Muses A Lunar Orbiter (Hagoromo)

Muses A Lunar Orbiter (Hagoromo) [ISAS]

The Muses-A Lunar Orbiter (Hagoromo) was Japanese lunar orbiter built by ISAS.

It had a mass of 12 kg and a 26-faced polyhedral structure, 36 cm between opposite faces. A solid propellant (KM-L) retrorocket with a mass of 4 kg was mounted inside the spacecraft for lunar orbit insertion. Sixteen of the surfaces were covered with 1000 sheets of indium-phosphorus solar cells which could generate about 10 W. Two way communications with a ground station were provided by an S-band transponder and an omni-directional cross-dipole antenna mounted on top of the orbiter. No scientific instrumentation was included, only housekeeping data such as temperature was transmitted.

It was launched piggy-back on the Muses A (Hiten) probe into a highly elliptical Earth orbit which passed by the Moon ten times during the mission. At 19:37 UT on 18 March 1990 as Hiten approached its first lunar flyby, the small Hagoromo spacecraft was released into lunar orbit, making Japan the third nation to orbit the Moon. Although the S-band transmitter aboard Hagoromo had failed on 21 February 1990, the ignition of the Hagoromo deceleration rocket was confirmed by ground observation at 20:04:03 UT, the estimated orbit was 7400 × 20000 km with a period of 2.01 days. No contact could be established after orbit insertion.