Dec 30, 2015

ISRO begins countdown for launch of 6 Singapore satellites Seating Chair

The heaviest of these, at 712 kilograms, were the French Spot 6 and Spot 7 Earth observation satellites.

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Data can be stored aboard the spacecraft using a 64-gigabyte solid state drive, before being downlinked to multiple ground stations via the spacecraft’s 150-megabit X-band transceiver. The Galassia two-unit CubeSat, developed by NUS, is designed for atmospheric research. Around 46 minutes after the launch of the sixth satellite, the fourth stage will be restarted when it is in a lower altitude of 523.9 km.

In November, a communication satellite – GSAT-15 – using the Ariane rocket of the European space agency was launched taking the total in 2015 to 21 (17 foreign, 4 Indian). Athenoxat-1, a remote sensing nanosatellite built by Microspace Rapid Pvt. Thirteen satellites were launched with PSLV rocket and one communication satellite – GSAT-6-with geosynchronous satellite launch vehicle (GSLV). “We have taken up (this particular launch) in the month of November when the weather vagaries usually set over this region”, said P. Kunhikrishnan, director of Satish Dhawan Space Centre, Sriharikota.

TeLEOS 1 will not have the global coverage of a polar-orbiting Earth observing platform, but it will offer more regular imagery of equatorial locations, including Singapore. PSLV launches are shared between both pads. The vehicle, with a mass of 230 tons at liftoff does not include the six strap-on boosters used by the PSLV standard variant. For the first time, the PSLV’s fourth stage was successfully restarted in space 50 minutes and 0.05 seconds after it cut off. Burning UH-25 propellant – a mixture of unsymmetrical dimethylhydrazine (UDMH) and hydrazine hydrate – oxidised by dinitrogen tetroxide, its fuel combination is hypergolic and toxic. Though the sky was partially cloudy at dusk, most of the stage separation of the rocket was clearly visible to the naked eyes from the Media Centre here, even as the spacecraft was cruising towards the intended orbit, several kilometres away from the Earth’s surface.
Technically speaking, India will be testing a multiple burn fuel stage/rocket engine for the first time. The rocket’s first stage will separate about one minute and 53 seconds after liftoff. These satellites launched into a 550 km circular orbit would help the city-state gather information on disaster monitoring and urban planning.

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