By Jessica Delaval, ESA Clean Space Coordinator & Marco Trovatello, ESA Cross-Media Coordinator

On Thursday, 7 April, from 14:00 to 15:00 GMT (16:00 to to 17:00 CEST) the ESA Clean Space team is looking forward to answer questions via Twitter by using the hashtag #askESAcleanspace or tweeting to @ESAcleanspace.

Reaching for the sky leaves footprints on the ground. Through its Clean Space initiative, ESA is pioneering an eco-friendly approach to space activities. On the ground, that means adopting greener industrial materials, processes and technologies. In space, it means preserving Earth’s orbital environment as a safe zone, free of debris.

In the modern world, the quest to be environmentally friendly has been transforming the competitive landscape, as eco-friendly design turns into a new frontier of innovation. ESA is embracing this trend. Information on the environmental impact of Agency activities is, and will be, increasingly requested by ESA’s industrial, institutional and international partners, under pressure from customers, stakeholders and citizens.

Apart from general questions you might have with regard to Space Debris, eco-friendly design of spacecraft and satellites or space and environment, we would like to introduce a particular topic: Design For Demise – ‘D4D’ for the experts ;-)

The ESA experts who will answer your questions are:

Tiago Soares – Clean Space system engineer,

Antonio Gabriele – Earth Observation Programme system engineer,

Holger Krag – Head of the Space Debris office

Read more on D4D below or pose your general questions on a cleaner space to us this Thursday, starting 14:00 GMT / 16:00 CEST. Talk to you then!

Design for Demise is the intentional design of space system hardware to completely burn up or ‘ablate’ when reentering into the atmosphere. It is a technique under investigation through the CleanSat project. The objective is to decrease as much as possible the number of debris that a spacecraft will produce when reentering into the atmosphere.

What is the challenge?

Today’s space debris environment poses a safety hazard to operational spacecraft, as well as a hazard to the safety of persons and property on Earth in cases of uncontrolled re-entry events. As of November 2015, more than 5100 launches had placed some 7200 satellites into orbit, of which about 4100 remained in space; only a small fraction – about 1100 – are still operational today. These are accompanied by almost 2000 spent orbital rocket-bodies and a large number of fragmentation debris and mission related objects. This large amount of space hardware has a total mass of more than 8000 tonnes. More than 200 objects have meanwhile fragmented.

International guidelines applicable to future missions as well as domestic regulations in more than 20 countries worldwide state that at the end of their operational lifetime satellites and upper stages have to be passivated (i.e. internal energy sources have to be made safe) and need to be removed from protected zones (the Lower Earth Orbit (LEO) protected region, i.e. up to 2000 km, and the Geostationary Earth orbit (GEO) protected region).

These requirements will have significant impacts on future missions design and call for an evolution of the standard platforms, in particular in LEO. ESA’s answer to these requirements is the CleanSat project.

CleanSat, a project of the ESA Clean Space initiative

Clean Space, through its CleanSat project, aims at providing the technical solutions to promote the compliance of ESA’s future missions with the debris mitigation requirements as well as to actively removing space debris from critical regions.

In doing so, Cleanspace enables a European response to worldwide market demand for SDM*-compliant solutions through a new generation of LEO platforms.

An attractive solution is offered by Design for Demise, i.e. the intentional design of space system hardware so that it will completely burn up during uncontrolled atmospheric reentry as a means of post-mission disposal, in order to reduce the number of surviving parts that reach the ground and the associated casualty risk.

*SDM = Space Debris Mitigations