Saving Satellites: 8.1k ‘close approaches’, 21 collision avoidance moves in ’22

BENGALURU: Reiterating the growing concerns of protecting space assets from other objects including debris, India tracked more than 8,000 “close approaches” of objects in space, including 524 that were less than 1km from an Indian asset while Isro carried out 21 Collision Avoidance Manoeuvres (CAMs) to prevent another object hitting one of its satellites in just 12 months.
Comparatively, in 2021, for example, India had tracked 7,600 “close approaches”, about 6.6% less than the number of objects tracked in 2022. However, in that year, there were more than 4,300 close approaches that were less than 1km, six times more than in 2022.
According to Isro: “In 2022, 8,100 close approach alerts by catalogued space objects were generated using daily Space object proximity analysis (SOPA) including alerts from United States Space Command (USSPACECOM) screening of Indian space assets — 24 low Earth orbit (LEO) and 29 geostationary orbit (GEO) spacecraft. And, 524 critical alerts with less than 1km close approach distances for LEO and GEO spacecraft were analysed to rule out any CAM requirement.”
Isro added that the second lunar flyby of US’ Orion spacecraft was monitored and conjunction risks assessed for Chandrayaan-2 orbiter confirmed no close approaches.
“As part of daily assessment of atmospheric re-entry of large catalogued objects, alerts were generated for eight re-entered objects that were monitored out of which six had final ground traces over India,” it said.
CAMs Increasing
The number of CAMs Isro has been carrying out has been increasing year on year. Also, six out of the eight daily assessments of atmospheric re-entry of large catalogued space objects that were tracked and monitored had final ground traces over India in 2022.
The first five months of 2022 had seen Isro perform at least 10 CAMs to prevent damage to Indian space assets, as reported by TOI earlier and the next seven months saw another 11 such manouvres.
In 2021, Isro’s directorate of space situational awareness and management (DSSAM) carried out 20 CAMs. In fact, the number of CAMs are only increasing with at least 80 carried out since 2015 — 12 in 2022, eight in 2019 and 2018, five each in 2017 and 2016 and only three in 2015.
SSA & Project Netra
In order to enhance space situational awareness (SSA), India is implementing project Netra, which will acquire indigenous capabilities to detect, identify, track and catalogue space debris objects.
Under the project, Isro will have a control centre, multi-object tracking radar and optical telescope for space debris observation. An Isro official told TOI: “Work on installing the optical telescope, which will be capable of tracking objects of size 40cm or larger at geostationary orbit (GEO) has begun in Hanle in Ladakh, in collaboration with the Indian Institute of Astrophysics (IIA). This telescope will become operational in the next 24 to 27 months.”
DSSAM has already commenced activities from the SSA control centre at Peenya in Bengaluru, where operations related to safeguarding space assets like conjunction analysis for collision risk mitigation have started after deployment of relevant software and hardware elements.
Further, the multi-object tracking phased array radar under Netra — capable of tracking objects in size of 10cm or larger at a range of 2,500km — will come up near Guwahati in Assam. “The request for proposal (RFP) for this has received very good response and technical evaluation in progress,” the official added.