13 hours Ago By Martin Smith
European companies in the space sector have been developing novel technology to find their unique place in the market, allowing them to thrive and innovate while stepping towards developing their orbital vehicles. Some are supported by the European Space Agency (ESA), such as HyImpulse, Isar Aerospace, and Orbex, while other independent private companies, such as PLD Space, are forging their ambitious paths to reusability. Arianespace launched three European orbital missions in 2024 from the Guiana Space Centre in French Guiana.
The first was the maiden launch of an Ariane 6 rocket in July, the successor to the Ariane 5 as Europe’s premier heavy-lift vehicle. Ariane 6’s first flight also marked the debut of the ELA-4 pad at the launch site. Two other missions placed Sentinel Earth observation satellites into Sun-synchronous orbits aboard Vega rockets, with the most recent of which being the return-to-flight of the troubled Vega C.
Carrying the Sentinel-1C, which was originally intended to launch aboard a Soyuz vehicle, Vega C flew for the first time in almost two years. Vega launch site at the French Guiana Space Center. (Credit: ESA) On Dec.
18, ESA signed multiple contracts with Avio, the manufacturer of the Vega rocket, to increase the annual number of flights of the Vega-C and to advance the development of its successor, the Vega-E. The former Ariane 5 integration building in French Guiana will be adapted for the Vega-C, enabling two mission campaigns to be prepared simultaneously, with one on the pad and the other in the upgraded assembly building. Four launches are planned for 2025, including the Biomass and Sentinel-1D missions, and another five in 2026.
Avio took over Vega operations from Arianespace in late 2023 and will develop the next-generation Vega-E at the site, from the development of the rocket stages through to assembly and on-ground qualification testing. The Ariane 5 launch pad, fuelling, and support systems will be modified for the new vehicle. Vega-E stands slightly taller than Vega-C at 35 m with a 3.
3 m diameter fairing. Using the P120C and Z40 motors developed for Vega C, it will have a liftoff thrust of 4,500 kN. The Zefiro 9 third stage and liquid-propelled Avum upper stages of the Vega-C will be replaced by a third, cryogenic MR10 upper stage, loaded with liquid methane and oxygen propellants just before launch.
Vega-E’s maiden launch is currently scheduled for 2027. Render of the Vega-E. (Credit: ESA) ESA recently awarded contract extensions to four companies as part of its Boost! program, which was designed to stimulate and support the development of space transportation services in member states.
The program funded three companies in 2019 to reward industrial entrepreneurship and encourage competition within the private sector. November’s €44.2 million funding extensions went to Isar Aerospace (€15 million), HyImpulse (€11.
8 million), Rocket Factory Augsburg (€11.8 million), and UK-based Orbex (€5.6 million), who also began to receive funding from the program in 2021.
German launch service company Isar Aerospace could potentially debut its Spectrum rocket in early 2025. This would also be the first orbital launch from the Andøya spaceport in Norway, which has supported over 300 suborbital missions for NASA since 1966. This site launched one of ten European suborbital launches for the Łukasiewicz Institute of Aviation.
Most European suborbital flights have launched from the Esrange Space Center in Sweden, including the Red Kit, VSB-30, Dart, and the Improved Orion. Render of the Spectrum rocket on the pad at Andøya. (Credit: Isar Aerospace) German private aerospace company HyImpulse chose the Koonibba Test Range in Australia for its maiden flight.
Headquartered in Neuenstadt am Kocher, it has been developing a series of products based around a hybrid rocket engine using a combination of paraffin-based fuel and liquid oxygen as propellant. The environmentally friendly technology is already being proven on the company’s SR75 suborbital sounding rocket and will feed into the development of the forthcoming three-stage orbital SL1 using the same HyPLOX75 hybrid engine. In mid-December, the company also announced an orbital transfer vehicle (OTV) called HyMove, which will use the same propellant technology.
This OTV, also called a “space tug,” will enable the company to deploy multiple satellites into different orbital planes from a single launch. The craft will support “last mile” payload delivery, precision orbital insertion, and hosted payload services. The company has partnered with leading nanosatellite mission provider Spacemanic to launch up to ten missions using HyMove from 2026 through 2036.
The pair plan to capitalize on the expanding small satellite market in Europe, which is expected to grow to $30 billion by the decade’s end. HyImpulse expects to wrap up ground testing of the space tug next year and begin flying commercial missions in 2029. Render of the HyMove OTV.
(Credit: HyImpulse) In May this year, the HyImpulse team launched its 12 m-long SR75 suborbital sounding rocket from the Koonibba Test Range. The rocket’s name comes from the abbreviation “sounding rocket” and the engine’s 75 kN of thrust. It represented a significant change from the team’s previous rockets.
“The oxidizer change was the hard thing to do,” Christian Schmierer, CEO of HyImpulse, told NSF. “That took roughly four years of intensive testing on the ground.” The company was initially granted permission to launch from SaxaVord Spaceport in the Shetland Islands, with a 12-month window starting last December.
While the Spaceport was yet to receive its launch license, the Civil Aviation Authority (CAA) granted permission to launch the SR75, considering the target altitude. Because the infrastructure was not yet in place, their first vehicle instead launched from Koonibba, reaching 50 km, and was recovered after a parachute descent. The team was on-site for three weeks, from the launch preparations and setting up the pad to the recovery of the rocket and packing away.
SR75 lifts off from Koonibba Test Range in Australia. (Credit: HyImpulse) 95% of the vehicle’s technical development has been done in-house, and the company developed the automated fiber-winding technology and production capability to build its engines, composite tanks for both liquid oxygen and helium, avionics, and software. Constructed from a carbon-fiber-reinforced polymer, the company’s Type 5 fully composite tank is both lightweight and strong, removing the need for a metal liner.
Hybrid rocket engines HyImpulse is disruptive because of its hybrid rocket engine, which uses liquid oxygen and paraffin as liquefying fuel. The suborbital debut mission was dubbed “Light This Candle” as a nod to astronaut Alan Shepard’s famous quote. The forthcoming SL-1 orbital rocket will benefit from utilizing a flight-proven engine design using this technology.
Production of the SR75. (Credit: HyImpulse) “There are three major challenges with a hybrid rocket engine,” Schmierer told NSF. “The first is the structural challenge of the large combustion chamber.
There’s 3,000 Kelvin inside, but you want to make it as light as possible, so you want to use composite fibers that will break at 80 degrees Celcius.” If managing this wasn’t enough of a challenge, the second difficulty is vaporizing the oxidizer. The student group used nitrous oxide, which is more or less already a monopropellant, so once ignited, it can keep the flame stable.
“Liquid oxygen is highly reactive,” Schmierer notes, “but also cryogenic, so it cannot decide if it wants to make this flame burn really fast or to extinguish it if it’s not refined.” The third challenge is with the propellant fuel itself. “The classical hybrid rocket fuels, for example, Hydroxyl-terminated Polybutadiene (HTPB), is a chemical compound you’ll also find in solid rocket motors as a binder.
This burns faster than Hydrogen Peroxide (HTP) or other polymers, but it’s still super slow. That has made it necessary in the past to have hybrid engines with complex geometries like a wagon wheel or a multiport, where there’s a lot of holes in the fuel grain for the oxidizer to flow through. This increases the surface of the fuel and, therefore, the mass flow, which is dependent on the surface, but it has a big issue towards the end.
The complex structure starts breaking apart as the fuel gets thinner, so you cannot fully burn [everything], and you have a huge amount of residual fuel.” He notes that the solution is a circular port, limiting the design to one hole through which the oxidizer can be injected. The combustion then moves from inside to outside until it reaches the skin.
However, with just one hole, there is no longer a large surface, so the fuel needs to burn faster to manage the regression rate. “This is where the liquefying technology comes in,” Schmierer explains. “The paraffin fuel melts and forms a liquid layer on the surface, which forms waves and entrains droplets into the flow.
This is the solution to the higher regression rate – by bringing droplets from the surface into the flame, you don’t need to bring the flame to the surface. You reduce the necessary thermal heat exchange between the flame and the fuel by bringing the fuel to the flame.” SR75 ignites during its maiden launch.
(Credit: HyImpulse) Paraffin is easily sourced, cheap to produce, and safely stored, but the choice is not without its challenges. In its pure form, it is very brittle and is sourced as a byproduct of the oil industry. HyImpulse has refined its recipe for the fuel with around five percent additives, fine-tuning the manufacturing process of mixing, melting, cooling down, and casting the solidified grain into blocks, which are then wrapped with composite fibers.
“It’s not an easy process – you can melt a few candles at home and try to pour it into a big shape and it will always break apart while solidifying because it shrinks extremely. As soon as you go to a three-meter paraffin with 60 cm diameter, then it starts to get really challenging.” On the plus side, paraffin is chemically similar to kerosene and has the same specific impulse (ISP).
HyImpulse views the suborbital SR75 as a progressive step towards scaling up its technology for the SL1 orbital rocket, nurturing and developing the team and the technology. “One use-case [for the SR75} is inaugural flights for multiple spaceports because they would like to have a rocket launch before they go orbital. We know that for microgravity research, there’s a very limited market in Europe, and we could maybe launch two rockets a year in this market, so we never wanted to offer that service.
” “There is a lot of technology testing that is possible with this kind of rocket, such as testing material samples for supersonic and hypersonic flight, or payloads for space on a suborbital trajectory, for example, re-entry capsules. We have quite some customer interest and it could be as many as four to six launches per year.” To support these future flights, an upgrade will increase the 30-second burn duration from the maiden flight and add active guidance to follow a predefined path with a fixed pitch.
This is important for rockets of this size, which are wind-sensitive. The next flight will launch in Q1 of 2026 from Saxavord in the UK, which can be very windy while offering its customers more diverse mission profiles. As demonstrated by Firefly, responsive launches could be an emerging market that suits smaller rockets.
However, the more significant challenge would be regulations and airspace impacts rather than the logistics of preparing hardware for launch. “Right now, the time for a license in the UK is nine to 18 months, so the first step is to bring this down to nine months, then three, and of course, all these government institutions need to work together”, Schmierer notes. He adds that regulators are unlikely to agree to less than the 72 hours Firefly currently works with because of the lead time to close the airspace.
Paperwork aside, in the case of a paraffin engine, only the liquid oxidizer must be loaded for launch and is already available at most sites. HyImpulse could potentially store several launch-ready rockets at once, all already loaded with the paraffin propellant. This could even allow for the development of mobile launch sites.
“Simplicity translates into lower cost, not only in the manufacturing but in the whole process from testing, development, storage, and logistics. The biggest advantage for the customer is that we offer a small launcher that will be economically sustainable without government subsidies. It will be in the same order of magnitude as a Transporter mission, so while we will not reach $6,000 per kilogram — it may be two or three times as high in the beginning — we’ll get closer to $8,000 or even $7,000.
” Orbex Prime seen from below. (Credit: Orbex) SaxaVord Spaceport Five companies intend to launch from SaxaVord, which has a range license to launch 30 rockets annually. These include Orbex, which announced its plans to move flights to Shetland in early December after it decided to pause construction of its spaceport in Sutherland, Scotland, where the team first broke ground in May 2023.
Using SaxaVord will enable Orbex to direct more of its funding to developing its medium-class launcher, Proxima. “The decision will help us reach the first launch in 2025 and provide SaxaVord with another customer to further strengthen its commercial proposition”, said Orbex CEO Phil Chambers. This move came on the heels of the spaceport losing another customer, ABL Space Systems, which recently announced a pivot to missile defense programs in Nov.
2024. SaxaVord is also the choice for Edinburgh-based Skyrora and Rocket Factory Augsburg, whose RFA One rocket’s first stage experienced an explosion during a static fire test of all nine Helix engines in August, causing “minor repairs” to be carried out on the launch stool. However, some customers see themselves outgrowing SaxaVord’s capacity in their broader roadmap.
“If you divide it by five and assume that, in five to ten years, all five are still there, you would have only six launches per company on average, which is not enough for us,” Schmierer from HyImpulse says. “Either some competitors drop out of the race, or we need a second launch site.” For this reason, the company has already utilized a launch opportunity from Australia, which would give it a considerable advantage, as it is becoming geographically diversified and within reach of a growing customer base in the Asia-Pacific region.
RFA One static fires at SaxaVord in May 2024. (Credit: Rocket Factory Augsburg) “Of course, French Guiana would be a nice launch site to reach orbits that are not highly inclined, but these are only around five percent of customer requests, so they are not a high priority right now. There is currently a regulation that a small amount, which could become bigger in the future, of European Union (EU) payloads have to be launched from EU territory.
This could disqualify even the UK at this time.” Future EU payloads that will stretch Europe’s currently limited launch capacity will notably include the Infrastructure for Resilience, Interconnectivity, and Security by Satellite (IRIS2). By the end of the decade, this multi-orbital constellation will consist of 290 satellites in low and medium-Earth orbit.
SpaceRISE, a consortium of European operators SES, Eutelsat,, and Hispasat, will operate the network. SL1 Orbital Launcher HyImpulse’s 33 m long Small Launcher 1 (SL1) is planned to be capable of launching up to 600 kg on its first iteration. This is almost double that of Rocket Lab’s Electron in height and payload capacity, with expectations to increase this capacity by at least a third in the future.
With an optional kickstage for precise deployment into multiple orbital planes or inclinations, this three-stage vehicle suits rideshare and dedicated missions. The 2.2 m diameter design includes a new turbopump system for liquid oxygen.
Side view of the SL1 orbital vehicle. (Credit: HyImpulse) “If you look at all the small launchers, I would claim that none of them are profitable, and you see this already in the U.S.
— they either develop a larger vehicle or have integrated services such as launching their own satellites that they build for customers.” Schmierer cites Rocket Lab with Neutron, Firefly with its MLV, Relativity skipping the Terran 1 to move to Terran R, and the incentives the European Space Agency is giving companies in this space with its funding of medium and heavy-lift rockets. “Liquid rockets don’t make sense on a small scale,” he notes.
“If you make something smaller, you reduce the material price a little, but the complexity of the vehicle assembly stays almost the same. If you reduce the payload by 90%, you will never reduce the price by [the same proportion].” “To compare HyImpulse’s hybrid engine with more traditional liquid engines, we need to compare the hybrid rocket casing with the thrust chamber of a liquid motor,” Schmierer explains.
The company expects to reduce the cost of a casing from the current €40,000 to half or a quarter of this cost over time. In contrast, a liquid thrust chamber will cost between €50,000 to €100,000, even with modern manufacturing technologies. The SL1 will use four of these casings in its first stage — four pumps will each feed two hybrid thrust chambers for the eight engines.
By contrast, its competitors could use between 16 and 20 thrust chambers, depending on the number of engines. Even accounting for the economies of scale that come from higher production rates, the company sees this cost difference and the lower propellant cost as its competitive edge. Render of the engine section of the SL1.
(Credit: HyImpulse) The first two stages of the SL1 will use hybrid engines, while the third will use a liquid engine. This avoids complexities such as the high structural mass introduced by a long, thin hybrid motor on this upper stage. While the first SR75 flight was not actively controlled, the guidance and navigation control (GNC) algorithms have already been tested and are in the process of being refined, which helps the company step towards getting its orbital launch license in time.
The engine section of the SL1 is where the rocket is visually distinct, with a square base. Initial designs were circular, with seven engines in a circle, but the change to feed two thrust chambers with one pump moved the count to an even number. “We played around with grouping eight engines and saw a few advantages,” Schmierer told NSF.
“It’s symmetric — you could also arrange eight in a circle, but it’s not symmetric, so here we basically have four propulsion units of the same configuration with the pumps together.” He added that the outer dimensions have been checked to fit in a standard sea shipping container, whereas a circular design would not have fit. Reusability in Europe Spanish aerospace company PLD Space announced plans to upgrade its Miura 5 rocket with partial reusability in Nov.
2024, at the same time announcing a new family of rockets, Miura NEXT. This includes a range of medium to heavy-lift variants as part of an aggressive 10-year scale-up plan, including its production facilities. Following the successful launch of the company’s Miura 1 pathfinder in late 2023, its focus has moved to the Muira 5, which will debut no earlier than late 2025.
Five missions are initially planned yearly for its own SPARK program rather than paying customers. Starting with expendable launches, early missions will see the first stage returned under parachute. PLD is already targeting 2028 for the first stage of Miura 5 to return to land propulsively at a landing pad in the Guiana Space Center.
The company performed a Liquid Propulsion Stage Recovery (LPSR) test with a subscale version of its Miura 5 in 2019, using a 15 m version of the vehicle. Dropping the test article from a helicopter into the Gulf of Cádiz, the company learned about the structural impacts of recovery even under parachute. The testing also enabled PLD to explore iterating around the greater-than-expected corrosion effects on aluminum and copper in the combustion chamber from exposure to the sea.
The company focused on propulsive landing as the best way to recover and reuse a first stage. “We can’t recover and reuse Miura 5 just using parachutes because the salty water will not allow this,” Raul Torres, CEO and co-founder, told NSF. “Propulsive landing has other throwbacks because you need to bring much more propellant on board that is not used for reaching orbit, just to bring back the stage.
On the other hand, the loss in delta-V or loss of performance in orbit with that propellant gives you the chance to bring it back in one piece.” Other launch companies are working towards reusability. Orbex, whose Orbex Prime vehicle uses 3D-printed engines that can be reignited in orbit, states on its website that the rocket is designed to be reusable and that “what does not burn up harmlessly in the atmosphere will be recovered and reused.
” With one launch under its belt, HyImpulse is analyzing the SR75 vehicle, looking for which parts can be reused after splashdown, and performing pressure testing of the tanks. The motor design, where composite fiber is wrapped directly onto the paraffin, does not immediately suit reusability. The necessary design changes to afford a cartridge-style replacement of the propellant would add considerable mass, so this remains a consideration for the future.
Follow Europe’s path to space with NSF’s bi-weekly “Europe’s Future In Space” video series, released on Wednesdays on NSF’s YouTube channel. (Lead image: Render of the Vega E vehicle. Credit: Avio).
