In Conversation with space physicist, Minna Palmroth

Minna Palmroth leads the Finnish Centre of Excellence in Research of Sustainable Space and is also affiliated with both the University of Helsinki and the Finnish Meteorological Institute. She says that the low earth orbit is critical for maintaining life as we know it, and that sustainability is as much of an issue there as it is on earth itself.

Text: Lara McCoy Photo: Wärtsilä

1. What is the intersection between Wärtsilä’s work and sustainable space?

Wärtsilä is interested in autonomous shipping as part of its future vision and if you’re going to send ships to sea without crews, then that has a space angle because the signal that commands the ships comes from the space environment. 

2. Who are the biggest users of the low-earth orbit? 

Fifty years ago, during the Cold War, the biggest users of space were military and defence satellites. Defence and military are still one large group using space, but for example in 2017, over 70% of satellites launched were commercial. These commercial-use cases are broadcasting, navigating and positioning to, for example, track ships at sea, communicate and undertake different earth observation tasks like monitoring the ice. 

3. How does space weather affect satellites? 

As shipping companies are interested in the environmental conditions on the seas where they send their vessels, a spacecraft can be considered as a vessel in a heavenly sea. The space that the vessel is traversing is not empty; it is full of material and this material is in dynamic change. There is weather in space as there is weather on earth, and this weather can sometimes be so bad that it deteriorates the spacecraft. It can even cause the spacecraft to malfunction, so the weather itself sometimes creates space debris.  

4. What do you see as the greatest threats posed by ‘space junk’?

Space is already now holding over 8,000 tonnes of space debris and the usage of space is increasing. There are many companies that are already sending spacecraft and many companies are wondering if space could be used to improve their business. So, if this is going to continue in the future, the space debris problem needs to be solved. Otherwise the space environment won’t be available for future utilisation.  When a spacecraft is launched, it always produces waste, so now you have the spacecraft itself as well as the things used to launch it. Litter in space is increasing all the time and the more stuff you have in space, the bigger the risk it will threaten operations.  

5. Are there technological innovations you can foresee to help tackle the problem of space junk in the future?

You can divide space debris into two categories. The space debris that is already there and new debris that is coming from new launches. This division also creates the strategy for mitigation. The old debris is very difficult to dispose of, so difficult that it requires a huge organization like the European Space Agency or NASA. But the new debris, if we could prevent it, that would already be a good starting point. On way to do this is to prolong the life of the spacecraft so we don’t have to send them so often. The other is to add a de-orbiting device into the spacecraft so that when its mission is done, it can be taken out of orbit. There are basically two options here — to lift the spacecraft up to a kind of graveyard orbit or drop them down so that they burn up in the atmosphere. And, if they are too big to burn up in the atmosphere, to put them into a graveyard in the Pacific Ocean. There is already a zone in the South Pacific where there are hundreds of spacecraft. It probably does damage to the marine environment, but it’s a smaller threat on the bottom of the ocean than it is in orbit. 

6. What do you think the future of the low-earth orbit looks like?

In the old space era, you were more certain about the future because the only players were large organisations like NASA or the ESA. But now we have companies launching their own spacecraft and they have their own agendas that may not be so public. And, there are military satellites, which do not give their positions. So, I think that the future is more unsure. This is not just a technological or environmental problem, it’s also a regulation and diplomatic problem. We Earthlings have to agree on how to use space, so it stays useable in the future. 

7. Do you think there are lessons we can learn – or apply – from the use of the oceans in terms of sustainability, usage and international cooperation be applied to space?

Economists talk about the problem of the commons — if nobody owns an asset, everyone uses it until it is used up. There are numerous examples in history of how this ruins the environment. Nobody owns the oceans and no one takes care of them. You can see the same problem in space. Economists are thinking about this, and they say if you have an incentive, for example environmental taxes, this will decrease littering. 

But one thing I’ve been thinking is how the climate crisis has built a new market for clean tech. There is a market for renewable energy like solar cells and wind power because of the climate crisis. So, I’ve been thinking about how this could be applied to space. Could there be a market for cleaning space? I’ve asked lots of experts and economists and they say they can’t determine the size of this market, but probably it would be big.

Also, there should be a neutral body that everyone trusts and guidelines everyone accepts. 

The UN is a logical leader here. This is one place where a regulatory body could be established, but that’s not very easy. I think it is accepted now that we have a space debris problem, but the actual actions, what to do about it, is the question. My guess is that all the players will protect their own spacecraft first. But even this would be great. If you could make sure your own spacecraft is not a threat to anyone else, that would already be a great step forward.