Student-built Satellite Uses 'Beach Ball' for an Antenna
CatSat is a small satellite carrying a new communications concept – an inflatable antenna – into space.
Engineering students Aman Chandra (left) and Shae Henley are two of many UA students who have helped prepare CatSat for launch. Here, they carefully handle the system that will eject and inflate a large mylar membrane in space. The upper half of the ball-shaped antenna is reflective, so it can relay electromagnetic waves to Earth. TaMya Reliford, University of Arizona
Near the University of Arizona’ main campus, students gather inside a cleanroom wearing lab coats, gloves and hairnets. On their lab bench sits a complex maze of wires and metal, the dimensions of a family-size cereal box. Each component has been optimized to survive a rocket launch and orbit the Earth.
After years of designing, building and testing, a team of students has readied CatSat, a small satellite known as a CubeSat, for launch into space. The spacecraft was designed to demonstrate new space technology and overcome a major challenge in space exploration: high-speed, low-cost communication across vast distances. Reminiscent of a beach ball, the satellite's antenna is expected to transfer information from space to Earth at high data rates.
The satellite is planned to probe the ionosphere – a layer of charged particles at the boundary between the Earth's atmosphere and space – so that the team can better understand the ionosphere's ever-changing structure. This structure impacts the propagation of high-frequency radio signals.
CubeSats are miniature cube-shaped satellites that orbit Earth and range in size from a 10-centimeter cube to a desktop computer. CubeSats are made with modular, relatively low-cost components.
Unlike other CubeSats, CatSat has an inflatable antenna, developed by Freefall Aerospace, a Tucson-based startup company and spinoff that was brought to be with the help of the university's commercialization arm, Tech Launch Arizona. Stored inside of CatSat is a high-performance, software-defined radio named AstroSDR, which was designed, built and donated by Rincon Research Corporation. After launch, the inflatable antenna, AstroSDR and other components will work together to send down high-resolution images of Earth almost instantaneously.
"Following a successful launch, this inflatable antenna will be the first of its kind in space," said Hilliard Paige, a systems engineering student and the project's lead systems engineer. "If it works, it will be a pathfinder for future missions."
Inflatable Antennas Could Give an Edge to Small Spacecraft
All spacecraft require antennas to transmit and receive signals, allowing for communication with Earth. Yet, the capabilities of CubeSat antennas have historically been restricted, as CubeSats can only carry very small antennas. Signals from these small antennas can take days to finally reach Earth.
CatSat's inflatable antenna, invented at the UA and further developed by Freefall Aerospace, combats this problem thanks to its lightweight material that tightly folds within the spacecraft. After launch, CatSat will stabilize its orientation so that it can eventually deploy the stowed antenna membrane and inflate it with helium and argon gas.
