Orbital Launch Vehicles
The first orbital launch of a UK rocket in 50 years is set to take place in the near future, making this one of the most exciting times to be involved in the UK space industry. When this historic moment takes place, the launch vehicle will make its way into space from British soil, but what is an orbital launch vehicle?
What is an Orbital Launch Vehicle?
An orbital launch vehicle is a rocket-propelled vehicle, used to deliver a payload from our planet into the Earth’s orbit, or to other planets. These payloads deposited into orbit or beyond can range from satellites to spacecraft to interplanetary probes. Payloads like these are crucial for the wellbeing of those of us on Earth, providing vital Earth Observation data.
How Do Orbital Launch Vehicles Work?
The launch of an orbital vehicle is a complex process that requires collaboration between several factors. Fuelled by either solid or liquid rocket fuel, an orbital launch vehicle is launched by a propulsion system. Simply put, we can consider rocket propulsion to be like letting the air from a balloon. An inflated balloon does not move, however, when a hole is made in it, air releases and creates pressure on the outside of the balloon which pushes it forward. The pressure which moves the balloon forward is called thrust, a phenomenon that occurs on an increased scale when the engines of a rocket propulsion system are fired.
Once an orbital launch vehicle reaches space, it again utilises thrust to reach its desired location. The fuel used to launch has burned off by this point, meaning that most of the technology in the vehicle, such as tanks, pumps, and some engines is useless. Thus, to avoid carrying this unnecessary weight, multiple sections tend to drop off and fall back to Earth, leaving only the stage which houses the payload. This section of the vehicle then releases the payload into its desired orbit.
Types of Orbits and What They’re For
Launch vehicles are used to deposit systems into orbit, and the extent to which these systems will help those of us on Earth is vast. The orbit of Earth is the curved path that an object in space follows to move around the planet. Different types of orbit allow systems to fulfill different objectives. These orbits include geostationary orbit (GEO), low Earth orbit (LEO), polar orbit (PO), and sun-synchronous orbit (SSO).
Geostationary orbit is utilised by satellites that need to be stationed above one particular place over Earth. This means Earth-based antenna can consistently point to this satellite and benefits telecommunication and weather monitoring satellites which generally serve a specific area of the Earth. Satellites in this orbit cover a large portion of Earth due to its situation far from the planet meaning that few satellites are required to achieve global coverage.
Low Earth Orbit is situated close to the surface of the Earth, at an altitude of less than 1000km. This is a commonly utilised orbit, with a multitude of possible satellite routes due to the LEO’s ability to deviate from just one path around the Earth. Most often, this orbit is employed for satellite imaging as its proximity to Earth grants higher resolution images. This is also the orbit in which the International Space Station is positioned, offering easier access to space for astronauts, again due to its proximity to Earth.
Polar orbits are a subset of low Earth orbits, sitting at altitudes between 200 and 1000km. Within the definition of polar orbits is sun-synchronous orbits (SSO), sitting between 600 to 800km from the Earth. Satellites in this orbit remain in the same position relative to the Sun, hence always passing points at the same local time. This is advantageous for satellites looking to capture images to be compared across time, such as the monitoring of weather patterns, natural disasters and climate change.
A Famous Launch Vehicle – Black Arrow
The Black Arrow programme placed the first UK-designed and manufactured artificial satellite into Earth’s orbit. 1971 saw the successful orbital launch of this vehicle, which made use of previously established methods and technologies used by the Blue Steel Missile and Black Knight rocket. A total of 5 Black Arrow rockets were manufactured in the UK, with the fourth being the first to reach orbit and deposit the Prospero satellites into space.
Black Arrow was a three-stage, 13-metre-tall rocket, weighing 18 tonnes and with the capability to carry up to 135kg of payload into a Low Earth Orbit. The vehicle was designed for single-use and fuelled by a combination of Hydrogen Peroxide and Kerosene.
Sadly, the Black Arrow project was cancelled on the 29th of July 1971, with the fifth rocket never to be launched due to a lack of funding. This leaves the UK as the only country to successfully institute a programme catered to small satellite launches but discard it. Skyrora hopes to pick up where Black Arrow left off.
Great Strides in Orbital Launch Technology
The first orbital rocket was launched from Kazakhstan in 1957, carrying the Sputnik 1 satellite. This was followed closely by the Juno I vehicle with Explorer 1 onboard, launched from Cape Canaveral in 1958. Since these early launches, and ever since the launch of Black Arrow, the technology and capabilities housed in orbital launch vehicles have grown exponentially.
This improvement ranges from the in-orbit capability to the wider environmental impact of these vehicles. Skyrora’s orbital launch vehicle technology demonstrates this improvement. The use of Ecosene fuel aids the overall environmental clean-up mission, recruiting the necessary technology to enable the conversion of unrecyclable plastic waste into high-grade Jet-A1 aerospace fuel. This fuel also facilitates the reduction of CO2 emissions in fuel production and in the launch.
Skyrora’s Space Tug technology housed in the upper stage of our orbital launch vehicle provides a solution for clearing orbital debris, as well as correcting satellite or spacecraft orbit, de-orbiting space debris, and refueling satellites or spacecraft, and carrying out lunar orbits or interplanetary missions. Alongside this accompanying technology, Skyrora demonstrates innovation in the development of our orbital launch vehicle itself.
Skyrora’s main orbital launch vehicle, the Skyrora XL, is hoped to launch in the near future. Standing at over 22m tall, this orbital launch vehicle can carry up to 315kg of payload and deposit it directly to its required orbit. The vehicle which utilises proven technology inspired by the previous Black Arrow Programme, uses the liquid bi-propellant combination of HTP (hydrogen peroxide) and kerosene, soon to be eco-friendly alternative Ecosene. Stage three of the Skyrora XL hosts our space tug, boasting in-orbit maneuverability and servicing capabilities. The payload module in this vehicle is comprised of two halves, each consisting of a 3-layer composite shell, which are released by push-rod springs once the desired altitude is required and payload can be deposited by the third stage.
Skyrora is excited to present XL as a means to get the UK back into space for the first time in 50 years!
European Space Agency. (2020). Types of Orbits. Available: https://www.esa.int/Enabling_Support/Space_Transportation/Types_of_orbits#GEObits. Last accessed 23rd March 2022.
Skyrora. (2022). Technology. Available: https://www.skyrora.com/technology. Last accessed 23rd March 2022.
Skyrora. (2021). The History of the Black Arrow Rocket Programme. Available: https://www.skyrora.com/post/the-history-of-the-uk-black-arrow-rocket-programme. Last accessed 23rd March 2022.