View source for Ariel 5

{{use dmy|date=March 2020}}
{{Infobox spaceflight
| name               = Ariel 5
<!--image of the spacecraft/mission-->| names_list         = Ariel5, PL-732B, UK 5, United Kingdom 5
| image              = Ariel-5.jpg
| image_caption      =
| image_alt          =
| image_size         = <!--Basic details-->
| mission_type       = [[Astronomy]]
| operator           = [[Science Research Council|SERC]] / [[NASA]]
| COSPAR_ID          = 1974-077A
| SATCAT             = 7471
| website            =
| mission_duration   =
| distance_travelled = <!--How far the spacecraft travelled (if known)-->
| orbits_completed   = <!--number of times the spacecraft orbited the Earth - see below for spacecraft beyond Earth orbit-->
<!--Spacecraft properties-->| spacecraft         =
| spacecraft_type    =
| spacecraft_bus     =
| manufacturer       = [[Goddard Space Flight Center]]
| launch_mass        = {{convert|130.5|kg|lb|abbr=on}}
| BOL_mass           =
| dry_mass           =
| payload_mass       =
| dimensions         =
| power              = <!--Launch details-->
| launch_date        = {{start-date|15 October 1974, 07:47:00|timezone=yes}}&nbsp;UTC
| launch_rocket      = [[Scout (rocket family)|Scout]] B-1
| launch_site        = [[Broglio Space Centre|San Marco]]
| launch_contractor  =
| entered_service    = <!--date on which the spacecraft entered service, if it did not do so immediately after launch-->
<!--end of mission-->| disposal_type      = <!--Whether the spacecraft was deorbited, decommissioned, placed in a graveyard orbit, etc-->
| deactivated        = <!--when craft was decommissioned-->
| destroyed          = <!--when craft was destroyed (if other than by re-entry)-->
| last_contact       = <!--when last signal received if not decommissioned-->
| decay_date         = 14 March 1980
| orbit_reference    =
| orbit_regime       =
| orbit_semimajor    =
| orbit_eccentricity = 0.00325
| orbit_periapsis    = {{convert|512|km|mi|abbr=on}}
| orbit_apoapsis     = {{convert|557|km|mi|abbr=on}}
| orbit_inclination  = 2.9&nbsp;degrees
| orbit_period       = 95.3&nbsp;minutes
| orbit_RAAN         =
| orbit_arg_periapsis =
| orbit_mean_anomaly =
| orbit_mean_motion  =
| orbit_repeat       =
| orbit_epoch        = 14 October 1974, 23:00:00&nbsp;UTC<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1974-077A|title=Ariel 5 Trajectory Details|website=NASA Space Science Data Coordinated Archive|access-date=8 March 2020}}</ref>
| apsis              = gee
<!--Telescope parameters-->| instrument_type    = <!--converts telescope fields to suit a camera or other similar instrument-->
| telescope_name     =
| telescope_type     = <!--type of telescope, mirror arrangement, etc-->
| telescope_diameter = <!--diameter of telescope-->
| telescope_focal_length = <!--focal length of telescope-->
| telescope_area     = <!--collecting area-->
| telescope_wavelength = <!--wavelengths at which the telescope operates-->
| telescope_resolution = <!--resolution of telescope-->
| instruments        = {{unbulleted list|Rotation Modulation Collimator|2- to 10-KeV Sky Survey Instrument|High-Resolution Source Spectra|Bragg Crystal Spectrometer|High-Energy Cosmic X-Ray Spectra|All-Sky Monitor}}
| programme          = [[Ariel programme|Ariel]]
| previous_mission   = [[Ariel 4]]
| next_mission       = [[Ariel 6]]
}}
'''Ariel 5''' (or UK 5) was a joint British and American [[space telescope]] dedicated to observing the sky in the [[X-ray]] band. It was launched on 15 October 1974 from the [[San Marco platform]] in the [[Indian Ocean]] and operated until 1980. It was the penultimate satellite to be launched as part of the [[Ariel programme]].
==Background==
Ariel 5 was the fifth and penultimate satellite of the joint British and American [[Ariel programme]].<ref name=heasarc>{{cite web | url=http://heasarc.nasa.gov/docs/ariel5/ariel5.html | title=HEASARC: Observatories - The Ariel V Satellite | publisher=[[NASA]] | access-date=2008-03-03 | archive-url=https://web.archive.org/web/20131227165403/http://heasarc.nasa.gov/docs/ariel5/ariel5.html | archive-date=27 December 2013 | url-status=dead }}</ref> It was the third satellite in the series built entirely in the UK.<ref name=gunter /> It was named UK 5 before launch and renamed to Ariel 5 after the successful launch.{{sfn|Smith|Courtier|1976|p=422}}
Plans for Ariel 5 were first discussed between the UK and US in May 1967 at the [[Ariel 3]] launch. The [[Science Research Council]] (SRC) advertised a request for proposal for experiments in June. Experiments were formally proposed to NASA in July 1968.{{sfn|Smith|Courtier|1976|p=421}}
==Satellite design==
===Development===
[[Marconi Space and Defence Systems]] (MSDS) in Portsmouth was selected as the prime contractor in 1969. SRC had them select MSDS Frimley for the attitude control system (ACS) and MSDS Stanmore for the core stores.{{sfn|Smith|Courtier|1976|p=422}}
A study was performed to see if the [[Scout (rocket)|Scout rocket]]'s heat shield could be enlarged to accommodate larger experiments for this mission. A larger heat shield was designed which allowed for a US experiment and five British experiments.{{sfn|Smith|Courtier|1976|p=422}}
===Operation===
Ariel 5 was spin-stabilized.<ref name=gunter>{{cite web|url=https://space.skyrocket.de/doc_sdat/ariel-5.htm|title=Ariel 5 (UK 5)|website=Gunter's Space Page|last1=Krebs|first1=Gunter|access-date=8 March 2020}}</ref> The satellite improved on the attitude control of [[Ariel 4]].{{sfn|Dalziel|1979|p=413}} It used liquid propane that was expanded through a reducing valve and heated with the bulk tank temperature.{{sfn|Smith|Courtier|1976|p=429}}
Power was derived from solar cells that were mounted to 7/8 of the circumference of the spacecraft. It was stored in a 3.0 Ah [[Ni-Cd battery]].{{sfn|Smith|Courtier|1976|p=429}}
===Sensors===
The all-sky monitor (ASM) was two one-dimensional pinhole cameras scanned most of the sky every spacecraft revolution.<ref name=Priedhorsky/> The angular resolution was 10° × 10°, with an effective area of {{convert|abbr=on|3|cm2|sqin|3}}, and a bandpass of 3–6 keV. The ASM was designed to fit a resource budget of {{convert|2|kg|abbr=on}}, 1 bit per second, and 1 W.<ref name=Priedhorsky>{{ cite journal |author=Priedhorsky WC |author2= Holt SS |title=Long-term cycles in cosmic X-ray sources |journal=Space Sci Rev |volume=45 |issue=3–4 |date=1987 |pages=291–348 |bibcode=1987SSRv...45..291P |doi = 10.1007/BF00171997 |s2cid= 120443194 }}</ref>
The sky survey instrument (SSI) had an angular resolution of 0.75 × 10.6°, with an effective area of {{convert|abbr=on|290|cm2|sqin}}, and a bandpass of 2–20 keV.<ref name=Priedhorsky/>
==Mission==
===Launch===
Launch operations took six weeks, starting from the time the [[Guppy (aircraft)|Guppy]] took off from Thorney Island.{{sfn|Smith|Courtier|1976|p=428}} The satellite was launched on 15 October 1974 from the [[San Marco platform]] in the [[Indian Ocean]] off the coast of Kenya.<ref>{{cite news|url=https://www.newspapers.com/clip/46389303/grand-prairie-daily-news/|title=Cooperative Space Mission Provides New Knowledge|newspaper=Grand Prairie Daily News|location=Grand Prairie, Texas|date=18 October 1974|via=Newspapers.com|page=8}}</ref>
===Operations===
The satellite was controlled via a mission control centre in Appleton Lab.<ref name=nssdc /> It spun at over 10 revolutions/minute.<ref name=nssdc>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1974-077A|title=Ariel 5|website=NASA Space Science Data Coordinated Archive|access-date=9 March 2020}}</ref> Ariel 5 operated until 1980.<ref name=heasarc />
==Results==
Over 100 scientific papers were published within four years of the launch.{{sfn|Harvey|2003|p=99}}
{{Portal|Spaceflight}}
== Notes ==
{{Reflist}}
==References==
*{{cite conference|conference=Automatic Control in Space: 8th IFAC Symposium|isbn=9781483158976|date=2-6 July 1979|location=Oxford, England|last1=Dalziel|first1=R.|title=The Significance of UK Spacecraft Control to Space Science|url=https://books.google.com/books?id=shajBQAAQBAJ}}
*{{cite book|title=Europe's Space Programme: To Ariane and Beyond|last1=Harvey|first1=Brian|isbn=9781852337223|year=2003|publisher=Springer}}
*{{cite journal|journal=Proceedings of the Royal Society of London|series=Mathematical and Physical Sciences|last1=Smith|first1=J.F.|last2=Courtier|first2=G.M.|volume=350|number=1663|date=1 October 1976|title=The Ariel 5 Programme|pages=421–439|location=Great Britain|doi=10.1098/rspa.1976.0115|jstor=78979|bibcode=1976RSPSA.350..421S|s2cid=128761336}}
== Further reading ==
*{{Cite journal| issn = 0080-4630| volume = 350| issue = 1663| pages = 491–503| last1 = Sanford| first1 = P. W.| last2 = Ives| first2 = J. C.| title = Ariel Results on Extragalactic X-Ray Sources| journal = Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences| date = 1976| doi = 10.1098/rspa.1976.0120| jstor = 78984| bibcode = 1976RSPSA.350..491S| s2cid = 83270830}}
{{Ariel programme}}
{{Orbital launches in 1974}}
{{Use British English|date=January 2014}}
[[Category:Space telescopes]]
[[Category:Space programme of the United Kingdom]]
[[Category:1974 in spaceflight]]
[[Category:Satellites formerly orbiting Earth]]
[[Category:Spacecraft launched in 1974]]