Prospero (spacecraft)

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title: "Prospero (spacecraft)" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["1971-in-the-united-kingdom", "derelict-satellites-orbiting-earth", "satellites-of-the-united-kingdom", "satellites-orbiting-earth", "space-programme-of-the-united-kingdom", "spacecraft-launched-by-black-arrow-rockets", "spacecraft-launched-in-1971"] description: "British experimental satellite launched in 1971" topic_path: "geography/united-kingdom" source: "https://en.wikipedia.org/wiki/Prospero_(spacecraft)" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary British experimental satellite launched in 1971 ::

::data[format=table title="Infobox spaceflight|auto=all"]

Field	Value
name	Prospero
names_list	Puck
image	Prospero X-3 model 2012.JPG
image_caption	Flight spare of the Prospero satellite in the Science Museum, London.
mission_type	Technology
operator	RAE
COSPAR_ID	1971-093A
SATCAT	5580
mission_duration	(in orbit)
manufacturer	BAC
Marconi
launch_mass	66 kg
launch_date	GMT
launch_rocket	Black Arrow R3
launch_site	Woomera LA-5B
disposal_type	Deorbit
last_contact
decay_date	2070 (planned)
orbit_epoch	24 January 2015, 04:50:31 UTC
orbit_reference	Geocentric
orbit_regime	Low Earth
orbit_semimajor	7295.54 km
orbit_eccentricity	0.053451
orbit_periapsis	534 km
orbit_apoapsis	1314 km
orbit_inclination	82.04 degrees
orbit_period	103.36 minutes
apsis	gee
::

| name = Prospero | names_list = Puck | image = Prospero X-3 model 2012.JPG | image_caption = Flight spare of the Prospero satellite in the Science Museum, London.

| mission_type = Technology | operator = RAE | website = | COSPAR_ID = 1971-093A | SATCAT = 5580 | mission_duration = (in orbit) | spacecraft_bus = | manufacturer = BAC Marconi | dry_mass = | launch_mass = 66 kg | power = | launch_date = GMT | launch_rocket = Black Arrow R3 | launch_site = Woomera LA-5B | launch_contractor = | disposal_type = Deorbit | deactivated = | last_contact = | decay_date = 2070 (planned) | orbit_epoch = 24 January 2015, 04:50:31 UTC | orbit_reference = Geocentric | orbit_regime = Low Earth | orbit_semimajor = 7295.54 km | orbit_eccentricity = 0.053451 | orbit_periapsis = 534 km | orbit_apoapsis = 1314 km | orbit_inclination = 82.04 degrees | orbit_period = 103.36 minutes | apsis = gee

The Prospero satellite, also known as the X-3, was launched by the United Kingdom in 1971. It was designed to undertake a series of experiments to study the effects of the space environment on communications satellites and remained operational until 1973, after which it was contacted annually for over 25 years. Although Prospero was the first British satellite to have been launched successfully by a British rocket, Black Arrow, the first British satellite placed in orbit was Ariel 1, launched in April 1962 on a US rocket.

Construction

Prospero was built by the Royal Aircraft Establishment in Farnborough. Initially called Puck, it was designed to conduct experiments to test the technologies necessary for communication satellites. Two experimental solar cells setups were tested. One was a test of a lightweight cell and mounting. The detector worked on the principle of impact ionisation. When the Ministry of Defence cancelled the Black Arrow programme, the development team decided to continue with the project but renamed the satellite Prospero when it was announced it would be the last launch attempt using a British rocket. An earlier Black Arrow launch, carrying the Orba X-2 satellite, had failed to achieve orbit after a premature second stage shut-down.

Launch

::figure[src="https://upload.wikimedia.org/wikipedia/commons/c/ce/Black_Arrow_R3_Stage_1.JPG" caption="Anna Creek Station]]."] ::

Prospero was launched at 04:09 GMT on 28 October 1971, from Launch Area 5B (LA-5B) at Woomera, South Australia, on a Black Arrow rocket, making Britain the sixth nation to place a satellite into orbit using a domestically developed carrier rocket. The Black Arrow's final stage Waxwing rocket also entered orbit, "rather too enthusiastically", as it continued to thrust after separation and collided with Prospero, detaching one of the satellite's four radio antennae.

Operations

The satellite was operated from R.A.E Lasham. For the satellite's early orbits additional reporting was provided by the European Space Research Organisation's ESTRACK system. In regular operation real time data support was provided by a Science Research Council station at Port Stanley in the Falkland Islands.

Results

The lightweight solar cell design was found to be successful.

Status

Prosperos tape recorders stopped working in 1973. As was noted in an episode of the BBC television series Coast, radio transmissions from Prospero could still be heard on 137.560 MHz in 2004, though the signals used in the episode would actually come from an Orbcomm satellite, rather than Prospero (as the later Orbcomm used the same 137.560 MHz frequency since Prospero was considered no longer active). Prospero had officially been deactivated in 1996, when the UK's Defence Research Establishment decommissioned their satellite tracking station at Lasham, Hampshire but the satellite had been turned on in past years on its anniversary. It is in a low Earth orbit and is not expected to decay until about 2070, almost 100 years after its launch.

In September 2011 a team at University College London's Mullard Space Science Laboratory announced plans to re-establish communications with Prospero, in time for the satellite's 40th anniversary. As of September 2012, not much progress had been made in establishing contact with the satellite due to time constraints. At perigee, Prospero can be seen through binoculars at magnitude +6 overhead, steady.

References

Notes

Bibliography

References

1. (24 January 2015). "PROSPERO (BLACK ARROW) Satellite details 1971-093A NORAD 5580". N2YO.
2. Krebs, Gunter. "Prospero (X-3)". Gunter's Space Page.
3. Harvey. 2003
4. (1975). "Observations of the micrometeoroid flux from Prospero". Proceedings of the Royal Society A.
5. Hill, C. N.. "The Cancellation of Black Arrow". SpaceUK.org.
6. {{Harvnb. Baker. 1978
7. (2008). "Spies in the sky: surveillance satellites in war and peace". Springer.
8. {{Harvnb. King-Hele. 2005
9. Wheeler, Brian. (12 January 2004). "Britain's first space pioneers". [[BBC News]].
10. ''Coast'', 26 October 2006, Series 2 Episode 1, BBC
11. Graham, William. (2021-10-28). "On the 50th anniversary of Black Arrow, British space industry is on the verge of a return".
12. Roger J A, Duthie. (4 April 2012). "Long Overdue Update". UCL Blogs.
13. Hollingham, Richard. (5 September 2011). "Plan to revive 1970s UK satellite". [[BBC News]].
14. "British Space Race".

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