NASA Finds India’s Lost Chandrayaan 1 Lunar Spacecraft
In October 2008 ISRO launched the first unmanned lunar spacecraft, the Chandrayaan 1.
the mission was supposed to be operational for 2 years, but then it vanished.
On August 29, 2009, the communication, radio contact was abruptly lost.
Now, after 8 years, US’ space agency NASA has found the Chandrayaan 1.
On Thursday Marina Brozovic, a radar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California said "We have been able to detect NASA's Lunar Reconnaissance Orbiter [LRO] and the Indian Space Research Organization's Chandrayaan-1 spacecraft in lunar orbit with ground-based radar,"
"Finding LRO was relatively easy, as we were working with the mission's navigators and had precise orbit data where it was located."
The Chandrayaan-1 was more of a challenge because the last contact with the spacecraft was in August 2009.
Chandrayaan-1 spacecraft is very small, a cube about five feet (1.5 meters) on each side -- about half the size of a smart car.
Although the interplanetary radar has been used to observe small asteroids several million miles from Earth, researchers were not certain that an object of this smaller size as far away as the Moon could be detected, even with the world's most powerful radars. Chandrayaan-1 proved the perfect target for demonstrating the capability of this technique.
Optical telescopes cannot search for small objects because of the bright glare of the moon.
Chandrayaan-1, the radar team utilized the fact that this spacecraft is in polar orbit around the Moon, so it would always cross above the lunar poles on each orbit. So, on July 2, 2016, the team pointed Goldstone and Green Bank at a location about 100 miles (160 kilometers) above the Moon's north pole and waited to see if the lost spacecraft crossed the radar beam. Chandrayaan-1 was predicted to complete one orbit around the Moon every 2 hours 8 minutes. Something that had a radar signature of a small spacecraft did cross the beam twice during four hours of observations, and the timings between detections matched the time it would take Chandrayaan-1 to complete one orbit and return to the same position above the Moon's pole.
The team used data from the return signal to estimate its velocity and the distance to the target. This information was then used to update the orbital predictions for Chandrayaan-1.
"It turns out that we needed to shift the location of Chandrayaan-1 by about 180 degrees, or half a cycle from the old orbital estimates from 2009," said Ryan Park, the manager of JPL's Solar System Dynamics group, who delivered the new orbit back to the radar team. "But otherwise, Chandrayaan-1's orbit still had the shape and alignment that we expected."
Radar echoes from the spacecraft were obtained seven more times over three months and are in perfect agreement with the new orbital predictions. Some of the follow-up observations were done with the Arecibo Observatory in Puerto Rico, which has the most powerful astronomical radar system on Earth. Arecibo is operated by the National Science Foundation with funding from NASA's Planetary Defense Coordination Office for the radar capability
In Depth about Chandrayaan 1 –
Mission Type: Impact, Orbiter
Launch Vehicle: Polar Satellite Launch Vehicle C11
Launch Site: Satish Dhawan Space Center in Sriharikota, India
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 523.0 kg
Spacecraft Instruments: Bus: 1) Terrain Mapping Camera; 2) Hyper Spectral Imager; 3) Lunar Laser Ranging instrument; 4) X-ray Spectrometer; 5) Sub-keV Atom Reflecting Analyzer; 6) Moon Minerology Mapper (NASA); 7) Near Infrared Specrtometer; and 8) Miniature Synthetic Aperture Radar
Impact Probe: 1) video camera; 2) radar altimeter; and 3) mass spectrometer
Spacecraft Dimensions: 1.5-meter cube
Spacecraft Power: Solar array and rechargable lithium ion batteries
Maximum Power: 750.0 W
Project Manager: Dr. Jayati Datta, ISRO
Total Cost: Estimated $83 million U.S.
Chandrayaan-1 was an Indian Space Research Organization (ISRO) mission designed to orbit the Moon over a two-year period with the objectives of upgrading and testing India's technological capabilities in space and returning scientific information on the lunar surface.
It was based on the India's Kalpansat meteorological satellite. Power was provided by a solar array which generates 750 W and charges lithium ion batteries. A bipropellant propulsion system was used to transfer Chandrayaan-1 into lunar orbit and maintain attitude. The spacecraft was a 3-axis stabilized by using attitude control thrusters and reaction wheels. Telecommand communications were in S-band and science data transmission in X-band.
The spacecraft carried instruments provided by India, the United States and the European Space Agency.
Chandrayaan-1 also carried a 34 kg Moon Impact Probe (MIP) equipped with a video camera, a radar altimeter, and a mass spectrometer. The side panels of the box-like probe were painted with the Indian flag.
The spacecraft launched on a PSLV C11 (Polar Satellite Launch Vehicle) from the Satish Dhawan Space Center in Sriharikota on the southeast coast of India on 22 October 2008 at 00:52 UT. The PSLV injected Chandrayaan-1 into a 255 x 22860 km transfer orbit with an inclination of 17.9 degrees. Reaching lunar transfer trajectory involved five firings of the LAM increasing the eccentricity of the orbit around the Earth to a final apogee of 380,000 km on 4 November. On 8 November Chandrayaan was put into a 7502 x 504 km lunar polar orbit, and then lowered into a 100-km circular polar orbit. On 14 November at 14:36:54 UT the Moon Impact Probe was released and hit the lunar surface at 15:01 UT near the Moon's south pole. All three instruments returned data before the crash.
The Indian Space Research Organization announced on 31 August that the Chandrayaan 1 mission has been officially terminated after contact was lost abruptly at 20:00 UT on 28 August.
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Friday, March 10, 2017
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10 March 2017
NASA Finds India’s Lost Chandrayaan 1 Lunar Spacecraft