P120C explained

The P120C is a solid-fuel rocket motor designed for use as the first stage of the Vega-C and as the boosters of the Ariane 6 launch vehicles. The solid rocket motors were developed by Europropulsion, a joint venture of Avio and ArianeGroup, for the European Space Agency. The "C" in the name signifies its "Common" use across these vehicles.

As of July 2022, it holds the title of the world's largest and most-powerful single-piece solid-fuel rocket motor, surpassing its predecessor, the P80.

Development and Testing

Initially, production of the P120C was planned to be divided between Avio's main facility in Italy and MT Aerospace in Germany. However, in 2018, ESA decided to consolidate production entirely in Italy, with MT Aerospace focusing on Ariane 6's turbopumps.^[1]

The first successful test firing occurred at the Guiana Space Centre in July 2018, lasting 140 seconds and simulating a complete first-stage burn.^[2] Subsequent tests in 2019 and 2020 confirmed the motor's flight readiness for both launcher configurations.^{[3] [4]}

Design and Performance

The P120C builds upon the P80's design, utilizing a carbon fibre casing constructed via filament winding and fabric deposition techniques. It houses a 143.6t of HTPB 1912 propellant, a blend of 19% aluminium powder, 69% ammonium perchlorate with 12% of hydroxyl terminated polybutadiene binder.^[5] The motor's thick walls require a of carbon fiber, wound over 33 days in a climate-controlled environment. When operational, the P120C generates an average thrust of .^[6]

P160C

See main article: P160C. In 2022, development began on the P120C+ variant, which would evolve into the P160C. This extended version adds to the motor's length and an additional of propellant.^[7] This upgrade translates to a roughly 2t improvement in lift performance on the Ariane 64 with four boosters.^[8] Notably, 16 of the planned 18 Kuiper launches by Ariane 6 will utilize this enhanced booster.

See also

• P80 (rocket stage)
• Zefiro (rocket stage)
• Solid rocket
• Vega (rocket)

Notes and References

1. Web site: 30 May 2018 . Germany trades P120 booster production for Ariane 6 turbo pumps, upper stage carbon fiber research . 14 April 2019 . SpaceNews.
2. Web site: 16 July 2018 . Hot firing proves solid rocket motor for Ariane 6 and Vega-C . 14 April 2019 . ESA.
3. Web site: 28 January 2019 . Successful second test firing for the P120C solid rocket motor for Ariane 6 and Vega-C . 14 April 2019 . ArianeGroup.
4. Web site: 8 October 2020 . The qualification model of the P120C motor configured for Ariane 6, has been static fired on the test stand at Europe's Spaceport in French Guiana in a final test to prove its readiness for flight. . 8 November 2020 . ESA.
5. Web site: VEGA C: 1° Stage – P120C Motor . 14 April 2019 . Avio.
6. Richard Priday . 11 June 2018 . This is the fastest rocket on Earth . 14 April 2018 . Wired.
7. News: ESA-developed P120C solid rocket motor enters production . 8 July 2024.
8. News: Foust . Jeff . 5 April 2022 . Amazon launch contracts drive changes to launch vehicle production . 8 July 2024 . . en-US.