Europe's Themis Reusable Rocket Prototype Installed on its Launch Pad
'Combined Tests' on the Ground will Lead to First Flight
Since its arrival at Sweden's Esrange Space Center in June, ArianeGroup teams have completed the integration of the Themis prototype. It was then transferred to the Launch Zone and erected on its launch pad.
This milestone marks the beginning of the 'combined tests', during which the interface between Themis and the launch pad's mechanical, electrical and fluid systems will be thoroughly trialed, with the aim of completing a test under cryogenic conditions.
These 'combined tests' will subsequently lead to a first low-altitude flight test including lift-off and landing ('hop test') carried out as part of the European Union SALTO program.
Themis is a European reusable main-stage demonstrator developed by ArianeGroup under a contract with the European Space Agency (ESA). Standing 30m tall and equipped with a 100-tonne thrust class reusable engine, Prometheus, Themis is similar in dimension to a medium/heavy launcher.
According to ESA, the first Themis flights will be from Europe’s launch center in Esrange. The first flight will be a small “hop”, where the engine will fire continuously but at varying ‘throttles’ – this in itself will be a first for Europe with the use of cryogenic propulsion. Flying up to 100 m (≈330 feet) on its first trip towards space, the hop-test is a significant milestone and allows engineers to focus on the critical landing and ground sequences for such a rocket.
Themis will have a busy landing, as the mission designers want to recover any excess fuel in the light-weight stainless steel tanks as quickly as possible after touchdown to avoid any possible incident that could damage the landing pad.
Themis is designed to touchdown on land within an area of just 20 x 20 square meters (≈215 square feet) where a swarm of robots will be on standby at the landing pad to scuttle to the rocket, connect hoses and pump out the leftover fuels.
Themis will also demonstrate technologies needed for more sustainable rocket operations, such as the use of ‘biomethane’ – methane derived from renewable sources – to power its flights and any release of gaseous methane in the atmosphere will also be avoided with the robotic swarm of robots to recuperate any unburned methane.