TITUSVILLE, Fla. — The European Space Agency is looking at options for launching missions that were to fly on Russia’s Soyuz rocket, including both non-European rockets and early use of the Ariane 6.

The ESA Council meeting that concluded March 17 addressed Russia’s Feb. 26 decision to halt Soyuz launches from French Guiana and withdraw its personnel there in response to European sanctions on Russia after the invasion of Ukraine. That decision puts five European missions in limbo: two launches of Galileo navigation satellites, ESA’s Euclid space observatory and EarthCARE Earth science satellites, and a French reconnaissance satellite.

ESA officials said at a briefing after the meeting that they had made no decisions on how to launch those payloads originally manifested on Soyuz. “We will look into all the options,” said Josef Aschbacher, ESA’s director general. “We need to make sure that we have a robust launcher setup that can launch our satellites.”

The first priority, he said, is to move those payloads onto the new Vega C and Ariane 6 vehicles. Vega C is scheduled to make its first flight in May while Ariane 6 is set to make its debut no earlier than the second half of this year.

Aschbacher said they won’t rush Ariane 6 to make its first flight. He declined to give a specific launch date for the first Ariane 6 launch, citing an upcoming hotfire test of the Ariane 6’s upper stage engine in Germany and tests of the vehicle at the launch site in Kourou, French Guiana. “We cannot stabilize a date until these two tests are carried out,” he said.

The first Ariane 6 will carry a mass demonstrator and instrumentation, along with several small satellites and experiments from companies and institutions selected in February. Daniel Neuenschwander, ESA’s director of space transportation, would not rule out using that launch instead for one of the missions that was to launch on Soyuz, but said that it was not a leading option.

“It’s not the baseline, to be clear, to use this launch for one of the payloads,” he said. “But, we are assessing it and we will come back with a clear assessment and a proposal to our member states.”

Using the first Ariane 6 launch for one of the former Soyuz missions might also delay that launch, he said. “It is equally important to keep the timing and then increase the pace of launching again.”

Vega C, meanwhile, faces a complication also linked to Russia’s invasion of Ukraine. The rocket’s upper stage, called AVUM, uses an RD-843 engine built by Ukrainian company Yuzhnoye/Yuzhmash. While the AVUM engines for the first three Vega C launches have been delivered, ESA officials acknowledged uncertainty about the Ukrainian company’s ability to produce more engines.

“We’re assessing availability over the next few months,” Neuenschwander said. The Yuzhmash facilities are in the Ukrainian city of Dnipro, a place where “hostile actions are ongoing,” he said, but didn’t provide details about the state of those facilities. “We are in contact with colleagues from Yuzhmash on a daily basis.”

ESA is looking at potential replacements for the RD-843. Neuenschwander said the preference is for an engine from an ESA member state that permits a “rapid adaptation” of the AVUM upper stage. “We are also assessing non-European options because, here, time is of the essence and, consequently, you need to work with an engine that has the right maturity level.”

Aschbacher said that while ESA’s preference is to launch payloads on European rockets, he would not rule out using vehicles from other countries. “First and foremost, we will focus on European launchers and then, if we see there are gaps, we will look into other partners,” he said.

That option will be included in a new review of options for replacing the Soyuz launches, which will be done in about a month. “Then we’ll see what is a realistic scenario of launcher opportunities in the next months and years,” he said. “I’m not excluding looking at launchers outside of European ones, if needed.”

Quelle: SN