Another ISRO Success

Chennai: Isro’s workhorse Polar Satellite Launch Vehicle has done it again. Exactly at 1.32 am on Thursday in the backdrop of a half moon, PSLV-C26 lifted off from the Satish Dhawan Space Centre in Sriharikota lighting up the night sky in crimson red. And exactly 20.25 minutes later, the PSLV placed India’s navigation satellite IRNSS-1C in its precise orbit.

This was the 28th flight of the PSLV and the seventh successful flight of its extended version.

Minutes after the mission was declared a success to the cheers of hundreds of scientists at the Mission Control Room, Isro chairman K. Radhakrishnan announced that the injection of the satellite into its orbit was ‘very precise’.

Congratulating the entire team of scientists gathered at the Mission Control Room, Radhakrishnan said that the PSLV vehicle was integrated at Sriharikota in a record time of 60 days as had been promised.

“A team of more than 1,000 members worked round the clock for more than four days to make this mission possible,” he said.

Mission Director K.P. Kunhikrishnan said the satellite went into a very precise orbit, with a perigee of 282 km and an apogee of 20,670 km.

Minister of State, PMO Mr. Jitendra Singh who was present at the launch said that the country was actually realising the PM’s vision of ‘Make in India’ through Isro’s space technology.

“Any role in world leadership should be based on a sound scientific foundation. In space technology, we have truly emerged as world leaders,” he said.

Isro chairman later announced that the most significant launch of the year for Isro, the GSLV-Mark III will take place within the next 45 days.

GSLV Mark III has been conceived and designed to make ISRO fully self reliant in launching heavier communication satellites of INSAT-4 class, which weigh 4,500 to 5,000kg.

It would also enhance the capability of the country to be a competitive player in the multimillion dollar commercial launch market. The vehicle envisages multi-mission launch capability for Geostationary Transfer Orbit, Low Earth Orbit, Polar and intermediate circular orbits.

According to Isro GSLV-Mk III is designed to be a three stage vehicle, with 42.4 m tall with a lift off weight of 630 tonnes. It will also carry an unmanned crew module, which is a forerunner to India sending its astronauts into space.

The IRNSS-1C, the third of the seven navigation satellites in the Indian Navigation Satellite System (IRNSS), has wide-ranging applications in terrestrial, aerial and marine navigation.

From vehicle tracking to fleet management and from disaster management to mapping, the satellite extends services to its clients.

The IRNSS-C1 carried two types of payloads, one for transmitting navigation service signals to the users and another consisting of a C-band transponder to facilitate Cube Retro Reflectors for laser ranging.

The first two satellites in the series, IRNSS-1A and IRNSS-1B were launched from Sriharikota on July 1 2013 and April 4 this year respectively.

The next satellite IRNSS-1D in the Indian Navigational Satellite system is also likely to be launched before the end of the year.

Launch during wee hrs helps save fuel

Most satellite launches of Isro are generally during the day. However, PSLV-C26/IRNSS-1C was launched during the early hours (1.32 am) of Thursdayto enable the satellite to reach the orbital slot (83 degrees East longitude above the Equator in this case) at a specific time, spending minimum propellant (fuel).

Navigational satellites are placed at a geo stationary orbit that is located 36,000 kms above earth.

The International Telecommunications Union (ICU), a special organisation functioning under the UN, allots the orbit slot to prevent signal interference with other existing satellites in the same orbit.

All countries under the United Nations are members in the ICU.

Countries obtain permission for he required slot at least 6 to 7 years before the scheduled launch. ICU allots the orbital slot to each satellite.

Interestingly, as many as 30 satellites belonging to different countries are there within 20 degrees unlike in the past where there used to one satellite for every 5 degrees.

When contacted, SHAR Director Dr M.Y.S. Prasad, who is on his way to the master control facility of Isro located in Hasan, 300 km away from Bengaluru to oversee IRNSS-1C satellite operations from Thursday night, said that they give top priority to save fuel since it helps orbit manoeuvring exercises, in case it is placed in the wrong orbit, apart from increasing the life of the satellite.

“Of the 1,425 kg weight of IRNSS, 825 kgs is propellant and nearly 700 kg of fuel is spent for reaching the orbital slot; the balance is used for orbit correction exercise if necessary. Any saving will increase the life of the satellite,” Dr Prasad said.

Referring to 83 degrees geostationary orbit, at 83 degree East longitude earmarked to IRNSS-1C, he said that the earlier two satellites IRNSS-1A and 1B were allotted 55 degree  East longitude.