Pressure drop in rocket led Isro to abort moon mission
Isro had to abort Chandrayaan-2 due to drop in pressure in one of the tanks of the upper stage of the rocket.
The Indian Space Research Organisation (Isro) now has a window of a minute every day till July 31 to attempt a relaunch of its second moon mission.
“In order to maintain the temperature of liquid hydrogen at -253 degree centigrade, the upper stage of the rocket has nine helium tanks maintained at a pressure of around 300 PSI (pound per square inch). Pressure dropped by 10% in one of these tanks. This is not a big problem and Isro would have gone ahead with the launch for most missions,” one of the persons said. “Considering the significance of the moon mission, Isro did not want to take chances and aborted the launch.”
An hour before the designated time for the launch early on Monday, scientists found a marginal drop in pressure, which prompted them to be cautious in going ahead with the planned schedule.
The agency will drain the fuel — highly pressurised liquid hydrogen and liquid oxygen — from the indigenous geo synchronous satellite launch vehicle (GSLV-MkIII) before it carries out a thorough test to identify a possible leak that could have led to the anomaly.
Analysing the Situation: Isro
“The process should take around a week,” said an Isro scientist. “We should launch the mission soon”.
It is normal for space agencies to abort launches in the last minute if they find glitches as they do not want to incur loss of expensive rocket and spacecraft. An Isro spokesperson responded to a message saying it is “still analysing the situation”.
The Chandrayaan-2 is the first operational flight of GSLV-MkIII. So far, it has done two successful development flights. Five decades ago, when the US launched its first manned mission to the moon, its powerful rocket Saturn V, with a capacity to carry 48.6 tonnes, took around eight days to reach the earth’s satellite. India’s mission is modest. Its heaviest rocket GSLV-MkIII has the capacity to carry a spacecraft of 4 tonnes to the higher earth orbit. The Chandrayaan-2 mission — the spacecraft with an orbiter, lander and rover — weighs 3.8 tonnes.
Isro is adopting a proven strategy of Chandrayaan-1 to use the earth’s gravitational force to act as a sling to hurl the spacecraft to the moon’s orbit. The process takes over 35 days before it reaches the moon’s atmosphere. The lander will touch in the region of the south pole of the moon, a territory that is unexplored and has potential of water streams.
Chandrayaan will primarily study the elements on the moon, map its topography through high-resolution pictures, study its minerals and, most importantly, confirm sub-surface water/ice presence.
“Advanced synthetic aperture radar in Chandrayaan-2 has the ability to look for water—identify the presence of water rise at depths of a few meters: an important input for sustaining a future human presence on the moon,” said P Sreekumar, director-SSPO, Isro, in an official video from the space research organisation. The Chandrayaan-2, an ?978-crore project, is expected to place the country in a niche league of nations such as the US, Russia and China to have landed a spacecraft on moon.