Emerging Technology for Space: Distributed Space Systems
In the second edition of the Emerging Technology for Space webinar series, hosted by Satellite Applications Catapult and the University of Glasgow, we covered the topic of Distributed Space Systems (DSS). This webinar brought together experts from both academia and industry, to explore some of the latest research and discuss some of the opportunities and challenges of such concepts, to enable new satellite applications.
Many satellites comprise of a single platform, including a set of self-contained subsystems to deliver power, communications, and payload functions. In contrast, DSS can comprise of multiple satellites which are networked together to deliver new or enhanced services. An example of this could be constellations of small satellites in lower orbits that deliver a global network of communications services.
Background to Distributed Space Systems
Distributed Space Systems are not as new as one may think with origins dating back to the 1960s when half a billion copper dipoles were deployed in-orbit for passive ground-to-ground communications through reflection. We are however, now formally in the era of DSS.
One driver of DSS is that in low-Earth orbit (LEO), multiple platforms enable distributed sensing with a global footprint. Emerging sensing technologies will then drive future applications. Furthermore, mega-constellations for communication are now real, with the emergence of Starlink and OneWeb driving future launch needs. Disaggregated systems allow the separation of the traditional spacecraft into its separate subsystems, which could allow for easier access to replace, maintain, and upgrade subsystems, leading to a more sustainable sector.
Applications of Distributed Space Systems
The first session involved a talk by Professor Zhili Sun, University of Surrey, on satellite communications and networks with mega-constellations. Continuously increasing satellite capacity and decreasing earth station size has reduced the cost per bit for communications and enabled many communication applications for mega-constellations. The resulting features of mega-constellations include enhanced mobile broadband, enormous machine-machine communication possibilities (e.g., smart cities and IoT), and ultra-reliable and low latency communications. With the dawn of mega-constellation service providers such as Starlink and OneWeb, we will continue to unlock new applications. On the horizon, we also see developments on 6G, furthering more applications. Ultimately, the role of satellites will be to provide a global information infrastructure.
In the second talk, Dr Gilles Bailet introduced the concept of femtosatellite swarms which are based on a 2D, centimetre-scale PCB satellite (with a mass of approx. 10 g). This platform has the potential for growth on a similar scale seen with CubeSats. At the University of Glasgow, a platform has been developed with coarse attitude control and a low-resolution camera. When deployed in a swarm, a range of new scientific applications can be enabled such as: large sparse radar antennae, enhanced weather services, and planetary exploration and atmospheric characterisation. A benefit of this platform is that it is cheaper to launch many of these nodes which provides redundancy and leads to a more robust entire system.
The Emerging Technology for Space webinar series continued with Spire who have launched over 110 CubeSats, with over 300 years of flight heritage. Spire focused on their RF and radio occultation data providing applications in maritime, aviation, agriculture, and weather. DSS in LEO provides superior global coverage over land and sea that weather balloons cannot provide, or conventional satellites cannot provide data at the same temporal resolution. Spire concluded by introducing their “Space Services” product. This product not only allows customers to launch their ideas but allows them to interact with the operations of their experiments or instruments in space through an API/cloud-based constellation management and synchronisation system. This reduces the customer’s work on mission planning and operations.
Panel Discussion Summary:
- Nanosatellites are not there to replace traditional satellites but there is an augmentation on how they can work together to serve different needs.
- Traditional satellites, nanosatellites, and femtosatellite can work together to overcome the limited power and processing budgets of smaller platforms, but the smaller platforms can allow specific interesting science cases and market opportunities.
- DSS are a great tool and resource for better understanding our planet and allowing us to make data driven decisions.
- Technology developments now allow us to evolve satellite communications in way like that of the rapidly developing mobile communications.
- Physical standards on form factors have helped the space sector (i.e., CubeSat standard), and an analogous data standard could be used in space to allow for a seamless space infrastructure on communication.
- It is generally now more expensive to move data than process it in-situ and we expect to see increased processing power on satellites. There is an interesting decision to be made on where it is most efficient to process data, i.e., with the instrumentation, using edge computing, or download all data and then process it?
- A strength of DSS is that they allow for the loss of some nodes without a large loss of performance.
- People putting spacecrafts into orbit have a responsibility for end-of-life (EOL) de-orbiting and DSS are not adding significantly to a space ‘garbage’ problem.
Pitches on Distributed Space Systems
OrbAtsro: provide in-orbit infrastructure through their platforms. Their Guardian network provides optical interlink providing customers with data relay with low latency, semi-autonomous management system for customers’ missions, and semi-autonomous comprehensive space traffic management.
PolyChord: optimisation tool which maps out the objective space and gives back all possible solutions and rates them. This can include optimising the orbit for coverage, revisitation frequency, connection to ground stations, collision avoidance, and minimising the number of satellites required.
Matteo Ceriotti: distributed Earth observations (EO) using super resolution. Suggestions to replace large aperture optics with low resolution optics on distributed CubeSats. Slewing instruments is necessary to provide on-demand, on-spot EO. Using data fusion, the combination of images can provide super resolution imaging.
The webinar was a success. Thank you to everyone that joined us and engaged with the speakers and we look forward to hosting more webinars soon. If you would like to suggest a topic for the next emerging space technologies webinar, then please get in touch with us.