More and more miniature satellites are being launched every year, which is driving demand for smaller rockets.
Modern life would hardly be possible without satellites. Much of what people do on Earth today depends largely on what happens high above their heads — from monitoring wildfires, deforestation, and sea surface temperatures to enabling connections to new mobile technologies like 5G in hard-to-reach areas.
The recent wave of cheaper mini-satellites being sent into orbits as low as 500 to 1,000 kilometers above Earth by the likes of Elon Musk’s SpaceX and UK-based OneWeb points to a growing trend.
Less is more
With some tracking the entire area of Earth and providing unprecedented detail, these satellites can be the size of a shoebox or even smaller. More than 2,500 They are expected to be launched every year on average over the next decade.
To get to space economically, small satellites often need to share rides on large rockets. Developing smaller rockets could allow for faster and more personalized access to space, opening the market to a broader range of specialized providers.
said Xavier Llairó, Chief Commercial Officer and Co-Founder of Pangea Aerospace in Barcelona, Spain. “The companies that launch these, you need dedicated access to space.”
the RRTB The Pangea-led project has been examining cost-effective ways to put small rockets that can carry up to 500 kilograms of cargo into space. We hope to have an engine ready to fly by 2025.
The key is finding ways to reuse these precision launchers by reducing the impact they have on re-entry into Earth’s atmosphere and by enabling them to land safely. This would also be more environmentally friendly than just using launchers once.
“By reusing, you can lower the investment, use less means of production and increase the frequency of launches,” Llairó said.
For now, Europe lacks a proven way to do this, according to the RRTB, which ends this month after three years.
RRTB focused on reusing the first part – or stage – of the missile at its base. This section provides most of the thrust immediately after launch, before separating and returning to Earth, often in the ocean. With a lighter payload, the rocket’s other stages compress to move their payload into orbit.
But the first stage can be damaged during its high-speed descent through the Earth’s atmosphere and also by seawater. The difficulties and costs of recovering and returning the missile to the launch site may be more trouble than it is worth.
“When they fall into the sea, it makes reuse very difficult,” Llairó said.
The answer is to find a way for the first stage to safely re-enter Earth’s atmosphere and land at a docking station near the launch site or on a floating barge, according to Ellero.
At the same time, the design of the missile needs to be allowed to carry a large enough payload to make operation economically viable.
To find ways to minimize damage to small bombers during re-entry into Earth’s atmosphere and landing, the RRTB team tested a scale model of a small rocket in a wind tunnel.
The ideal goal for smaller bombers, according to Llairó, is to avoid firing the engines in order to re-enter. This would allow bombers to carry a larger initial payload by reducing the weight of fuel they needed to carry.
The team struggled when the rocket had a traditional bell-shaped nozzle around its engine, but found more hope in a conical shape. This “aerospike” nozzle helps spread heat in a way that reduces knocks to the vehicle.
“It makes penetration into the atmosphere much smoother,” Llairó said. “This is valid not only for small launch vehicles but also for larger ones. It was an unexpected find because we weren’t initially looking for this.”
While bicycles also burn less fuel than conventional engines, Llairó said those benefits have so far been offset by the complexities and costs of engineering them, including cooling difficulties. However, technologies such as 3D printing — which Pangea is harnessing — make it more viable.
“Aerospike technology will change how we get to space and how we return to Earth,” said Llairó. “It’s a major enabler of missile reuse.”
Meanwhile, he said the engine the team plans to use will rely on methane from biological sources as propellant.
An endeavor is also underway to make individual rocket parts more reusable, for example by using an aluminum-based material for the fuel tanks.
“You need to get most of the missiles down safely and reuse as many of their components as possible to make things economically viable,” Llairó said.
Preparing to launch
While RRTB has focused on rocket reuse, UK aerospace company Orbex is preparing to launch its own small, lightweight and environmentally friendly launcher.
under prime Project Orbex in May last year unveiled a prototype of its 19-meter rocket – it’s set to be Europe’s first full orbital small launcher for small satellites.
The missile is also designed to be reusable by recovering parts that do not burn up in the atmosphere. While the company has yet to reveal how to do this, an Orbex spokesperson said the method would be “completely new.”
The company hopes that the Prime rocket will be able to launch for the first time this year, pending some prerequisites including the granting of a launch license.
“We have sold a number of launch slots to commercial satellite providers, but we have not yet announced our inaugural launch date,” said Chris Larmor, CEO of Orbex. He was also the coordinator for PRIME, which ran for three years until June 2022.
The rocket will use clean biofuel formed as a by-product in the production of biodiesel, made from sources such as waste vegetable oil and used cooking oil.
This would be combined with liquid oxygen, a “cooled propellant” – a gas cooled to near-freezing temperature and condensed into a highly combustible liquid.
Through these measures, the missile can Reduce carbon emissions by up to 96% Compared to similar sized fossil fuel powered launch vehicles.
“Orbex Prime is set to be the most environmentally friendly space rocket in the world, powered by renewable biofuels,” said Larmour.
The fuel tanks are made of carbon fiber which combines high strength with light weight.
Orbex estimates that Prime weighs about 30% less than conventional launchers, enabling the kind of high efficiency and performance critical for small satellites. Furthermore, the rocket is designed to leave no debris on the ground and in orbit.
At its spaceport in Sutherland on the northern coast of Scotland, the company expects to be able to launch up to 12 rockets a year. The port is also expected to be carbon neutral in its construction and operation.
Its relative proximity to Glasgow will help benefit the region’s thriving space industry, as the city produces more satellites than anywhere else in Europe. Orbex believes this will provide the right setup to help zone players fly.
“The satellite industry and its requirements for launchers that can put satellites into specific orbits have grown in recent years and continue to grow exponentially,” Larmore said. “This creates a huge demand for dedicated, sustainable launches.”
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