The Defense Advanced Research Projects Agency (DARPA) recently issued a solicitation for two technical areas of the Space-Based Adaptive Communications Node (Space-BACN) project. Space-BACN will be a reconfigurable, multi-protocol, intersatellite optical communications terminal used to connect satellite constellations which are currently not able to communicate.
DARPA is faced with the problem of new satellite constellations using single-waveform crosslink communication systems that only interconnect within their own constellation, but not with others. These single-waveform systems are almost exclusively composed of custom-made components, and have little to no reconfigurability. Though functioning within the same wavelength band, they differ in wavelengths, polarization, clock rate, spatial acquisition sequence, modulation format, framing, and error correction coding. This has led to satellite communications (SATCOM) becoming severely fragmented with only isolated islands of connectivity.
Therefore, the primary goal of Space-BACN is to overcome the current lack of on-orbit interoperability among current and future space communications – achieving a standardization of communications or optical intersatellite links. It expects to achieve this goal by creating a reconfigurable space-to-space optical communications terminal that can connect heterogeneous constellations that operate on different optical intersatellite link specifications.
Space-BACN’s terminal will need to be low size, weight, power, and cost (SWaP-C); easy to integrate into most current and future single wavelength waveforms in space to speeds of 100 gigabits per second; and operate on platforms in low Earth orbit (LEO). The project involves space-based communications, optical intersatellite links, reconfigurable modems, modular components, and space command and control. It should use less than 100 Watts of power, and cost less than $100,000.
The Space-BACN program consists of three technical areas, with DARPA currently soliciting for two of them: a modular, low SWaP-C optical aperture to separate the front end of the optical intersatellite link from the signal processing via single-mode fiber; and a reconfigurable modem able to support several optical waveforms as fast as 100 gigabits per second on one wavelength.