Thursday, July 1, 2010

After two setbacks, Isro set to launch five satellites on 12 July

After two setbacks this year, India’s space agency is set to launch five satellites on 12 July, including one that can shoot pictures of small objects on land and compress the time needed for building high-resolution maps by half.

Isro had deferred the launch of its workhorse polar satellite launch vehicle (PSLV) scheduled in May after it found leaks in the rocket’s second stage. The leaks were detected when pressurized nitrogen was pumped in the rocket as part of tests on the launch pad.

The same rocket will be fired now, following repairs and further tests, said an Isro official from Sriharikota. He did not want to be named.

“Even if the leak is minor, it takes many days to rectify and certify it fit,” said U.R. Rao, a former chairman of Isro. “In space, you don’t take risks.”

The rocket will also launch Alsat-2A, a remote sensing satellite from Algeria and India’s first African customer, two nano satellites from the University of Toronto, and Studsat, a small satellite built by engineering students in Karnataka and Andhra Pradesh.

Isro’s commercial arm, Antrix Corp. Ltd, has already signed a second satellite launch from Algeria for next year.

So far, PSLV has launched 39 satellites, nearly half of them from India, in 16 missions.

Isro expects Cartosat-2B to join two other satellites that are already in orbit—the Cartosat-2 and 2A—and return more high-resolution images to earth and provide complete coverage of the subcontinent, said S. Satish, director, Isro.

Cartosat-2B has a high resolution of 0.8 metre, allowing it to photograph objects the size of a typical bicycle.

Typically, satellites that can snap high resolution images can cover a small width or swath of 10km. To cover a larger area, a satellite would have to come back to a specific spot repeatedly, which would take a long time as it would have to complete one orbit of the earth to do this. A constellation of three satellites, on the other hand, can cover the entire country.

“It is like a camera; you want sharp images you need to be closer. You can go farther to cover a larger area, but you won’t get minute details,” said Rao.

As for the GSLV, Satish said a panel that’s studying what led to its crash is set to announce its report next week.

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