had launched 46 CubeSats flown on 12 ELaNa Missions from 28 unique organizations and has selected 119 CubeSat missions from 66 unique organizations. [[Educational Launch of Nanosatellites]] (ELaNa) missions have included: BisonSat the first CubeSat built by a tribal college, TJ3Sat the first CubeSat built by a high school and STMSat-1 the first CubeSat built by an elementary school. NASA releases an Announcement of Opportunity<ref>{{cite web |title=Announcement of Partnership Opportunity for CubeSat Launch Initiative |website=[[NASA]] |archive-url=https://web.archive.org/web/20221225011141/https://www.nasa.gov/content/announcement-of-opportunity-for-cubesat-launch-initiative/ |archive-date=2022-12-25 |url-status=live |url=http://www.nasa.gov/content/announcement-of-opportunity-for-cubesat-launch-initiative}}</ref> in August of each year with selections made the following February.<ref>{{cite web|last1=Galica|first1=Carol|title=NASA CubeSat Launch Initiative|url=http://www.nasa.gov/content/about-cubesat-launch-initiative|publisher=NASA|access-date=18 October 2016}}</ref>
=== Artemis 1 ===
NASA initiated the Cube Quest Challenge in 2015, a competition to foster innovation in the use of CubeSats beyond low Earth orbit. The Cube Quest Challenge offered $5&nbsp;million to teams that met the challenge objectives of designing, building and delivering flight-qualified, small satellites capable of advanced operations near and beyond the Moon. Teams competed for a variety of prizes in lunar orbit or deep space.<ref>{{Cite web| title = Cube Quest Challenge| url = http://www.nasa.gov/cubequest/details/| website = NASA.gov| access-date = 2016-08-01| language = en-US| archive-date = 2016-07-26| archive-url = https://web.archive.org/web/20160726123934/http://www.nasa.gov/cubequest/details/| url-status = dead}}</ref> 10 CubeSats from different teams were launched to cislunar space as secondary payloads on board the [[Artemis 1#Payloads|Artemis 1]] in 2022.
=== ESA "Fly Your Satellite!" ===
"Fly Your Satellite!" is the ongoing CubeSats programme of the Education Office of the [[European Space Agency]]. University students have the opportunity to develop and implement their CubeSat mission with support of ESA specialists.<ref>[http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite Fly Your Satellite!] ESA.</ref> Participating student teams can experience the full cycle from designing, building, and testing to eventually, the possibility of launching and operating their CubeSat.<ref>{{Cite web| title= Call for Proposals Fly Your Satellite| url= http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/Call_for_Proposals_Fly_Your_Satellite| website= esa.int| access-date= 2016-09-28}}</ref> The fourth iteration of the Fly Your Satellite! programme closed a call for proposals in February 2022.<ref>{{Cite web |title=Call for proposals: Fly Your Satellite! 4 |url=https://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/Call_for_proposals_Fly_Your_Satellite!_4 |access-date=2022-04-02 |website=www.esa.int}}</ref>
=== Canadian Cubesat Project ===
The Canadian Space Agency announced the Canadian CubeSat Project (CCP) in 2017, and the participating teams were selected in May of 2018. The programme provides funding and support to one university or college in each province and territory to develop a CubeSat for launch from the ISS. The objective of the CCP is to provide students with direct hands on experience in the space industry, while preparing them to enter into a career in the space domain.<ref>{{Cite web |last=Agency |first=Canadian Space |date=2018-05-02 |title=What is the Canadian CubeSat Project |url=https://www.asc-csa.gc.ca/eng/satellites/cubesat/what-is-the-canadian-cubesat-project.asp |access-date=2022-04-02 |website=www.asc-csa.gc.ca}}</ref>
===QB50===
QB50 is a proposed international network of 50 CubeSats for multi-point, ''in-situ'' measurements in the lower [[thermosphere]] (90–350&nbsp;km) and re-entry research. QB50 is an initiative of the [[Von Karman Institute]] and is funded by the European Commission as part of the 7th Framework Programme (FP7). Double-unit (2U) CubeSats (10×10×20&nbsp;cm) are developed, with one unit (the 'functional' unit) providing the usual satellite functions and the other unit (the 'science' unit) accommodating a set of standardised sensors for lower thermosphere and re-entry research. 35 CubeSats are envisaged to be provided by universities from 22 countries around the world, among them 4 are from the US, 4 from China, 4 from France, 3 from Australia and 3 from South Korea.<ref>{{cite web |url=https://upload.qb50.eu/listCubeSat/ |title=QB50 CubeSat List |access-date=20 April 2017 |archive-date=17 May 2018 |archive-url=https://web.archive.org/web/20180517005648/https://upload.qb50.eu/listCubeSat/ |url-status=dead}}</ref> Ten 2U or 3U CubeSats are foreseen to serve for in-orbit technology demonstration of new space technologies.
The Request for Proposals (RFP) for the QB50 CubeSat was released on February 15, 2012. Two "precursor" QB50 satellites were launched aboard a [[Dnepr (rocket)|Dnepr rocket]] on June 19, 2014.<ref>{{cite web |url=https://amsat-uk.org/2014/05/04/two-qb50-satellites-with-ham-radio-payloads-delivered/ |title=Two QB50 satellites with ham radio payloads delivered |publisher=AMSAT-UK |date=4 May 2014}}</ref>
All 50 CubeSats were supposed to be launched together on a single [[Tsyklon-4|Cyclone-4]] launch vehicle in February 2016,<ref>{{cite web |title=QB50 |url=https://www.qb50.eu/index.php/schedule |archive-url=https://web.archive.org/web/20150402091248/https://www.qb50.eu/index.php/schedule |url-status=dead |archive-date=2015-04-02 |publisher=[[Von Karman Institute]] |access-date=2015-03-30}}</ref> but due to the unavailability of the launch vehicle, 36 satellites were launched aboard [[Cygnus CRS OA-7]] on 18 April 2017 and subsequently deployed from the [[ISS]].<ref>{{cite web |title=QB50 launch campaigns |url=https://www.qb50.eu/index.php/launch-campaigns |access-date=7 December 2016 |archive-url=https://web.archive.org/web/20161220081422/https://www.qb50.eu/index.php/launch-campaigns |archive-date=20 December 2016 |url-status=dead }}</ref><ref>{{cite web |url=https://www.qb50.eu/index.php/news/78-qb50-iss-ready-to-be-launched.html |title=QB50-ISS CubeSats ready to be launched |access-date=2020-07-15 |archive-date=2020-07-29 |archive-url=https://web.archive.org/web/20200729004831/https://www.qb50.eu/index.php/news/78-qb50-iss-ready-to-be-launched.html |url-status=dead }}</ref> A dozen other CubeSats were manifested on the [[PSLV-XL]] C38 mission in May 2017.<ref>{{cite web |url=http://space.skyrocket.de/doc_lau_det/pslv-xl.htm |title=PSLV-XL |work=Gunter's Space Page |first=Gunter |last=Krebs |access-date=March 9, 2017}}</ref>{{update inline|date=December 2018}}
==Launch and deployment==
[[File:Dnepr rocket lift-off 1.jpg|thumb|upright|left|A [[Dnepr (rocket)|Dnepr]] rocket launching from [[ISC Kosmotras]] ]]
Unlike full-sized spacecraft, CubeSats can be delivered as cargo to, and deployed by the International Space Station. This presents an alternative method of achieving orbit apart from deployment by a [[launch vehicle]]. [[NanoRacks]] and [[Made In Space, Inc.|Made in Space]] are developing means of constructing CubeSats on the International Space Station.<ref>{{Cite web |title=In-Space Satellite Construction May Be Coming Soon |url=http://www.space.com/30225-3d-printing-cubesats-made-in-space.html |website=Space.com |date=12 August 2015 |access-date=2015-10-21}}</ref>
=== Existing launch systems ===
NASA's CubeSat Launch Initiative launched more than 46 CubeSats on its ELaNa missions over the several years prior to 2016, and 57 were planned for flight over the next several years.<ref>{{cite web|last1=Galica|first1=Carol|title=NASA CubeSat Launch Initiative Selections|url=http://www.nasa.gov/content/cubesat-launch-initiative-selections|publisher=NASA|access-date=18 October 2016|archive-date=23 October 2016|archive-url=https://web.archive.org/web/20161023094514/http://www.nasa.gov/content/cubesat-launch-initiative-selections/|url-status=dead}}</ref> No matter how inexpensive or versatile CubeSats may be, they must hitch rides as [[secondary payload]]s on large rockets launching much larger spacecraft, at prices starting around $100,000 as of 2015.<ref name="Dean2015">{{cite news |last=Dean |first=James |url=http://www.floridatoday.com/story/tech/science/space/2015/05/16/nasa-seeks-launchers-smallest-satellites/27392049/ |title=NASA seeks launchers for smallest satellites |work=Florida Today |date=16 May 2015 |access-date=2015-05-16 }}</ref> Since CubeSats are deployed by P-PODs and similar deployment systems, they can be integrated and launched into virtually any launch vehicle. However, some launch service providers refuse to launch CubeSats, whether on all launches or only on specific launches, two examples {{asof|2015|lc=y}} were [[International Launch Services|ILS]] and [[Sea Launch]].<ref>{{Cite web|title = The Space Review: Reusability and other issues facing the launch industry |website=www.thespacereview.com |url=http://www.thespacereview.com/article/2476/1 |access-date=2015-12-21}}</ref>
[[SpaceX]]<ref>{{cite web |title=Commercial launch of SpaceX Falcon 1 rocket a success | author = Stephen Clark | year = 2009 | publisher = Spaceflight Now | url = http://www.spaceflightnow.com/falcon/005/ | access-date = 2010-07-13 }}</ref><ref>{{cite news |url=http://www.citizeninventor.com/news--events/cubesats-launched-with-spacex |title=CubeSATs launched with SpaceX |work=Citizen Inventor |date=18 April 2014 |access-date=2015-05-22 }}</ref> and [[Japan Manned Space Systems Corporation]] (JAMSS)<ref>{{cite news |url=http://spaceflightservices.com/spaceflight-partners-with-japan-manned-space-systems-corporation-jamss-to-launch-eight-cubesats-on-the-jaxa-astro-h-mission/ |title=Spaceflight Partners with Japan Manned Space Systems Corporation (JAMSS) to Launch Eight CubeSats on the JAXA Astro-H Mission |work=Spaceflight |date=5 November 2014 |access-date=2015-05-22 |url-status=dead |archive-url=https://web.archive.org/web/20150309064535/http://spaceflightservices.com/spaceflight-partners-with-japan-manned-space-systems-corporation-jamss-to-launch-eight-cubesats-on-the-jaxa-astro-h-mission/ |archive-date=9 March 2015 }}</ref><ref>{{cite news |url=http://iss.jaxa.jp/en/kiboexp/news/150205_aesp14.html |title=Brazilian AESP-14 CubeSat was deployed from Kibo |work=JAXA |date=5 February 2015 |access-date=2015-05-22 |quote=AESP-14 takes an opportunity of Kibo's paid utilization and is deployed by Japan Manned Space Systems Corporation (JAMSS) at the request of Brazilian Space Agency. }}</ref> are two recent companies that offer commercial launch services for CubeSats as secondary payload, but a launch backlog still exists. Additionally, India's [[ISRO]] has been commercially launching foreign CubeSats since 2009 as secondary payloads. On 15 Feb 2017, ISRO set the world record by launching 103 CubeSats on board its [[Polar Satellite Launch Vehicle]] for various foreign companies.<ref>{{cite web |title=ISRO launches CubeSats |work=Indian Space Research Organisation |date=2009 |url=http://www.isro.gov.in/search/cubesat |access-date=2015-05-22 }}{{Dead link|date=December 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> [[ISC Kosmotras]] and [[Eurockot Launch Services|Eurockot]] also offer launch services for CubeSats.<ref>{{cite web |title=FOCUS: CubeSats — A Costing + Pricing Challenge |author=Jos Heyman |year=2009 |url=http://www.satmagazine.com/cgi-bin/display_article.cgi?number=602922274 |publisher=SatMagazine |access-date=2009-12-30}}</ref> SpaceX beat the record in 2021 with the [[Transporter-1 (spaceflight)]] carrying 143 spacecraft to orbit. [[Rocket Lab]] specializes in launching CubeSats on its [[Electron (rocket)|Electron]] from New Zealand.<ref>{{cite news| title=Sky Skimmer: Rocket Lab Sets Date for Lightweight Spacecraft Test Launch| work=Space Daily| url=http://www.spacedaily.com/reports/Sky_Skimmer_Rocket_Lab_Sets_Date_for_Lightweight_Spacecraft_Test_Launch_999.html| access-date=22 May 2017| date=May 17, 2017}}</ref>
=== Future and proposed launch systems ===
On 5 May 2015, [[NASA]] announced a program based at the [[Kennedy Space Center]] to develop a class of rockets designed to launch very small satellites: the NASA [[Venture Class Launch Services]] (VCLS),<ref name="Dean2015" /><ref name="solicitation2015">{{cite web |url=https://prod.nais.nasa.gov/cgibin/eps/sol.cgi?acqid=165148 |title=NASA Solicitations: VENTURE CLASS LAUNCH SERVICE – VCLS, SOL NNK15542801R |last=Wolfinger |first=Rob |work=NASA |date=5 May 2015 |access-date=2015-05-16 |url-status=dead |archive-date=18 May 2015 |archive-url=https://web.archive.org/web/20150518094232/https://prod.nais.nasa.gov/cgibin/eps/sol.cgi?acqid=165148}}</ref><ref>{{cite news |last=Diller |first=George H. |url=http://www.nasa.gov/centers/kennedy/news/release-20150507.html |title=NASA Hosts Media Call on Draft Solicitation for New Class of Launch Services |work=NASA |date=7 May 2015 |access-date=2015-05-16 }}</ref> which will offer a payload mass of 30&nbsp;kg to 60&nbsp;kg for each launcher.<ref name="solicitation2015" /><ref>{{cite news |url=http://spaceref.biz/cubesat/nasa-issues-request-for-proposals-for-cubesat-launches.html |title=NASA Issues Request for Proposals for Cubesat Launches |work=NASA |publisher=SpaceRef |date=12 June 2015 |access-date=2015-06-15 |archive-date=2015-06-14 |archive-url=https://web.archive.org/web/20150614082659/http://spaceref.biz/cubesat/nasa-issues-request-for-proposals-for-cubesat-launches.html |url-status=dead }}</ref> Five months later, in October 2015, NASA awarded a total of $17.1&nbsp;million to three separate startup launch companies for one flight each: $6.9&nbsp;million to [[Rocket Lab]] ([[Electron (rocket)|Electron rocket]]); $5.5&nbsp;million to [[Firefly Space Systems]] ([[Firefly Alpha|Alpha rocket]]); and $4.7&nbsp;million to [[Virgin Galactic]] ([[LauncherOne|LauncherOne rocket]]).<ref name="Venture2015">{{cite news |last=Wall |first=Mike |url=http://www.space.com/30826-nasa-small-satellites-rocket-rides.html |title=NASA Picks New Rocket Rides to Launch Small Satellites |work=Space.com |date=14 October 2015 |access-date=2015-10-15 }}</ref> The payloads for the three flights under the VCLS contract have not yet been assigned.<ref name="Venture2015" /> Other small satellite launch systems are under development that would carry CubeSats alongside a small payload, including the ''Neptune'' series of rockets by [[Interorbital Systems]], [[Garvey Spacecraft]]'s ''Nanosat Launch Vehicle'',<ref>{{Cite web|title = Garvey Spacecraft Corporation – NLV|url = http://www.garvspace.com/NLV.htm|website = www.garvspace.com|access-date = 2015-12-13}}</ref> and the [[SPARK (rocket)|SPARK]] rocket. In addition to conventional launch vehicles and facilitators like KSF Space, several [[air launch to orbit]] vehicles are in the works by [[Generation Orbit Launch Services]] and [[Boeing]] (in the form of their [[Boeing Small Launch Vehicle|Small Launch Vehicle]]).
Many aspects of CubeSats such as structure, propulsion, material, computing and telecommunications, power, and additional specific instruments or measurement devices pose challenges to the use of CubeSat technology beyond Earth's orbit.<ref name=":02">{{Cite web| url=http://www.planetary.org/blogs/guest-blogs/van-kane/20131023-the-potential-of-cubesats.html|title=The Potential of CubeSats|website=www.planetary.org|access-date=2019-03-12}}</ref> These challenges have been increasingly under consideration of international organizations over the past decade, for example, proposed in 2012 by NASA and the Jet Propulsion Lab, the INSPIRE spacecraft is an initial attempt at a spacecraft designed to prove the operational abilities of deep space CubeSats.<ref name=":13">{{Cite web |url=https://www.jpl.nasa.gov/cubesat/missions/inspire.php |website=JPL {{!}} CubeSat |title=Interplanetary Nano-Spacecraft Pathfinder in Relevant Environment (INSPIRE) |access-date=2019-03-12|archive-date=2019-07-25|archive-url=https://web.archive.org/web/20190725131443/https://www.jpl.nasa.gov/cubesat/missions/inspire.php|url-status=dead}}</ref> The launch date was expected to be 2014,<ref name=":03">{{Cite web|url=http://www.planetary.org/blogs/guest-blogs/van-kane/20131023-the-potential-of-cubesats.html|title=The Potential of CubeSats|website=www.planetary.org|access-date=2019-03-12}}</ref> but has yet to occur and the date is listed by NASA as TBD.<ref name=":13"/>
=== Deployment ===
[[File:CSSWE CubeSat and PPOD prior to integration.png|thumb|[[CSSWE]] next to its P-POD before integration and launch]]
P-PODs (Poly-PicoSatellite Orbital Deployers) were designed with CubeSats to provide a common platform for [[secondary payload]]s.<ref name="esappod"/> P-PODs are mounted to a [[launch vehicle]] and carry CubeSats into orbit and deploy them once the proper signal is received from the launch vehicle. The P-POD Mk III has capacity for three 1U CubeSats, or other 0.5U, 1U, 1.5U, 2U, or 3U CubeSats combination up to a maximum volume of 3U.<ref>{{cite web | title = NPS CubeSat Launcher Design, Process And Requirements | url = https://apps.dtic.mil/sti/pdfs/ADA501503.pdf | author = Matthew Richard Crook | year = 2009 | publisher = [[Naval Postgraduate School]] | access-date = 2009-12-30 | archive-date = 2012-08-25 | archive-url = https://www.webcitation.org/6ABSrbf2p?url=http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA501503 | url-status = dead }}</ref> Other CubeSat deployers exist, with the NanoRacks CubeSat Deployer (NRCSD) on the International Space Station being the most popular method of CubeSat deployment as of 2014.<ref name="database">{{Cite web|title = CubeSat Database – swartwout|url = https://sites.google.com/a/slu.edu/swartwout/home/cubesat-database|website = sites.google.com|access-date = 2015-10-19}}</ref> Some CubeSat deployers are created by companies, such as the ISIPOD (Innovative Solutions In Space BV) or SPL (Astro und Feinwerktechnik Adlershof GmbH), while some have been created by governments or other non-profit institutions such as the X-POD ([[University of Toronto]]), T-POD ([[University of Tokyo]]), or the J-SSOD ([[JAXA]]) on the International Space Station.<ref>{{Cite web|title = CubeSat concept – eoPortal Directory – Satellite Missions|url = https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/cubesat-concept|website = directory.eoportal.org|access-date = 2015-10-19}}</ref> While the P-POD is limited to launching a 3U CubeSat at most, the NRCSD can launch a 6U ({{cvt|10x10x68.1|cm}}) CubeSat and the ISIPOD can launch a different form of 6U CubeSat ({{cvt|10x22.63x34.05|cm}}).
While nearly all CubeSats are deployed from a launch vehicle or the International Space Station, some are deployed by the primary payloads themselves. For example, [[FASTSAT]] deployed the [[NanoSail-D2]], a 3U CubeSat. This was done again with the [[Cygnus Mass Simulator]] as the primary payload launched on the maiden flight of the [[Antares (rocket)|Antares]] rocket, carrying and later deploying four CubeSats. For CubeSat applications beyond Earth's orbit, the method of deploying the satellites from the primary payload will also be adopted. Eleven CubeSats were launched on the [[Artemis 1]], placing them in the vicinity of the [[Moon]]. [[InSight]], a [[Mars]] [[Lander (spacecraft)|lander]], also sent CubeSats beyond Earth orbit to use them as [[Communications satellites|relay communications satellites]]. Known as [[Mars Cube One|MarCO]] A and B, they are the first CubeSats sent beyond the [[Earth–Moon system]].
[[Chasqui I]] saw a unique deployment process, when it was deployed by hand during a spacewalk on the International Space Station in 2014.{{clear}}
== See also ==
* [[AMSAT]]
* [[Canadian Advanced Nanospace eXperiment Program]]
* [[CubeRover]], a similar concept applied to small rovers
* [[Cubesat Space Protocol]]
* [[Israeli Nano Satellite Association]]
* [[List of CubeSats]]
* [[Nanosatellite Launch System]]
* [[OSCAR]]
* [[PocketQube]], a similar but smaller format measuring 5x5x5 cm
== References ==
{{reflist}}
==External links==
{{Commons category|CubeSat satellites}}
* {{official website|www.cubesat.org}}
*[http://nanosats.eu CubeSat Database and Nanosatellites] – lists over 2,000 CubeSats that have been and are planned to be launched since 1998
* {{cite web |url= https://stemn.com/fields/cubesats/projects |website= Science, Technology, Engineering, and Mathematics ([[Science, technology, engineering, and mathematics|STEM]]) network |title= CubeSats projects |first1= Jack |last1= Yeh |first2= David |last2= Revay |first3= Jackson |last3= Delahunt |quote= 'GitHub' for science |access-date= 2016-02-18 |archive-date= 2020-07-29 |archive-url= https://web.archive.org/web/20200729024809/https://stemn.com/fields/cubesats/projects |url-status= dead }}
*[http://hyperionorbital.com/resources/ CubeSat developer resources and regulatory data]
*{{cite web |first=Stephen |last=Murphey |title=what are cubesats |website=[[YouTube]] |url=https://youtube.com/watch?v=50_AntgK8ZA |archive-url=https://ghostarchive.org/varchive/youtube/20211221/50_AntgK8ZA |archive-date=2021-12-21 |url-status=live |date=2012}}{{cbignore}}
* [https://librecube.org/ LibreCube] an [[Open source]]-platform for developing CubeSats
*[https://web.archive.org/web/20170819062734/http://oscw.space/ Open Source CubeSat Workshop (OSCW)]
*[https://www.nasa.gov/sites/default/files/atoms/files/nen_cubesat_communications_march_2016.pptx.pdf NEN CubeSat Support (NASA)]
{{Spaceflight lists and timelines}}
[[Category:Satellites by type]]
[[Category:CubeSats| ]]