By packing big antennas into tiny satellites, JPL engineers are making space science cheap Illustration: John MacNeill
One morning in November 2014, Kamal Oudrhiri, a colleague of mine at the Jet Propulsion Laboratory (JPL), in Pasadena, Calif., burst into my office with an intriguing proposition. A first-of-its-kind satellite was headed for Mars. The satellite would fly alongside NASAs InSight Mars Lander, relaying data in real time back to Earth during the landers critical entry, descent, and landing. We have to achieve 8 kilobits per second, and were limited in terms of power. Our only hope is a large antenna, Oudrhiri explained. Oh, and the satellite itself will be only about the size of a briefcase.
Nothing as diminutive as the Mars satellitewhich belongs to a class called CubeSatshad ever gone farther than low Earth orbit. The antenna would be stowed during launch, occupying only about 830 cubic centimeters. Shortly thereafter, it would unfurl to a size three times as large as the satellite itself. It would have to survive the 160-million-kilometer flight to the Red Planet, including the intense vibration of launch and the radiation and extreme temperatures of deep space. How hard could that be?
Fortunately, my colleagues and I love a challenge, and we welcomed the chance to push CubeSat technology to its limits. These tiny spacecraft have become the go-to vessel for researchers and startups doing Earth imaging and monitoring. Compared with traditional satellites, they are relatively inexpensive and small, weighing just a few kilograms, and they can be ready to launch in a matter of months, rather than the years it typically takes to prepare a standard spacecraft. Over time, the onboard sensors and processing that CubeSats can carry have been the beneficiaries of Moores Law advancements in electronics, growing more powerful and sophisticated, lighter in weight, and energy efficient.