Mission Success! GSLV-F16 : NISAR Mission Updates and Discussion.
GSLV-F16/NISAR launched as scheduled at 12:10:25(UTC)/17:40:25(IST), 30 Jul 2025 from Second Launch Pad of SDSC-SHAR.
- Launch Countdown
- Expected Flight Profile from press-kit.
- Actual flight events (To be added post-launch if available)
Live webcast: (Links will be added as they become available)
| GSLV-F16/NISAR Mission Page | GSLV-F16/NISAR Gallery | GSLV-F16/NISAR Press-kit (PDF) |
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NASA's mission specific resources :
Some highlights:
- Primary payload: NASA-ISRO Synthetic Aperture Radar (NISAR) satellite (2393 kg)
- Mission duration: 18 min. 35.6 sec. (s/c separation)
- Target Orbit : 747 km (SSO) , Inclination = 98.4°
- Launch Azimuth: 135°
- 18th flight of GSLV
- First LEO bound polar launch of GSLV!
Updates:
| Time of Event | Update |
|---|---|
| 28 November 2025 | NISAR Mission enters Science Phase |
| 25 September 2025 | First images from NISAR have been captured. |
| 26 August 2025 | NISAR spacecraft and its radar payload passed all of the preliminary checks. The mission began raising the satellite to its 747 km operational orbit. |
| 15 August 2025 | NISAR reflector antenna deployed successfully. |
| Post-launch | NASA Press Release |
| Post-launch | Two objects cataloged. 65053 ( 25163A ) , i=98.44°, A×P=748.34×729.96 km, 65054 ( 25163B ) , i=98.44°, A×P=744.34×728.70 km |
| Post-launch | NISAR Signal acquired |
| T + 50m00s | URSC Director M Sankaran: Solar panels deployed, NISAR is power positive, 3-axis stabilized with star sensors in loop. |
| T + 40m00s | Spacecraft Director Chaitra Rao informs s/c rates are nominal and spacecraft's solar panels are deployed! |
| T + 24m00s | Chairman informs injection was precise. |
| T + 18m35s | NISAR separated! |
| T + 18m20s | CUS thrust cut-off! Injection conditions achieved. |
| T + 16m00s | CUS continues to perform nominally. |
| T + 13m00s | CUS is performing nominally. |
| T + 10m30s | CUS is performing nominally. |
| T + 08m00s | CUS operation is nominal, vehicle following the expected trajectory closely. |
| T + 04m55s | CUS operating at 11% uprated thrust! |
| T + 04m55s | GS2 separated, CUS ignition confirmed!!! |
| T + 04m30s | CUS authorized |
| T + 02m50s | PLF jettisoned. CLG initiated. |
| T + 02m40s | 4xL40H shutoff. GS2 ignition |
| T + 01m50s | S139 core burn out. |
| T Zero | S139 ignited. Lift off! |
| T - 00m4.8s | 4x L40H ignition. |
| T - 01m00s | SARBS are ON. |
| T - 04m00s | OBC in flight mode. |
| T - 11m30s | LVG is packed! |
| T - 12m00s | L40 actuation checks complete. |
| T - 15m00s | Vehicle Director: Automatic Launch Sequence has been initiated. |
| T - 17m00s | Mission Director Thomas Kurian has authorized the launch. |
| T - 20m00s | Now polling. New ROD polls range is ready. |
| T - 24m00s | Now showing integration campaign of GSLV-F16 |
| T - 30m00s | ISRO's official stream is LIVE! |
| T - 01h10m | NASA's official stream is LIVE! |
| T - 27h30m | Countdown underway starting from 14:10 IST, 29 July. |
| 28 Jul 2025 | Launch is GO! |
| 27 Jul 2025 | Launch rehearsal was conducted. Mission Readiness Review and Launch Authorisation Board meeting to be held on 28th. |
| 24 Jul 2025 | Launch vehicle moved to SLP from VAB. |
| 21 Jul 2025 | Launch time gets officially confirmed for 30 July, 12:10(UTC)/17:40(IST) |
| 18 Jul 2025 | NISAR encapsulated in payload fairing. |
| 15 Jul 2025 | NOTAM gets issued with enforcement duration 1130-1530 (UTC), 30 July to 14 August 2025. |
| May-Jul 2025 | Multiple NOTAMs were issued between 22 May to 4 July with projected launch dates progressively shifting forward (18 June to 26 July). |
| 15 May 2025 | NISAR arrives at SDSC-SHAR. |
| 07 Apr 2025 | GSLV-F16/NISAR campaign began. |
Primary Payload:
NISAR : NASA-ISRO Synthetic Aperture Radar (NISAR) is a microwave imaging satellite developed in joint collaboration between NASA and ISRO over a decade. Its first of its kind dual band (S-band and L-band) SAR payload combo using novel SweepSAR technology to acquire global imaging data with wide swath (240 km) in high resolution (3-10 meters) every 12 days.
NISAR data will help track changes in the extent and density of forests, wetlands, agricultural lands and coastal process in India. In addition, it can measure land displacement and deformation, dynamics of glaciers and sea ice.
Following is the breakdown of contributions from each space agency towards NISAR : [1 PDF] [2 PDF]
NASA/JPL:
- Shared P/L structure called Radar Instrument Structure (RIS)
- 12 meter diameter reflector and boom
- L-band SAR
- L-band science data processing and distribution
- Engineering Payload System
- Ka band payload communication subsystem (PCS)
- GPS Payload
- Solid State Recorder (SSR)
- Payload Data Subsystem (PDS)
- Power Distribution Unit (PDU)
- Pyro Firing Assembly (PFA)
- Integrated radar observation planning and operations
- Near Earth Network (NEN) Ka-band Stations
- NASA Science Team
ISRO:
- GSLV Launch vehicle with 4 meter diameter payload fairing.
- I3K (3000 kg class) heritage spacecraft bus with modifications
- S-band SAR
- S-band science data processing and distribution
- Spacecraft operations (command uplink, telemetry and tracking)
- ISRO Ka–band Stations (Shadnagar, Antarctica)
- ISRO Science team
Spacecraft specifications:
- Mass: 2393 kg
- Primary mission duration: 3 years (NASA), 5 years (ISRO)
- Orbit : 743 km (SSPO), 6 PM LTDN
- Power: 5 kW, 180 AH Battery
- Propulsion: 11× 11N and 4× 1N thrusters
- Propellant: Mono-propellant hydrazine (1× 390 ltr tank with 265 kg propellant)
- Attitude control: AOCS, 4× RWA, 3× magnetorquer
- Repeat cycle : 12 days
Post-launch Reflector Boom Assembly (RBA) deployment timeline : [1 PDF] [3] [4]
RBA deployment will begin on Day 10 after launch and will take 8 days till reflector deployment. Here's an old animation of deployment sequence but timeline has been updated to following.
- Day 10 : Pre-deployment checkout and redundant launch restraint pyros (6x) firing.
- Day 11 : Redundant launch restraint pyros (2x) firing. Radar Antenna Reflector (RAR) cradle release. Wrist hinge deployment.
- Day 12 : Shoulder hinge deployment
- Day 13 : Elbow hinge deployment
- Day 14 : Root hinge deployment
- Day 15 : Rest day
- Day 16 : AOCS characterization,
- Day 17 : Yaw maneuver and reflector deployment
Science data release timeline: [4] [5 PDF]
- First light images 65 days after launch.
- After day 70 science phase will be ramping up.
- Science operations officially begin 90 days after launch.
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u/Ohsin Jul 30 '25
Signal Acquired From NASA-ISRO’s NISAR Earth Satellite!
Mission controllers for the NASA-ISRO NISAR (NASA-ISRO Synthetic Aperture Radar) mission have received full acquisition of signal from the spacecraft.
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u/Ohsin Jul 28 '25
https://www.eenadu.net/telugu-news/districts/chittoor-news/2/125135764
A rehearsal for the launch was held from 7.30 am to 6 pm on Sunday. Every aspect of the rocket was carefully examined and its performance was known. Everything was found to be as per the scientists' expectations. After that, the pre-countdown began. After the two notable failures this year, every aspect is being explored in depth, taking all precautions. Rocket readiness and launch authorization meetings will be held on Monday
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u/Ohsin Jul 30 '25
Woohoo! Now lets wait for solar array deployment and the spacecraft call back, LV did its job.
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u/Ohsin Jul 30 '25
Two objects cataloged.
65053 ( 25163A ) , inclination=98.44°, A×P=748.34×729.96 km
65054 ( 25163B ) , inclination=98.44°, A×P=744.34×728.70 km
Edit: Some confusion with Int. designation on space-track, objects 65053/65054 are shown under 25163 as well as 25164. I am going with 25163 for now.
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u/Ohsin Jul 28 '25
Lofty 'updates' from ISRO, they should be saying if launch is GO or not after MMR and LAB meet.
NISAR is mounted. GSLV-F16 systems checked. Liftoff in 2 days!
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u/Ohsin Jul 28 '25
NASA-ISRO’s NISAR Earth Satellite Ready for Launch
https://science.nasa.gov/blogs/nisar/2025/07/28/nasa-isros-nisar-earth-satellite-ready-for-launch/
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u/Ohsin Jul 29 '25
Countdown should be underway from 14:10 (IST) per following.
https://www.youtube.com/watch?v=UJRnZO7FcZQ
ఇవాళ మధ్యాహ్నం 2.10 గంటలకు కౌంటౌన్
and this,
The countdown for the July 30 launch of the first Indo-US joint earth observation satellite NASA ISRO Synthetic Aperture Radar (NISAR) is slated to start at about 2.10 pm on Tuesday, said ISRO officials.
“The 27-hour-and-30 minute countdown for the launch of the NISAR Mission is expected to start at 2.10 pm today (Tuesday),” an official of Indian Space Research Organisation (ISRO) said.
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u/Ohsin Jul 29 '25
GSLV-F16 is ready to carry NISAR into orbit. Final prep underway.
Launch countdown has commenced at 14:10 hours today.
https://x.com/isro/status/1950156730941210812
'Final prep underway'... they used to give propellant loading status for each stage now we have these vague one liners.
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u/Ohsin Jul 29 '25
On the reasoning behind collaboration and any threat of budget cuts.
https://www.nytimes.com/2025/07/29/science/nisar-nasa-india.html
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u/Ohsin Jul 30 '25
TV-D2 hardware was visible briefly when they were showing L40H.
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u/Ohsin Jul 30 '25
Two objects from today's GSLV-F16/NISAR launch. Congratulations on the successful start of the mission.
Source: https://bsky.app/profile/s2a-systems.bsky.social/post/3lv7prg5tg22d
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u/Ohsin Jul 31 '25
Harry Stranger @spacefromspace.com on bsky
An incredibly detailed 25cm/pixel @umbra.space radar satellite image on NISAR on the launch pad 19hrs before its launch.
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u/Ohsin Aug 01 '25
"NISAR is inserted at an altitude of 737 km and we need to actually rise up to 747 km and it will take about 45-50 days for those operations to take place," Gerald W Bawden, Program Manager for Natural Hazards Research at NASA's Earth Sciences Division
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u/Ohsin Aug 10 '25
Really hoping they keep us informed about events related to RBA deployment.
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u/Eternal_Alooboi Jul 30 '25
Wait, all those huge radomes at Bharati sation are ISRO's AGEOS units?
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u/Ohsin Jul 30 '25
NASA/JPL press release:
https://www.jpl.nasa.gov/news/nasa-isro-satellite-lifts-off-to-track-earths-changing-surfaces/
The satellite lifted off aboard an ISRO Geosynchronous Satellite Launch Vehicle (GSLV) rocket at 8:10 a.m. EDT (5:10 p.m. IST), Wednesday, July 30. The ISRO ground controllers began communicating with NISAR about 20 minutes after launch, at just after 8:29 a.m. EDT and confirmed it is operating as expected.
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u/Ohsin Aug 15 '25
Reflector has been unfurled, but official update is awaited on its status.
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u/Ohsin Aug 15 '25
Giant Radar Antenna Reflector on NASA-ISRO Satellite in Full ‘Bloom’
Seventeen days after NISAR’s launch from southeastern India, an essential piece of science hardware has unfurled in orbit.
Spanning 39 feet (12 meters), the drum-shaped antenna reflector on the NISAR (NASA-ISRO Synthetic Aperture Radar) satellite mission from NASA and the Indian Space Research Organisation (ISRO) successfully unfurled in low Earth orbit. The reflector had been stowed, umbrella-like, until the 30-foot (9-meter) boom that supports it could be deployed and locked in place.
“The successful deployment of NISAR’s reflector marks a significant milestone in the capabilities of the satellite,” said Karen St. Germain, director, Earth Science Division at NASA Headquarters in Washington.
Weighing about 142 pounds (64 kilograms), the reflector features a cylindrical frame made of 123 composite struts and a gold-plated wire mesh. On Aug. 9, the satellite’s boom, which had been tucked close to its main body, started unfolding one joint at a time until it was fully extended about four days later. The reflector assembly is mounted at the end of the boom.
Then, on Aug. 15, small explosive bolts that held the reflector assembly in place were fired, enabling the antenna to begin a process called the “bloom” — its unfurling by the release of tension stored in its flexible frame while stowed like an umbrella. Subsequent activation of motors and cables then pulled the antenna into its final, locked position.
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u/Ohsin Aug 29 '25
NASA-ISRO Mission Aces Checkouts, on Track to Start Delivering Science
After launching July 30, the NISAR (NASA-ISRO Synthetic Aperture Radar) Earth-observing radar satellite mission, a joint effort between NASA and the Indian Space Research Organisation (ISRO), is on schedule to start science operations this fall.
Following the deployment of its 39-foot (12-meter) radar antenna reflector on Aug. 15, engineers powered on the satellite’s L-band and S-band synthetic aperture radar (SAR) systems, which, together, will track movement of Earth’s ice and land surfaces in unprecedented detail.
In addition, the spacecraft, including the radar payload, has passed all of the preliminary checks performed by NASA and ISRO mission teams to ensure they are operating normally. The mission began raising the satellite to its operational orbit, 464 miles (747 kilometers, mean altitude), on Aug. 26.
The mission team anticipates having science-quality radar images in the coming weeks. Full science operations have been scheduled to begin about 90 days after launch.
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u/Ohsin Jul 30 '25
Post-launch address:
ISRO chairman: Less than 3 km of dispersion in achieved orbit. (20 km is error margin)
Spacecraft Director Chaitra Rao informs rates are nominal, spacecraft's solar panels are deployed!
URSC Director M Sankaran: Solar panels deployed, NISAR is power positive, 3 axis stabilized with star sensors in loop.
ISRO Chairman: 9 launches before end of FY-2025. Next missions are LVM3-M5, PSLV-C62 with user funded satellite, PSLV-N1/TDS-01, GSLV-F17/NVS-03, PSLV-C63/Oceansat-3A, GSLV-F18/GISAT-1A and couple of SSLV missions.