Translated with DeepL
There will be more space stations in the future. We must therefore expect more soot and rocket debris in space. How do you assess the risks here?
Due to the commercialisation of access to space, traffic in low Earth orbit (LEO) is becoming increasingly dense. Knowing that more than two thirds are Starlink satellites from SpaceX, and there will be even more with the ongoing Amazon Leo programme, which plans about 3000 satellites to start with. The situation is definitely not environmentally friendly, and all these satellites will also be scrap in the future.
What will happen if we don't take countermeasures?
If we don't develop new technologies to capture junk now, a "Kessler syndrome" could lead to an uncontrolled state. This risk also increases exponentially if we continue to shoot up such numbers of satellites. This is a cascade effect of collisions triggered by a single uncontrolled collision - and could make space virtually unusable.
Are there concrete figures on space debris?
Yes, and they are alarming. There are over 40,000 pieces that can be tracked - old satellite parts, old launch vehicle parts and so on. In addition, there are over 1.2 million parts that are larger than 1 centimetre - 50,000 of which are even larger than 10 centimetres - and cannot be controlled or tracked.
The satellites fly at around 27,000 km/h in low earth orbit - even the smallest parts under 1 centimetre can become projectiles. At these speeds, even a tiny piece of scrap becomes a serious threat.
How long do these objects stay in space?
Nowadays, satellites in low Earth orbit have a requirement to make a controlled departure from orbit within five years. They are either manoeuvred into the Earth's atmosphere to burn up or are decommissioned in a so-called "graveyard orbit". If the satellites have no active control to remove them from their orbit, it can take up to 25 years for them to burn up.
What is Switzerland doing about space debris?
Switzerland is a pioneer in this area. The Lausanne-based start-up ClearSpace has developed a satellite that approaches larger, trackable pieces of scrap, captures them with a robotic system and steers them into the atmosphere in a controlled manner, where they burn up. Technologically fascinating, but currently not economically viable, as one satellite is needed to capture another.
ESA, on the other hand, is working with its Clean Space Group to promote such technologies and raise awareness of the need for international regulation and continuous monitoring. The ESA also publishes an annual space environment report with detailed information.
How must satellites develop in the future?
There is an urgent need for more intelligent satellites. In order to cope with heavy traffic without collisions, satellites will need automated control directly on board in future so that they can react more quickly without first sending signals to earth and uploading commands. At speeds of 27,000 km/h, every second counts. Added to this is the increasing light pollution of the night sky due to satellite light reflection and signal interference. There are global UN guidelines in the area of "Dark and Quiet Skies" to curb this. For example, with darker colour coatings and communication control to enable our astronomers to continue long-term observations (e.g. deep sky).
These satellites are both a blessing and a curse. How do we solve this?
This is indeed a dilemma. Today's satellites enable a continuous communication and internet network that serves both the consumer society and the economy. In addition, it is central to earth observation in order to observe, analyse and understand weather and climate processes as well as changes and to issue alerts at an early stage. This is a real benefit for society.
The geostationary satellites at an altitude of 36,000 kilometres - known as GEO - are used for navigation and localisation on Earth with constellations such as GPS, GLONASS, Beidou or Galileo. Today, these services are essential for our modern society.
But the consequences of climate change are no longer just terrestrial. They also affect space, and vice versa, space has an impact on our climate. We need to keep both in mind and act responsibly.
What do we need for the future?
We definitely need more international cooperation and regulation. ESA is doing important pioneering work here, but ultimately space is a global common good. Only if all nations and all private stakeholders work together can we get to grips with the problem of space debris.
With innovations such as ClearSpace and the wooden satellites, Switzerland shows that small countries with good ideas and technologies can play an important role. But we need global standards, continuous monitoring and the willingness of everyone involved to take responsibility.
However, we must also bear in mind that space technology usually has a dual-use application. It can be used for both civilian and military applications. This is why independent geopolitical access to space is so important for Europe and Switzerland. Equally fundamental is the sovereignty over the data, the resilience of the systems and the knowledge of who, what, when and where is flying over Switzerland. This allows us to get a complete picture of the security of our society.
Read part 1 of the interview series here: "New Space" - The new era of space exploration
