File picture of the NISAR (NASA-ISRO Synthetic Aperture Radar) satellite at the Satish Dhawan Space Centre, before it was launched on July 30
| Photo Credit: AP

ISRO’s C20 cryogenic engine. File
| Photo Credit: The Hindu

ISRO on Saturday (February 8, 2025) said that it has successfully carried out the ignition trial of the indigenous CE20 cryogenic engine powering the upper stage of LVM3, with a multi-element igniter under vacuum conditions, which simulates the engine ignition in the vacuum condition of space.

This test was carried out on Friday (February 7, 2025) in the High Altitude Test Facility at ISRO Propulsion Complex, Mahendragiri, Tamil Nadu, ISRO said in a statement.

This engine is crucial for the Gaganyaan mission, India’s ambitious crewed space mission.

During this test, the ignition of the engine Thrust Chamber was carried out with a multi-element igniter in a vacuum, under the tank pressure conditions that are expected to prevail at the time of restarting the cryogenic engine in flight. The performance of the engine and the facility during the test was normal and as expected.

Restarting a cryogenic engine is inherently complex and as part of the studies related to the restart operation, ISRO is exploring the initiation of turbopumps in bootstrap mode rather than the stored gas system.

In this approach, both the thrust chamber and gas generator are expected to re-ignite under tank head conditions. ISRO has outlined a series of tests aimed at engine starts in bootstrap mode towards enhancing the capability for multiple cryogenic engine restarts during flight.

Previously, the engine ignition trial using multi-element igniter was carried out in the ground conditions outside the vacuum chamber.

“The engine is already qualified to operate for thrust levels ranging from 19t to 22t in flight with single start and is qualified for Gaganyaan mission,” ISRO said.

The engine was developed by Liquid Propulsion Systems Centre of ISRO.

New Delhi:

The Indian Space Research Organisation (ISRO)’s 100th rocket mission hit a hurdle after its navigation satellite, which was launched on Wednesday, suffered a technical glitch on Sunday. 

In an update on the mission on its website, ISRO said the “orbit raising operations towards positioning the satellite to the designated orbital slot could not be carried out as the valves for admitting the oxidizer to fire the thrusters for orbit raising did not open”. 

The satellite – NVS-02, made by U R Rao Satellite Centre – was to be placed in a geostationary circular orbit at the designated spot over India. Since the liquid engine onboard the satellite is not functioning optimally, the effort to send it to its designated orbit is either delayed or may be abandoned altogether.

“The satellite systems are healthy and the satellite is currently in elliptical orbit. Alternate mission strategies for utilising the satellite for navigation in an elliptical orbit is being worked out,” ISRO said.

At 6:23am on Wednesday, ISRO successfully launched their GSLV-F15 carrying the NVS-02 at Sriharikota in Andhra Pradesh, marking its 100th mission. The mission is also the first for the space agency’s Chairman V Narayanan, who assumed office recently. It is also ISRO’s maiden venture this year.

Space experts said the satellite will not be able to perform its designated tasks from the highly elliptical orbit of nearly 170 kilometres to the nearest point around Earth and nearly 36,577 kilometres at the farthest point from the Earth.

The 2,250kg satellite – second of the second generation – was part of the Navigation with Indian Constellation (NavIC), a regional equivalent of the Global Positioning System or GPS. 

NavIC, which India developed after the 1999 Kargil war with Pakistan, has given India its own share of challenges. In that conflict, India was denied access to high quality GPS data and then Prime Minister Atal Bihari Vajpayee later promised to make a regional version of the GPS for the country’s strategic community.

Many satellites in the NavIC series, however, fell short of expectations. Since 2013, a total of 11 satellites have been launched as part of NavIC and of these, six have either entirely or partially failed for various reasons, and now the latest one also faces major technical glitches.

A satellite launch vehicle lifts off from the Satish Dhawan Space Centre in Sriharikota, Andra Pradesh.
| Photo Credit: File photo

Indian Space Research Organisation (ISRO) is gearing up for the 100th launch from the Satish Dhawan Space Centre in Sriharikota, which is scheduled to take place at the end of January with the launch of the GSLV-F15 NVS-02 mission.

The GSLV-F15 with indigenous cryogenic stage will place NVS-02 satellite in a Geosynchronous Transfer Orbit. The launch is scheduled to take place from the spaceport’s second launch pad.

The NVS-02 is the second satellite in the NVS series, and part of India’s Navigation with Indian Constellation (NavIC).

According to ISRO, NavIC is India’s independent regional navigation satellite system designed to provide accurate Position, Velocity and Timing (PVT) service to users in India as well as the region extending about 1,500 km beyond the Indian landmass, which is its primary service area.

NavIC provides two types of services, namely, Standard Positioning Service (SPS) and Restricted Service (RS). NavIC SPS provides a position accuracy of better than 20 metres (2σ) and timing accuracy better than 40 nano seconds (2σ) over the primary service area.

Five second-generation NavIC satellites viz. NVS-01/02/03/04/05 are envisaged to augment NavIC base layer constellation with enhanced features for ensuring continuity of services. The NVS series of satellites incorporates L1 band signals additionally to widen the services.

NVS-01, the first of the second-generation satellites, was launched on board GSLV-F12 on May 29, 2023. For the first time, an indigenous atomic clock was flown in NVS-01.

NVS-02, the second satellite in the NVS series, is configured with navigation payload in L1, L5 and S bands in addition to ranging payload in C-band like its predecessor-NVS-01. It is configured on standard I-2K bus platforms with a lift-off mass of 2,250 kg and power handling capability of ~3 kW. It will be placed at 111.75ºE, replacing IRNSS-1E. NVS-02 uses a combination of indigenous and procured atomic clocks for precise time estimation.

NVS-02 satellite was designed, developed and integrated at the U. R. Satellite Centre (URSC) with the support of other satellite-based work centres.

Dr. V. Narayanan, Secretary DOS, Chairman Space Commission and Chairman ISRO, congratulated the team ISRO after SpaDeX docking, on January 16, 2025
| Photo Credit: X/@ISRO

The Indian Space Research Organisation (ISRO) in the early hours of Thursday (January 16, 2025) successfully executed the SpaDeX docking experiment making India the fourth country after the USA, Russia and China this historic feat.

The two satellites SDX01 (Chaser) and SDX02 (Target) which were launched by the PSLV C60 on December 30, 2024, successfully docked as the space agency officials from the Mission Operations Complex (MOX) at ISRO Telemetry, Tracking, and Command Network (ISTRAC) oversaw the complex docking procedure.

“Docking Success Spacecraft docking successfully completed! A historic moment. Let’s walk through the SpaDeX docking process: Manoeuvre from 15m to 3m hold point completed. Docking initiated with precision, leading to successful spacecraft capture. Retraction completed smoothly, followed by rigidisation for stability. Docking successfully completed. India became the 4th country to achieve successful Space Docking. Congratulations to the entire team! Congratulations to India!,” ISRO posted on X.  

ISRO further added that post docking, control of two satellites as a single object is successful. “Undocking and power transfer checks to follow in coming days,” ISRO said.

Earlier this week, ISRO had moved the satellites within three metres in a trial attempt. It then moved the spacecraft back to safe distance.

The SpaDeX mission is an important project by ISRO which is designed to develop and demonstrate the technology needed for spacecraft rendezvous, docking and undocking using two small satellites.

The demonstration of this technology is essential for futuristic missions such as sending an Indian astronaut on the Moon, sample return from the Moon, the building and operation of the Indian Space Station.

The other objectives of the mission include demonstration of the transfer of electric power between the docked spacecraft which is essential for future applications such as in-space robotics, composite spacecraft control and payload operations after undocking.

According to ISRO, after the docking and undocking events, the spacecraft will be separated and used for application missions.

“After successful docking and rigidization, electrical power transfer between the two satellites will be demonstrated before undocking and separation of the two satellites to start the operation of their respective payloads for the expected mission life of up to two years,” ISRO said.

The SpaDeX Docking was scheduled on January 7 but was postponed.

“The docking process requires further validation through ground simulations based on an abort scenario identified today (Jaunary 6),” ISRO had cited as the reason for the postponement of the experiment.

On January 8, 2025, hours before it was scheduled to carry out the SpaDeX docking experiment, ISRO said that the docking experiment which was scheduled to take place on January 9 has been postponed as the drift between the satellites was found more than expected.

It later arrested the drift between the spacecraft.

ISRO launched the SpaDeX mission on December 30, 2024 from the Satish Dhawan Space Centre in Sriharikota. Few minutes after liftoff, the two satellites (Target and Chaser) weighing about 220 kg each were launched into a 475-km circular orbit as intended.

Bengaluru:

Two Indian satellites came as close as three metres in a trial attempt for space docking and are now moving back, the Indian space agency said this morning. The satellites will then move closer to each other at a speed of 10 millimeters per second.

“A trial attempt to reach up to 15 m and further to 3 m is done. Moving back spacecrafts to safe distance. The docking process will be done after analysing data further,” the Indian Space Research Organisation (ISRO) said in its latest update on the Space Docking Experiment (SpaDeX) mission.

SpaDeX Docking Update:

SpaDeX satellites holding position at 15m, capturing stunning photos and videos of each other!

#SPADEX #ISRO pic.twitter.com/RICiEVP6qB

— ISRO (@isro) January 12, 2025

Docking is a very complex process with the satellites being moved back and forth to achieve what ISRO has described as an “exciting handshake” of the two satellites in space. India is using the indigenously developed Bhartiya Docking System to achieve this feat.

The SpaDeX mission was launched on December 30 with the satellites, SDX01 (Chaser) and SDX02 (Target), being lifted off on board a PSLV C60 rocket and placed into a 475-kilometre circular orbit.

Read: ‘Ballet In Space’: How India Is Planning Historic Docking Experiment

With this mission, India is set to become the fourth nation to achieve the feat that will help the country in its future space explorations such as the Bharatiya Antariksh Station and Chandrayaan 4.

ISRO had postponed the historic docking of the two satellites’ twice with its chief Dr S Somnath saying it was India’s first attempt at docking and that every first attempt has its own challenges.

“The docking exercise will be done only when all sensors have been fully calibrated and tested to satisfaction. All algorithms and scenarios are also tested on the ground before commands are sent to the spacecraft to do the docking autonomously,” Mr Somnath had earlier said.

The two satellites will be controlled as a single spacecraft after the docking. Electrical power will be transferred from one satellite to another to check if the docking is successful. The process will be declared successful after the satellites are undocked and they start functioning independently.

Backup-Group Captain Prasanth Balakrishnan Nair seen during ISS Emergency Scenario Training. The Gaganyatris assigned for Axiom Mission 4 (Ax-4) have completed initial orientations for mission-related ground facility tours, initial overview of mission launch phases, SpaceX suit fit checks, and selected space food options.
| Photo Credit: Special arrangement

The Indian Space Research Organisation (ISRO) on Friday (November 29, 2024) said that Indian astronauts Group Captain Shubhanshu Shukla and Group Captain Prasanth Balakrishnan Nair who have have been selected for the upcoming Axiom-4 mission to the International Space Station (ISS) have completed the initial phase of training.

“Towards the goal of accomplishing a joint ISRO-NASA effort to the International Space Station, the two Gaganyatris (Prime-Group Captain Shubhanshu Shukla and Backup-Group Captain Prasanth Balakrishnan Nair) assigned for Axiom Mission 4 (Ax-4) commenced their training in the U.S.A from first week of August, 2024. The initial phase of training has been completed successfully by the Gaganyatris,“ ISRO said. 

The space agency added that during this phase of training, the Gaganyatris have completed initial orientations for mission-related ground facility tours, initial overview of mission launch phases, SpaceX suit fit checks, and selected space food options.

“Furthermore, the training also included familiarisation sessions with the SpaceX Dragon spacecraft and various onboard systems of the International Space Station, including photography from space, daily operations routine, and communication protocols. One of the important highlights of this phase was training for various types of emergencies in space, including medical emergencies,” ISRO said.

It further said that upcoming training will primarily address the remaining modules of the U.S. Orbital Segment of the space station along with training towards conducting scientific research experiments in microgravity environment during the mission. In addition, the crew will train and perform different mission scenarios in the SpaceX Dragon spacecraft.

New Delhi:

Seismic activity in the Moon’s soil could be due to impact from meteorites in the past or local heat-related effects, according to ISRO’s preliminary analysis of data received from Chandrayaan-3’s quake-detecting instrument.

However, detailed studies are needed to get more insights from the data, they said.

Their research paper, published in the journal Icarus, is a summary of observations made on 190 hours of data recorded by the Instrument for Lunar Seismic Activity (ILSA).

ILSA is one of the five major major scientific instruments, all of them carried by Chandrayaan-3’s Vikram lander and Pragyaan rover together. Chandrayaan-3 made a soft-landing on the Moon’s south pole on August 23, 2023.

The quake-detecting ILSA was operated continuously until September 2, 2023, after which it was switched off and was packed back up, before the lander was relocated to a new point roughly 50 centimetres away from the initial one, the researchers from the Indian Space Research Organisation (ISRO) explained.

ILSA operated on the lunar surface for about 218 hours, of which 190 hours of data are available, they said.

“We have identified more than 250 distinct signals of which about 200 signals are correlated to known activities involving the physical movements of the rover or the operation of science instruments,” the study authors wrote.

The 50 signals, which could not be linked to movements of either the lander or the rover, were deemed “uncorrelated events” by the authors.

“The uncorrelated signals recorded by ILSA might be due to impact of micrometeorites at near ranges of the instrument, local thermal effects on the soil, or thermal adjustments within the lander subsystems,” they wrote.

A micrometeorite is a very small meteorite, or a remnant of a meteoroid, with diameter usually less than a millimetre.

The researchers also found that during its course of operation, ILSA also recorded a wide-range of changes in temperature — from (minus) 20 degrees Celsius to (plus) 60 degrees Celsius.

ILSA was operated during a lunar day where the sun elevation angle had changed steadily. After the initial five hours of operation, the temperature started to decrease, which was noted by shadows cast by the lander’s parts on the instrument, the authors said.

They said detailed studies are required to understand potential sources of ILSA’s data.

“Even though the possible causes of signals due to uncorrelated events are presented, detailed analysis has to be conducted to get more insights from the records,” the authors wrote.

ILSA is the first instrument ever to have recorded seismic data from the Moon’s polar region and the second one to record ground movements on the Moon after NASA’s Apollo mission about four decades back.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

The winged vehicle, Pushpak, was released from an Indian Air Force Chinook Helicopter at an altitude of 4.5 km.
| Photo Credit: Special Arrangement

The Indian Space Research Organisation (ISRO) completed the third Reusable Launch Vehicle (RLV) Landing Experiment (LEX) on June 23 at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka.

This is the third and final test in the series of LEX (03) which was conducted at 7.10 a.m.

“Following the success of the RLV LEX-01 and LEX-02 missions, RLV LEX-03 re-demonstrated the autonomous landing capability of the RLV under more challenging release conditions (cross range of 500 m against 150 m for LEX-02) and more severe wind conditions,” ISRO said.

On Sunday morning the winged vehicle, Pushpak, was released from an Indian Air Force Chinook Helicopter at an altitude of 4.5 km.

ISRO said that from a release point 4.5 km away from the runway, Pushpak autonomously executed cross-range correction manoeuvres, approached the runway and performed a precise horizontal landing at the runway centreline.

“Due to this vehicle’s low lift-to-drag ratio aerodynamic configuration, the landing velocity exceeded 320 kmph, compared to 260 kmph for a commercial aircraft and 280 kmph for a typical fighter aircraft. After touchdown, the vehicle velocity was reduced to nearly 100 kmph using its brake parachute, after which the landing gear brakes were employed for deceleration and stop on the runway. During this ground roll phase, Pushpak utilises its rudder and nose wheel steering system to autonomously maintain a stable and precise ground roll along the runway,” the space agency said.

Also Read | ISRO successfully conducts second ‘Pushpak’ Reusable Landing Vehicle landing experiment 

It added that this mission simulated the approach and landing interface and high-speed landing conditions for a vehicle returning from space, reaffirming ISRO’s expertise in acquiring the most critical technologies required for the development of a Reusable Launch Vehicle (RLV).

“Through this mission, the advanced guidance algorithm catering to longitudinal and lateral plane error corrections, which is essential for the future Orbital Re-entry Mission has been validated,” the space agency said.

It said that the RLV-LEX uses multisensor fusion including sensors like the Inertial sensor, Radar altimeter, Flush air data system, Pseudolite system and NavIC. Notably, the RLV-LEX-03 mission reused the winged body and flight systems as such without any modification, from the LEX-02 mission, demonstrating the robustness of ISRO’s capability of design to reuse flight systems for multiple missions.

“This mission simulates the approach & landing interface and high-speed landing conditions for a vehicle returning from space, which will reaffirm ISRO’s expertise in acquiring the most critical technologies required for the development of a Reusable Launch Vehicle (RLV),” ISRO said.

ISRO Captures the Signatures of the Recent Solar Eruptive Events from Earth, Sun-Earth L1 Point, and the Moon, on May 14, 2024.
| Photo Credit: ANI

The Indian Space Research Organisation (ISRO) has captured the signatures of the recent solar eruptive events from Earth, Sun-Earth L1 Point, and the Moon.

A powerful solar storm impacted Earth earlier this month, triggered by the highly active region AR13664. This region unleashed a series of X-class flares and coronal mass ejections (CMEs) directed at Earth.

“This is the biggest Geomagnetic storm since 2003 in terms of its strength, as the flaring region on the Sun was as big as the historically important Carrington event that took place in 1859. Multiple X-class flares and CMEs have hit the Earth in the past few days. This had severe effects over high latitudes where trans-polar flights are already being reported to get diverted. More events are expected in the next few days,” ISRO said.

However the space agency said that the Indian sector got less affected as the main hit of the storm happened in the early morning of May 11, when the ionosphere was not developed fully.

“Also, being at lower latitudes, widespread outages haven’t been reported in India,” ISRO said.

Observations from Ground

ISRO said that the Global navigation satellite system network observations at the National Atmospheric Research Laboratory at Gadanki, Andhra Pradesh show decrease of the Total Electron Content (TEC) by more than 50% from May 10 midnight to May 11 morning.

“On 11 May daytime TEC was high by about 10% with large variations indicating disturbed ionosphere. In the evening TEC is nearly 30% more. No L band scintillation has been observed. Radar observations showed no bubble, consistent with TEC and scintillation observed by GNSS receivers,” ISRO said.

It added that the observations by the Thumba node of the Indian Network for Space Weather Impact Monitoring network was more dramatic.

“This is expected, as the ionospheric ring current, which is enhanced during geomagnetic storms, passes over the sky of Thumba,” ISRO said.

Observations from Space

ISRO said that it had mobilised all its observation platforms and systems to record the signatures of this event and that both Aditya-L1 and Chandrayaan-2 have made observations and signatures have been analysed.

It said that the ASPEX payload on-board Aditya -L1 is showing high speed solar wind, high temperature solar wind plasma and energetic ion flux till now.

“The X-ray payloads on-board Aditya-L1 (SoLEXS and HEL1OS) have observed the multiple X- and M-class flares from these regions during the last few days while the in-situ magnetometer (MAG) payload has also observed the events as it passed by the L1 point,” ISRO said

While the Aditya-L1 observes the Sun from the first Sun-Earth Lagrange point, the Chandrayaan-2 orbiter has also captured the signatures of these solar eruptive events from the lunar polar orbit. XSM has observed many interesting phenomena associated with this geomagnetic storm.

Indian spacecraft health

ISRO said that its Master Control Facility team was on alert and watchful of any Geomagnetic activity experienced by geo spacecrafts.

“Momentum Wheel speed deviations were observed along with MTC current saturation in few spacecraft. Spacecraft with one-sided panels had predominant signature variations which required frequent momentum dumping. Otherwise, overall operations were normal. No single event upsets were seen. Star Sensor (SS-2) in INSAT-3DS and Star Sensor (SS-3) in INSAT-3DR were turned off as per mission. Other than this there has not been any major upsets or anomaly observed in any of the 30 GEO spacecrafts so far,” ISRO said.

It added that none of the Earth Observation Satellites of ISRO which were visible from ISRO’s ground stations had any upsets or latch-ups.

Besides, the ISRO Navigation Centre has not noticed any significant degradation in the NaVIC service metrics till now, indicating no or negligible impact from the geomagnetic storm.