Isn’t it strange that we simply discard satellites when they run out of fuel or a component fails? ESA and European industry have joined forces to ensure our satellites are habitable.
In-orbit servicing (IOS) refers to extending the life or functionality of spacecraft already in orbit. This can be done by performing maintenance, adjusting a spacecraft’s orbit, changing its heading, adding more fuel, or changing or upgrading onboard equipment.
ESA has carried out extensive work at IOS as part of the Clean Space initiative to remove and prevent space debris. As part of this research, ESA Preparation invited industry stakeholders to outline their vision for Europe’s first IOS mission, which will be launched as early as 2028.
Astroscale, ClearSpace, D-Orbit and Telespazio (in collaboration with Thales Alenia Space) were funded to mature their ideas and present their results at ministerial level for the 2022 ESA Council.
“In-orbit servicing could fundamentally change the way future satellites are designed and operated. By 2030, satellites will need to be designed with interfaces and other features that will allow servicing and disposal spacecraft to do their jobs,” says Ross Findlay. IOS Systems Engineer at ESA.
Future satellites may carry less fuel and larger instruments. The option of in-orbit assembly means that future satellites can be designed to consist of modules that are easy to assemble and replace individually. For the same reasons as standard shapes for electronics’ plugs and sockets, discussions have already begun on standardized ‘docking’ structures to make it easier for a model servicing spacecraft to connect to different types of satellites.
In-orbit service is a commercial question
More than half of all satellites launched are commercial, so commercial operators need to be involved if we want to make servicing a standard procedure. “We made it a mandatory endpoint for all four teams to have some kind of relationship with a real customer who wanted to provide this service,” Ross notes.
“This has led to very interesting discussions between ESA and the companies interested in setting up the IOS missions, and the companies that own the satellites for the service. Take for example the legal implications: If two satellites collide while in service, who is responsible?”
ESA’s base operations readiness component is uniquely positioned to support these mission evaluation studies, including big-picture commercialization opportunities. “These activities and their contribution to the Ministerial Council meeting demonstrate the importance of the Preparation Program in supporting the realization of ideas,” says Moritz Fontaine, ESA Discovery & Preparation Officer.
The telecommunications industry wants life extension services
Four selected companies investigated the potential for IOS operation for satellites in Low-Earth Orbit (LEO) and Geostationary Orbit (GEO). LEO hosts important satellites such as the Hubble Space Telescope, the Copernicus Sentinel Earth observation satellites, and the International Space Station. GEO hosts Europe’s Meteosat series of weather satellites and, importantly, most of the satellites used for telecommunications.
A clear takeaway from the four studies is that the telecommunications industry wants to enable life extension services as soon as possible. Orbital maintenance is especially relevant: operators must make sure the spacecraft is exactly where it needs to be, and change its orbit or rotation if it moves over time.
Doing so will incur fuel costs. The instructions detail how to dock defueled satellites to a servicing spacecraft and perform the necessary orbit control. The servicing spacecraft can stay attached as long as needed, after which it places the satellite in a so-called ‘graveyard orbit’ and moves on to the next satellite that needs servicing.
Fresh eyes from New Space
Interestingly, three of the four proposals you have come from ‘new space’ companies. “These are new actors with slightly different ways of approaching design and development, often involving smaller teams and more rapid iterations. It was refreshing to compare different workflows and discuss possible forms of collaboration,” Ross says.
Following these four studies, ESA’s space safety program decided to move forward with two specific missions. The program envisions that IOS operations will continue to expand in terms of the number of missions and their capabilities. European industry aspires to make iOS standard procedure by the early to mid-2030s.