Scientists have revealed how data from a NASA telescope was secured thanks to creative thinking and a batch of Raspberry Pi computers.
The telescope was the Super Pressure Balloon Imaging Telescope (SuperBIT), launched on April 16, 2023, from Wānaka Airport in New Zealand. The telescope was raised to approximately 33km in altitude by NASA’s 532,000-cubic-meter (18.8-million-cubic-foot) balloon and, above circa 99.5 percent of the Earth’s atmosphere, it spent over a month circumnavigating the globe and acquiring observations of astronomical objects.
The plan had been for the payload to transmit its data to the ground using SpaceX’s Starlink constellation and the US Tracking and Data Relay Satellite System (TDRSS). However, the Starlink connection went down soon after launch, on May 1, and the TDRSS connection became unstable on May 24. The boffins decided to attempt a landing on May 25 due to poor communications and concerns the balloon might be pulled away from further land crossings by weather.
The telescope itself was destroyed during the landing; it was dragged along the ground for 3km by a parachute that failed to detach, leaving a trail of debris in its wake. Miraculously, though, SuperBIT’s solid-state drive was recovered intact. However, other than as a reference, its data was not needed thanks to the inclusion of Raspberry Pi-powered hardware in the form of four Data Recovery System (DRS) capsules.
Each capsule included a Raspberry Pi 3B and 5TB of solid-state storage. A parachute, a Global Navigation Satellite System (GNSS) receiver, and an Iridium short-burst data transceiver were also included so the hardware could report its location to the recovery team. The capsules were connected to the main payload via Ethernet, and 24V DC was also available.
The plan had been to release the first DRS capsule on day 40, and then another every 20 days after that, whenever SuperBIT passed over land. However, when it became clear that SuperBIT would have to come down on May 25, it was decided to drop two DRS capsules over Argentina’s Santa Cruz Province.
Both of the DRS capsules released were recovered from their reported locations – a curious cougar apparently nosed around one of them without causing damage – and the data was fully intact. Of the unreleased DRS capsules, one failed for unknown reasons at launch – the team speculated that perhaps a cable came loose – but the other also contained an intact data set.
In an era of high-bandwidth communication, the idea of simply copying data to an SD card and dropping it from a balloon has a certain retro charm. Yet engineers noted that the 75 percent hardware reliability rate means more development is needed.
However, the cost saving is undeniable, as is the benefit of ensuring precious science data doesn’t get lost when things go wrong. The team recommended that future balloon missions consider the technology and said: “For a relatively small cost, we insured the scientific returns of superBIT against a loss event that came true: high bandwidth communication links failed, then the telescope was destroyed upon landing.”
The design and software is open source and freely available. According to the team, further development is continuing at NASA. ®
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
