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The 62 and half hour countdown activity of PSLV-C28/DMC3 Mission has commenced at 07:28hr (IST) on Wednesday. The launch is scheduled at 21:58 hr on July 10, 2015 from Sriharikota space station, near Chennai. Of the five British satellites, together weighing around 1,440 kg, three are identical DMC3 optical earth observation satellites each weighing 447 kg.
On Thursday, Isro said that the countdown operations are progressing normally. "Preparations for Mobile Service Tower (MST) withdrawal and Propellant filling operation of second stage (PS2) are in progress," it said. On Wednesday, it has been carrying out various stages of fule filling operations. This would be the first commercial launch of Isro this year.
It may be noted, on Tuesday, the Isro's Launch Authorisation Board (LAB) gave its nod for the July 10 launch. The Mission Readiness Review (MRR) committee and Launch Authorisation Board (LAB) have cleared the starting of the countdown on the day.
The British satellites will be put into a 647-km sun-synchronous orbit. Of the other two satellites, CBNT-1 weighs 91 kg and also is an optical earth observation technology demonstration microsatellite, while the De-OrbitSail weighs 7 kg.
Isro said that this is an experimental nano satellite for demonstration of large thin membrane sail and drag deorbiting.
The three DMC3 and the CBNT-1 satellites are built by Surrey Satellite Technology Ltd. The De-OrbitSail is built by Surrey Space Centre.
The three satellites each with a height of about three metres within the existing payload fairing or the heat shield of the PSLV was a challenge. Thus, a circular L-adaptor and a triangular Multiple Satellite Adapter-Version 2 (MSA-V2) were newly designed and realised by Isro for this specific purpose, said Isro.
The PSLV-XL, which costs around Rs 140 crore, is operated in four stages and has a vehicle lift-off mass of 320 tonne and a height of 44.4 metre.
According to Isro sources, so far the heaviest exclusive commercial mission the Space Organisation handled was in the PSLV-C23, launched on June 30, 2014. The launch vehicle PSLV-C23, with a height of 44.4 metres, lifted off at 9.52 am on that day, carrying SPOT-7, a 714 kg, French earth observing satellite as the main payload, which was injected into a 655 km Sun Synchronous Orbit (SSO). Other satellites include 14 kg AISAT of Germany, NLS7.1 (CAN-X4) & NLS7.2 (CAN-X5) of Canada each weighing 15 kg and the 7 kg VELOX-1 of Singapore.
The second heaviest commercial launch was in September 9, 2012, when the PSLV-C21 carried Frech satellite SPOT-6 weighing 712 kg and Japanese satellite PRIORITIES weighing 15 kg.
Interestingly, the highest number of foreign satellites were commercially launched by ISRO in April, 2008, when it launched eight satellites from various countries inclding Canada, Japan, The Netherlands, Denmark and Germany, in PSLV-C9 mission. However, the total weight of these eight satellites was 48.5 kg.
From 1999, the Space Organisation has so far launched 40 satellites of other countries through PSLV, both in exclusive missions and along with the Indian satellites.
Mars Orbiter MissionIndia's prestigious interplanetary mission Mars Orbiter Mission (MOM) is expected to see extended life as it has come out of the short black out period healty, said Isro Chairman Kiran Kumar in Chennai.
Speaking to the reporters here, he said, "Mangalyan satellite has come out of its black out phase and is orbitting well which means we can extend the Mars mission duration,"
It may be noted that the mission, which reached the Mars orbit on September 24, 2014, was expected to have a life time of six months and in March, the Space Research Organisation announced that its life has been extended to another six months, considering the 1,340 kg orbiter has sufficient fuel left to do so.
However, the risk was that there was a black out phase, of 15 days in June, during when the Satellite would not be visible to the Earth bound communicators, resulting in a communication black out. Reddy, today said that the orbiter has come out from the communication black out healthy.
Speaking about the Isro's role to find missing Coast Guard's Dornier aircraft, he said the plane should emit some sort of radio frequency for them to find out the source. The sea bed can't be mapped as it would be like searching a needle in a hay stack, he added. The Coast Guard Dornier Aircraft CG 791, deployed for surveillance along the Tamil Nadu Coast and Palk Bay from the Coast Guard Air Station Chennai last evening failed to return to the base on June 9, 2015. While search has been going on continuously, there were no positive signs of finding out the missed flight so far.
On SAARC satellite, promised by Prime Minister Narendra Modi, Kumar said Isro is currently researching on frequency and spectrum location to place the satellite. Once it is all finalised, the work will commence.
It may be noted during his first visit to Isro after he took over as Prime Minister, Narendra Modi announced that India will gift a satellite to SAARC countries.
