As an Indian rocket is getting ready to put five British satellites into orbit on July 10, officials at the Sriharikota space port are also working on an Indian satellite launch, an official said on Monday.

India will launch a communications satellite GSAT6 sometime after July 10.

"Work is progressing smoothly for the July 10 night rocket launch. The PSLV (polar satellite launch vehicle) rocket is ready. We are carrying out the launch rehearsal now. We will be rehearsing the activities that are to be done on the launch day," a senior official of Indian Space Research Organisation (Isro) told IANS on Monday.

According to him, the four stage/engine PSLV rocket in XL variant is slated to blast off at 9:58pm on July 10 and the 62.5-hour countdown is expected to start at 7:28 am IST on July 8.

The official said the Launch Authorisation Board (LAB) is slated to meet on July 7 and take a decision on the PSLV rocket launch.

Of the five British satellites, together weighing around 1,440kg, three are identical DMC3 optical earth observation satellites weighing 447kg. These will be put into a 647km sun-synchronous orbit.

Of the other two satellites, CBNT-1 weighs 91kg and also is an optical earth observation technology demonstration microsatellite, while the De-OrbitSail weighs 7kg. 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.

According to Isro , accommodating the three DMC3 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.

France's SPOT 7 satellite weighing 714kg was the heaviest single foreign satellite carried by a PSLV rocket till now. It was launched on June 30, 2014.

Meanwhile, the GSAT6 communication satellite is expected to reach Sriharikota space port on July 6 after it was flagged off from Bengaluru, the official said on the condition of anonymity.

He said the GSAT6 communication satellite will be put into space aboard a heavier rocket called geosynchronous satellite launch vehicle (GSLV).

The GSLV rocket's first stage/engine has been assembled and the activities relating to that rocket assembly are progressing smoothly.

Only after the GSLV rocket launch the testing of a small model of reusable launch vehicle shaped like an aeroplane would be done, the Isro official said.

Earlier, it was said the test reusable launch vehicle would happen in July 2015.

Isro officials had told IANS that the test model reusable launch vehicle would be mounted on a strap-on solid booster of PSLV rocket with 9-tonne fuel.

At an altitude of 70km, the model would get separated and would glide back to earth. The descent speed would be around 2 kilometres per second.

"The descent speed would be controlled through the fins on the machine. In order to protect the equipment from friction heat when it comes back, necessary protective tiles are fixed," the Isro official had told IANS.

The experimental vehicle would weigh around 1.5 tonne which is a far cry from the actual vehicle that is expected to carry a satellite.

In December 2014, Isro sent up a 3.7-tonne giant cup cake shaped module - called Crew Module Atmospheric Re-entry Experiment - to study its re-entry characteristics, aero-braking and validation of its end-to-end parachute system.

A 630-tonne rocket went up to 126km when the crew capsule got detached and fell into the Bay of Bengal, 20 minutes after the blast off.

The descent speed of the crew module was controlled by three parachutes.

However, the aircraft shaped vehicle will not have any parachutes to control the descent speed but the fins and other parts would do so.

Quelle: NDTV

In its thirtieth flight, conducted from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota today night (July 10, 2015), ISRO's Polar Satellite Launch Vehicle PSLV-C28 successfully launched three identical DMC3 commercial Earth Observation Satellites, along with two smaller satellites from United Kingdom, into a polar Sun Synchronous Orbit which was very close to the intended orbit of 647 km height. The five satellites together weighed about 1440 kg at lift-off. 

These five satellites were launched as part of the agreement entered into between DMC International Imaging (DMCii), a wholly owned subsidiary of Surrey Satellite Technology Limited (SSTL), UK and Antrix Corporation Limited, the commercial arm of the Indian Space Research Organisation (ISRO), a government of India Company under the Department of Space (DOS).  This was the twenty ninth consecutively successful flight of PSLV.

PSLV was launched today in its heaviest ‘XL’ version with six strap-on motors of the first stage. This flight was unique since for the first time, the ‘XL’ version of PSLV was used to launch foreign payloads exclusively.  Till now, the lighter ‘core alone’ version of PSLV has been used to launch foreign payloads exclusively. PSLV has successfully launched 45 satellites for customers from abroad including five UK satellites launched today.

Through 29 successful flights during 1994-2015 period, PSLV has launched a total of 77 satellites with a total mass of 32.04 tons, of which 4.64 tons (about 14%) comprises 45 satellites for customers from abroad. The vehicle has repeatedly proved its reliability and versatility by successfully launching satellites into a variety of orbits including polar Sun Synchronous, Geosynchronous Transfer and Low Earth orbits thereby emerging as the workhorse launch vehicle of India.    

After a 62.5 hour smooth count down, the 320 ton PSLV-C28 lifted off from the First Launch Pad (FLP) at SDSC SHAR at 2158 hrs (9:58 pm) IST with the ignition of its first stage. The important flight events included the ignition and separation of strap-ons, separation of the first stage, ignition of the second stage, separation of the payload fairing at about 118 km altitude after the vehicle had cleared the dense atmosphere, second stage separation, third stage ignition and third stage separation, fourth stage ignition and fourth stage cut-off.  

Once in proper orbit, the three DMC3 satellites were successfully deployed about 18 minutes after lift-off in quick succession.  Following this, the 7 kg Nanosatellite De-OrbitSail and the 91 kg Microsatellite CBNT-1 were also successfully deployed.

Today’s successful commercial launch of PSLV further underscores the country’s capability in launch vehicle technologies

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