The European Space Agency (ESA) has concluded a key phase in the development of the new large P160C solid propellant rocket motor. Following a detailed analysis of data collected during a test firing in April 2025 at Europe’s Spaceport in French Guiana, the motor passed its qualification review and has been officially approved for installation on future Ariane 6 and Vega rocket flights. This rounds off a development cycle of more than three years that directly impacts the future competitiveness of the European space industry.
The qualification of the P160C comes at a time when Europe is restructuring its own fleet of launch systems and seeking a way to maintain independence in access to space, amidst increasingly sharp global competition. The new motor is not just another technical upgrade, but a central element of the modernization of the Ariane 6 and Vega rockets, aimed at increasing payload capacity, mission flexibility, and reducing costs per launch.
Successor to the P120C: what the P160C brings new
The P160C is the direct successor to the P120C solid rocket motor, which currently serves as a strap-on booster for the Ariane 6 rocket and as the first stage of the Vega-C rocket. It is developed by Europropulsion, a joint venture between the Italian company Avio and the Franco-German ArianeGroup, under the technical and financial leadership of ESA. Compared to its predecessor, the new motor is about one meter taller and can carry approximately 14 tons of additional solid fuel, which brings the total mass of the propellant charge to about 167 tons.
The motor retains the concept of a unique carbon-composite casing – it is one of the largest monolithic solid-fuel motors in the world. Inside is a composite fuel based on HTPB polymer, ammonium perchlorate, and aluminum, a proven combination that has been used in European solid-fuel stages for years. During operation, the P160C develops a maximum thrust of the order of 4700 kilonewtons and burns for slightly more than two minutes, which is enough to provide the rocket with powerful thrust in the first moments of flight, when the vehicle is heaviest.
It is precisely those additional 14 tons of fuel that bring a series of concrete gains. For the Ariane 64 configuration – the version with four strap-on boosters – it is estimated that the P160C can enable approximately two tons higher payload compared to the P120C, depending on the orbit and mission profile. In practice, this means a larger number of satellites in a single mission, a heavier platform in a higher orbit, or additional maneuver reserves for more complex deep space missions.
From test firing to qualification
The turning point in the development of the new motor occurred on April 24, 2025, when a test firing of the P160C qualification model was performed on the BEAP test stand at the Guiana Space Centre. The motor operated for about two minutes and twenty seconds, while dozens of sensors recorded pressure, temperature, structural deformations, and the behavior of the nozzle and thrust vectoring system.
Unlike a launch, during a so-called hot-fire test, the motor remains attached to the vertical construction of the test stand. Upon ignition, it rises only a few centimeters, but massive steel holders keep it in place, while a powerful jet of hot gases exits into an open channel below the test tower. Such a configuration allows for the most faithful simulation of actual loads during takeoff, with complete control and precise measurement of all key parameters.
The test was followed by a detailed analysis – the so-called first-level analysis – in which teams from ESA, the French space agency CNES, and industrial partners checked whether the expected thrust, chamber pressure, mass of remaining fuel after shutdown, vibration levels, and thermal loads were achieved. The qualification review that has now been completed confirms that the motor behaves in accordance with design expectations and is ready to transition from the development phase to serial production and operational use.
The conclusion of qualification also represents a symbolic milestone: the P160C transitions from prototype status to the status of a motor that can be installed in spacecraft. Work is already underway in industrial facilities on the first four flight units, which will be integrated as strap-on boosters for the upcoming, enhanced configuration of Ariane 6.
First use on Ariane 6, and then on Vega
According to the plans of ESA and industrial partners, the P160C will be used for the first time on the Ariane 6 rocket in the version with four boosters, in a flight scheduled for 2026. In that configuration, the new motors will provide the strongest starting thrust that Ariane 6 has had to date, further opening up space for more demanding commercial and institutional missions.
On the lighter Vega-C launch vehicle, the P160C will take over the role of the first stage in the so-called Vega-C+ upgrade, and later in the completely new Vega-E rocket. According to current plans, its debut on Vega is linked to the missions of the Space Rider spacecraft around 2028. Thus, the new motor extends through the entire line of European launchers – from light to heavy – which justifies the letter “C” in its designation, which points to “common” use on multiple rockets.
A special incentive for the development of the P160C was also given by growing market pressure, primarily through large contracts for launching satellites from the Project Kuiper constellation of the American company Amazon. Most of the planned 18 Ariane 6 launches for that program are expected to use the P160C, which means dozens of motors ordered in advance. Such generous commercial contracts provided the necessary security that it pays off to invest in a new, more powerful motor and adapt the launch infrastructure to it.
Industrial chain: a motor from multiple European countries
The P160C is a typical example of a European industrial “mosaic” in which key components are created in different countries, and final integration takes place in French Guiana. The composite motor casing is produced by Avio at facilities in Colleferro, not far from Rome. There, with the help of automated winding and laying of carbon fibers impregnated with resin, a massive cylinder is made that must withstand high pressures and temperatures, but also remain light enough not to “eat up” the gain in payload capacity.
The nozzle – the heart of every rocket motor – is manufactured by ArianeGroup in Le Haillan near Bordeaux. High-resistance composite materials are used that withstand temperatures around 3000 degrees Celsius, while also allowing for precise shaping of the internal geometry to “extract” maximum thrust from the motor. The nozzle is gimbal-mounted, which means it can pivot in multiple directions and thus control the thrust vector and stabilize the rocket’s flight.
The third key element is the composite igniter, i.e., the system for initial ignition of the motor, developed and produced by the Norwegian company Nammo in Raufoss, under the responsibility of Avio. Its task is to ensure reliable and uniform ignition of the entire stage, where it is extremely important that the chamber pressure develops at exactly the predicted speed, without sudden jumps that could damage the structure.
The final phase of production takes place in French Guiana, where the joint ventures Regulus and Europropulsion fill the motor with fuel and perform final integration. The finished motors are then transported by road and rail within the space center to the assembly buildings for Ariane 6 and Vega, where they are joined with the rest of the launch vehicle.
Why booster motors are crucial for launch systems
Although the terms “motor” and “booster” are often used synonymously in everyday speech, engineers distinguish between these concepts. A booster is a rocket motor mounted on the side of the launcher, responsible for providing the largest part of the thrust during the first minutes of flight. In the case of the Ariane 6 rocket, the strap-on boosters provide about 90 percent of the total thrust at takeoff, while the central cryogenic stage takes over the role of the main propulsion only after the boosters have finished their job and separated.
The current configuration of Ariane 6 uses the P120C as a booster, with two (A62) or four (A64) units depending on the mission. With the introduction of the P160C in the Block 2 variant, the rocket gets a more powerful starting “kick” without changing the basic concept. This is particularly important for launching heavy geostationary satellites, multiple commercial payloads, or large series of smaller satellites in low Earth orbit.
On the Vega-C rocket and the future Vega-E, the same motor takes over the function of the first stage, and additional boosters or upper stages are adapted to the mass and target orbit. The common use of the same motor on different rockets reduces development and production costs, simplifies spare parts logistics, and allows for larger production series, which is key to achieving a competitive price.
BEAP: a unique test stand in French Guiana
The test firing of the P160C was carried out on the BEAP test stand (Banc d’Essai des Accélérateurs à Poudre), the only large facility for vertical testing of solid-fuel motors under the management of the French agency CNES. Located at the Guiana Space Centre near Kourou, the BEAP is about 50 meters high and equipped with a deep channel for directing the exhaust gas jet, as well as a control station located hundreds of meters away for the safety of personnel.
This facility has already been used for testing the large boosters of the Ariane 5 rocket, the P80 motor for the original Vega, and the P120C that currently powers Ariane 6 and Vega-C. The modular design allows adaptation to different motor configurations, which was key to the relatively quick transition from the P120C to the P160C over a period of only a few years.
During each test, meteorological conditions are monitored, including wind speed, precipitation, and the distribution of smoke and particles in the environment. For each test firing or launch, CNES activates a network of several dozen fixed and mobile sensors that measure air and water quality, the impact on local flora and fauna, and noise levels in populated areas like Kourou and Sinnamary. Such an approach allows the environmental impact to be precisely quantified and, where necessary, further mitigated.
Serial production and planned launch pace
Passing the qualification review opens the door to industrial “ramp-up” – a gradual increase in motor production. ESA and industrial partners aim for an annual production capacity of at least 35 P160C motors, and more if necessary, to keep up with the expected launch pace of Ariane 6 and Vega rockets.
Such a production volume requires careful supply chain planning and a high level of automation, from the manufacture of composite structures to precise fuel filling. Each motor undergoes strict inspections and tests before being sent to French Guiana, and additional checks are performed after arrival at the spaceport. The goal is to maintain very high reliability while simultaneously shortening the cycles between individual launches.
In the background of it all is a strategic goal: to increase the annual number of Ariane 6 and Vega variant flights so that Europe can respond to the growing demand for launching commercial satellites, European Union institutional missions, and scientific observatories. The new solid-fuel motor is a prerequisite for such a pace to be achieved without compromise in safety and performance.
P160C and the future of European space policy
The introduction of the P160C fits into the broader picture of the transformation of the European space sector following the retirement of Ariane 5 and the transition to a new generation of launch vehicles. Ariane 6 and the modernized versions of Vega are conceived as a flexible platform that can respond to different needs – from launching large telecommunications satellites to building and maintaining large constellations in low orbit.
For ESA member states, reliable access to space is a matter of strategic autonomy, but also of economic competitiveness. In a world where private companies from the USA and other countries are aggressively lowering launch prices, Europe must offer a combination of reliability, flexibility, and competitive costs. The P160C is one of the key tools in that strategy – it enables higher payload per flight and better utilization of each mission.
At the same time, technological challenges such as making large carbon-composite structures, precise control of solid fuel combustion, and the development of advanced thrust vectoring systems create knowledge and competencies that can be applied beyond the space industry. From advanced materials to high-reliability industrial automation, projects like the P160C stimulate technological development in a wide range of sectors.
Finally, the experience gained during the test firing in April 2025 and the subsequent qualification of the motor is an important foundation for future upgrades. As market needs and institutional missions change, the P160C can become a stepping stone for even more powerful or partially reusable systems. For now, however, its primary task is clear: to solidify Ariane 6 and Vega as the backbone of European access to space in the second half of the 2020s and the beginning of the 2030s.
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