Manas Dasgupta
NEW DELHI, Aug 7: Indian Space Research Organisation’s (ISRO) newly developed Small Satellite Launch Vehicle (SSLV) mission suffered a setback on Sunday as the two satellites that were on-board the first flight of the rocket got placed in an unstable orbit and are no longer usable.
Announcing the setback to the mission, the space agency said the overall mission objectives of the launch were not met as SSLV suffered “data loss” at the terminal stage, although three stages “performed and separated” as planned and the scientists were “currently analysing” the data to ascertain the cause behind it. The two satellites were no longer usable as the SSLV D1 placed them into the elliptical orbit instead of circular orbit, ISRO said.
The SSLV-D1/EOS-o2 in its mission to place an earth observation satellite and students satellite into the low earth orbit, blasted off precisely at 9.18 a.m. amid cloudy skies from the first launch pad at Satish Dhawan Space Centre in this spaceport. The 34-metre long rocket soared majestically on completion of its nearly seven-and-half-hour countdown on Sunday.
The scientists at the Mission Control Centre gave updates about the health of the rocket soon after lift-off. Screens at the Media Centre showed that the satellite was well on its trajectory in the first three stages before suffering “data loss” as described by ISRO Chairman S. Somanath.
“All stages performed as expected. The first stage performed and separated, second stage performed and separated, the third stage also performed and separated, and in the terminal phase of the mission, some data loss is occurring and we are analysing the data and we will comeback on the status of the satellites as well as the vehicle performance soon,” he said from the Mission Control Centre, minutes after the launch.
“Issue is reasonably identified. Failure of a logic to identify a sensor failure and go for a salvage action caused the deviation. A committee would analyse and recommend. With the implementation of the recommendations, ISRO will come back soon with SSLV-D2,” the space agency said in a series of tweets. The update on the status of the mission came hours after it experienced data loss in the final phase of the flight.
The SSLV was carrying Earth Observation Satellite -02 and a co-passenger satellite AzaadiSAT — developed by the student team of “Space Kidz India,” an aerospace organisation that aims to create basic understanding and knowledge of space in government school students.
The “AzaadiSAT” comprises 75 payloads built by 750 school students to mark the 75th Anniversary of Independence. The girl students who designed the satellite also witnessed the SSLV-D1 launch at the spaceport in Sriharikota.
“Three groups from our school have participated in this SSLV launch. I am very glad that we got this opportunity. We really worked hard on it and today we will witness the launch of the AzaadiSAT satellite,” some students said. This was the maiden launch of SSLV by the space agency after the successful mission launches through its trusted workhorse Polar Satellite Launch Vehicles (PSLV) and Geosynchronous Launch Vehicle (GSLV).
On Sunday morning, the jubilant mood at the Mission Control Centre soon made way to anxiety as scientists were seen glued to the computer screens and confused before Somanath updated the mission status.
After establishing itself with successful launches of various satellites using its PSLV and GSLV vehicles, ISRO had targeted the SSLV market which places the satellites into 500 kms low earth orbit. The Earth Observation Satellite EOS-02 and the co-passenger students satellite AzaadiSAT were the major payloads for the SSLV.
The EOS-02 is an experimental optical remote sensing satellite with a high spatial resolution. It is to realise and fly an experimental imaging satellite with a short turnaround time and to demonstrate launch-on-demand capability. EOS-02 belongs to the microsatellite series of spacecraft.
The AzaadiSAT is a 8U CubeSat weighing around 8 kilograms. It carries 75 different payloads each weighing around 50 grams. Girl students from rural regions across the country were provided guidance to build these payloads.
It is not the first time for ISRO to face a setback on its maiden launch missions as PSLV — dubbed as one of the trusted workhorses for the space agency — was not successful in its first flight way back on September 20, 1993. After its first successful launch in October 1994, PSLV emerged as the reliable and versatile launch vehicle of India with 39 consecutively successful missions by June 2017.
It had successfully launched the CHANDRAYAAN-1 in 2008 and also the Mars Orbiter Spacecraft in 2013 that later travelled to the Moon and Mars, respectively. The first flight of GSLV in April 2001 carrying GSAT-1 was successful for ISRO. From January 2014, the vehicle has achieved four consecutive successes, ISRO said. The first developmental flight of GSLV Mk-III, successfully placed GSAT-19 satellite to a Geosynchronous Transfer Orbit (GTO) on June 5, 2017.
The SSLV, which uses three solid fuel-based stages and a liquid fuel-based velocity trimming module (VTM) to place the satellite in orbit, was designed keeping in mind the quick turnaround time needed for commercial launch. The launch using the vehicle can be carried out within a week, the vehicle can be integrated in two days, tested for the next two, with rehearsal and launch in another two days. This was achieved during the current mission, Somanath said.
