Russian rocket stage about to make an uncontrolled re-entry

Russian rocket stage about to make an uncontrolled re-entry

Science

A week ago, Russia succeeded in launching a prototype of its new-generation Angara rocket. This was the third attempt for this new device which is to replace the Proton launchers. This test was presented as a real success. In reality, not everything went as planned.

Russia has been developing its new Angara rocket family for about two decades. Among them is the Angara A5 heavy launcher which aims to replace aging and highly polluting Proton rockets. Its deployment was slow, with a first test flight attempted in 2014. As part of this test, the launcher placed a two-ton mass simulator in geosynchronous orbit. A second flight was then attempted six years later, in December 2020. Again, it involved placing a dummy payload into orbit (2.4 tonnes).

Why did it take so long between these two test flights? Probably the biggest factor was the cost of building the Angara A5 (around $ 100 million per vehicle).

Last December, the Angara A5 rocket nevertheless finally resumed service with a third flight. From then on, Russia planned to start flying military payloads aboard this vehicle, but also to compete for commercial satellite launch contracts. However, not everything went as planned.

Uncontrolled reentry
This Angara rocket configuration offered the same first stage as the two previous flights: a single “Universal Rocket Module” core powered by an RD-191 engine with four additional “URM” cores serving as attached boosters. In contrast, for this new test, Russia relied on a new upper stage called “Persei”, powered by liquid oxygen and kerosene.

For its third flight, the Angara A5 vehicle took off from the Plesetsk Cosmodrome on December 27, carrying another dummy load with it. Main stage and boosters worked successfully. The second stage performed a nominal initial burn of its RD-0124 engine, but the second, allowing the payload to be placed in the intended orbit, failed.

Oddly enough, Russian officials celebrated the launch as a success. As Ars Technica points out, the Russian news service RT has indeed published an article pointing out that the Persei top stage will significantly improve the performance of the Angara A5 vehicle. The upper stage (followed as IPM 3 / Persey) has never turned on again and is currently sailing below 200 km altitude. It will probably make an uncontrolled comeback this Wednesday. Hopefully he dives into the ocean.