Among the 70 spacecraft sent so far to study the moon, Chandrayaan-1 had the largest number of instruments on board, that is, 11. Of the 11 instruments, five were from India, and six from different countries including the U.S., the U.K., Germany, Sweden and Bulgaria. It was thus an international mission with India as the captain. The latest spacecraft to orbit the moon are NASA’s Lunar Reconnaissance Orbiter (LRO) and the Lunar Crater Observation and Sensing Satellite (LCROSS), which were launched together on the same vehicle in June 2009.
Analysing Data
What is puzzling Indian Space Research Organisation (ISRO) scientists about their losing radio contact with Chandrayaan-1 is that they “were able to converse with the spacecraft” at 0025 hours on Saturday but could not do so after an hour. “It was O.K. at 0025 hours. However, around 1.30 a.m., nothing was there. We had totally lost radio contact with the spacecraft. Why? We are analysing the telemetry data. It was very unfortunate,” said an ISRO scientist.
If the ISRO faced problems with Chandrayaan-1 with its two star-sensors failing from April 2009 and it was put in the “gyro-mode” to orient the spacecraft towards the required area of the moon, the LCROSS is now facing problems with its gyroscopes.
The instruments from India on board Chandrayaan-1 and those from abroad were integrated at the ISRO Satellite Centre, Bangalore. It was the first time that any spacecraft sent to the moon helped in preparing a three-dimensional atlas of the entire surface of the moon. The instruments also looked for the presence of helium-3 on the moon’s soil.
The five Indian instruments are the Terrain Mapping Camera, the Hyper-Spectral Imager, the Lunar Laser Ranging Instrument, the High-Energy X-ray Spectrometer and the Moon Impact Probe. While the Terrain Mapping Camera took black and white pictures of the moon’s surface, the Hyper-Spectral Imager took colour pictures by recording the visible and infra-red light reflected from the moon. The Lunar Laser Ranging Instrument was a laser radar that provided information on the height of the hills or mountains, or the depth of the craters or valleys. The High-Energy X-ray Spectrometer explored the moon’s polar regions for possible presence of water-ice. The Moon Impact Probe, by impacting on the moon on November 14, 2008, demonstrated the technologies required for landing the rover of Chandrayaan-2 on the moon. Thus, it was a technological forerunner to Chandrayaan-2.
The six instruments from abroad are Chandrayaan-1 Imaging X-ray Spectrometer (CIXS), Smart Near Infrared Spectrometer (SIR-2), Sub Kiloelectronvolt Atom Reflecting Analyser (SARA), Mini Synthetic Aperture Radar (Mini-SARA), Moon Mineralogy Mapper (M3) and Radiation Dose Monitor (RADOM). They helped in providing information on minerals such as magnesium, calcium and aluminium on the moon; the origin of the moon; the relationship between the sun and the moon; the possible presence of water-ice; and the moon’s radiation environment.
Novel experiment
On August 21, ISRO and NASA performed a novel experiment that could provide information on the possible existence of water-ice in a permanently shadowed crater near the moon’s North Pole. The experiment involved Chandrayaan-1 and NASA’s LRO.
Of 11 instruments, 5 were from India, and 6 from countries including U.S., U.K., Germany, Sweden and Bulgaria.
