The first and second stages of the rocket are both powered by the company’s LOX/RP-1 staged-combustion Helix engine, which it touts as being the only one of its kind in Europe. The first stage utilises nine Helix engines, each producing 100 kN with an ISP of 325 seconds. The second stage makes use of one vacuum-optimized Helix engine producing 100 kN with an ISP of 350 seconds.
To date, a flight configuration Helix engine has completed a 74-second long-duration hot fire test
campaign. An integrated stage test of the engine is expected to take place later this year.
Much less is known about the propulsion system for the third stage. According to RFA, it’s a re-ignitable green propellant engine. However, thanks to my look into the RFA ONE User Guide, we also know that the engine provides a specific impulse of >300 s with up to 1.5 kN thrust and 2.5 km/s ΔV.
During a conversation with Tweraser for the European Spaceflight Podcast
earlier this year, the CEO explained that the third stage is “instrumental to the way we serve space.” Tweraser went on to explain that the third stage engine would be “part of an orbital transfer vehicle that can stay in space between three and five years.
Potential applications for the multiuse third stage include the precise deployment of multiple satellites for rideshare missions, in-orbit servicing, and, at the end of its life, the targeted removal of space debris.
While many small launch companies are making reusability a core tenant of their design and marketing material, RFA has mostly avoided talking about their reusability efforts. However, the company is planning to recover its first stage for reuse using a system that will make use of parachutes. Over and above that, little is known about the system.
RFA is examing the use of several launch facilities. Currently, the company is expected to complete its maiden flight from either Andøya Space in Norway or Esrange Space Center in Sweden.
The company was also recently preselected by CNES to launch its RFA ONE vehicle from a new commercial launch facility being created at the Guiana Space Centre in Kourou, French Guiana.
In addition to the above, RFA is also examining additional launch facilities.
RFA is targeting an aggressive starting launch price of just €3 million. However, even CEO Stefan Tweraser acknowledges that this is an ambitious goal.
During our podcast interview, Tweraser explained that the €3 million price target served as a marker for technical decisions and a declaration of intent to the industry.
“It helps our engineers think about cost when they make technical decisions,” Tweraser told me. “It’s also a signal to the market to say that getting stuff into space doesn’t need to be expensive.”
If the company does manage to get anywhere close to €3 million, it would make the vehicle incredibly competitive, possibly even with rideshare market leader SpaceX.
With its 1,300 kg payload capacity, the RFA ONE is, on paper at least, the most capable commercial vehicle being developed by a European launch startup. It also makes it significantly more powerful than international competitors, with the Rocket Lab Electron capable of just 300 kg per flight and Virgin Orbit’s Launcher One 500 kg per flight. This enables RFA to offer larger rideshare missions at more affordable prices.
To accommodate these rideshare missions and equip the RFA ONE for a wider array of missions, RFA will offer the vehicle with three different fairing sizes. The standard fairing is approximately 3.8 metres tall, with a max inner diameter of 2.1 metres. The largest of the RFA ONE fairing options is approximately 8 metres tall with a max inner diameter of 3.3 metres.