Credit: ESA / CNES / Optique video du CSG / S. Martin
A shared solid-fuel booster upgrade that will be used for the first time aboard an Ariane 6 rocket later this year will not be introduced aboard Vega C until 2028. The European Space Agency says the delay reflects the requirements of the smaller rocket’s launch manifest and the need to prioritise early P160C production for Ariane 6.
Development of the P120C booster began in 2015 and was led by Europropulsion, a joint venture between ArianeGroup and Avio. ArianeGroup’s Ariane 6 rockets are launched with either two or four P120C boosters strapped to their core stage, while aboard Avio’s Vega C launch system, the booster serves as its first stage. A P120C booster flew for the first time in July 2022 on the inaugural flight of Vega C.
In March 2022, months before the booster’s first flight, ESA announced that it would fund the development of an upgraded variant of the booster, initially referred to as the P120C+. Later renamed the P160C, the upgraded booster carries an additional 14 tonnes of solid propellant, increasing its total propellant load to approximately 160 tonnes.
On 19 December 2025, ESA announced that it had completed the final review of the P160C booster, clearing it for flight. The agency said the booster would be used for the first time aboard an Ariane 6 rocket in 2026 but would not be introduced aboard Vega C until 2028. The announcement, however, did not include an explanation for the two-year delay.
Speaking to European Spaceflight, an ESA spokesperson said that early production of the booster was being prioritised for Ariane 6 and that the Vega C launch system did not initially require the additional payload capacity.
“ESA has no urgency to implement the P160C until 2028, as the planned missions do not require additional performance [with respect to] Vega C with P120C,” said the ESA spokesperson. “And this will allow [the utilization of] the P120C units already manufactured and under manufacturing, while available P160C [units] will be dedicated to Ariane 6.”
Many, if not all, of the initial P160C-equipped Ariane 6 rockets will be dedicated to flights that Arianespace, the commercial operator of Ariane 6, has been contracted to launch on behalf of Amazon for its low Earth orbit megaconstellation. According to the initial 2022 contract announcement, Arianespace will complete 18 flights for Amazon over a three-year period aboard Ariane 64 rockets. While two of the flights will utilize P120C-equipped Ariane 64 rockets, including the first, which will be the rocket’s first flight of 2026, the remaining 16 will utilize P160C boosters. That means Arianespace will require 64 P160C boosters over the next three years just to fulfill its contract obligations to Amazon.
The first flight of a P160C-equipped Vega C rocket will carry the inaugural mission of ESA’s Space Rider vehicle. The reusable spacecraft is designed to host scientific payloads and technology demonstrations in orbit for up to two months before returning them to Earth. It employs a steerable parafoil to enable precise landings, after which it can be refurbished and reused.
Keep European Spaceflight Independent
Your donation will help European Spaceflight to continue digging into the stories others miss. Every euro keeps our reporting alive.