The importance of space for our security and economic prosperity grows with the number of assets we deploy there. There is a lot to be gained by placing infrastructure in space—it’s an excellent environment for scientific research, Earth observation, and communications infrastructure. As more spacecraft orbit our planet, more opportunities for the creation of dangerous space debris arise. Currently, an estimated 8400 tons of debris are in Earth orbit. That’s a lot of mass moving very quickly, with a high potential for damage.
All space agencies have an interest in decreasing and mitigating the risks associated with space debris and space collisions. The European Space Agency has devoted a large amount of resources to ensure the security of space assets. In March, ESA, together with the European Centre for Space Law, hosted the ESA-ECSL Space Debris Regulation, Standards and Tools Workshop. We had the chance to attend and give you some insights into the proceedings and their implications for space safety!
The ESA-ECSL Space Debris Regulation, Standards and Tools Workshop
The workshop took place at the European Space Operations Centre in Darmstadt, Germany. This is where ESA controls its space assets from, and it was a perfect setting for a workshop focused on limiting risks to space operations. 159 participants from industry, international organizations, and national space agencies gathered from around Europe, as well as places as far away as the Middle East, the Americas, and Asia. Together, the participants explored the legal framework surrounding space debris mitigation and active debris removal, non-binding standards for being “good citizens” in space, and tools offered by ESA to assist interested parties in implementing these standards.
Europe’s Space Strategy for Space Debris Mitigation
In Europe, ESA plans to reflect the interests of its member states in the area of space debris with its new Space Safety Program. The program focuses on detecting and potentially eliminating space-based hazards. In the area of space debris, efforts concentrate on European-based space debris detection and tracking capabilities.
Beyond the detection and tracking of space objects, ESA also strives to limit the amount of space debris produced. This is accomplished in part by providing technologies and standard for the safe disposal of satellites after they have completed their missions, as well as tools for planning all stages of a spacecraft’s lifecycle. Several of these tools were introduced at the workshop and are readily available via ESA’s Space Debris User Portal. They cover all stages of mission planning and verifying compliance with ESA space debris mitigation requirements, from collision avoidance and modeling atmospheric re-entry. Tools that help simulate impacts and collision avoidance maneuvers are also available.
Interview with Holger Krag, Head of the ESA Space Safety Program
At the workshop, the Astropreneurs took the opportunity to talk to Holger Krag, the head of the ESA space safety program.
Astropreneurs: Dr. Krag, how would you characterize the significance of this workshop?
Holger Krag: The significance is clear: international law is in place and asks states to supervise the space actors in their countries. This is normally implemented by defining a national legal framework in the space faring countries. For that to work well, actors in the space sector from industry and the public sector need to understand the legal framework. They also need access to tools that help them comply with it. Everywhere, but in Europe in particular, there are many benefits to have from harmonizing the regulation while under development. Europe is a special region with many member states which offer a single market for the space industry. It makes it easier for industry if the various national regulations are consistent. We are also interested in seeing high and best standards everywhere for the sake of the environment. ESA also would like to ensure that good tools for planning and executing missions that comply with space debris avoidance and mitigation legislation are available and this workshop is part of our contribution in that area.
Astropreneurs: How do you characterize the effects of commercial spacecraft and small spacecraft on the likelihood of collisions in orbit?
Holger Krag: Until a few years ago, small spacecraft such as cubesats used to produce a lot of worry because they’re difficult to track and often have no maneuvering capabilities. This means that when launched to an orbit shared with other spacecraft, they have no means of avoiding collision, the onus is on the other spacecraft controller. In the beginning, when cubesats were launched on flights of opportunity, they were in high orbits that degraded quite slowly. Now, the economies of scale have actually come to our aid. With the high number of cubesat launches, commercial launch providers tend to use dedicated launches for cubesats and release them at low altitudes. It’s the same situation when cubesats are launched from the International Space Station. The low orbits mean that there is much more drag than at higher altitudes, so cubesats tend to deorbit quickly, clearing the way for new spacecraft.
Astropreneurs: And spacecraft disposal? With the space industry so crowded, are the various companies playing according to the rules?
Holger Krag: Spacecraft disposal is an issue. Of course, every company has a vested interest in the preservation of the space environment. However, with so many missions taking place, the risks of accidents increase despite the best of intentions. Large constellations at 1200 km altitude could be disastrous if they don’t deorbit properly. By most national regulation, spacecraft must deorbit cleanly after 25 years at the latest, but often there aren’t any consequences if an operator acts in good faith and nonetheless fails to dispose of their satellite. We’re optimistic that orbits will be cleared as planned, but it’s too early to say that that will work consistently.
Astropreneurs: We’ve focused so far on low Earth orbit, but a lot of communications infrastructure is in geostationary orbit. Are you worried about the geostationary ring getting crowded?
Holger Krag: In geostationary orbit, the strategy is to push retired satellites into the so-called graveyard orbit, located higher than geostationary orbit. It would simply be too expensive to bring a satellite from geostationary orbit back to Earth, too much fuel would be required. It’s not a perfect solution, and it was never meant as a permanent one, but so far, we’ve found no other viable option. Nonetheless, it doesn’t look like we’ll have problems with collisions in the graveyard orbit any time soon. Low Earth orbit is so much easier to reach that it’s much more interesting commercially, and plus it’s a much smaller space to move around in. This means that the collision risk there is 10,000 times higher than in geostationary orbit. That’s why most of our effort goes into mitigating risk there.
Astropreneurs: Do you see a lot of opportunities for space entrepreneurship in the area of space safety?
Holger Krag: Oh, certainly. You hear a lot of hype around active removal, and there are reasons to be optimistic that this will work well. It’s probably necessary for the public sector to provide funding and guidance in developing these technologies. Space is a competitive environment and so companies can’t afford to invest huge sums in research and development out of the goodness of their heart. But many companies have interest and capabilities, so with the proper conditions a lot could happen there.
The area of spacecraft servicing has perhaps more opportunities than active removal. Why bring down a good satellite just because it’s had a few problems? Companies specializing in servicing other satellites, keeping them alive and on orbit, will likely find many customers in the year to come.
Where can I learn more?
ESA provides some excellent resources on space debris, including answers to frequently asked questions, videos on space debris and how it makes its way back to Earth, and explanatory material concerning ESA’s space debris activities and space safety activities.
Posted by Daniel Lee