ISRO to launch India's first indigenous 'Electric Propulsion Spacecraft' in December

Indian Space Research Organisation (ISRO) chairman S. Somanath announced that the organization will launch its first domestically built electric propulsion-led spacecraft in Dec, in an effort to make its satellites lighter in the future.

He also set new deadlines for the agency's upcoming major missions, including Gaganyaan, Chandrayaan-4 and -5, and the Indo-US NISAR satellite project.

The Technology Demonstrator Satellite (TDS-1), which will be steered in space to its intended orbit using electric propulsion rather than fuel-run thrusters, is ready, Somanath said while delivering a lecture on ‘Indian Space Odyssey: In Search of New Frontiers’ at the prestigious Sardar Patel Memorial Lecture at Akashvani in New Delhi.

"TDS-1 and ISRO's first spacecraft docking experiment (SPADEX), which will help in setting up India's own space station in the future, are ready and will be launched in December," said Somanath.

"The electric propulsion system (EPS) will reduce the overall mass of a satellite, as chemical fuel is not required in bulk. EPS uses the energy of the sun to move a satellite from the launch orbit to a geostationary orbit. It is a very interesting technology," Somanath added.

More than two tons of liquid fuel are carried by a four-ton communication satellite, which is used to power thrusters that move the satellite through orbit.

However, only 200 kg of fuel is needed for electric propulsion. The electric propulsion system-based spacecraft will have the power of a four-ton satellite while weighing no more than two tons due to the reduction in fuel load.

Solar energy is used to ionize the propellant gases, such as argon, which are used as fuel in electric propulsion systems (EPS).

The South Asia Satellite, GSAT-9, which ISRO launched in May 2017, was powered by EPS for the first time, although all of that EPS was imported from Russia.

Somanath also mentioned that India has launched nine navigation satellites so far under its own navigation system, NavIC. These satellites primarily use the L5 band, which is mostly reserved for strategic services by the military.

“However, now we are introducing the L1 band in satellites that will allow civilians to easily access our own navigation system on their mobile devices. Our NavIC is much more accurate than other navigation systems. We are going to launch five more satellites with the L1 band,” Somanath said.

Somanath shared the precise dates for its next major missions, stating that the Indo-US collaborative space mission is expected to take place next year, the Gaganyaan manned mission is expected to launch in 2026, and the Chandrayaan-4 lunar sample return mission will be conducted in 2028.

The fifth lunar mission with the Japanese space agency JAXA, formerly known as LUPEX but now called Chandrayaan-5, is expected to have a new timetable after 2028, according to Somanath.

According to Somanath, the radar antenna reflector for the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite, which is regarded as the priciest Earth imaging satellite in the world, is finished, and the essential part has been transported from ISRO's spacecraft integration and test facility in Bengaluru to NASA's Jet Propulsion Laboratory in California.

Somanath said that it will take roughly two months to integrate the radar antenna reflector with the satellite. "We will schedule it for launch in February," he added.