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The VRAD (Very Long Baseline Interferometry) subsatellite, Ouna (also designated Vstar), part of the Kaguya mission, is an octagonal cylinder 0.99 x 0.99 x 0.65 m in size with a mass of 53 kg. A dipole antenna protrudes from the top center of the subsatellite. The spacecraft is spin-stabilized at 10 rpm and has no propulsion units. Power is provided by a 70 W Si solar cell array covering the sides of the satellite which charges a 13 AH, 26 V NiMH battery. It holds one X-band and three S-band radio sources. The satellite in conjunction with the relay satellite will enable differential VLBI observations from the ground. The spacecraft was released from Kaguya at 04:28 UT on October 12, 2007 (1:28 p.m. Japan Standard Time, JST). The spacecraft started in a 127 x 795 km polar orbit. Telemetry command was terminated on 29 June 2009. The orbit is assumed to have decayed and Ouna crashed into the lunar surface at an unknown time and location. The VRAD and Relay satellites were mounted on top of the mission module before release.

Alternate Names

  • 32056
  • VRAD

Facts in Brief

Launch Date: 2007-09-14
Launch Vehicle: H-2A
Launch Site: Tanegashima, Japan

Funding Agency

  • Japan Aerospace Exploration Agency (Japan)


  • Planetary Science

Additional Information

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



NameRoleOriginal AffiliationE-mail
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