Saturday, August 29, 2009

Chandrayaan-1 goes silent

Just days after a joint radar surveillance exercise of Erlanger crater, relayed by NASA's Lunar Reconnaissance Orbiter (LRO), India has lost contact with Chandrayaan-1.

India's first lunar orbiting probe was launched October 22, 2008, and had recently been raised to a 200 km orbit after completing most of its primary mission.

Chandrayaan-1 project director M. Annadurai announced the end of the mission, telling the PTI news agency, "the mission is definitely over. We have lost contact with the spacecraft."

Annadurai said Chandrayaan-1, "has done its job technically...100 per cent. Scientifically also, it has done almost 90 to 95 per cent of its job."

Scientists earlier informed reporters that the Indian Space Research Organization (ISRO) did not hold much hope of continuing the mission as telemetry began to fail and finally "ended abruptly."

The mission had almost come to an end, nearly as abruptly, one at least two occasions when on-board temperatures rose to their tolerance levels. Lunar exploration has become so "normalized" in the minds of many, it is easy to forget the Moon presents one of the harshest environmental extremes in the solar system.

ISRO sources said "connectivity revival" was unlikely, and without orbital maintenance Chandrayaan-1 would eventually crash into the moon. Low lunar orbit is notoriously unstable because the Moon's gravity is punctuated by both higher and lower than mean concentrations of mass near its irregular surface.

Chandrayaan-1 was incorrectly being described as the "cheapest moon mission ever," though it's $80 million price tag rivaled the "bang per buck" ratio delivered by such missions as Lunar Prospector in 1998, which cost the United States $60 million.

With Chandrayaan and its PSLV-1 booster, ISRO has propelled India into the club of "space-faring nations," including India with the United States and the late Soviet Union, and more recently, the European Union, China and Japan.

Powered by a single solar panel, the Chandrayaan's mission included taking high-resolution pictures of the moon, preparing a three-dimensional atlas of its surface, chemical and mineralogical mapping and searching for the source of the strong hydrogen signal discovered in the 1990's in and around the lunar poles.

Chandrayann hosted 11 payloads - five designed and developed in India, three from the European Space Agency (ESA), one from Bulgaria and two from the United States.

"The spacecraft has completed 312 days in orbit, making over 3,400 orbits around the moon, providing a large volume of data from sophisticated sensors, like its terrain mapping camera, hyper-spectral imager, its moon mineralogy mapper, and so on, meeting nearly all of the scientific objectives of the mission," the ISRO said in its released statement.

ISRO Official Statement HERE.

1 comment:

Joel Raupe said...

Congratulations to ISRO. The PSLV-1 booster performed excellently, on only it's second fligh, and subsequent navigation to lunar orbit and afterward was first-rate. Thermal problems remain the second most difficult challenge for robotic and manned missions to Earth's Moon.

To quote from a report from designers of LRO, "The lunar thermal environment is one of the harshest in our solar system with the heavy
infrared loading of the moon due to low albedo, lack of lunar atmosphere, and low effective regolith conduction. This set of constraints required a thermal design which maximized performance (minimized radiator area and cold control heater power) and minimized thermal hardware build at the orbiter level."