ISRO puts intel sat in orbit with 28 others

The Indian Space Research Organisation (ISRO) on Monday successfully launched an intelligence-gathering satellite along with 28 smaller satellites from its Sriharikota facility, a feat that was witnessed by more than 1,000 visitors — a first in ISRO’s history.

Until now, only officials and authorised people were allowed to view the lift-off from the island of Sriharikota.

“This is a mission of many firsts. This is the first time a PSLV [Polar Satellite Launch Vehicle] will place objects in three different orbits. This is the first time the PSLV has been used in the four strap-on engine configurations. [The launch vehicle usually uses two, six or none of the strap-on engines]. The industry also played a big role in the mission with 95% of the hardware and 60 to 70% of the satellite being fabricated from outside ISRO,” said Dr K Sivan, chairperson, ISRO. “Around 1,200 people watched the mission and for the next one, we will accommodate 5,000 people in the viewing gallery. It will later be expanded to seat 10,000. Those who missed out on the chance today will be able to enjoy our next launch,” he added.

The 47th flight was also the longest mission of the PSLV, lasting around three hours.

Weighing 436 kg, the main payload was the India satellite EMISAT, which has been designed for electromagnetic-spectrum monitoring and will be used for intelligence gathering.

The Indian satellite was put in a 749-km orbit in 17 minutes of the mission. The last stage of the launch vehicle was brought to a 485-km orbit at the three-hour mark. In this mission, the last stage of the rocket will be kept alive for several weeks before it becomes space debris, another first.

The PS4 was used as an orbital platform for the first time in January for the world’s smallest satellite, KalamSat that was developed by students. “This use of PS4 as an experiment platform will allow study of the ionosphere in the real-time and help scientists in developing better ionospheric models. This, in turn, will be helpful in improving the accuracy of satellite navigation signals,” said an ISRO official.

Monday’s mission comes six days after India test-fired an anti-satellite (ASAT) missile in the Mission Shakti operation, which had left around 300 pieces of debris in the low earth orbit.

“An assessment of the space debris is done before every mission and Isro has had to delay a couple of mission by a few seconds to ensure there is no collision with the debris during the launch or even in the orbit. For this mission, no such risk was detected,” the official added.

Of the 28 satellites launched on Monday, 24 are from the US, two from Lithuania, one each from Spain and Switzerland.

Chandrayaan delayed again?

This year’s much-awaited launch of India’s second mission to the moon, between March 25 and April-end, appears to be delayed.

Speaking about future missions after Monday’s launch, Sivan said, “In May, we will launch PSLV C46, followed by PSLV C47 and Chandrayaan 2.”

“In its next mission, PSLV-C46 will launch RISAT-2B in May 2019,” said an official release from Isro.

The delay is because of mission optimisation. “...The delay is for mission optimisation, selecting the window that ensures the satellite reached the intended orbit with the least fuel,” said another Isro official on condition of anonymity.