WASHINGTON — The European Space Agency continues to study options to ensure a continuous supply of engines for the Vega C rocket in the upper stage as that vehicle prepares for its inaugural launch.
The maiden flight of the Vega C, an upgraded version of the small Vega launch vehicle, is scheduled for July 13 at 7:13 a.m. East from Kourou, French Guiana. The primary payload of the four-stage rocket is an Italian physics satellite, Laser Relativity Satellite-2 or LARES-2, a 295 kilogram spacecraft whose orbit will be closely monitored to test general relativity. The missile also carries six cubes at secondary payloads.
The Vega C has several upgrades, including two new solid-propellant engines, the P120 first stage – which will also be used as strap-on boosters for the Ariane 6 – and Zefiro-40 second stage. Those upgrades will increase payload from about 1,500 to 2,300 kilograms to circular polar orbit.
“We have a completely new launch vehicle that stems from Vega’s heritage,” said Stefano Bianchi, head of ESA’s Flight Programs Division, during a media briefing on July 7 about the upcoming launch of Vega C.
However, Russia’s invasion of Ukraine has created uncertainty about Vega C’s future. The missile’s AVUM upper stage uses a motor manufactured by the Ukrainian company Yuzhmash, and European officials admitted in the spring that they were looking at options like it would lose access to those engines.
Bianchi said ESA is studying several options, including “business as usual.” “We want to continue our cooperation with Ukraine for reasons that you can certainly understand. They have been a very reliable partner so far,” he said.
Avio, the prime contractor for Vega, has stock of AVUM engines in Italy, he said, but did not disclose how many engines are in that stock. In an interview in April, Josef Aschbacher, director general of ESA, said six engines had been delivered, enough for launches until 2023.
ESA is also looking at several options to replace the AVUM engine. One is accelerating the development of Avio’s M10 engine, a liquid oxygen/methane engine the company is developing for the future Vega E vehicle. Bianchi said testing of the M10 engine is underway.
ESA is also considering two other engines that could replace AVUM in the short term if supply of that engine is interrupted, but has not disclosed which are under investigation. “We are doing everything we can to avoid any shutdown of the launch of Vega because it is crucial.”
There was no risk of a “mid-term” launch interruption, he said, due to the stock of AVUM engines. “We’re working on risk mitigation for whatever happens.”
Through 2025, there are 14 Vega C launches on the vehicle manifest, including five in 2023 and four in 2024 and 2025. Bianchi said the launches are for a mix of institutional clients such as ESA, the European Union and the Italian space agency ASI. , as well as commercial customers he did not identify.
The Vega C is more than two years behind schedule, with its maiden flight originally scheduled for late 2019. Bianchi blames the delays on two Vega launch failures in 2019 and 2020 that took engineers away from the Vega C program. The pandemic also slowed progress, he added.
“We had no major problems developing” Vega C, he said, noting that work on the P120 and Zefiro-40 stages “went quite smoothly.”
Ettore Scardecchia, head of engineering at Avio, said the company felt better prepared for the inaugural Vega C launch than it did for the first Vega launch a decade ago. “Now we are more aware of what it means to launch. We are more aware of all the risks,” he said.
“The team is very motivated, as it was in the first flight,” he added. “We rely on this motivation from the whole team, from all companies, to have a good flight.”