Orbex secures international patent for coaxial rocket fuel tanks

This coaxial tank structure is central to the design of Orbex’s Prime rocket and allows for a uniquely low mass rocket that is around 30 percent lighter than similarly sized launchers while offering greater power, higher performance, and better economy.

Very small rockets, which copy the traditional `stacked` tank architecture of larger rockets, are less efficient and cost-effective than their larger counterparts as they carry much less fuel per unit of ‘dry mass.‘ This central inefficiency was the major engineering challenge that the Orbex team set out to solve with the Orbex Prime architecture.

The Orbex team created a unique answer to that challenge, by nesting the fuel tank within an outer tank of liquid oxygen. This tank arrangement has unique synergies with Orbex’s choice of bio-propane as a rocket fuel because bio-propane does not freeze solid when chilled to the same temperature as liquid oxygen. The coaxial tank structure thus removes surplus components and sub-systems such as insulation, extra bulkheads, external pipework, heavy tank walls and thermal conditioning equipment.

Orbex decided to use the renewable form of propane, bio-propane (that is chemically identical to propane) to deliver a sustainable solution for deploying satellites into Earth’s orbit. A study by the University of Exeter showed that a single launch of the Orbex Prime rocket will produce up to 96 percent lower carbon emissions than comparable space launch systems using fossil fuels. Prime is also a re-usable rocket which has been engineered to leave zero debris in orbit.

Prime became the first full orbital microlauncher rocket to be unveiled in Europe when revealed to the world in May of 2022. The rocket will launch from Sutherland Spaceport on the north coast of Scotland, where Orbex was granted a 50-year lease to construct and operate what will become their ‘home spaceport.” Orbex plans to launch as many as 12 rockets into orbit each year, providing a boost to the local economy and creating both technical and non-technical job vacancies.

The spaceflight company also secured £40.4 million in a Series C funding round led by Scottish National Investment Bank, allowing it to scale up its capabilities as it prepares for its inaugural launch. Orbex has already received interest from many commercial satellite manufacturers and has signed launch contracts for seven launches with six customers. Satnews