Hyderabad: The Cartosat Two series programme has been one of the most complex missions handled by the Indian Space Research Organisation. It involved injecting into Space a record total of 104 satellites in a delicate sequence — within a deadline — without them colliding with each other.
It has been revealed that Isro scientists used 25 quart boxes with four satellites in each box. The boxes were then ejected in a sequence and satellites were released in pairs after the doors of the boxes opened through commands from Mission Control. Moreover, the orientation had to be designed in such a way that the satellites would not collide with each other in Space.
Also, in addition to the existing ground stations of Isro, scientists tied up with another ground station operating out of Mauritius to track the complete operation.
Cartosat and two nano satellites of the Isro were deployed sequentially before releasing the other small satellites, said the Mission Director B. Jayakumar.
He added that it was a challenging task to accommodate all the satellites in a single flight. Mr Jayakumar said after the latest launch, Isro had put a total of 226 satellites into orbit — including 180 from foreign nations.
Meanwhile, noted space scientist G. Madhavan Nair on Wednesday said Isro’s feat was achieved by proven technology, and the rocket was capable of launching even 400 nano spacecraft.
“This is no new technology. We started with ten satellites (on board a single rocket), then went to 18 or something; then it’s 35. Now it’s 100. If you make 3 or 4 kg satellite, it (PSLV) can take 300 to 400 satellites at a time,” the former Isro chairman said.
US ‘planet-scanner’ is top client
Among the 101 foreign nano-satellites, which were part of the total 104, 96 are from the United States and other five are from Israel, Kazakhstan, The Netherlands, Switzerland and the UAE.
Out of the 96 satellites from the US, 88 satellites have been built by US-based company Planet Inc. These nanosatellites are a fleet of remote-sensing satellites that will image the entire Earth, every day for commercial, environmental and humanitarian purposes.
Each Dove satellite — which is part of a space constellation above Earth — has 200mbps “internet connection” and can scan generate imagery from more than 2 million sq km per day.
“Tonight is the culmination of a huge effort over the past five years. After Wednesday’s launch, Planet operates 144 satellites in orbit. We have reached our milestone,” Robbie Schingler, Planet’s co-founder, wrote in company blog post.
As far as the remaining eight are concerned, they are LEMUR satellites from the United States and are meant for providing vessel tracking information using the Automatic Identification System (AIS), besides carrying out weather measurement using GPS Radio Occultation. The PSLV also carried two nano satellites of Isro — INS-1A and INS-1B.
The INS-1A nanosatellite is also carrying experimental payloads to measure the bi-directional reflectance distribution function of the Earth’s surface and a Single Event Upset Monitor, which will monitor atmospheric upsets high above the planet due to the high-energy radiation from the Sun.