Ng Zhen Ning — Lucy in the Sky with Debris

Conversation with Ng Zhen Ning, Co-Founder and CEO, NuSpace

Interview conducted on
15/06/2023

Speakers
Ng Zhen Ning (ZN), Isabella Ong (IO), Seet Yun Teng (YT)

NuSpace is a Singaporean nano-satellite company that aims to be the go-to small satellite service provider in the Asia-Pacific region, providing Satellite-as-a-Service (SatAAS) and satellite-based Internet of Things (IoT) connectivity. NuSpace was founded in 2018, when its co-founders realised that there were few companies in Asia that knew how to design satellite missions. Prior to setting up NuSpace, Zhen Ning was a research engineer in NUS developing Cubesats, a ground station engineer involved in ground operations and payload operations. He formerly worked in the defense industry also focusing on satellite development.

Could you tell us how Nuspace started and your core area of expertise?

NuSpace started as a spin-off of National University of Singapore, where I was a researcher dealing with small satellites. Our core capability is building and integrating small satellites, which we felt that there was a lack in such commercially available capabilities within Asia Pacific. In late 2018, we spun out from NUS, and that's how NuSpace was born. Today, NuSpace is a small satellite company building satellites to provide IoT connectivity to remote areas. Our goal is to build a network of satellites that can help to relay IoT data from different parts of the world.

The driving force behind this is a personal experience I had on a trip to the Grand Canyon where I faced problems calling for help. It made me realise that even simple connectivity, just pinging for help and sending out a message, could have made a significant difference. But on a grander scale of things, the connectivity that we're aiming to provide is application-agnostic. It can be used for tracking people for personal safety, for monitoring trees in the rainforest, deployed in life-saving vests and so on. We believe that the impact that can be delivered is huge because connectivity is important. In some ways, we are like a telco service provider (such as Singtel, M1, Starhub) where we provide the infrastructure and the connectivity, but we work with application service providers to use our network.

There are other such service providers in America and European regions, but they're not coming to APAC. So when we launch our satellite NuLion in July, it's actually going to be the first in Asia Pacific to be able to provide this kind of connectivity.

Could you share more about NuLion, and the impact of one nano-satellite versus a group of them?

It's scalable in the sense that with one satellite, we can already provide connectivity, but the quality of service is not as good as compared to a constellation of satellites. With one satellite, depending on the location of the sensor and its orbit, you could get up to 15 updates per day. With 15 daily updates of about once every 100 minutes or so, you could serve some applications such as forestry monitoring or simple wildlife tracking. But if you're trying to do something that's a little more real-time, for example, flood monitoring where you need to inform the authorities immediately when rising water levels are detected, then you would need more satellites, because with more satellites, the update rates are increased. Hence, it depends — with one satellite we can already provide connectivity, but with more, we can achieve better quality.

Is there a reason why you chose to focus on small satellites and not big ones?

There is always an engineering trade-off between small and big satellites. Big satellites are extremely capable, but the approach and methodology used by the industry is rather dated. Because big satellites are so expensive, typically stakeholders would want to make sure that the satellite really works. To do so, you would use components that are radiation-hardened or have had flight heritage testing in space. As a result, the technology that's used on it can be limited. Just because certain chips have been launched in space and they can confirm its effectiveness, they would want to use the same chip again, even if the technology might be 10 years old and hence not updated.

On the other hand, small satellites can accommodate more trial and error. Their lifespan is much shorter, but you can put new technology on them. Typically, you would just require the satellites to work for 3 to 6 months, or up to a year. Big satellites require at least 5 years because of the amount that is invested in it. However, nowadays, the small satellites are starting to catch up because of how people are testing and experimenting with small satellites. The lifespan of small satellites can now stretch to 3 to 5 years, and they are very comparable to big satellites. At the same time, the cost is still manageable. I decided that since there are already big satellite providers in the market and the upfront capital expenditure of big satellites is much more, small satellites are the way to go. The barrier of entry is much lower, and it was something that I was already researching in university.

Are small satellites the focus of Singapore's space industry or are there players who are developing larger satellites?

There are both. The large satellite developers include ST Engineering, who are building big satellites of 100kg and above. From a policy making point of view, Singapore's space ecosystem is looking at both small satellites as well as big satellites. But at the end of the day, it's always about what kinds of applications can be derived from space technology. The satellite is just a means, and if you don't have a killer application, you’re going nowhere.

How do you see Singapore’s space ecosystem currently, and where do you think it will develop in the future? What are your thoughts about the new space race moving away from military needs towards commercialisation, and do you see this shift happening in Singapore as well?

In my opinion, right now, the local space ecosystem is geared towards serving local economies and local needs, primarily in defence. However, I know that OSTIn (The Office for Space Technology and Industry) is trying to develop space capabilities and technologies that can serve other applications like the aviation and maritime industries, and scoping projects that serve more commercial aspects.

The companies in Singapore typically don't build satellites – we are one of the exceptions, together with ST Engineering. Other companies mainly build sub-systems or applications around space. Right now, there is no law preventing you from sending satellites up, so as long as you can pay for it, you probably can get your satellite up into space. To some extent, yes, the new space race is about sending up constellations of satellites so that you secure your market share. Look at Starlink or Project Kuiper, who are sending thousands of satellites so that they can provide internet connectivity from space. But the only reason why they're launching so many satellites is because they need that amount to provide that level of service to the end consumers. They are racing not because they want to put the satellites up there, but to gain market share for that level of connectivity. The faster you can capture market share, the more likely you'll survive. I think it's more application-driven rather than for the sole purpose of reserving a space.

The exception is for geostationary satellites, which are primarily used for communications. The geostationary belt is hotly contested — to get an orbital slot you have to pay large sums and bid for it. So it's only in that region then yes, you're fighting for the slots, but that's the classical kind of space race — the ‘new space’ people don't really go into geostationary orbit.

I assume that you're also operating in low earth orbit because you're doing small satellites. How long is the lifespan for your satellites?

Yes, we are in low Earth orbit. In fact, the satellite that is launching in July will be about 530km in orbit. To go to geostationary, there are engineering tradeoffs, so ‘new space’ is typically in lower orbits. For this satellite, we want to make it last for five years. In 2015, a group in NUS launched a slightly smaller satellite which was designed for a lifespan for one year, but up to today, it’s still running. So that's like 7, coming to 8 years. It has way exceeded its supposed lifespan and it’s still running. So we will never know.

I read of instances where they thought a satellite is defunct and not active, but a couple of years later, it starts to come back to life.

It's possible. Some people studied older geostationary satellites which were supposed to be decommissioned. The owners of the satellite had already moved it into a parking / graveyard orbit, but it's still operational and powered up. It turns out that some people in Indonesia, particularly pirates, were transmitting up to these satellites, and having it repeat the signal back onto the ground. So they could do very far communications with other pirates and coordinate based on those satellites. There are YouTube videos talking about this, it’s very cool.

There was an astrophysicist I was talking to based in Western Australia who was tracking a defunct satellite. The battery on board had died out, but because it is a circular sphere with solar panels, as it rotates, the sun will hit the solar panel. Whenever it hits, it will come back to life and send a signal, so you get this pattern of intermittent signals being sent. He's trying to calculate the rotational motion just by the patterns of the pings. It’s quite fascinating, and goes against the idea that a satellite is supposed to live for a certain number of years, and thinking about the afterlife of orbits.

We were speaking with Astroscale recently and they had mentioned that there are a few strategies that they use, not just reducing waste and removing things from space, but also refuelling or reviving ‘dead’ satellites. At the moment, that's not something that we have capability for, without the infrastructure for refuelling stations and such, but they're working towards it in the next 20-30 years. What are your thoughts on refuelling and are there other ways to reactivate satellites?

Why refuelling is done is more of trying to keep that satellite in orbit. Although we are in space, which can be a very hard vacuum, there are still particles in space like hydrogen atoms which can go all the way up. In the low earth orbit (400–1000 km), satellites still experience drag, and they would eventually come back down. What we can do is to have propulsion systems to push ourselves up when we slow down due to drag. But if you have a propulsion system, it means that we have to carry fuel, and every time we propel, we lose fuel.

What Astroscale is trying to do is when these satellites run out of fuel, they can come along and top up the fuel to extend the satellite’s orbital lifespan. But if the electronics have failed because of radiation, there's nothing we can do about it. This is particular for geostationary satellites; although they are in geostationary, by right there should be very, very little particles already. But because of solar pressure, they constantly have to use fuel to adjust themselves to get back into their particular slot allocation in order to provide the coverage. So once you've run out of fuel, you actually drift away and cannot provide that service anymore. Even if you’ve run out of fuel, the electronics might still be operational. Hence, they are proposing to top up their fuel to extend its lifespan – for example, if the geostationary satellite is designed for a lifespan of 20 years, topping it up might extend it to 40 or 50 years.

Talking about afterlives, what do you have planned for your satellites after 5 years?

If it’s still functional, we will just leave it in space so it can continue to generate revenue for us. But if it's dead already, or we know that it’s going to die, we will try to orient it such that the surface area will be in the direction of travel, meaning that it will increase its drag. By analysis, we predict that it will stay in orbit for at least 8 years, but if we try to increase the drag surface area, then we can probably bring it down in 5 years. It's not immediate and will still take a while.

From what we know, it's not mandatory for companies to have a de-orbiting plan, or at least it’s not enforced. Why would you decide to speed up its de-orbiting?

More and more launch companies, or even the frequency licensing administrators, now require you to have a de-orbit plan. It need not be foolproof, but you must have a plan. For us, when we filed for frequencies for this satellite, we did it through Germany and the German regulators had asked us for our de-orbiting plan. Recently, the FCC (Federal Communications Commission) also changed the ruling from 25 years to 5 years. At the end of its mission, you have to de-orbit your satellite within 5 years. It’s a blanket rule. Everybody must comply. So let's say, if you fly higher, then you need a propulsion system or you need to have a very large drag sail to bring it down. For geostationary orbits, you have to go to a graveyard orbit.

If you wanted to launch your satellite from China, by state law, your satellite must have a de-orbiting mechanism. If you don’t have a de-orbiting mechanism, you can prove by drag analysis that your satellite will come down within five years. Different countries have different rules and regulations when it comes to de-orbiting.

For this upcoming launch, you're launching from India. Could you tell us more about this launch?

This upcoming launch is to send up a big main satellite payload. There was spare capacity on the rocket, and they opened up the opportunity for others to launch their satellites to space. So that’s how we ended up in India. I’ll be travelling to India to integrate the satellite. When it's launched, we’ll probably be here, waiting for the satellite to come on and trying to talk to it.

This sort of state launches doesn't happen very often. In 2015, there was one in which Teleos-1, Singapore’s first commercial Earth observation satellite was launched. After Teleos-1, there was a long break, until last year, where another satellite was launched. Then this year, there was another one around three months ago, where Teleos-2 was launched. After Teleos-2, the next one is this one coming up. But after this one will be another long break.

It’s interesting that you mentioned that China has enforced very strictly that you need a de-orbiting mechanism. Do you see a difference in priorities between emerging space nations like Singapore and Southeast Asian countries, versus the United States, China or India?

Now that you mention it, there is a difference. The more established space nations are more updated and aligned to the rules. They tend to comply with space sustainability issues more. Even if we wanted to launch with SpaceX, they will question your sustainability practice and check with the satellite owner how they plan to de-orbit their satellites. But whether they enforce it, I’m not sure. They check, but whether they will say no if you don’t have any de-orbit plans, I don’t know. But China is definitely not possible if you don’t have any de-orbiting plans.

Because there is no international treaty that really enforces this, what do you think is motivating this? Do you think it is really an interest in sustainable practices, or is it for the longevity of their commercial investment?

I think it’s more geo-political. It has to do with the image they're trying to portray of themselves being a spacefaring nation. Sustainability is also one factor, but you don't see China, for example, launching as many satellites as the United States. It's only there where you’ve got companies like Starlink, who are launching satellites every other week. So in my opinion, countries like China are doing this for two reasons. The first one is perhaps sustainability of space use. The second is probably the image that they're trying to portray on an international level.

I was speaking to a space debris expert attached to Curtin University and UWA who has been looking at the space debris issue since the 1990s. He's been running calculations for the Kessler Syndrome where it will reach a point where the orbits cannot be used further. Maybe 10 or 20 years ago when he ran his calculation, it predicted that space will be unusable in around 100 years based on the current activity. But recently, he ran the calculation again, I think last year or this year, and the timeline has been drastically reduced to maybe 20 to 30 years. Is this something that is a worry for you? Do you think about this as a satellite company?

Do I think about this? It doesn't bother me, although I know that is a possibility. I think the reason why it doesn't bother me is because I don’t think about it too actively. I’m more busy trying to get the engineering side of things to work. But I suspect that if I had more capacity to think about these issues on a grander scale, then it might be a concern to me. If the orbit really becomes unusable, then it would affect the way we run the business and our plans will be affected.

As you mentioned, there has been a shift towards designing small or nano-satellites that operate in a swarm or constellation. Do you think this is more sustainable than creating large satellites, In terms of the issue of debris creation and collision risks?

Small satellites definitely contribute to more debris, because there’s just more of them. Small satellites are also harder to track from the ground than big satellites because of the radar cross-section, which might actually also contribute to the Kessler Syndrome. Typically what happens is if you have two satellites which are about to crash into each other, people on the ground can run calculations and predict the possibility of crashing with differing confidence levels, and propose evasive manoeuvres. For big satellites, typically the simulation accuracy is higher because they are easier to track, your measurements are better, and you can have a higher level of confidence in trying to evade collision. For small satellites, this is not the case, because firstly, your measurements are poor. It’s difficult to track them from the ground. Secondly, not all small satellites have propulsion systems or means of evading, so you rely on the big satellite to move away.

But I believe that the impact that small satellites can have compared to big satellites is greater, because you can have a higher interval where you can update data and technology. You can already see the impact of Starlink satellites on humanity; where previously we used to not have connectivity in the middle of the ocean, with Starlink it is possible now. It can change the lives of people, so I think the impact outweighs the concerns at this point in time.

Does NuSpace speak to work with many such international companies?

We speak more to subsystem and technology providers, not so much of sustainability companies. We have used Leolabs services to track satellites. We’re just a user, we retrieve TLE (two-line-element) data from their portal. Leolabs is like a commercial version of Space-Track (operated by the US Space Force) where they deploy ground data to make measurements in space. The main difference between Leolabs and Space-Track is that Leolabs updates almost every day, while Space-Track only updates once every two to three days, because of the sheer amount of things they’re trying to track.

Most TLEs that we get on Space-Track are based on ground measurements. But TLE has the issue of propagation. As time goes on and if you don't update your TLE, the error gets larger and larger. So that's why we have continuously make measurements from the ground to update the TLE. It seems like that's the only way right now to make observations. What Leolabs can do is they can show you the radar returns, especially when you just launch the satellite. Based on the radar returns, they tell you what time your object was observed overhead. Based on that, you can cross-check with the TLE if they overlap, and determine if your TLE is good.

I read somewhere that a lot of the uncertainty that comes from predicting the real-time position of satellites and debris is because companies and nations don't share their information. Of course, it takes a lot of money, so everyone collecting their own data has created this patchwork of different resources. So if companies were to share more, do you think we would have a finer resolution of where everything in space is in real-time?

I agree with that. It all boils down to the data that you have — if you have more data, naturally the accuracy will get better. But these are commercial companies that are for-profit, so the moment they start sharing data, their business case might be affected. Naturally, they don’t want to share. That’s where governments come in and say that, I’m going to allocate a budget for you, you make sure that the data that we get is good enough. So that's where your Space Force appears with your Space-Track.

What are your thoughts on a space agency in Singapore?

My gut feeling is if Singapore had a space agency, we would be more synergised in strategising the growth of the space economy in Singapore. It would also have allocated funding with greater agency and control. Earlier, I mentioned the example of frequency filing — if we had a space agency, we would be able to directly go to them. I hope that there will be a space agency in the future, but until then, a space office is all we have.