The launch of 104 satellites on a single PSLV mission on Wednesday has kept the space community agog.
The entire flight of the PSLV-C37 rocket takes nearly 29 minutes, just four minutes longer than a regular PSLV that may carry one or two satellites.
Some 17 minutes into flight, and in an eye-popping feat, the first and the last satellite will all be out in space within 11 minutes — a record that is expected to put the scientists and engineers of the Indian Space Research Organisation (ISRO) in the spotlight.
ISRO has scheduled the launch for 9.28 a.m. on February 15 from the Satish Dhawan Space Centre (SDSC) at Sriharikota in coastal Andhra Pradesh.
To date, the highest number of satellites, 37, in a single mission was made in June 2014 by a Russian Dnepr rocket.
Of the 104 on the PSLV, 96 satellites belong to two U.S. customers: 88 Doves with Planet Labs and eight LEMURs with Spire Global Inc. ISRO chairman A.S. Kiran Kumar, who has said ISRO is not after making any record, was recently reported as saying that half the cost of the PSLV was covered by launch fees from the seven customers. A PSLV is estimated at around ₹ 200 crore.
The rocket will release the first passenger, Cartosat-2 series, about 17 minutes after lift-off. The last satellite will be out by 29th minute, all neatly out of each other’s way.
The commercial payloads will be released a minute after Indian satellites. All satellites are programmed to come out in a sequence of singles or doubles.
Two earlier rockets, also in the extended XL format, have carried ten and 20 satellites to space. However, the current PSLV-C37 is "mission intensive" as it carries five times the number it did in June 2016, according to PSLV Project Director B.Jayakumar of the Vikram Sarabhai Space Centre. The VSSC based in Thiruvananthapuram is the main centre for ISRO's launchers.
Meticulous planning
Preparations for the mega release began about six months ago, with meticulous detailing of the sequence of release for each of the 104 satellites into space.
Mr. Jayakumar said the main consideration was the safety of all the satellites in orbit after release. “The task before us was to separate them in a non-colliding manner. A minimum gap should be ensured between releases. A few innovative approaches had to be studied and implemented for this mission,” he told The Hindu.
Accommodation of all the satellites within the space available in the last and fourth stage of the rocket was another daunting task; it was handled by using customised components called adapters.
Vigil from space
The main purpose of Mission PSLV-C37 is to put in space the fifth satellite in the fleet of the country’s high-resolution Earth observation spacecraft.
The Cartosat-2 series is often said to be ISRO’s open secret for the military and the sharp-seeing eyes that keep vigil over the country and its borders from space. The space agency literally averts its eyes whenever it is asked about it.
The spacecraft’s cameras are said to have a resolution of 60 cm, if not better; it means they can spot any object or person, stationary or moving on ground and sized less than 1 metre. This is a key requisite for the security forces.
Four spacecraft have been launched in the Cartosat-2 series since the first was put in orbit ten years back. The last one was put in orbit last June.
ISRO said the new Cartosat-2A, when it starts working over the coming weeks, would detect changes in land use in cities, villages, coasts and on farms, besides monitor roads and water resources across the country.
Visit: http://www.isro.gov.in/sites/default/files/pslv_c37-final.pdfCartosat 2 series
