Isro's IRNSS-1H launch unsuccessful: 10 things to know about the mission

 

The Indian Space Research Organisation's (Isro's) mission on Thursday to launch the IRNSS-1H, India's eighth navigation satellite, from the Satish Dhawan Space Centre at Sriharikota, Andhra Pradesh, on board its workhorse PSLV launch vehicle failed as the heat shield separation did not take place and the satellite got trapped within the shield. 

However, the failure is not expected to affect the navigation satellite network since the system can function with four efficient satellites. At present, the network has six functional satellites in orbit, according to sources.

Thursday's failure is the first for the PSLV since 1994 when the rocket became operational, though the maiden launch in 1993 was unsuccessful. Prior to Thursday’s failure, the rocket had been successful in 39 consecutive missions, delivering 48 Indian and 209 foreign satellites to space.

The IRNSS-1H was supposed to replace the IRNSS-1A satellite, which was launched in July 2013, in the seven-satellite constellation. The IRNSSS-1A developed problems in delivering navigation services due to the failure of three Rubidium Atomic Frequency Standard atomic clocks, which are a key component of a satellite navigation system.

Isro has been developing navigation satellites for the Indian satellite navigation system, which will be used for defence purposes. The system is similar to the US' Global Positioning System, Russia's GLONASS, Europe's Galileo, and China's BeiDou.

Here are 10 things to know about Thursday's launch: 

• After all the due process, at 7 pm on Thursday, the PSLV rocket, which stood around 44.4 metre tall and weighed 321 tonnes, took off from the second launchpad with the 1,425-kg IRNSS-1H. After a few seconds, the Mission Control room announced that the lift off was normal 

• At 7:05 pm, the rocket crossed the first two stages normally. At 8:08 pm, the rocket entered into the third stage

• The scientists looked tensed as time went by and the graphs on the large displays showed that the rocket's path had deviated a little from the projected path. The usual jovial mood and the smiles on the faces of the scientists was missing inside the control room 

• After 20 minutes from launch, the spectators realised that things had not gone as expected

• The mission director announced that the heat shield was not separating and, within minutes, Isro Chairman A S Kiran Kumar announced that the mission had been unsuccessful. Kumar stated that the rocket's heat shield did not separate and that the satellite was still inside the heat shield. The Rs 250-crore mission officially failed. Detailed analysis is in progress to identify the cause of the anomaly in the heat shield separation event

• However, the failure is not expected to affect the navigation satellite network since the system can function with four efficient satellites. At present, the network has six functional satellites in orbit. Considering this will have a dent on its reputation in the international market, Isro will be taking up the issue seriously

• The PSLV has been Isro's "trusted workhorse" for decades now. The rocket has only failed once in its history, in its maiden flight in 1993. In the recent past, it has carried India's mission to the Moon and even to Mars, which were unparallelled victories for Isro

• The Isro chairman clarified that the space agency's workhorse PSLV performed normally in the mission. "Only the heat shield separation, command, and subsequent operations could not be completed. We have to analyse the details to pinpoint the exact reasons for the failure," said Kiran Kumar. The message to the customers of Antrix Corporation, the commercial arm of Isro, was clear: The PSLV continues to be the most reliable rocket in the World

• The PSLV-C39 managed to deliver the IRNSS-1H satellite to its designated orbit in space but with the heat shield still stuck on the satellite. Normally, the heat shield on the rocket is supposed to peel off and fall away after the rocket leaves Earth’s atmosphere and reaches an altitude of around 120 km. In this mission, this did not happen and the heat shield stayed attached through to the final rocket stage

• The IRNSS-1H satellite was also the first one Isro built jointly with a private consortium in its attempt to leverage India's private sector to build spacecraft in the country. "It would be unfair to target the private sector for the failure," Kumar said