SBIR-STTR Award

Over the last several years, the satellite landscape has seen the vast immergence of smaller and smaller satellites. These new satellite designs offer many benefits not only for science but also for reduced mission costs and increased mission robustness for exploration of our planet and beyond. Further, the notion of a ‘swarm’ of smallsats is being considered as a novel and useful way to do science and/or support the attendant communications. Swarm concepts—multiple satellites flying in formation near one another in similar orbits—are of growing interest, as a solution to the challenge of simultaneous measurement. However, communications for smallsats, and even more significantly swarms of smallsats, are challenged as a result of both the size limitations restricting available power for communications links, and the complexities of coordinating and collecting data from multiple spacecraft. JPL has explored the concept of an Earth receiver coherently combining the received deep space smallsat signals which each individually are too small to process. For the concept to succeed, each member of the swarm must phase its signal very accurately relative to all other swarm signals. This proposal not only seeks to address the deep space application but also expands to include swarm scenarios with higher dynamics – thereby involving signals that are much harder to coherently combine. Our Swarm Array Coherent Combining (SACC) scenarios span the complete space of possible orbiting swarms and their links to include lunar and other planetary orbiting swarm. Anticipated results of the effort include a recommended SACC architecture, modeling and simulation of the architecture that demonstrates viability of the concept, and prototype design for Phase II demonstration. Potential NASA Applications (Limit 1500 characters, approximately 150 words): Within the scientific community, there is growing interest in smallsat swarm operations for simultaneous measurement and observation, and NASA efforts are being applied to enabling swarm operations concepts as demonstrated by the NASA Ames support tool being developed to address control of satellite swarm. The swarm array coherent combining concept proposed here, will address not only deep space, but higher dynamic LEO swarms, as well as lunar missions which are anticipated to increase dramatically in this decade under the Artemis Program. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): The commercial space sector has grown rapidly, with a majority of spacecraft launched being commercial, and many new businesses being developed around data and applications that rely on space-based observations. Commercial companies in the remote sensing sector for example, often fly constellations of small satellites to meet data collection and could benefit directly from this capability. Duration: 6

Smallsats offer significant potential in allowing for relatively inexpensive, rapid deployment and robust space operations, communications, science, etc. However, these smallsats are inherently power-limited and thus are correspondingly limited in their data rate capabilities. Accordingly, focus has been on constructing a swarm of these smallsats wherein each smallsat (or ‘node’) would transmit its individual signal that is then ‘arrayed’ together to form a combined signal that has more power. The traditional approach to this arraying concept is to pre-condition each node signal in phase and time prior to transmission such that all signals arrive at the receiver coherently. This phase adjustment is very burdensome and problematic for the space node. We refer to this arraying approach as spaced-based arraying’. Our innovation performs this signal ‘arraying’ operation in a way that effectively eliminates all the node synchronization and coordination complexities noted above by implementing ground-based Arraying. We denote our innovative arraying technology as “Swarm Array Coherent Combining” (SACC). SACC uses ground terminal signal processing to extract node phasing and timing for coherent combining allowing each node signal to be ‘uncoupled’ from each other and have significantly relaxed time and phase requirements. Also, noteworthy is that SACC technology provides the basis for a novel satellite relay concept that offers all the benefits of a large Phased Array in space by merely using a swarm of simple uncoupled smallsat transponder nodes that perform as elements of the array. Our SACC ground technology extracts all the phase information of these noise-dominated signals to achieve coherent node arraying. These space nodes do not need precise intra-swarm frequency and time coordination. Another key feature is that there is no need to calibrate any of the communication links even crosslinks. We refer to this novel relay system as the SACC SmallSat Relay System (SSRS). Potential NASA Applications (Limit 1500 characters, approximately 150 words): As NASA continues to explore our solar system, there is always a need for communications. With the vast emergence of smallsats both to do science and to support communications, the SACC SSRS represents a resilient, flexible and efficient way to leverage these smallsats to provide these NASA communications needs. In particular, because the SSRS imposes negligible requirements both on the swarm and its constituent transponder nodes, it can be easily designed and operationalized to support NASA communications over all space regimes. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): There is an ever-growing number of commercial smallsat constellations being deployed to support connectivity to the INTERNET. There are always issues related to achievable data rates and visibility to ground stations. Our SSRS offers the robust flexibility to create swarms of any size to address data rates. The SSRS also accommodates crosslinks between swarms with no impact on our SACC processing. Duration: 24