Russia’s Angara A5 Booster has Serious Flaw

Angara A5 launch (Credit: Khrunichev)

If you are among the millions of space enthusiasts who have been losing sleep over why Russia’s new Angara rocket hasn’t flown in more than four years, be prepared to snooze soundly again.

Rueters reports that engineers have found a flaw in the engine of the Angara A5 booster that could cause it to explode in flight.

The issue with the Angara A5 was brought to attention by scientists at rocket engine manufacturer Energomash in a paper ahead of a space conference later this month.

The paper, reported by RIA news agency on Friday and published online, said the engines of the Angara A5 could produce low frequency oscillations that could ultimately destroy the rocket.

A special valve had been fitted to mitigate the issue, but in some cases the oscillations continued, it said. Energomash did not immediately reply to a request for comment.

The Angara A5 rocket is the most powerful of a family of boosters designed to replace the Proton and other launch vehicles currently in the Russian arsenal. The Angara series is based around a common first stage core with additional strap-on stages.

The Reuters story says that Russian President Vladimir Putin is eager to see the rocket start launching more frequently because it is vital to the nation’s national defense.

The Angara 1.2PP rocket made the maiden flight test of the series on July 9, 2014. The booster flew a suborbital mission carrying a mass simulator from the Plesetsk Cosmodrome in Northern Russia.

Angara A5 flew was launched from Plesetsk five months later on Dec. 23, 2014. Using a Briz-M upper stage, the booster placed a mass simulator into geosynchronous orbit.

The Wikipedia page for Angara lists two launches of the Angara A1.2 and one flight of Angara A5P for 2019. There is one Angara A1.2 flight listed for 2020. However, it is not clear whether this schedule is still valid; it came from a schedule compiled in late 2017.