by Douglas Messier
The CubeSat format has dominated the small satellite industry for many years. Their small size – a 1U Cubesat measures a mere 10 x 10 x 10 cm (3.94 x 3.94 x 3.94 in) – has made spacecraft cheaper and easier to build. The ability to combine these units into larger spacecraft has given satellite makers a variety of options. CubeSats can be launched in large numbers on rideshare missions or as secondary payloads to larger satellites.
However, CubeSats do have limitations in terms of mass, power and other key aspects. Engineers at The Aerospace Corporation believe it’s time for small satellites to go in another direction. Instead of a cube, they are modeling their new spacecraft on a compact disc. They hope their design, known as DiskSat, will become a new standard for small satellites.
The Aerospace Corporation’s Richard Welle gave a presentation about the DiskSat program during the recent Small Satellite conference in Logan, Utah. He said a key reason CubeSats have proved popular is containerization – they can be easily shipped and integrated with any launch vehicle. DiskSat has the same goal.
DiskSats measure 1 meter across (39.3701 in) and 2.5 cm (1 in) in width. They are designed to be stacked inside of a payload fairing the way that rewritable compact discs are stored in containers, Welle said. DiskSats would then be deployed one by one, turning on once they are flying in free space.
While DiskSat’s thin size enables them to be launched in large numbers, the 1-meter diameter will provide ample space for solar cells. Engineers are hoping to demonstrate ~200 watts of peak power.
Another goal is to demonstrate the ability of DiskSat to fly in a very low Earth orbit (VLEO), where high-powered cameras could return high-resolution images. The satellite is designed for low atmospheric drag, allowing it to stay at low orbits for extended periods of time.
Welle said the non-profit corporation recently received NASA funding needed for development. Aerospace Corporation plans to fly four DiskSats through the Pentagon’s Space Test Program in late 2023 or early 2024.
Welle said the demonstration mission will use legacy avionics and subsystems that have been proven on multiple previous missions. The DiskSat form is the key technology being tested on the flight. The DiskSat dispenser is also at a low technology maturity level at the present time.
If the mission is successful, Aerospace Corporation will issue a set of DiskSat standards for use by industry. It is currently seeking input from launch providers and potential users on these standards.