Initial indications are that the premature end to India’s Chandrayaan-1 lunar orbiter mission was the result of a miscalculation by scientists at the Indian Space Research Organisation (ISRO) of the thermal stresses the spacecraft would encounter in its operating environment.
Temperatures at Chandrayaan-1’s 100-kilometer orbit proved hotter than expected, causing some of the spacecraft’s components to overheat and malfunction. The issue was discovered in the weeks immediately following Chandrayaan-1’s October launch, forcing ISRO to take thermal control measures that culminated in May when the agency moved the spacecraft to a higher orbit. It appears, however, that by that time, the damage was done, and Chandrayaan-1 succumbed at the end of August — just nine months into what was supposed to have been at least a two-year mission studying the Moon.
In announcing Chandrayaan-1’s demise Aug. 29, ISRO noted that most of the mission’s scientific objectives had been achieved. In a subsequent press release, issued Sept. 8, ISRO said scientists from India and participating agencies in the United States and Europe found Chandrayaan-1 data to be of high quality and that initial analyses of that data “has already resulted in a notable shift in the understanding of the working planetary body.”
Indeed, ISRO has much to be proud of in the wake of its first planetary mission. Chandrayaan-1 was developed at a relatively low cost and launched reasonably close to its original schedule with a payload of 11 instruments, six of which were supplied by international partners. The spacecraft gathered data from its intended orbit for some six months before the overheating issue forced ISRO to raise its altitude.
The technical error that ultimately doomed Chandrayaan-1 likely could have been avoided given all that has been learned about the lunar-orbit environment through measurements taken by NASA and other space agencies dating back to the 1960s. The experience will inform ISRO’s future planetary endeavors, just as NASA has had to learn from past mistakes like the measurement-conversion error that led to the Mars Climate Orbiter failure a decade ago this month.
Hopefully, ISRO also has learned something about managing the disclosure of information about civilian space missions, particularly those involving international partners, even if the news is bad. Unfortunately, Chandrayaan-1 stands out as an example of how not to do it. In announcing that Chandrayaan-1’s orbit had been raised to 200 kilometers, for example, ISRO said the probe’s primary mission had essentially been completed and couched the maneuver as a means of carrying out additional studies. No mention was made of the overheating problem that appears to have been the actual reason for the maneuver.
ISRO demonstrated its ability to lead an international mission with Chandrayaan-1, and is collaborating with Russia on a follow-on mission that will include a lander and rover. Part of the responsibility that comes with such a leadership role is being forthright and up front with details when things go wrong. ISRO can and should do better. It can start by including representatives of its partner agencies in the investigation of Chandrayaan-1’s premature failure, and then by making the results of that probe fully available to the public.
