COLORADO SPRINGS – The European Space Agency will launch its Sentinel-1C radar imaging satellite on a Vega-C rocket in 2023 as the agency continues to study possible impacts of the Russian invasion of Ukraine on that launch vehicle.
Arianespace announced on April 7 that it has received an order from ESA to launch Sentinel-1C in the first half of 2023. Neither the company nor the agency shared the terms of the contract with them.
The selection of Vega C was to be expected as the mission was planned to fly on Vega C rather than the much larger Ariane 6. The first two Sentinel-1 missions were launched on Soyuz rockets from French Guiana, but Russia ended Soyuz launches from there in February in response to European sanctions against Russia following the invasion of Ukraine, and even before that, ESA halted its usage off.
Earlier this year, there had been discussions that Sentinel-1C’s launch could be brought forward because of a malfunction in Sentinel-1B that rendered it inoperable in December 2021. The spacecraft remains inoperative for its synthetic aperture radar (SAR) imaging payload due to problems with the power system.
At a March 17 briefing, ESA officials expressed pessimism about the recovery of Sentinel-1B, although efforts to recover the SAR payload continued. “It’s not looking very good, but for now it’s not the final word on 1B,” said Simonetta Cheli, Director of Earth Observation at ESA.
She then said that Sentinel-1C would be ready for launch as early as October, although at that point launch was only planned for mid-2023. “In the current situation, we are examining options for launch with Arianespace. We are looking at the earliest options because we want to support users.”
At the same briefing, ESA officials noted a possible problem with the Vega C, an upgraded, more powerful version of the existing Vega rocket, which is due to be launched for the first time mid-year. The rocket’s upper stage, called AVUM, uses a liquid-propellant engine built by the Ukrainian company Yuzhmash. The Russian invasion of Ukraine raised questions about the long-term availability of the engine.
At the March briefing, Daniel Neuenschwander, ESA Director of Space Transport, said Yuzhmash had supplied three of the engines, enough for Vega launches in 2022. The agency is considering options to potentially replace this engine with alternatives from European and other sources, said he called.
Avio, Vega’s prime contractor, issued a statement on March 25 downplaying any risk of losing access to Ukraine’s engine, saying it regularly receives engines and has built up a “strategic stockpile” in reserve. “As of today, Avio sees no specific risks related to engine availability in the medium term,” the company said. Inquiries about the number of AVUM engines in reserve were not answered.
In an April 6 interview during the 37th Space Symposium, ESA Director General Josef Aschbacher said three more engines had been delivered. “We now have enough AVUM engines for flights 22 and 23,” he said.
He said ESA is continuing to look at alternative engines for Vega-C missions beyond 2023. “We have different options there, which we are now pursuing: European, but also with the USA.”
“For Arianespace, this contract is a sign of confidence in the Vega-C system and a strong sign of the European institutions’ commitment to autonomous access to space,” said Stéphane Israël, CEO of Arianespace, in a statement from the company’s launch contract.