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Ariel 2



Ariel 2 (also designated S-52 or UK-2) was a scientific satellite launched for Great Britain by NASA. All three experiments were managed by the British National Committee on Space Research. Its mission was to study cosmic background noise, atmospheric ozone, and micrometeoroids.

Spacecraft and Subsystems

The basic spacecraft structure was a squat fiberglass cylinder, 58 cm in diameter and 27.2 cm high, with hemispherical domes on top and bottom, a total height of 89 cm and a mass of 68 kg. Four paddlewheel solar arrays extended radially from the base of the spacecraft. On top of the dome was a small cylinder topped by a long pole, the broad band ozone detector. Two inertia booms extended radially from the base of the bus on opposite sides, and two galactic noise dipole antennas extended from opposite sides of the base (40 m tip-to-tip) at 90 degrees to the booms. Four turnstile RF antennas extended at about 45 degrees from the upper dome, separated by 90 degrees and ferrite rod loop antennas were mounted on the side of the spacecraft. Power was supplied by the four solar paddle arrays, comprised of 5400 n-p solar cells, charging two NiCd battery packs. The arrays produced 8.1 W in sunlight, the spacecraft required 6.3 W. The satellite was spin stabilized, nominally at 5 rpm, using a yo-yo despin device with the two inertia booms. The spin axis was the central axis of the cylinder. Positional knowledge was provided by a solar aspect sensor. The satellite had no propulsion system. Passive thermal control was achieved by the paint pattern of the spacecraft.

Communication utilized the four canted RF antennas and the 40 m dipole antennas. The PFM telemetry transmitter was a single frequency (136.557 MHz) solid state device with an output of approximately 250 mW. The sub-carriers phase modulated the radio frequency carrier approximately +- 50 degrees. The command receiver was also a single-frequency solid-state device that could transmit in real time or from an onboard tape recorder on command. The spacecraft carried three science experiments: a galactic noise receiver, an ozone prism spectrometer and a broadband ozone photometer, and a pair of micrometeoroid detectors.

Mission Profile

Ariel 2 was launched from NASA Wallops Flight Facility on a four-stage Scout rocket on 27 March 1964 at 17:25:23 UT. It was put into an initial 290 x 1355 km orbit with an inclination of 51.6 degrees and a period of 101.3 minutes. The dipole antenna wire was deployed from a drum using the centrifugal force and booms on either side, which was also part of the despin sequence. The spectrometer output decreased rapidly to only about 10-20% after 3 weeks. The 5 rpm spin rate dropped to 2.16 rpm in early June, but increased to over 3 rpm by the end of the month. By September the spin rate had dropped too low to allow for good science results and the tape recorder, which had been working sporadically, failed. By November 1967 the orbit had decayed to a 211 x 358 km altitude, 90 minute period orbit. Final decay of the orbit and reentry occurred on 18 November 1967.

Alternate Names

  • 00771
  • Ariel2
  • S 52
  • S 52A
  • UK 2
  • UK-C

Facts in Brief

Launch Date: 1964-03-27
Launch Vehicle: Scout
Launch Site: Wallops Island, United States
Mass: 68 kg
Nominal Power: 6.3 W

Funding Agencies

  • Unknown (United Kingdom)
  • NASA-Office of Space Science Applications (United States)


  • Planetary Science
  • Space Physics
  • Astronomy

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Mr. Emil W. HymowitzProject ManagerNASA Goddard Space Flight Center
Dr. Lawrence DunkelmanProject ScientistNASA Goddard Space Flight Center

[Ariel 2 Diagram]

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