Since 2006, Dr. Holger Krag has been a Space Debris Analyst in ESA’s Space Debris Office located in Darmstadt, Germany. He has worked on establishing risk models and a collision avoidance system as well as contributing to the first space surveillance studies. In 2014, he was appointed Head of the Space Debris Office, which, among others, provides fundamental support to ESA’s then-Space Situational Awareness Programme. In 2019, he took over the position as the head of the programme and led its evolution into the new Space Safety Programme, which was established by ESA in 2019.
In 2022, Dr Holger Krag was presented with the T.S.Kelso award by the Space Data Association (SDA), in recognition of his outstanding contributions to space flight safety. We caught up with Dr Holger to discuss his distinguished career path, the most significant industry developments, and his thoughts on current STM regulation.
1. How did your career path lead you to your current role as a Space Safety Program Manager at ESA?
As a young Aerospace Engineer 25 years ago, the topic of space debris didn’t excite me too much. I felt it was too specialised and couldn’t offer me the flexibility I wanted. It was my professor at the time, who was head of the scientific sub-committee of the UN Committee on the Peaceful Uses of Outer Space and renowned in the subject of space debris, that convinced me to reconsider. And I’m glad I did. The topic has accelerated significantly over the years, as more and more severe events in space have happened. Events such as anti-satellite tests, and more recently, the collision between Iridium and Cosmos, have changed perceptions dramatically, enforcing States to act with greater authority than in the late 90s.
I quickly realised that the European Space Agency (ESA) is an agency that takes this topic very seriously and one of the earliest players in the community. When the ESA opened a space debris office, I successfully applied for a position. The role was to make operations safe, implementing collision avoidance for the ESA space missions flown and operated from Darmstadt. I later went on to become the head of the Space debris office.
During this time, the office helped preparing a program for space situational awareness The programme looked at uniting European forces in order to advance topics of space surveillance and space debris, space weather and planetary defence. 4 years ago, I became the head of this programme and to my satisfaction, the states in Europe are taking the space debris problem extremely seriously, so much so that the amounts subscribed to the programme have increased from a starting point of 100 million to 730million, which is quite a statement.
Looking back, you could say I was somehow lucky in having specialised early enough in a topic now of great relevance and I now have the pleasure of implementing a programme to tackle this problem.
2. What are the most significant developments you have seen in orbit during your career?
If I had to pick just one, it would be what we have observed in the last 3-4 years – The revolution of space.
Space was something for the public, scientific, and military sectors over the past 60 years but now we have discovered it to be economic space. A place where you can run businesses by operating space crafts, not only in the geostationary orbit but also in LEO, in a way that was not imagined 5 years ago.
We have witnessed a radical change in how we do space flight. Space traffic has moved from public to private hands and launch rates have increased by a factor of 15, which is a revolution.
Of course, we see lots of worrying trends too, but that has come slowly and steadily. Anti-satellite tests, fragmentation events, and collisions, which were predicted in the ’80s and ’90s and are now happening – they come with a poor rate of implementing mitigation and prevention options. Although they were formulated 20 years ago, you will find the success rate is small.
The combination of a poor success rate in preventing debris in combination with the rise in space traffic is another worry. However, space debris can now be tackled with technical solutions that provide active removal and increase prevention. We are seeing certain countries update regulation which is having a positive impact on making these activities happen. This has all happened in the last 5 years, which is quite some development in this field. I believe that if we bring the technology, we will also see more bold moves in intensifying regulation.
3. Do you feel there is enough legislation in place to manage STM?
The simple answer: No.
You won’t find the word “space debris” mentioned in any of the space laws because they were all created in the 60s and 70s. Implementing new legislation on an international level is difficult, so it usually falls on member states to handle regulation. And while many state regulations talk of space debris and mitigation measures, we still see several dozens of space objects stranded each year without removal. We are still seeing at least 10 breakups happening each year and several objects remaining on orbit while they should have been disposed onto lower orbits. This is far too much, and more than expected.
However, it is difficult to implement this kind of regulation with current technology. This is something I’m convinced of because nobody is ignoring the issue today. Everyone wants to try to dispose spacecraft and wants to make sure the spacecraft gets passivated at the end of the mission, but this can fail, because after years in space, the whole space system could suffer from a complete loss of function over the long time in space. When this happens, even with the best intentions, you cannot implement these measures anymore. What we need is robustness to make sure that our space systems and these mitigation actions are failsafe. They need to work under all circumstances, but again, this requires technology to enable this and regulation that asks for this.
Therefore, we are proposing a regulation that works similarly to rules in a National Park – what you bring in, you need to take out. We call this the “zero debris approach”: Independent of the root cause of why certain debris prevention actions didn’t work, the end result must be that the object is removed, which would imply that active removal becomes mandatory. This is what we are working on in ESA and will apply to our own missions in the future. I think this zero debris principle would really advance mitigation and should become a common rule.