Bhopal: The Indian Space Research Organisation (ISRO) is all set to carry out the first landing demonstration of its Reusable Launch Vehicle (RLV) Saturday, its chairperson S. Somanath has said.
Somanath, who was speaking to ThePrint on the sidelines of the 8th India International Science Festival in Bhopal, said the demonstration will continue as planned provided climate and weather conditions are suitable.
An RLV is a launch vehicle that is designed to return to the Earth substantially intact and could, therefore, be reused.
ISRO’s Reusable Launch Vehicle-Technology Demonstration (RLV-TD) Programme is a series of technology demonstration missions, seen as the first step towards realising a two-stage-to-orbit (TSTO) fully reusable vehicle. A TSTO, or a two-stage rocket, is a spacecraft in which two distinct stages provide propulsion consecutively in order to achieve orbital velocity.
This is the first time ISRO is conducting a landing demonstration for its RLV-TD Programme.
ISRO has also planned the launch of a Small Satellite Launch Vehicle (SSLV) with a payload capacity to deliver 500 kg to low Earth orbit (500 km), Somanath told ThePrint.
The SSLV launch, planned between 10-15 February, comes six months after ISRO’s maiden SSLV-D1 failed to reach stable orbit because of a sensor fault in the separation stage.
Recalling that mission, which was launched on 7 August last year, Somanath said he was “not very enthused” about ISRO’s achievement in 2022.
“For me, it was not enough. My goals were much higher,” he told ThePrint. “SSLV was not successful. It was narrowly missed and was a huge disappointment for me personally. But then we are working hard on the launch this year.”
He added that ISRO also wanted to conduct an abort test — that would check the system meant to help crew escape from a spacecraft in case of emergency — for its space mission Gaganyaan last year, but couldn’t do it.
In addition to the RLVs and SSLV, the space agency also has plans to launch a spacecraft to study the Sun this year, the scientist said.
A NASA-ISRO mission & more this year
According to ISRO’s website, Saturday’s landing demonstration will involve a “landing experiment (LEX)” in which the RLV will be carried using a helicopter to an altitude of 3-5 km and released at approximately 4-5 km from the runway with a horizontal velocity.
After the release, the RLV glides and navigates toward the runway, and carries out a conventional autonomous landing. This is planned in a defence airfield near Chitradurga in Karnataka.
Somanath also spoke about ISRO’s other launches this year — including Aditya L1, a coronagraphy spacecraft that’s aimed at helping scientists study the Sun’s corona.
The scientist said that the spacecraft is on schedule, with ISRO planning to carry out the launch in April or May. “The important payload of this mission — the solar coronagraph — will be flagged off from the Indian Institute of Astrophysics (IIA) to ISRO Satellite Centre on Republic Day.”
The solar coronagraph is a telescope that is designed to block out direct light from the Sun to help study it better. The IIA has developed the coronagraph that will be used in ISRO’s space mission.
“Over the next two months, other payloads will also be brought and assembled in time for the launch,” Somnath said.
In addition, the NISAR (NASA-ISRO Synthetic Aperture Radar) will be brought from the US on 1 February to India, Somnath said, adding that he plans to travel to NASA’s Jet Propulsion Lab to oversee the flagging off. This is the first project jointly developed by NASA and ISRO.
A Synthetic Aperture Radar (SAR) refers to a technique for producing fine-resolution images from a resolution-limited radar system.
NISAR, which is being jointly developed by NASA and ISRO “will be the first radar of its kind in space to systematically map Earth”, according to the US federal space agency.
According to Somanath, there are two important payloads on this mission — the US-made radar L-Band and the Indian-made S-Band.
“We first prepared our payload and sent it to the US. The US payload is now integrated and testing was done over the last few months,” he said.
ISRO is scheduled to launch NISAR in September.
Joshimath and NDMA’s ‘gag order’
Somanath also spoke about ISRO’s report on land subsidence in Joshimath and why it was taken down last week.
On 14 January, the report was taken off ISRO’s website, a day after the National Disaster Management Authority’s gag order asking government agencies to refrain from interacting with media and sharing information on social media.
ISRO’s chairperson told ThePrint that “there was no directive to the ISRO to take down the report”, and that the decision to do so was voluntary.
“There has been no ban on us as such. The warning we got was that we should not reveal data without it going through different administrations levels who can take the required actions,” Somnath said. “News and its analysis can create a scare and somebody might misuse it. The warning was not to give too much information to the public such that it creates panic.”
The agency, he said, continued to provide information “to all the agencies, for example, the NDMA”.
“We have only been told not to put info in the public domain,” he said. “All scientists who need the data are getting it, we can assure (you) that. We’ve mechanisms to share this data with experts.”
Work on methane engine
The ISRO was working to develop a methane-fuelled rocket engine, Somanath said.
“Methane is identified as the fuel of the future. Its density is lower than kerosene. But its advantage is that it has high efficiency and does not produce soot, which is very dangerous for engines,” he said.
ISRO, one of several science organisations in India trying to develop methane-based engines, has also tested a 20-tonne methane engine and has completed the design of the hundred-tonne one, the scientist said.
“It’s a very simple reaction that can be carried out anywhere, and will be valuable for long-term space missions when enough fuel for the entire duration of the mission may not be feasible to carry,” Somanath said, adding that it will take the agency four-odd years to fully develop the engine.
“We have recently done a successful demonstration of producing methane from carbon dioxide and water at the lab scale. We are now scaling up to implement it in space missions,” he said.
(Edited by Uttara Ramaswamy)