Processing Solutions for Evolving Space Application Requirements

A new space race is officially upon us, one that brings the “Final Frontier” much closer to home than ever before. While we regularly see headlines about shuttle launches, there is another space application that’s much more common today – the growing number of satellites occupying the space sector known as “low Earth orbit,” aka “LEO.” This is where most of the “action” is taking place, making what once seemed remote and inaccessible to many, more approachable and relevant to everyday life than ever.

LEO encompasses Earth-centered orbit with an altitude of less than 2000 km. The launch of satellites into LEO began about 30 years ago, when less than 100 LEO satellite fleets, or “constellations,” were put into orbit by government entities. In 2021 alone, approximately 1400 satellites were launched into LEO, according to Space.com, with an almost complete shift from government to commercial operations. This figure is expected to grow further in 2022 and onwards – with some estimates close to 60,000 satellites in LEO by the year 2030.

The majority of the satellite launches are operated by emerging space 2.0 companies planning constellations of small satellites to service internet services and earth observation applications constrained by power consumption and cost. Government operators are also deploying smaller satellites with lower launch cost to enable the next generation of satellite services.

No matter the use case, space deployments come with a rigorous set of requirements to ensure they can handle the extreme conditions of the environment. Some key considerations include:

Processing Power
Large LEO constellations have numerous “inter”-satellite communications links, increasing the need for on-board data processing and creating a “distributed” network architecture that includes satellite functions such as imaging, flight control operations, and communications to Earth stations or direct to end users. In fact, because the communications channels can only transmit so much information at one time, the demands for on-board processing will only increase.

Reliability
Another key requirement of any space deployment is reliability. Once launched, these satellites are not easy to access. They need to be dependable and largely self-sufficient. If an error occurs, they need to be able to come back online quickly and resume functionality. If an update is required, they must be capable of being updated remotely. Another aspect of reliability comes in the form of handling the harsh space environment, including radiation tolerance.

Cost
Thousands of satellites in LEO means that costs must be competitive to reach price points that would make a service like internet connectivity comparable or less expensive than terrestrial alternatives. Competitive cost initiatives are seen throughout the LEO ecosystem: from making satellites lighter and more compact (so more can be launched at a time), to improving aerodynamic efficiency (to save fuel and extend life), to using reusable rockets, and incorporating electronic components that improve operational reliability, power efficiency, and the ability to withstand the extreme LEO environment. This combination of on-board processing and a distributed architecture creates a scenario that is very similar to the “edge computing” concept.

Lattice FPGA Benefits for Space Applications
Overall, the exploration and commercialization of space is increasing exponentially and will bring new features necessary to successfully achieve mission objectives. We believe that FPGA technology is integral to this emergent infrastructure.

Lattice FPGAs offer low power and low latency, making them an ideal solution to address the above requirements for distributed processing and communications architectures in space. Lattice product families such as Certus™-NX, CertusPro™-NX, and CrossLink™-NX, which are based on the low power Lattice Nexus platform, excel in applications that require high-speed data aggregation and bridging and in those that accelerate computationally intensive operations. The Lattice Nexus platform is built on 28nm FD-SOI semiconductor manufacturing technology. With this platform, Lattice has introduced multiple device families that deliver industry-leading low power, high performance, high reliability, and small form factor, resulting in up to 100X higher reliability.

Soft errors occur when high-energy charged particles (such as those found in UV radiation) alter the stored charge in a memory cell in an electronic circuit. Essentially, a bit can be changed from a “1” to a “0” and the system will continue to operate, but in the wrong mode. The Nexus platform enables 100X higher reliability with features such as single bit error detection and correction, multi-bit error detection, support for external scrubbing, and a robust memory architecture that help significantly reduce multi-bit upsets.

The Lattice Nexus platform can perform these functions in an “auto-correct” mode that scrubs “upset” bits and mitigates multiple-bit errors with a feature made possible only by the intrinsic nature of the Nexus memory architecture – the ability to separate bits and correct each individually. A charged particle may attract multiple bits, but Lattice can maintain an adequate degree of separation between them. This feature is extremely valuable as multiple bit errors often require a complete system reboot in order to eliminate them. It also demonstrates robust radiation resistance, which is critical to the operations of a LEO satellite during its lifetime (typically 5 to 10 years), as there is no opportunity for “on-board repair” once it’s launched.

Total Dose, SEL and SEE responses in presence of heavy ions have been measured by independent agencies. Preliminary results demonstrate the robustness of FDSOI based FPGA. Lattice Nexus is an SRAM-based FPGA allowing it to be re-programmed in-orbit after launch. The Nexus platform supports on-orbit reconfiguration that helps extend the duration of a given mission. There are no limitations on the number of times Nexus FPGAs can be reconfigured in-orbit. This capability coupled with instant-on reconfiguration reduces the downtime during the mission.

To make it easier than ever for the space industry to achieve their design objectives, Lattice has been working closely with multiple partners on radiation testing and flight screening. And, in a recent announcement, we discussed a new collaboration with CAES, whereby CAES will qualify and sell radiation-tolerant Lattice FPGAs for space and satellite applications. The collaboration addresses the growing demand for reprogrammable, commercial off-the-shelf (COTS) programmable devices in satellite networks that require a high degree of redundancy and radiation tolerance.

We encourage you to download our whitepaper on the benefits of the Lattice Nexus FPGA platform for mission-critical applications for a deeper dive on this technology. And, to learn more about Lattice space-grade solutions, please contact us at sales@latticesemi.com or reach out to your usual Lattice contact.