NASA prepares for twin launches of climate science cubesats

The first of twin cubesats for NASA's Polar Radiant Energy in the Far Infrared Experiment, or PREFIRE, mission is scheduled to launch no earlier than May 22 on an Electron rocket from Rocket Lab's Launch Complex 1 in New Zealand. The other cubesat will be launched on another Electron within three weeks.

Each 6U cubesat carries a thermal infrared spectrometer based on technologies flown on several other spacecraft but repackaged to fit within the size and mass constrains of the cubesat. The instruments will collect information on emissions at far infrared wavelengths, longer than 15 microns, at the Earth's poles.

The data, project and NASA officials said at a May 15 briefing, will help scientists better understand how much heat the Earth loses to space at the poles, which can be used to improve climate models.

"The Arctic is warming faster than anywhere else on Earth. That has huge potential consequences," said Tristan L'Ecuyer, principal investigator for PREFIRE at the University of Wisconsin-Madison. Those consequences are both local and global, with the latter including sea level rise and broader weather systems.

PREFIRE will make the first detailed measurements of radiant heat emitted at the poles, he explained. "What that's going to allow us to do is, for the first time, understand what the different processes in the polar regions, like clouds, humidity in the atmosphere and the changing surface — going from an ice surface to a liquid surface — does in terms of altering that heat loss."

Those measurements can be done with a single cubesat, but having two satellites, launched into different sun-synchronous orbital planes, enable additional measurements. "Having one cubesat would be able to map out what the emission looks like in the polar regions," L'Ecuyer said, "but by having a second cubesat that flies over about six hours later, we will be able to understand how changes, like melting of the ice sheet or a cloud formation or an increase in the amount of moisture in the atmosphere, affect the emissions."

That drives the unusual approach to this mission, with dedicated launches of individual cubesats on an Electron rocket to place them into their required, specific orbits. NASA selected Rocket Lab to launch the PREFIRE spacecraft in August 2023 through a task order on the Venture-class Acquisition of Dedicated and Rideshare (VADR) contract. NASA did not disclose the value of the task order.

While Electron has significant excess capacity for each PREFIRE launch, Peter Beck, chief executive of Rocket Lab, said at the briefing that the company doesn't plan to carry any secondary payloads or perform any technology demonstrations on the two launches. "It's absolutely dedicated to this mission," he said. "Just these spacecraft on board."

NASA selected PREFIRE in 2018 at part of its Earth Venture line of instruments and missions with a cost cap of nearly $33 million. The mission "is a really great example of how we can target our research efforts: how we can answer targeted research questions with more affordable options," said Karen St. Germain, director of NASA's Earth science division.

"Cubesats like PREFIRE represent the flexibility in our efforts to reach space," she said. "It's a much smaller payload with launch services provided by a commercial partner, all at a lower cost."