SeaHawk-1, the innovative ocean colour monitoring CubeSat, has captured and downlinked its first multi-spectral image from orbit. This satellite is a proof of concept of a system which has the potential to greatly increase the availability and resolution of scientifically important ocean colour data through a network of satellites that are much smaller and cheaper than those currently used for this purpose.

Comparison of the spatial resolution between HawkEye and MODIS/Aqua
(Image credit: Gene C. Feldman https://oceancolor.gsfc.nasa.gov)

This excerpt from the first SeaHawk image data highlights the improved spatial resolution achieved by the instrument compared to the previous state-of-the art, a satellite with a mass of nearly 3 tons to SeaHawk’s mass of around 4 kg. Please see this article from the NASA OceanColor website for more information about this image.

Bright Ascension wrote Seahawk-1’s Flight Software and Mission Control Software so this milestone, demonstrating the end-to-end capability of the system, has been a real cause for celebration for us.

We’ve been involved in the mission from the early stages, helping to define the payload interface and concept of operations for the mission, and are providing ongoing technical assistance during the on-orbit operations. It’s gratifying to see the work of the whole SeaHawk team start to pay off and we are looking forward to support the move towards routine operation.

We’ve tackled a few interesting challenges during this mission, including:

  • High speed data transfers: The HawkEye payload generates a lot of data which needs to be transferred to the satellite’s mass memory quickly. To get that data down to the ground, we use a high speed X-Band radio which also needs to be kept busy within pretty strict timing requirements. Doing this with a relatively low-powered CPU has meant cooperating closely with Clyde Space to take advantage of the flexibility offered by their FPGA-based On Board Computer.
  • Using the NASA Near Earth Network (NEN): The NEN is a global network of satellite ground stations which is normally used by much larger spacecraft. We believe this is the first time that a CubeSat has used the NEN. To do this meant ensuring that our transmissions followed the international ‘CCSDS’ standards. This process was helped by the fact that we had an existing library of CCSDS protocol implementations to draw on.
  • Reducing Operational Complexity: SeaHawk is unusual for a CubeSat in that the payload and the platform are operated by two distinct groups using different ground stations. The satellite itself is commanded by Clyde Space in Glasgow, Scotland using our Mission Control Software product. Payload data is downlinked to the NASA Near Earth Network and processed by NASA Goddard Space Flight Centre. Tasking requests are passed from the payload to the platform team but there was a desire to keep this interface as simple as possible. In addition, since this is a pilot mission, some aspects of the performance of the system are uncertain, so there is a need to remain flexible. We’ve facilitated this through a design which ensures that the payload data set includes all of the necessary platform data to allow processing of the payload data and which is robust to drop-outs in the X-band link. We also automated the on-board processing and management of payload data, while providing flexibility to respond to the changing needs of the mission. Coupled with the on-board scheduling and scripting capabilities provided by our flight and ground software, it will be possible for the majority of spacecraft operations to be automated.

SeaHawk is one of nine satellites currently in orbit with flight software developed using our GenerationOne Flight Software Development Kit. Of these, four are customers of our FSDK product while five are ‘turnkey’ solutions developed by Bright Ascension using the same technology. With several other missions in the pipeline and several customers with satellites in development, we’re looking forward to an eventful year.

Further information:
https://oceancolor.gsfc.nasa.gov/forum/oceancolor/topic_show.pl?pid=44266
https://uncw.edu/socon/index_new.html
https://twitter.com/UNCWcubesat