India鈥檚 Chandrayaan spacecraft is set to eject a television-sized probe that will crash onto the lunar surface on Friday. The probe will make observations as it descends, testing systems needed to land future robotic spacecraft on the Moon.
Chandrayaan, which launched on 22 October, has been travelling on an elongated path around the Moon since it went into orbit there on Saturday. But engine firings on Tuesday and Wednesday should move the craft into a circular orbit that brings it just 100 km from the surface.
After letting the spacecraft circle the Moon for two days, mission planners will release the 29-kilogram (MIP) on Friday evening India time. Scheduled to hit the surface near the south pole, it is not designed to survive the impact.
Advertisement
The probe, which was built by the (ISRO), will take 20 minutes to descend to the surface.
During that time, it will film the surface with an onboard video camera, says T K Alex, director of ISRO鈥檚 Satellite Centre (ISAC) in Bangalore.
Soft landings
An altimeter will measure the probe鈥檚 height as it nosedives, helping to test technologies needed to make 鈥榮oft鈥� landings on the Moon. India鈥檚 next lunar mission, scheduled for 2010, involves not only an orbiter but also a Russian-built lander that will study samples of lunar soil.
鈥淚 think the main purpose [of the Moon Impact Probe] is preparations for future soft landings,鈥� says Christian Erd, mission project manager at the European Space Agency in Noordwijk, The Netherlands. 鈥淚t is a demonstration of the separation mechanism and getting to the surface.鈥�
The probe will also carry a mass spectrometer that will measure traces of gas and dust floating above the Moon. Signals from all three onboard instruments will be relayed back to the spacecraft and from there to ground stations on Earth.
Dust plume
鈥淚t is a sort of mini-satellite, equipped with its own instruments, batteries, and telemetry,鈥� says Rajagopal Sreedharan, head of the space physics laboratory at the Vikram Sarabhai Space Centre (VSSC), which built the six Indian instruments onboard Chandrayaan.
MIP will strike the surface near the lunar south pole, a region that shows hints of water ice in the soil. Parts of the terrain there also receive near-constant sunlight, providing prime spots to set up future solar power stations.
鈥淲e are impacting the Moon鈥檚 south pole because of the huge amount of interest in the region,鈥� he told 麻豆传媒.
When the probe hits the surface, it is expected to kick up a huge amount of dust that will be analysed by instruments on the Chandrayaan orbiter.
