All You Need to Know About ISRO’s LVM3 M2/OneWeb India-1 Mission
The LVM3-M2 mission was launched successfully from Satish Dhawan Space Center (SDSC), Sriharikota at 12:05 AM (IST) on Sunday, 23rd October. It represents NewSpace India Ltd's (commercial arm of ISRO) maiden dedicated commercial mission. The mission is being carried out as part of a business agreement between the UK’s Network Access Associates Ltd (OneWeb Ltd), and NewSpace India Ltd.
The OneWeb mission is the first time the GSLV Mk III will launch to LEO and will carry a commercial payload. Since the launch of the Italian AGILE astronomy satellite in 2007, ISRO has carried out commercial missions with its PSLV rocket, but these missions have mainly comprised smaller satellites and rideshares. The 36 OneWeb spacecraft when combined provide for a substantially heavier payload of 5,796 kg that necessitates the use of ISRO’s most powerful launch vehicle. The GSLV Mk III launch vehicle has been renamed to LVM3-M2 by ISRO because its most recent version can carry 8,000 kg of payloads into Lower Earth Orbit (LEO) and 4,000 kg of satellites into Geostationary Transfer Orbit (GTO).
Flight Events and Mission Timeline
LVM3-M2 is a three-stage launch vehicle consisting of two solid propellant S200 strap-ons on its sides and a core stage comprising L110 liquid stage and C25 cryogenic stage. The launch vehicle handled multiple satellite separation events with data availability throughout the mission due to the mission’s ground station network located at Sriharikota, Bangalore, Thiruvananthapuram, Antarctica, Svalbard and Ship Borne Terminal (SBT) deployed in the Indian Ocean.
The first stage of the three-stage GSLV Mk III rocket is made up of two S200 solid rocket motors that ignite at T0 and propel the GSLV away from the launch pad. The solids are fastened to either side of the vehicle’s second stage, an L110 liquid-fueled core. The rocket used a dog-leg trajectory to reach its intended near-polar orbit, first travelling to the southeast before veering to the south after it was far enough east to avoid dropping debris over Sri Lanka.
The L110, which is propelled by two High Thrust Vikas Engines (HTVEs), ignites 106 seconds or so after liftoff and burns alongside the S200s for the final 26 seconds of the first stage burn. The solid motors burn out and split two minutes and ten seconds into the flight when the rocket is at an altitude of roughly 73 kilometres.
To make sure the satellites are sufficiently distanced to prevent any potential accidents, the deployment sequence itself entails a series of movements over five phases and nine separation events. Four minutes after the C25 stage’s burn ended, the first four spacecraft were released, and separations started when the upper stage turned perpendicular to its course of the flight. At this orientation, a second batch of four satellites was also released, and the stage then reversed orientation to return to the direction of flight for a brief “velocity addition.”
For stages two, three, and four, the top level followed the same pattern. The deployment of the final four satellites to start their missions resulted in only one separation that occurred during the fifth phase. The C25 stage realigns itself once more after separating its last payloads before downlinking telemetry and passivating itself. The used stage will stay in orbit, and passivation will lessen the chance that any remaining propellant will cause it to explode.
ISRO confirmed the injection of 36 satellites into their orbits around 75 minutes after the rocket blasted off from the spaceport.
ISRO on Twitter: LVM3 M2/OneWeb India-1 mission is completed successfully. All the 36 satellites have been placed into intended orbits.
Mission Features and its Significance
With a goal to provide global broadband internet services by the end of 2023, OneWeb plans to deploy a constellation of 648 satellites in 12 near-polar orbit planes of 49 satellites (plus some on-orbit spares) at an altitude of 1,200 km at 87.9° orbital inclination. After this launch, 144 satellites are scheduled to be launched by SpaceX by early 2023 in a series of three launches and the final group of 36 satellites is scheduled to be launched in February 2023 by ISRO.
As of 23rd October 2022, OneWeb has 462 operational satellites. These satellites will provide user service in the Ku-band and link to gateway ground stations in Ka-band. They will communicate in the microwave range of frequencies in the 12–18 GHz band of the electromagnetic spectrum. Internet access will be available at speeds of 50+ Mbps downlink and 10–20 Mbps uplink through the deployment of dual motorized tracking antennas or phased array antennas on the ground. To prevent interference from Ku-band satellites in geostationary orbit, the satellites use a technique known as progressive pitch, in which the spacecraft is slightly tilted.
Next Launch for ISRO
Before the year is out, ISRO is believed to have one more launch with PSLV to carry the environmental research satellite EOS-06, also known as OceanSat-3. According to updates from September, this was scheduled to launch in October, but no more updates have been provided subsequently, thus it is now doubtful that it will take off this month.
We can probably observe ISRO’s first launch of 2023 in February as the second (and final) set of 36 OneWeb satellites is scheduled to be launched during this month and ISRO also has its Aditya-L1 mission planned for February 2023. It is the first observatory-class mission of ISRO that will use a solar coronagraph to examine the solar corona as well as a near-UV instrument to explore the chromosphere. As the solar events travel from the Sun to Earth, an in-situ payload will monitor them while an X-ray spectroscopic equipment will provide flare spectra.
According to a recent update from ISRO, the Chandrayaan-3 mission is expected to be launched in August 2023.
