P120 (rocket stage)

P120

Closeup view of P120s of an Ariane 6 mockup at ILA Berlin Air Show 2016
Country of origin	Italy  European Union
First flight	13 July 2022 (2022-07-13)
Designer	Avio
Manufacturer	Europropulsion
Associated LV	Ariane 6, Vega C
Predecessor	P80
Status	In use
Solid-fuel motor
Propellant	HTPB / AP / Al
Performance
Thrust, sea-level	4,323 kN (972,000 lbf)
Specific impulse, sea-level	279 s (2.74 km/s)
Burn time	135.7 seconds
Propellant capacity	141,634 kg (312,250 lb)
Dimensions
Length	13.38 m (43.9 ft)
Diameter	3.4 m (11 ft)
Gross mass	155,027 kg (341,776 lb)

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.^{[not verified in body]}

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]

The P120C builds upon the P80's design, utilizing a carbon fibre casing constructed via filament winding and fabric deposition techniques. It houses a 143.6 tonnes (317,000 lb) of HTPB 1912 propellant, a blend of 19% aluminium powder, 69% ammonium perchlorate with 12% of hydroxyl terminated polybutadiene binder.^[5] The motor's 25 centimetres (9.8 in) thick walls require a 3,500 kilometres (2,200 mi) of carbon fiber, wound over 33 days in a climate-controlled environment. When operational, the P120C generates an average thrust of 4.5 meganewtons (1,000,000 lb_f).^[6]

In 2022, development began on the P120C+ variant. This extended version adds 1 metre (3 ft 3 in) to the motor's length and an additional 14 tonnes (14 long tons; 15 short tons) of propellant.^[7] This upgrade translates to a roughly 2 tonnes (4,400 lb) 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.^[8]

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