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!
ATV – demising as it was designed to.
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.
The distribution of space debris. Image: ESA.
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
Discussion: 4 comments
DfD is a waste of expensively produced and orbited material – and it can only apply to controllable hardware: active satellites.
But each new satellite launch also creates at least 4 items of uncontrollable junk – rocket stage, split fairing and nose cone – not to mention the microjunk: e.g. remnants of explosive fasteners.
Far better to “bite the bullet” and make an international collaboration for orbital workshops to refuel and/or refurbish “dead” satellites to reduce the number of required launches; and “space tugs” to collect the rest of the 8 kilotonnes of junk & debris for recycling (I have suggested on the Moon, to minimize the mass to be shipped from Earth for a lunar settlement}.
Dear Tony,
the solution is not as easy as you describe. For sure servicing satellites and use of reusable launchers will decrease the amount of junk left if space (or falling back into oceans such as fairing). Having said that, you cannot increase the lifetime time of a satellite forever and eventually they will die. And satellites fail.
Therefore design for demise remains a necessity
best regards
Luisa
do you know how mad max post apocalyptic world came about? It is because Australia is the dumping ground; we are going to have to crash stuff there; and then salvage it.
absolutely massive location to hit; people will need to be evacuated ; it makes sense to have rubbish going to one place; not into the bloody ocean :D
I was wondering, when a launch vehicle separates stages while still in a suborbital trajectory, they say that the abandoned stage drops and burns in the atmosphere. Can a huge first stage really burn up completely in the atmosphere? Does the metal from which the stage is made melt up and combine with stuff in the air completely? Or is there a chance for a relatively big chunk of spacecraft to crash into a town, for example? Is the ballistic trajectory of said spacecraft always calculated in such a way that it cannot hit a town, even if the stage has hundreds of KMs to go before it hits the ground? What if there is a stage failure?