WASHINGTON — European officials say the Vega C rocket is ready for its return to flight next week despite a technical issue that will delay the launch of an Earth science satellite by at least a day.
Arianespace announced Nov. 27 that the upcoming Vega C launch of the Sentinel-1C spacecraft would be delayed from Dec. 3. The launch services provider said it needed to “conduct further precautionary checks and activities” on the rocket. Arianespace said it estimated the launch would be delayed by a day, with an updated launch date provided by Nov. 29. Liftoff, regardless of the day, will be at 4:20 p.m. Eastern in an instantaneous launch window.
The announcement took place a few hours before a previously scheduled European Space Agency media briefing about the launch. At the briefing, officials from Arianespace and Avio, the prime contractor of the Vega C, provided little additional details but suggested the issues causing the delay were minor.
“I don’t think there is a lot to elaborate on,” said Stéphane Israël, chief executive of Arianespace, when asked for details about the delay. “We are speaking about something which, I would say, has very limited consequences.”
“When we see something that we are not completely satisfied with, we love to intervene and conduct more checks,” added Giulio Ranzo, chief executive of Avio.
Both executives, along with ESA, expressed confidence in the Vega C in its first launch since a December 2022 launch failure blamed on the Zefiro-40 second stage. That led to a redesign of the nozzle on that solid-fuel motor and two ground tests, the second of which took place Oct. 3, that verified the performance of the new design.
“The two tests that we have performed, and joint work with the European Space Agency, have revealed a very good performance of the Zefiro-40 with the new design,” Ranzo said.
Both Israël and Ranzo noted that a “tiger team” reviewed the overall Vega C design while work was underway to redesign the Zefiro-40 motor, verifying the performance of other vehicle components. “We have taken the time to increase the robustness in the design and, more importantly, in the manufacturing of the launcher over the last couple of years to make sure it will be fully robust and flightworthy,” Ranzo said.
“They have implemented all of the recommendations to the letter,” Toni Tolker-Nielsen, ESA’s director of space transportation, said of Avio’s work on Vega C at the briefing.
The Vega C return to flight comes five months after the inaugural launch of the Ariane 6. Both are key milestones in ending the so-called “launcher crisis” in Europe that forced ESA and the European Commission to turn to SpaceX to launch several science and navigation spacecraft since last year.
“This is an important step for Europe’s independent access to space, or, let’s say, reestablishment of this independent access to space,” Tolker-Nielsen said. “It is a very important step for Europe that we can return the Vega C to flight.”
The payload itself is critical for Europe. The Sentinel-1C spacecraft, built by Thales Alenia Space, will replace the Seintel-1B radar imaging satellite that malfunctioned nearly three years ago and was declared a loss in August 2022. It will join the existing, but aging, Sentinel-1A spacecraft in providing radar imagery for Copernicus, the Earth observation program jointly run by ESA and the European Commission.
“The launch of Sentinel-1C next week is of crucial importance,” said Christoph Kautz, director of satellite navigation and Earth observation for the European Commission. He called the Sentinel-1 family the “workhorse” of Copernicus, noting that 150,000 data products using Sentinel-1 data are published monthly.
One improvement for Sentinel-1C, said Simonetta Cheli, ESA’s director of Earth observation programs, is the addition of an Automatic Identification System (AIS) payload on the spacecraft that will allow it to track ships that broadcast AIS signals, supporting the use of Sentinel-1 radar imagery for marine surveillance.
Once launched, Cheli said it will take about three to six months to complete commissioning of the spacecraft before it enters regular operations. “We’ll try to do this as fast as possible, but it’s going to be a minimum of three months,” she said.