When the UK government announced plans to have rocket launches conducted from British soil as early as 2020, many questioned the feasibility of such a vision – especially the ambitious timeline.

The spaceport itself might not be a problem. One important element, however, is missing – a functional small-satellite launcher. The UK doesn’t aim to fly those Falcons, Arianes or Soyuzes that lift massive satellites to all sorts of orbits from established spaceports in the USA, Russia or French Guiana. It aims to target the small satellite market – quite understandably, since the country is among the global leaders in the development and manufacture of small satellites with masses below 500kg.

The UK’s aspiring spaceport operators hope to capitalise on the presence of established manufacturers of small satellites, such as Surrey Satellite Technology Ltd (SSTL), or relative newcomers, such as Glasgow-based cubesat maker Clyde Space.

Customers of these companies could benefit from being able to launch from the north of Scotland or Cornwall, rather than having to transport their spacecraft to the other side of the world.

The global market for small satellites is forecast to grow significantly. This growth, fuelled by the arrival of low Earth orbit mega-constellations such as OneWeb, will raise demand for small-satellite launches. Developers of small-satellite constellations are already complaining about the limited launch opportunities available to them and the high prices they must pay to launch as a secondary payload on a mission dictated by the needs of a primary large-satellite-owning customer.

Globally, two vehicles designed specifically for launching small satellites are in operation – the Pegasus launch system, developed originally by American aerospace manufacturer Orbital Sciences Corporation, now owned by defence giant Northrop Grumman, and Electron from New Zealand-based start-up Rocket Lab.  

In operation since 1990, the three-stage Pegasus rocket, capable of carrying small payloads of up to 450kg into low Earth orbit, launches horizontally from a carrier aircraft that lifts to an altitude of 12km. The atmosphere at this altitude is already thinner than near the Earth’s surface, so the rocket requires much less propellant.

Following a successful test flight in April 2018, newcomer Rocket Lab carried out its first commercial mission later in the year, on 11 November. During the flight, the two-stage carbon-fibre vehicle, which features 3D-printed engines, deployed six small satellites into a low Earth orbit.

However, the aspiring British spaceport owners hope not to rely only on imported vehicles but preferably to offer rides on brand-new home-grown launchers.

At the Farnborough International Airshow in July 2018, an Edinburgh-based start-up called Skyrora announced plans to try out its rocket engines in the next few months. The company will trial at Cornwall Airport in Newquay, taking advantage of the hardened aircraft shelter previously used for the testing of rocket engines for the Bloodhound Super Sonic Car.

Skyrora, backed by a Ukrainian entrepreneur, emerged from obscurity only recently, but says it’s on track to test-fly a sub-orbital rocket next year, launching probably from somewhere in the north of Scotland.

“Our sub-orbital vehicle will take a 100kg payload to the altitude of about 100km and then it will fall back,” says Robin Hague, Skyrora’s lead engineer. “Our ultimate goal is to build a bigger, orbital, launcher and we believe we can fly it around 2021.”

Skyrora, founded only last year, uses a rather unusual propulsion technology. The 3D-printed engines of the company’s sub-orbital vehicle Skyrora 1, as well as those of the orbital Skyrora XL, will digest a combination of the disinfectant hydrogen peroxide and aviation fuel kerosene.

According to Hague, this fuel mix has certain advantages that might come in handy, especially in the UK.

“It’s storable, it’s non-cryogenic,” says Hague. “We don’t need to deal with super-cold liquids like liquid oxygen. It can be stored at room temperature and therefore it’s easier to accept weather holds.”

He adds the ability to keep the rocket’s tanks full if bad weather hampers the > < launch will be invaluable for Skyrora, as the rocket builder plans to operate from one of the spaceports expected to be established in the north of Scotland, where weather is notoriously unstable.

For example, SpaceX, which uses liquid oxygen as an oxidiser in its Falcon 9 rockets, has to empty the tanks every time the launch gets delayed due to bad weather, says Hague. Launching from sunny Florida, SpaceX might not feel too inconvenienced. The north of Scotland, however, is a different story.

Hague lists further advantages that prompted Skyrora to opt for hydrogen peroxide: it’s more environmentally friendly than liquid oxygen, it’s self-igniting – which means the engine doesn’t need a separate ignition system – and the fuel is denser, allowing the vehicle to be smaller.

“We have combined this with a relatively minimalist and simple vehicle design,” says Hague. “It’s quite a conventional vehicle, to minimise the risk. We are combining that with modern techniques such as 3D printing, which allows us to simplify the engine manufacturing process. We can create cooling passages of all sorts of shapes that you would struggle to do conventionally otherwise.”

Skyrora says inspiration for the use of hydrogen peroxide came from the UK’s Black Arrow rocket – a vehicle that engineers from the Royal Aircraft Establishment and Westland Aircraft developed in the 1960s.

The story of Black Arrow is somewhat bittersweet. The rocket successfully orbited the experimental satellite Prospero in 1971. However, the programme was discontinued soon after for financial reasons.

Until today, the story of Black Arrow makes the UK the only country in history to have developed a launch capability only to throw it away.

The current generation of British rocketeers is, in a sense, taking over where UK politicians once decided to stop.

Only five specimens of Black Arrow were manufactured. The final one – Black Arrow R4 – now hangs under the ceiling of the Exploring Space Gallery of London’s Science Museum.

“It was a lightweight launcher designed to launch a maximum of 150kg, which is a very small satellite, to low Earth orbit,” says Doug Millard, deputy keeper of technologies and engineering at the Science Museum, London. “Prospero itself was only about 73kg. At that time, the UK was about the sixth nation to launch a satellite.”

According to Millard, who wrote the book ‘The Black Arrow Rocket: A History of a Satellite Launch Vehicle and Its Engines’, in those early days of spaceflight, the UK was positioned to become the world’s third space superpower after the USA and USSR.

“British policy at that time was to have a defensive ballistic missile that could carry a nuclear warhead,” he says. “The UK had a ballistic missile development programme called Blue Streak, which could have served as a basis for development of a significant space rocket programme. As part of the Blue Streak programme, the UK built a smaller rocket called Black Knight. Black Arrow was essentially a souped-up version of this.”

The rocket’s first- and second-stage Gamma engines were based on technology developed during the Second World War by Germany for the V2 rocket.

The rocket’s components were manufactured at various sites across the UK including the Isle of Wight, Coventry and Westcott. From the UK, the rockets were transported by air to Australia and launched from the Woomera Range Complex, where the Blue Streak missiles had previously been tested.

The rocket flew only four times. Two of these flights ended in failure, one performed a successful sub-orbital flight, and the final one successfully launched Prospero. By that time, however, the government had already decided Black Arrow’s fate.

“There weren’t enough satellites for Black Arrow to launch to justify expenditure on the development of the rocket,” says Millard. “It was cheaper to buy American Scout rockets than manufacture the Black Arrow. Even though the programme was cancelled, the decision was taken to let the R3 launch. If they had stopped R3 from launching, we would never have known whether Black Arrow was capable of launching a satellite.”

The redundant R4 subsequently found its way to the Science Museum, where it hangs together with a Prospero flight spare right next to the Scout rocket, the one that brought about its demise.

Millard says some new-generation rocketeers have been scouring the Science Museum’s archives hoping to learn from knowledge captured in engineering documentation from the Black Arrow era.

“In principle, rockets are quite straightforward – you chuck something out of one end at a great rate and that makes you go in the opposite direction,” says Millard. “However, to make it work effectively requires a very sophisticated set of systems, and much of what is known to any one team kind of disappears when that team is dismantled. When a new team comes along, it has to learn from scratch.”

‘We are developing a reusable space plane that could be deployed from anywhere in the world’

Not all British rocket-builders look to the past. Some projects in the pipeline explore truly 21st-century solutions.

At the Farnborough International Airshow 2018, a company called Orbex announced that it had raised £30m in public and private funding to develop its Prime launch vehicle.

The company, which says most of its staff are former engineers from Nasa and the European Space Agency (ESA), describes Prime as a “completely rethought and redesigned launch vehicle” that can be up to 30 per cent lighter and 20 per cent more efficient than other small-satellite launchers under development. The vehicle will use renewable fuel bio-propane, which Orbex says will result in 90 per cent less carbon emissions.

Capable of launching satellites of up to 220kg mass, Prime features a range of innovative technologies including a novel payload separation system called Magic that leaves zero orbital debris. The rocket will fly from the Sutherland spaceport in Scotland, which recently received a £23.5m grant from the UK Space Agency.

The agency also promised to divide a further £2m between Cornwall, Glasgow Prestwick and Snowdonia airports. These three airports are looking to develop infrastructure that would enable horizontal rocket launches. Horizontally launched rockets, such as Northrop Grumman’s Pegasus, are carried to a high altitude by an aircraft and released at a convenient location to reach the desired orbit.

Glasgow Prestwick-based Orbital Access is hoping to develop a vehicle that could service these airports. The firm’s CEO Stuart McIntyre says the company, which cooperates with BAE Systems on the project, had completed a feasibility study, and is now defining the system and its architecture in detail.

“We are developing a reusable space plane that could be deployed globally from anywhere in the world,” says McIntyre. “We hope to conclude the definition phase by the middle of 2019. We will then be able to move into the preliminary design phase and then into our final design, prototype and test phase. We are hoping to test-fly in 2021, which is obviously dependent on availability of funding.”

Orbital Access has previously received funding from the UK Space Agency and ESA. The company is now trying to raise £2m to pay for the next stage of the development.

Orbital Access’s system, called Orbital 500R, is a 21st-century iteration of the Pegasus. It uses a carrier plane that allows the rocket to avoid what McIntyre describes as the most difficult stage of the launch – the climb through the first 12km where the atmosphere is thickest.

Instead of a simple rocket, as in the case of Pegasus, Orbital Access’s aircraft has attached to its belly a 23m-long autonomous space plane. At the desired altitude, the aircraft releases the space plane, which then fires its rocket engines to propel itself at Mach 9 to an altitude of 90km. Here, the space plane releases its payload attached to small rockets, which then place the satellites into their orbits.

The space plane, designed to be fully reusable, then glides back towards the Earth using its 12m-wide wings and lands at an airport from where it can be picked up by the carrier aircraft ahead of its next mission.

McIntyre says the concept space plane had been developed with the Reaction Engines Sabre engine in mind. Although it will rely on traditional rocket engines in the early years of its operations, in the more distant future Orbital 500R could become a test platform for the innovative air-breathing rocket engine.

“The Reaction Engines Sabre programme is acting as a design constraint to our system,” says McIntyre. “We are now using traditional rocket engines we obtain from a former Soviet Union country, but we want to be able to replace them with the Sabre engine.”

Reaction Engines, McIntyre says, was involved in Orbital Access’s feasibility work in 2016, and the two firms maintain close communication to align their projects.

“I like to see our project as a technology roadmap that will take the UK aerospace industry into designing and building future generations of space planes based on incremental technological achievements in our programme and programmes that follow,” says McIntyre.

“This programme offers strategic opportunities for the UK aerospace industry and a long-term engineering roadmap for all the myriads of sub-system opportunities that emerge from the supply chain.”

Millard says the current generation of UK rocket builders, unlike its predecessors that built the Black Arrow, is benefiting from a completely different political climate.

The launch of Prospero in 1971 was the beginning, but also an end for British rocketry for the subsequent 40 years.

In parallel to the Black Arrow, the UK also participated in development of the first European launcher, Europa. The Blue Streak missile served as the vehicle’s first stage. Marred with failures and technical problems, the Europa programme was eventually scrapped. Europa’s final flight took place only about a week after the final flight of Black Arrow.

After that, the European countries reorganised their efforts and moved towards the eventually very successful Ariane programme. At the time, the UK government decided rocketry was not for them and focused on building satellites instead.

“We provided the clamps to stop Ariane rockets from being launched prematurely,” Millard says, chuckling at historical facts. “They were the old Blue Streak clamps. We also provided the guidance computer. The whole Blue Streak episode scared successive British governments and the permanent civil servants, so anything that was rocket-related was a no-no.”

Led by the French and Germans, Ariane went on to become one of the most reliable and sought-after launchers in the world.

The UK government, as well as the new generation of British rocketeers, now hope the Black Arrow fiasco can be replaced with a new and more successful chapter.

When the UK government announced plans to have rocket launches conducted from British soil as early as 2020, many questioned the feasibility of such a vision – especially the ambitious timeline.

The spaceport itself might not be a problem. One important element, however, is missing – a functional small-satellite launcher. The UK doesn’t aim to fly those Falcons, Arianes or Soyuzes that lift massive satellites to all sorts of orbits from established spaceports in the USA, Russia or French Guiana. It aims to target the small satellite market – quite understandably, since the country is among the global leaders in the development and manufacture of small satellites with masses below 500kg.

The UK’s aspiring spaceport operators hope to capitalise on the presence of established manufacturers of small satellites, such as Surrey Satellite Technology Ltd (SSTL), or relative newcomers, such as Glasgow-based cubesat maker Clyde Space.

Customers of these companies could benefit from being able to launch from the north of Scotland or Cornwall, rather than having to transport their spacecraft to the other side of the world.

The global market for small satellites is forecast to grow significantly. This growth, fuelled by the arrival of low Earth orbit mega-constellations such as OneWeb, will raise demand for small-satellite launches. Developers of small-satellite constellations are already complaining about the limited launch opportunities available to them and the high prices they must pay to launch as a secondary payload on a mission dictated by the needs of a primary large-satellite-owning customer.

Globally, two vehicles designed specifically for launching small satellites are in operation – the Pegasus launch system, developed originally by American aerospace manufacturer Orbital Sciences Corporation, now owned by defence giant Northrop Grumman, and Electron from New Zealand-based start-up Rocket Lab.  

In operation since 1990, the three-stage Pegasus rocket, capable of carrying small payloads of up to 450kg into low Earth orbit, launches horizontally from a carrier aircraft that lifts to an altitude of 12km. The atmosphere at this altitude is already thinner than near the Earth’s surface, so the rocket requires much less propellant.

Following a successful test flight in April 2018, newcomer Rocket Lab carried out its first commercial mission later in the year, on 11 November. During the flight, the two-stage carbon-fibre vehicle, which features 3D-printed engines, deployed six small satellites into a low Earth orbit.

However, the aspiring British spaceport owners hope not to rely only on imported vehicles but preferably to offer rides on brand-new home-grown launchers.

At the Farnborough International Airshow in July 2018, an Edinburgh-based start-up called Skyrora announced plans to try out its rocket engines in the next few months. The company will trial at Cornwall Airport in Newquay, taking advantage of the hardened aircraft shelter previously used for the testing of rocket engines for the Bloodhound Super Sonic Car.

Skyrora, backed by a Ukrainian entrepreneur, emerged from obscurity only recently, but says it’s on track to test-fly a sub-orbital rocket next year, launching probably from somewhere in the north of Scotland.

“Our sub-orbital vehicle will take a 100kg payload to the altitude of about 100km and then it will fall back,” says Robin Hague, Skyrora’s lead engineer. “Our ultimate goal is to build a bigger, orbital, launcher and we believe we can fly it around 2021.”

Skyrora, founded only last year, uses a rather unusual propulsion technology. The 3D-printed engines of the company’s sub-orbital vehicle Skyrora 1, as well as those of the orbital Skyrora XL, will digest a combination of the disinfectant hydrogen peroxide and aviation fuel kerosene.

According to Hague, this fuel mix has certain advantages that might come in handy, especially in the UK.

“It’s storable, it’s non-cryogenic,” says Hague. “We don’t need to deal with super-cold liquids like liquid oxygen. It can be stored at room temperature and therefore it’s easier to accept weather holds.”

He adds the ability to keep the rocket’s tanks full if bad weather hampers the > < launch will be invaluable for Skyrora, as the rocket builder plans to operate from one of the spaceports expected to be established in the north of Scotland, where weather is notoriously unstable.

For example, SpaceX, which uses liquid oxygen as an oxidiser in its Falcon 9 rockets, has to empty the tanks every time the launch gets delayed due to bad weather, says Hague. Launching from sunny Florida, SpaceX might not feel too inconvenienced. The north of Scotland, however, is a different story.

Hague lists further advantages that prompted Skyrora to opt for hydrogen peroxide: it’s more environmentally friendly than liquid oxygen, it’s self-igniting – which means the engine doesn’t need a separate ignition system – and the fuel is denser, allowing the vehicle to be smaller.

“We have combined this with a relatively minimalist and simple vehicle design,” says Hague. “It’s quite a conventional vehicle, to minimise the risk. We are combining that with modern techniques such as 3D printing, which allows us to simplify the engine manufacturing process. We can create cooling passages of all sorts of shapes that you would struggle to do conventionally otherwise.”

Skyrora says inspiration for the use of hydrogen peroxide came from the UK’s Black Arrow rocket – a vehicle that engineers from the Royal Aircraft Establishment and Westland Aircraft developed in the 1960s.

The story of Black Arrow is somewhat bittersweet. The rocket successfully orbited the experimental satellite Prospero in 1971. However, the programme was discontinued soon after for financial reasons.

Until today, the story of Black Arrow makes the UK the only country in history to have developed a launch capability only to throw it away.

The current generation of British rocketeers is, in a sense, taking over where UK politicians once decided to stop.

Only five specimens of Black Arrow were manufactured. The final one – Black Arrow R4 – now hangs under the ceiling of the Exploring Space Gallery of London’s Science Museum.

“It was a lightweight launcher designed to launch a maximum of 150kg, which is a very small satellite, to low Earth orbit,” says Doug Millard, deputy keeper of technologies and engineering at the Science Museum, London. “Prospero itself was only about 73kg. At that time, the UK was about the sixth nation to launch a satellite.”

According to Millard, who wrote the book ‘The Black Arrow Rocket: A History of a Satellite Launch Vehicle and Its Engines’, in those early days of spaceflight, the UK was positioned to become the world’s third space superpower after the USA and USSR.

“British policy at that time was to have a defensive ballistic missile that could carry a nuclear warhead,” he says. “The UK had a ballistic missile development programme called Blue Streak, which could have served as a basis for development of a significant space rocket programme. As part of the Blue Streak programme, the UK built a smaller rocket called Black Knight. Black Arrow was essentially a souped-up version of this.”

The rocket’s first- and second-stage Gamma engines were based on technology developed during the Second World War by Germany for the V2 rocket.

The rocket’s components were manufactured at various sites across the UK including the Isle of Wight, Coventry and Westcott. From the UK, the rockets were transported by air to Australia and launched from the Woomera Range Complex, where the Blue Streak missiles had previously been tested.

The rocket flew only four times. Two of these flights ended in failure, one performed a successful sub-orbital flight, and the final one successfully launched Prospero. By that time, however, the government had already decided Black Arrow’s fate.

“There weren’t enough satellites for Black Arrow to launch to justify expenditure on the development of the rocket,” says Millard. “It was cheaper to buy American Scout rockets than manufacture the Black Arrow. Even though the programme was cancelled, the decision was taken to let the R3 launch. If they had stopped R3 from launching, we would never have known whether Black Arrow was capable of launching a satellite.”

The redundant R4 subsequently found its way to the Science Museum, where it hangs together with a Prospero flight spare right next to the Scout rocket, the one that brought about its demise.

Millard says some new-generation rocketeers have been scouring the Science Museum’s archives hoping to learn from knowledge captured in engineering documentation from the Black Arrow era.

“In principle, rockets are quite straightforward – you chuck something out of one end at a great rate and that makes you go in the opposite direction,” says Millard. “However, to make it work effectively requires a very sophisticated set of systems, and much of what is known to any one team kind of disappears when that team is dismantled. When a new team comes along, it has to learn from scratch.”

‘We are developing a reusable space plane that could be deployed from anywhere in the world’

Not all British rocket-builders look to the past. Some projects in the pipeline explore truly 21st-century solutions.

At the Farnborough International Airshow 2018, a company called Orbex announced that it had raised £30m in public and private funding to develop its Prime launch vehicle.

The company, which says most of its staff are former engineers from Nasa and the European Space Agency (ESA), describes Prime as a “completely rethought and redesigned launch vehicle” that can be up to 30 per cent lighter and 20 per cent more efficient than other small-satellite launchers under development. The vehicle will use renewable fuel bio-propane, which Orbex says will result in 90 per cent less carbon emissions.

Capable of launching satellites of up to 220kg mass, Prime features a range of innovative technologies including a novel payload separation system called Magic that leaves zero orbital debris. The rocket will fly from the Sutherland spaceport in Scotland, which recently received a £23.5m grant from the UK Space Agency.

The agency also promised to divide a further £2m between Cornwall, Glasgow Prestwick and Snowdonia airports. These three airports are looking to develop infrastructure that would enable horizontal rocket launches. Horizontally launched rockets, such as Northrop Grumman’s Pegasus, are carried to a high altitude by an aircraft and released at a convenient location to reach the desired orbit.

Glasgow Prestwick-based Orbital Access is hoping to develop a vehicle that could service these airports. The firm’s CEO Stuart McIntyre says the company, which cooperates with BAE Systems on the project, had completed a feasibility study, and is now defining the system and its architecture in detail.

“We are developing a reusable space plane that could be deployed globally from anywhere in the world,” says McIntyre. “We hope to conclude the definition phase by the middle of 2019. We will then be able to move into the preliminary design phase and then into our final design, prototype and test phase. We are hoping to test-fly in 2021, which is obviously dependent on availability of funding.”

Orbital Access has previously received funding from the UK Space Agency and ESA. The company is now trying to raise £2m to pay for the next stage of the development.

Orbital Access’s system, called Orbital 500R, is a 21st-century iteration of the Pegasus. It uses a carrier plane that allows the rocket to avoid what McIntyre describes as the most difficult stage of the launch – the climb through the first 12km where the atmosphere is thickest.

Instead of a simple rocket, as in the case of Pegasus, Orbital Access’s aircraft has attached to its belly a 23m-long autonomous space plane. At the desired altitude, the aircraft releases the space plane, which then fires its rocket engines to propel itself at Mach 9 to an altitude of 90km. Here, the space plane releases its payload attached to small rockets, which then place the satellites into their orbits.

The space plane, designed to be fully reusable, then glides back towards the Earth using its 12m-wide wings and lands at an airport from where it can be picked up by the carrier aircraft ahead of its next mission.

McIntyre says the concept space plane had been developed with the Reaction Engines Sabre engine in mind. Although it will rely on traditional rocket engines in the early years of its operations, in the more distant future Orbital 500R could become a test platform for the innovative air-breathing rocket engine.

“The Reaction Engines Sabre programme is acting as a design constraint to our system,” says McIntyre. “We are now using traditional rocket engines we obtain from a former Soviet Union country, but we want to be able to replace them with the Sabre engine.”

Reaction Engines, McIntyre says, was involved in Orbital Access’s feasibility work in 2016, and the two firms maintain close communication to align their projects.

“I like to see our project as a technology roadmap that will take the UK aerospace industry into designing and building future generations of space planes based on incremental technological achievements in our programme and programmes that follow,” says McIntyre.

“This programme offers strategic opportunities for the UK aerospace industry and a long-term engineering roadmap for all the myriads of sub-system opportunities that emerge from the supply chain.”

Millard says the current generation of UK rocket builders, unlike its predecessors that built the Black Arrow, is benefiting from a completely different political climate.

The launch of Prospero in 1971 was the beginning, but also an end for British rocketry for the subsequent 40 years.

In parallel to the Black Arrow, the UK also participated in development of the first European launcher, Europa. The Blue Streak missile served as the vehicle’s first stage. Marred with failures and technical problems, the Europa programme was eventually scrapped. Europa’s final flight took place only about a week after the final flight of Black Arrow.

After that, the European countries reorganised their efforts and moved towards the eventually very successful Ariane programme. At the time, the UK government decided rocketry was not for them and focused on building satellites instead.

“We provided the clamps to stop Ariane rockets from being launched prematurely,” Millard says, chuckling at historical facts. “They were the old Blue Streak clamps. We also provided the guidance computer. The whole Blue Streak episode scared successive British governments and the permanent civil servants, so anything that was rocket-related was a no-no.”

Led by the French and Germans, Ariane went on to become one of the most reliable and sought-after launchers in the world.

The UK government, as well as the new generation of British rocketeers, now hope the Black Arrow fiasco can be replaced with a new and more successful chapter.