Recently, when I spoke to ISRO chairman G Madhavan Nair (one of the best interactions I had in a long time), I could not resist but ask his views on space debris in light of the latest collision of US Iridium satellite with that of a defunct Russian satellite.

According to experts, there are currently at least 17,000 objects measuring 4 inches or greater circling the Earth. The US government estimates that there are 200,000 objects in the 1-3 inch range and tens of millions smaller than an inch. Thus, it poses a major hazard to any space mission, including the upcoming ones from ISRO.

Hence, I asked Mr. Nair, his views on the subject, and this is what he had to say:

“Space debris is a real issue and a serious concern, though the threat as of now is not very high as the probability of a collision happening is very bleak, approximately one in a million, less than that of a road accident. We have been facing this issue and need to take care of it because these objects are
travelling at around 7.5 km/sec and any collision at that speed can be
quite disastorous.

Of course during the launch of satellite, we keep a track of a catalog
of known objects and we ensure that they are taken care of. But beyond
that there is a lot of minute and small objects that are hovering
above the ear and pose a threat to any mission. Fortunately, an American agency has made a detailed catalog of the objects and they share it with us all the time. The issue of space debris will get more critical in the coming years as the clutter increases in the time to come.”

Coming from the man behind the Chandrayaan mission, this is indeed a serious concern. The big question is whether there is anything that we can do??