Ariel 4

Ariel 4

Company type	Satellite mission
Industry	Space research
Founded	December 11, 1971 (1971-12-11)
Founder	Science and Engineering Research Council
Fate	Reentered Earth's atmosphere on 12 December 1978
Headquarters	United Kingdom
Key people	British Aircraft Corporation (main contractor)
Products	Ionospheric research data
Parent	Science and Engineering Research Council

Ariel 4, initially designated UK 4 before launch, was a British satellite dedicated to ionospheric research, managed by the Science and Engineering Research Council. It was deployed into orbit on 11 December 1971 using an American Scout rocket. The satellite’s experiments were specifically crafted to address a singular scientific goal, marking it as the United Kingdom's first mission-focused satellite. Additionally, Ariel 4 was the inaugural satellite within the Ariel programme to include an experiment from the United States. The satellite remained in orbit until it re-entered Earth's atmosphere on 12 December 1978.

Development

To minimize expenses, Ariel 4 incorporated design elements and components from its predecessor, Ariel 3. It utilized parts from the previous mission’s flight backup unit along with spare hardware. The total cost of the satellite was approximately £1.25 million.

Operation

The main contractor responsible for Ariel 4 was the British Aircraft Corporation. The satellite had a launch mass of around 101 kilograms (223 lb). Notably, Ariel 4 was the first in the Ariel programme capable of performing attitude control maneuvers.

Sensors

Ariel 4 was distinguished within the Ariel series as the first satellite carrying a payload entirely devoted to a single scientific investigation. Its primary research aim was to examine the interactions between high-energy charged particles and electromagnetic radiation within both the upper ionosphere and magnetosphere. Building upon three experiments from Ariel 3 that targeted this objective, these were enhanced for Ariel 4 and supplemented by an additional experiment.

The instruments onboard accounted for 18.5 kilograms (41 lb) of the spacecraft’s total mass.

Furthermore, this mission marked the program's first inclusion of an American scientific experiment.

Launch

Ariel 4 was successfully launched at 20:47:01 GMT on 11 December 1971 from Space Launch Complex 5 located at Vandenberg Air Force Base. The launch operation was carried out by NASA employing a Scout B-1 launch vehicle.

Operations

The satellite was inserted into a low Earth orbit characterized by a perigee of approximately 473 km, an apogee near 590 km, an orbital inclination of 82.9 degrees, and an orbital period lasting about 95.3 minutes, as recorded on 10 January 1972. Ariel 4 remained in orbit until it reentered the Earth's atmosphere on 12 December 1978.

References

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