View source for AQT-D

{{Short description|Nanosatellite}}
{{technical|date=September 2019}}
{{Use British English|date=September 2020}}
{{Use dmy dates|date=September 2020}}
'''AQT-D''' ('''Aqua Thruster-Demonstrator''') was a [[nanosatellite]] project of the [[University of Tokyo]] (UT) Space Propulsion Laboratory with the purpose of testing water-fueled propulsion. The satellite was a [[CubeSat]] of 3U size; 1U was occupied by the propulsion system, while the remaining 2U was for the [[spacecraft bus]].<ref name="ISTS">{{cite web|url=https://www.researchgate.net/publication/333965311 |title=AQT-D: CubeSat Demonstration of a Water Propulsion System Deployed from ISS|access-date=11 August 2019}}</ref> AQT-D was carried to space inside the pressurized section of [[Kounotori 8]], a Japanese resupply vehicle for the [[International Space Station]] (ISS).<ref>{{cite news|last=Werner|first=Debra|date=27 August 2019|title=Water propulsion technologies picking up steam|url=https://spacenews.com/water-propulsion-technologies-picking-up-steam/|newspaper=[[SpaceNews]]|access-date=2019-09-11}}</ref> Kounotori 8 was launched on 24 September 2019. After arriving at the ISS, AQT-D was deployed to space on 20 November 2019 using the JEMRMS robotic arm at the space station's [[Kibō (ISS module)|Kibō]] laboratory module.<ref>{{cite web|url=http://iss.jaxa.jp/kibouser/pickout/69075.html|language=Japanese|script-title=ja:「きぼう」から超小型衛星3機放出に成功！|publisher=JAXA|date=21 November 2019|access-date=21 November 2019}}</ref>
The AQT-D project was led by Jun Asakawa of the University of Tokyo.<ref>{{Cite web|url=http://jasakawa9.wixsite.com/website|title=Home {{!}} AQT-D: AQUA Thruster-Demonstrator|website=マイサイト|language=ja|access-date=2019-09-11}}</ref>
AQT-D reentered the atmosphere on 20 April 2022.<ref>{{cite web |url=https://www.n2yo.com/satellite/?s=44791 |title=AQT-D |work=N2YO.com |date=20 April 2022 |access-date=26 April 2022}}</ref>
== Spacecraft ==
AQT-D's spacecraft bus was based on [[TRICOM-1R|Tasuki]] (TRICOM-1R), a previous satellite developed by the University of Tokyo and launched in 2017.<ref name="ISTS"/> The satellite was equipped with antennas for [[store and forward]] [[communication]].<ref name="ISTS"/>
== Propulsion ==
{| class="wikitable floatright"
|-
! Water thrusters !! Unit/performance
|-
| Propellant || Water
|-
| Thrust || 1 of 4 mN
|-
| [[Specific impulse]]|| >70 seconds
|-
| Water mass || < 0.4 kg
|}
AQT-D's propulsion system, called ''AQUARIUS-1U'' (Aqua Resistojet Propulsion System-1U), consisted of five water thrusters. A single [[delta-v]] thruster produced 4.0 [[Newton (unit)|mN]], and four [[Reaction control system|reaction control thrusters]] 1.0 mN, for [[Spacecraft attitude control|attitude control]].<ref name="ISTS"/><ref name="SmallSat33">[https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4398&context=smallsat AQT-D: Demonstration of the Water Resistojet Propulsion System by the ISS-Deployed CubeSat] (PDF). ''Small Satellite Conference''. University of Tokyo. 2019.</ref> The spacecraft carried less than 0.4 kg of water.<ref name="SmallSat33"/> The [[delta-v]] thruster produced a [[specific impulse]] (I<sub>sp</sub>) of 70 seconds, and a maximum 4.0 mN of thrust, which was dependent on available power.<ref name="SmallSat33"/> AQUARIUS-1U's design was based on the planned deep space probe [[EQUULEUS]]'s propulsion system.<ref name="SmallSat33"/> According to the [[University of Tokyo]], AQT-D was the first ISS-deployed satellite to have water-based propulsion.<ref name="ISTS"/><ref name="SmallSat33"/> While satellites deployed from the ISS typically have a short lifetime owing to the station's low altitude, satellites equipped with a propulsion system like AQT-D may potentially remain in orbit for an extended period of time.<ref name="SmallSat33"/>
== References ==
{{Portal|Spaceflight}}
{{Reflist}}
== External links ==
* [http://jasakawa9.wixsite.com/website AQT-D: AQUA Thruster-Demonstrator]
{{Japanese space program}}
[[Category:Satellites of Japan]]
[[Category:University of Tokyo]]
[[Category:CubeSats]]
[[Category:2019 in Japan]]
[[Category:Spacecraft launched in 2019]]
[[Category:Spacecraft which reentered in 2022]]
[[Category:Satellites deployed from the International Space Station]]