Overview

SeaHawk-1 is an innovative ocean colour monitoring CubeSat, designed by the University of North Carolina. It was built with our Flight Software Development Kit to accelerate mission development and is taking full advantage of the benefits offered by our Mission Control Software.

SeaHawk’s colour sensor observes changes in ocean surface colour, which relates directly to the substances and the organisms within it. Captured daily, high-resolution observations of ocean colour changes can be used for multiple environmental and maritime applications.

Challeges

The SeaHawk project utilises a 3U CubeSat platform to observe the changing biology of the ocean surface and its implication for various maritime applications.

Limitations on computing platform

The payload of the spacecraft generates a large amount of data at 1.1GB for a full observation sweep, and requires a high performance x-band downlink. This large volume of generated data put significant limitations on the computing platform, meaning that there was a demand for the software to use as minimal computing resources as possible.

From the software perspective, the restriction on computing power was the main challenge in this mission.

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 it was used by a CubeSat.

Reducing operational complexity

SeaHawk is unusual for a CubeSat because its payload and its platform are operated by two distinct groups using different operations centres. The satellite itself is commanded by AAC Clyde Space in Glasgow, Scotland, using our Mission Control Software product. Payload data is downlinked to the NEN 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 were uncertain, so there was a need to remain flexible.

Solutions

Limitations on computing platform

The FSDK allows the operator full control over how often the software performs certain actions such as checking the status of a component, or sending health checks to the operations centre. So the operator can decide which elements of the mission need to be prioritised.Flexibility is a crucial part of the software development process as requirements may change mid-development. The FSDK allowed software to be developed from previous iterations, so that the flight package design could be easily changed without rewriting from the ground up.

NASA Near Earth Network (NEN)

In order to enable NEN interactions, we needed to ensure that our transmissions followed the internationally-recognised CCSDS standards, which was easy to achieve as the FSDK has an existing library of CCSDS protocol implementations to draw on.

Reducing operational complexity

In order to help reduce operational complexity, we ensured that all of the necessary platform data was included in the payload set so it can be correctly processed. 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 is possible for the majority of spacecraft operations to be automated.

Outcome

SeaHawk was successfully launched in 2018 and soon after captured and downlinked its first multi-spectral image from orbit.

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.