Europe’s new satellite launch rocket is being built in Copenhagen
If you drive over the Kalvebod Bridge in Copenhagen to the west and look towards the large Avedøre Holme industrial quarter, you may not even notice it.
But between moving companies, a chocolate factory, and plumbers lies a sleek black building. It holds an arsenal of high technology of the kind that could revolutionise European spaceflight.
Orbex, the logo on the black building reads. Inside, people who were previously members of the Danish amateur rocketry community have been working full-time for eight years on an extremely ambitious project: enabling Europe to launch satellites from European territory, specifically Orbex’s spaceport in Scotland.
Two of the main forces behind the project are Jonas Bjarnø and Kristian von Bengtson. Jonas Bjarnø is Orbex’s chief technical officer and has a background as a space scientist at DTU Space. Kristian von Bengtson is the company’s chief development officer and has a past as a rocket builder and space architect. Both have previously developed rockets on an amateur basis in the Copenhagen Suborbitals project, which they left around 10 years ago, just like several other Orbex employees.
Now the two are at the head of a rocket factory in Hvidovre with soon 55 full-time employees on regular employment contracts. Many of them come from France, Germany, and elsewhere in the European aerospace industry due to a lack of rocket expertise in Denmark.
Millions are pouring in from large venture funds. For example, Orbex has secured DKK 350 million in a Series C funding round led by the Scottish National Investment Bank in order to prepare for the upcoming launch.
So, they have access to materials and equipment such as 3D printers that can otherwise only be found at SpaceX and Jeff Bezos’s rocket company Blue Origin, which are considered to be the world leaders.
Illustration: Orbex.
However, the department in Hvidovre is only one piece of the larger Orbex puzzle, which employs up to 155 employees. The company also has three major factories in Scotland and is completing its own launch facilities in the north of Scotland.
But the rocket engines are being developed in Hvidovre and tested in the Faxe Limestone Quarry, and in the words of Kristian von Bengtson, they “have been going full steam ahead, without much time for the press”.
“We have a very clear focus on our ultimate goal: to launch. We haven’t had time for much else. That’s probably also why the last of my hair has fallen off,” Kristian von Bengtson says with a smile, pointing to his now completely bald head.
The rocket that is to send satellites into space is a 19-metre tall two-stage rocket named Prime. The development is now so far along (and the engine tests so numerous) that Orbex is in the final development phase, where the design is being finalised. The first flight-ready engines will soon be assembled in a new cleanroom hall in Hvidovre by people in white coats working in a pressurized room.
Prime consists of carbon fibre tanks, and at the bottom of the first stage are six 3D printed engines with a thrust force of around 30 kilonewtons each. The fuel is chilled propane, which is mixed with liquid oxygen, and the liquids are pressurised into the fuel chamber with turbo pumps developed in Hvidovre.
Stage two, which is to carry the satellite into orbit, consists of a slightly larger engine that also burns propane and liquid oxygen but without turbopumps, so that the fuel is injected into the combustion chamber by pressurising the tanks with helium.
Kristian von Bengtson does not dare to put a date on Prime’s first flight—he has been in the rocket industry for too many years for that. But liftoff is approaching.
If the rocket takes off, it will be the first time since 1971 that a satellite has been successfully launched from British territory. The Black Arrow rocket succeeded in its mission on 28 October 1971, after several failed attempts. But the programme was scrapped soon after—and since then, several companies have failed in their attempts. Most recently, business magnate Richard Branson’s company Virgin Orbit was forced to close after a failed launch of the LauncherOne rocket aboard a converted Boeing 747.
Illustration: Orbex.
Kristian von Bengtson and Jonas Bjarnø themselves know all too well about failed launches from their time in the amateur rocketry community. But a lot has changed since then.
Ten years ago, the challenges were old lathes, dull tools, and perpetual pleading to private individuals and companies. Money, materials, and tools were always in short supply. In Hvidovre, the rocket builders have access to everything from expensive CNC machines to ultrasonic cleaning and one of the world’s largest 3D printers for the aerospace industry, which can print a metre-tall metal engine in one piece.
“It’s a completely different reality than ten years ago. At the time, I hadn’t thought that I would be standing in a professional rocket factory surrounded by many incredibly skilled and dedicated people. But here we are. And now we’re going all the way,” the Danish rocket builder says.
With plenty of government support, venture capital, and the right timing, Orbex has managed to join the growing competition in the satellite launch market. In recent years, the market for satellite launches has also grown tremendously, just as there is a growing interest in rockets led by Elon Musk and SpaceX.
But SpaceX in particular has also driven down the price of satellite launches with their Falcon 9 rockets, which send a tightly packed cluster of satellites into orbit all at the same time.
The price for sending a 150 kilogramme satellite into orbit with SpaceX is currently around DKK 5.6 million. A launch with Orbex will be significantly more expensive, but the company does not want to disclose the exact price.
However, the price is not necessarily the deciding factor for all customers. This has been proven by the American/New Zealand company Rocket Lab with their Electron rocket, whose business case is roughly the same as that of Orbex. And they have plenty of customers. Companies such as Rocket Lab and Orbex offer an exclusive launch, with the customer choosing the time and the exact orbit.
“The difference between us and SpaceX is like the difference between a bus and a taxi. At SpaceX, many passengers are sent off together and asked to get off at the same time. Then they have to figure out their orbits themselves with their own propulsion systems. We are the taxi that brings them all the way to their final destination,” Kristian von Bengtson explains.
Rocket Lab and Orbex are also similar in terms of their rockets. Rocket Lab’s Electron rocket also measures just under 19 metres and is also a two-stage rocket made of carbon fibre. Electron’s engines are also 3D printed, but Rocket Lab is experimenting with a number of new technologies such as electric turbo pumps and attempts to catch their rocket in the air with a helicopter.
Orbex has some innovations, such as the design of their fuel tanks, which they have patented. But otherwise, they have chosen a conservative approach.
“We’ve made a very conscious decision to proceed conservatively. We don’t—initially—aim to be super innovative or have superior fuel efficiency. We have lots of innovative ideas, also when it comes to recyclability, but we’ll take it one step at a time,” Kristian von Bengtson says.
On the other hand, Orbex builds most of the parts in-house to avoid being dependent on others. This applies, for example, to turbo pumps and onboard computers.
“An obvious place to source turbo pumps is Ukraine, and it would have been bad to depend on that today,” Kristian von Bengtson says.
Illustration: Orbex.
A focal point for engine development has been the Faxe Limestone Quarry, where Orbex has been testing its engines since 2017. Kristian von Bengtson spent the first year and a half at Orbex finding a test site:
“I actually visited mayors’ offices all around Denmark to find a suitable place. But the main challenge was noise, which bothered nursing homes, kindergartens, etc. But in Faxe, there was a viable option,” he says.
The fact that the Prime engines run on propane, so pollution is limited, also helped convince the municipality. The same was true of the three-year process to get permission to launch from the north of Scotland.
The choice of propane has also proven to be an advantage in terms of funding, including through ESA, which is working to make space travel greener. And luckily, propane can be made from biogas.
Propane also has some special properties that rocket builders have taken advantage of in building their patented fuel tanks.
Propane is the only hydrocarbon that can exist in liquid form at the same temperature as liquid oxygen. If Orbex had chosen methane (and oxygen)—which is used by SpaceX—then they would have had to make a classic tank structure, where the methane tank and the oxygen tank are separated, because otherwise the methane would freeze.
But propane does not freeze at the minus 180 degrees Celsius that oxygen needs to reach to be liquid.
That is why Orbex has chosen to build the propane tank inside the oxygen tank. This reduces the need for piping and saves weight. The so-called coaxial tank structure saves up to 30 percent weight compared to traditional tanks. And the colder the propane is, the less space it takes up, so more propane can be packed in the cold tank.
Illustration: Orbex.
These days, Orbex is starting to put their new cleanroom into use to assemble the rocket engines before they are shipped to Scotland, where all the components will end up as a 19-metre tall rocket on the launch pad of the Sutherland Spaceport, located at the end of the northernmost road in Scotland. And Orbex has secured a 50-year lease for the spaceport, where they plan to carry out 12 launches per year.
Orbex has already signed contracts for seven satellite launches with six customers.
And although Kristian von Bengtson is optimistic, he also has no doubt that Orbex will face some challenges:
“It’s rocket science, and in this industry, we’re used to experiencing things that put us a little behind schedule. But at the moment, we are steadily on our way towards our goal,” he says.
