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 714 kg 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.

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