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ANNA 1B (Army, Navy, NASA, Air Force 1B, also known as the Flashing Light Geodetic Satellite) was a joint US Army, Navy, NASA, and Air Force geodetic satellite launched from Cape Canaveral by a Thor Able Star rocket. It carried the first GaAs solar cells ever flown in space. It was launched on 31 October 1962, about 4 months after the 9 July Starfish Prime high-altitude nuclear test explosion. The remnant radiation from the blast caused some deterioration of the solar cells, but the GaAs cells were more resistant to damage than other types of solar cells, allowing the power system to operate successfully.

The program objectives were: 1) evaluation of orbital techniques for geodesy; 2) establish geocentric positions and general shape of the Earth; 3) study the geogravitational potential; 4) study air density by analysis of effects of air drag on the satellite; 5) calibration and evaluation of electronic ranging equipment; and 6) measurement of atmospheric attenuation of light.

Spacecraft and Subsystems

ANNA 1A and 1B were identical except for the exterior paint pattern. The spacecraft body was a 107 cm (42 in) diameter aluminum and fiberglass spheroid with a 35.5 cm (14 in.) wide, 12-sided polygonal band of solar cells encircling its equator. The band was 117 cm (46 in.) in diameter. Total mass of the satellite was 161 kg. A pair of xenon flashlamp stroboscopic beacons were mounted on opposite sides of the solar cell band, designed to emit a sequence of five 1.2 millisecond flashes (1100 Joules per flash) at 5.6 second intervals, controlled by a clock timer mounted inside the spacecraft and tracked on the ground by the Smithsonian optical net. The GaAs solar cells provided an average of 22 W to rechargeable NiCd batteries.

The spacecraft held eight transmitters, one at 136 MHz and 400 mW; two for geodetic measurements at 162 MHz (225 mW) and 324 MHz (400 mW); two for refraction studies and as spares for the geodetic measurements (54 MHz, 450 mW and 216 MHz, 225 mW), and two for the SECOR instrument (224.5 MHz, 100 mW and 449.0 MHz, 1 W). Passive thermal control was achieved via Kropschott insulation and a diffusively reflecting construction and paint pattern. A permanent magnet was mounted in the spacecraft to maintain the stable attitude of the spacecraft within 3 degrees with respect to the Earth's magnetic field, giving the spacecraft a "north" face and a "south" face.

The spacecraft carried two instruments in addition to the optical beacons. The SEquential COllation of Range (SECOR) instrument consisted of a transponder tracking system designed to allow ground tracking systems to make a phase comparison between a modulating frequency transmitted to and returned from the spacecraft. The instrument had a receiver and two transmitters using three frequencies in the VHF-UHF bands, one for transmission to the spacecraft and two coherent frequencies for transmission from the spacecraft to the ground. The TRANSIT range rate transmitters used four ultra-stable frequency transmissions broadcast continuously to observe Doppler shift. The transmitters comprise two stable oscillators, two frequency multipliers, and four power-amplifiers. All four transmissions are coherent.

Mission Profile

ANNA 1B was launched at 8:09:00 UT on 31 October 1962 into a 1076 x 1182 km altitude orbit with a period of 107.9 minutes and an inclination of 50.1 degrees. The SECOR navigation equipment failed at launch and could not be operated.

Starfish Prime

Starfish Prime was an American high-altitude nuclear test that took place on 9 July 1962. Launch took place from Johnston atoll in the Pacific Ocean (about 1330 km southwest of Honolulu) at 8:46:28 UT on 9 July 1962 (10:46:28 pm, 8 July local time) on a Thor rocket carrying a W49 thermonuclear warhead. Detonation of the warhead occurred at 09:00:09 UT on 9 July (11:00:09 pm local time, 8 July) at an altitude of 400 km. Total yield was 1.4 megatons. The explosion, occurring at a geomagnetic latitude 10.5 degrees, generated an electromagnetic pulse and generated large amounts of charged particles. These had the effect of damaging many operating satellites, both at the time of the blast and later, as the energetic particles remained trapped in the Earth's magnetic field, forming an artificial radiation belt that persisted for many weeks after the explosion. These damaged satellites include TRAAC, Transit-4B, Ariel 1, Cosmos 5, Telstar 1, Explorers 14 and 15, and possibly Injun 1, OSO-1, Alouette 1, and ANNA-1B.

Alternate Names

  • 1962 Beta Mu 1
  • 00446
  • Anna1B
  • Flashing Light Geodetic Satellite

Facts in Brief

Launch Date: 1962-10-31
Launch Vehicle: Thor-Able-Star
Launch Site: Cape Canaveral, United States
Mass: 161 kg

Funding Agency

  • Department of Defense-Department of the Navy (United States)


  • Navigation/Global Positioning

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail

Anna 1B diagram

Anna spacecraft diagram.

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