Pradeep's Space Newsletter #38
OneWeb on the GSLV Mk-III
In the editions of Pradeep’s Space Newsletter #35 and #36, I had shared updates on how the Russia-Ukraine war, affected India’s space program.
In the edition #36, I had said:
The rate at which we presently build the PSLV and the GSLV Mk-III is slow and we do not have the capacity to support these launches now. It is my opinion that these delays mean that India has lost an important opportunity to be a part of the global space economy.
OneWeb today announced that it had signed an agreement with New Space India Ltd. to launch OneWeb’s satellites. The press release says that the launch is anticipated in 2022 from Sriharikota. The press release ended with a note that it could not divulge more details.
OneWeb had thus far launched with Arianespace. It used the Russian Soyuz’s ST-B variant when flying from Kourou in South America and the Russian Soyuz’s 2.1b variant when flying from Russia.
OneWeb announced that they would return to flight onboard the SpaceX’s Falcon-9 in the summer of 2022.
Each OneWeb satellite weighs approximately 150 kg. Each Soyuz launch carried 34-36 satellites each. That puts the launch mass for each Soyuz launch at between 5,100-5,500 kg. OneWeb places its satellite into a 1200 km polar orbit. This limits the number of launch vehicles capable of launching the OneWeb constellation.
Internationally, this limits the possible launch vehicle possibilities to the Ariane V, the GSLV Mk III, the Falcon 9, and the Japanese H-IIs.
The PSLV-XL launches 1,300 kg to GTO. The GSLV launches 5,000 kg to LEO and 2,450 kg to GTO. The GSLV Mk-III launches 10,000 kg to LEO and 4,000 kg to GTO. LEO refers to Low-Earth Orbit and GTO refers to Geosynchronous Transfer Orbit. Given the payload mass, the GSLV Mk III is the only one capable of launching the OneWeb constellation.
A delay in the launch of Chandrayaan-III may have made available a GSLV Mk-III for this launch. ISRO may not want to mothball a launch vehicle for a long time. The launch vehicle has been in Sriharikota since January 2022. Chandrayaan-III is still undergoing tests at the Satish Dhawan Space Center, Sriharikota.
Twitter user, @Astro_Neel recently posted a thread on what causes some really long delays on the Moon mission:


In a reply to a question on the launches planned for 2022 in the Lok Sabha (India’s Lower House of Parliament), the Minister of State for Science, Dr. Jitendra Singh had said:
2 PSLV missions including 1 dedicated commercial mission and 1 mission for launching the EOS-06 earth observation satellite
2 developmental flights of ISRO's Small Satellite Launch Vehicle (SSLV)
1 GSLV mission for launching NVS-01 navigation satellite for NavIC
1 communication satellite mission (GSAT-24) through procured launch for commercial customer
1 GSLV Mk-III mission, which is a dedicated commercial mission
I think that the dedicated commercial mission of the GSLV Mk-III mentioned here may be a reference to the OneWeb mission.
In an article I wrote for The Wire Science on 10 July 2015, I had said:
ISRO is still developing its GSLV series and the new LVM-3 category of heavy lift vehicles which boast of a 4-ton capacity to GTO. Before it can be marketed to commercial players, it will have to also similarly demonstrate reliability provided by the PSLV. As we await for India to take a larger share in the pie of the commercial space launch market, here’s wishing luck to the five satellites being launched today.
LVM-3 is the name that ISRO used for the GSLV Mk-III in its development phase. I am sad to see that the GSLV is still struggling with both flights and commercialization but happy at the success that the GSLV Mk-III has found in this regard.
In the Letter of Intent that OneWeb signed with New Space India Ltd., they had also expressed interest in launching with the PSLV. In the response by Dr. Singh to the Indian Parliament, there is also mention of a commercial PSLV launch. It is presently not known who the customer is for the commercial PSLV launch.
Could this unknown customer also be OneWeb? But, it could possibly only launch less than 10 satellites. Perhaps, what PSLV lacks in capability, it could make up for with cadence? But, then again, ISRO has had a poor record when judged in terms of the number of launches per year.
From Parallel Spirals, my blog:
Space Stories
Love to watch these rocket tests! This is AgniKul Cosmos with the Agnilets.