The Indian Radar Imaging Satellite (RISAT)-1 Earth observation satellite experienced a fragmentation event on 30 September 2016 between 2:00 and 6:00 GMT due to an unknown cause. The spacecraft (International Designator 2012-017A, U.S. Strategic Command [USSTRATCOM] Space Surveillance Network [SSN] catalog number 38248), operated by the Indian Space Research Organization (ISRO), carries a C-band microwave synthetic aperture radar. The spacecraft had been on-orbit 4.4 years and was in a 97.6° inclination, 543 by 539 km orbit at the time of the event. Over 12 fragments were observed initially by the SSN. However, as of 8 November, only one piece (SSN 41797) had entered the catalog, having decayed from orbit on 12 October 2016; the remainder have decayed as well. At the current time, this event is categorized as an anomalous separation of multiple high area-to-mass ratio debris. Events like this are sometimes referred to as a shedding event.
So.... RIP RISAT-1?
The US space agency Nasa has reported that India’s earth observation satellite Risat-1 had experienced a “fragmentation event” in September last year, when pieces appeared to have broken off. The report, in Nasa’s quarterly magazine Orbital Debris, said the cause was not known. An Isro official said there was some anomaly which had been rectified, and the satellite was functioning normally.
It had been in space for 4.4 years when the incident reported by Nasa occurred. The magazine said Risat-1 experienced the fragmentation event between 0200 and 0600 GMT (7.30 am and 11.30 am IST). Over 12 fragments were observed by the Space Surveillance Network of the US, it said. By November 8, only one piece, designated SSN 41797, had entered the catalog, having decayed — from orbit on October 12, 2016. The other pieces had decayed — moved away from the satellite — as well. Eventually, space debris in the near earth orbit tends to enter the earth’s atmosphere and burn up.The magazine said the event was categorised as an “anomalous separation of multiple high area-to-mass ratio debris”. Events like this are sometimes referred to as a shedding event. Nasa’s Space Debris Programme continuously tracks 17,000 space objects and maintains record of all space debris — non-functional objects in space — as well as operational satellites.When contacted for clarification, Isro spokesperson Deviprasad Karnik said the satellite was functioning normally. He said Isro scientists had corrected some anomaly which had nothing to do with what was reported in the Nasa magazine.
Quote from: vyoma on 02/01/2017 08:58 pmSo.... RIP RISAT-1?Not yet because it LOM has not been declared. Again it is shedding event and no indication yet that critical hardware detached. I'd wait a couple of weeks until impacts of operations are made known
In GSAT-6A, there could be a power issue. A spark could have led to a short circuit. In the last three satellites — GSAT-6, RISAT and GSAT-6A — we have shifted to a higher-powered satellite bus. We saw there were similar problems in RISAT after it completed its life.