WASHINGTON — The upper stage of a failed Angara launch harmlessly reentered Jan. 5, capping another setback in the protracted development of that vehicle.

The U.S. Space Force’s 18th Space Control Squadron said the Persei upper stage from the Angara-A5 launch reentered at 4:08 p.m. Eastern over the South Pacific Ocean. The reentry took place far from any inhabited areas, and there were no reports of any debris reaching the surface.

The Persei stage was stranded in orbit after a Dec. 27 launch on the Angara from the Plesetsk Cosmodrome. The stage, carrying an inert payload, was to perform a series of engine burns to go to geostationary orbit, but malfunctioned during the second burn. That stranded the stage in a low transfer orbit that decayed over the next nine days.

The launch was the third for the Angara-A5 but the first to use the Persei upper stage, based on the Block DM-03 stage used on some Proton launches. The first two Angara-A5 launches, in December 2014 and December 2020, used the Breeze-M upper stage, both of which operated successfully.

Roscosmos announced the launch with a statement Dec. 27, noting that the Persei upper stage still had several maneuvers to perform to reach geostationary payload. The agency provided no further public updates about the launch and did not acknowledge the failure of Persei or its reentry.

Angara has long been touted as the successor to the Proton launch vehicle. Development of the rocket dates back to the 1990s but suffered extensive delays. The rocket had yet to carry an operational payload, flying only mass simulators on its three launches to date.

The Proton, once a workhorse of both the Russian government and commercial launch industry, has itself faded in recent years. There have been only three Proton launches in the last two years, two carrying pairs of Express communications satellites for Russian operator RSCC and one that sent the Nauka module to the International Space Station.

At Euroconsult’s World Satellite Business Week in December, Tiphaine Louradour, president of International Launch Services (ILS), offered an upbeat assessment of the future of Proton and Angara despite the lull in launch activity. She projected 14 or 15 launches of the Proton and Angara A5 over the next two years, but didn’t state how many would be commercial versus Russian government missions. ILS is also marketing the Soyuz rocket for commercial missions.

“We have the launch vehicle suite, between the Proton/Breeze-M, soon the Angara that will be available to the commercial market, and the Soyuz now, to meet a variety of mission needs,” she said.

That access, though, could be hindered by new regulations in the United States that restrict access to Russian vehicles. “ILS was very proactive and did submit and obtained over 15 licenses, which enable us to operate and meet our customers’ requirements” before those rules went into effect, she said. “Today, it would be a challenge.”

There is also the threat of sanctions should Russia invade Ukraine that would further restrict access to Russian vehicles, just as launch operators in Europe, Japan and the United States are transitioning to a new generation of vehicles. “It is ILS’s believe that any restrictions should not be imposed on the space sector,” she said.

Quelle: SN