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Ariel 3
	Ariel 3 with its paddles in the deployed position
Names	Ariel3, S 53, UK 3, UK-E
Mission type	Atmospheric studies
Operator	SERC / NASA
COSPAR ID	1967-042A
SATCAT no.	2773
Mission duration	43 months
Spacecraft properties
Launch mass	89 kilograms (197 lb)
Start of mission
Launch date	5 May 1967, 16:00:01 UTC
Rocket	Scout A
Launch site	Vandenberg SLC-5
End of mission
Disposal	Decommissioned
Deactivated	September 1969
Decay date	14 December 1970
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Eccentricity	0.008
Perigee altitude	496 kilometres (308 mi)
Apogee altitude	599 kilometres (372 mi)
Inclination	80.17 degrees
Period	95.69 minutes
Epoch	7 June 1967
	Ariel ← Ariel 2 Ariel 4 →

Ariel 3 (UK 3 or United Kingdom Research Satellite 3) was a satellite in the Ariel programme, a satellite partnership between the US and UK. Three of the onboard experiments continued research from the first two missions and two experiments were designed for new research topics. It was launched from Vandenberg Air Force Base on 5 May 1967, making it the first satellite of the program to launch from the West coast. Ariel 3 was shut down in September 1969, and re-entered the Earth's atmosphere 14 December 1970.

This was the first artificial satellite designed and constructed in the United Kingdom.

Design

Development

In 1961 the UK Space Research Group accepted proposals for experiments to be carried on the third satellite of the Ariel programme. The British National Committee for Space Research selected experiments from those proposals and submitted them to NASA in 1962. The scientific objectives for the mission were selected in January 1963, and full work on the satellite began in early 1964 due to organisational and financial difficulties.^[3] A total of 5 craft were constructed.^[4] One prototype, two engineering models, the final satellite and a flight spare.^[4] The flight spare was later used as the basis of Ariel 4.^[5]

Operation

Power could be drawn from the batteries or the solar panels. The batteries were considered the least reliable component in the system so this method was devised to mitigate the issue.^[6]

The spacecraft weighed 89 kilograms (197 lb).^[7]

Sensors

Ariel 3 carried five experiments.^[8] The experiments measured properties of the thermosphere as well as detected "terrestrial radio noise" from thunderstorms and measured large-scale galactic radio frequency noise.^[8] Ariel 3 was also fitted with a series of mirrors to observe the spin of the satellite.^[9]

High-speed data was transmitted continuously to the Satellite Tracking and Data Acquisition Network (STADAN). Low-speed data was recorded on tape recorders and was transmitted to ground stations in the high-speed mode when commanded.^[10]

Three experiments expanded on data from the previous two missions. Two experiments collected data on naturally occurring radio noise.^[8]

Mission

Launch

The launch was originally planned for Wallops; Ariel 1 and Ariel 2 had both launched on the East coast. In 1964 experimenters requested a change to the proposed orbit, from an inclination of 50–70° to 78–80° to maximize coverage at the geomagnetic latitude. This change precipitated the launch site moving to the West coast.^[11]

It was launched from Vandenberg Air Force Base on 5 May 1967 aboard a Scout rocket.^[12]^[1] This made it the first artificial satellite designed and constructed in the United Kingdom.^[7]

Operations

Ariel 3 had an orbital period of approximately 95 minutes, with an apogee of 608 km and a perigee of 497 km. It initially spun at 31 rpm for stability, though by the time the Ariel 3 deorbited, it had slowed to a rate of about 1 rpm.^[1]

On 24 October 1967 the tape recorder aboard Ariel 3 began to malfunction. This restricted observation to real-time operation only.^[1] Nevertheless, as of May 5, 1968, after one year in orbit, the satellite's five experiments were still functioning and had returned 400 million bits of usable data on the upper atmosphere.^[13] Ariel 3 suffered from a significant power failure in December 1968, restricting the satellite's operation to daylight hours only. The satellite was completely shut down in September 1969. Its orbit decayed steadily until on 14 December 1970 when Ariel 3 re-entered Earth's atmosphere.^[1]

Notes

^ ^a ^b ^c ^d ^e "Ariel 3". NASA Space Science Data Coordinated Archive. Retrieved 24 March 2020.
^ McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 6 December 2013.
^ Ladd & Smith 1969, p. 480.
^ ^a ^b Campbell, F. P. (December 1966). "Orbiting A High Atmosphere Experiment". Weather. 21 (12): 422–428. Bibcode:1966Wthr...21..422C. doi:10.1002/j.1477-8696.1966.tb02797.x.
^ Dalziel 1975, p. 163.
^ Sketch 1969, pp. 493–494.
^ ^a ^b Ladd & Smith 1969, p. 479.
^ ^a ^b ^c Ladd & Smith 1969, p. 481.
^ Dalziel 1979, p. 414.
^ Ladd & Smith 1969, p. 485.
^ Ladd & Smith 1969, pp. 482–483.
^ "'On This Day' for May 5, 1967 - First all-British satellite 'Ariel 3' launched". BBC News. 5 May 1967. Retrieved 1 January 2010.
^ "Aeronautics and Astronautics, 1968" (PDF). NASA. p. 105. Retrieved 28 April 2023.

References

Dalziel, R. (2–6 July 1979). The Significance of UK Spacecraft Control to Space Science. Automatic Control in Space: 8th IFAC Symposium. Oxford, England. ISBN 9781483158976.
Ladd, A.C.; Smith, J.F. (12 August 1969). "An Introduction to the Ariel III Satellite Project". Proceedings of the Royal Society of London. 311 (1507). Great Britain: 479–487. Bibcode:1969RSPSA.311..479L. doi:10.1098/rspa.1969.0129. JSTOR 2416326. S2CID 129064735.
Sketch, H. J. H. (1969). "Description of the Ariel III Satellite Project". Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. 311 (1507): 489–499. Bibcode:1969RSPSA.311..489S. doi:10.1098/rspa.1969.0130. ISSN 0080-4630. JSTOR 2416327. S2CID 140671893.
Dalziel, R. (1975). "The Ariel 4 Satellite". Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. 343 (1633): 161–165. Bibcode:1975RSPSA.343..161D. doi:10.1098/rspa.1975.0057. ISSN 0080-4630. JSTOR 78859. S2CID 202574658.