Hurricane-Tracking Cubesats Delivered Into Orbit By Rocket Lab

Less than a year after losing their ride to space, a pair of novel hurricane-tracking cubesats have been delivered into orbit for NASA, with another two due to lift off in two weeks. 

The first two members of the Tropics constellation were lost in June 2022 when the upper stage of Astra’s Rocket 3.3 vehicle shut down early. The company later decided to discontinue the booster, prompting NASA to look for a new partner to launch the four remaining satellites in the constellation. 

Tropics is an acronym for Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats.

The 12-lb., 3U-satellites, which are about the size of a loaf of bread, are designed to monitor the formation and development of hurricanes and tropical cyclones. Operating about 342 mi. above Earth and inclined 30 deg. relative to the equator, the Tropics satellites are designed to measure temperature, precipitation, water vapor and cloud ice over tropical cyclones. 

Each spacecraft is outfitted with a spinning radiometer to measure microwave frequencies ranging from about 90-205 gigahertz. With multiple spacecraft, the constellation will collectively be able to monitor storm changes about every hour. 

Current weather tracking satellites have a timing of about once every 6 hr., NASA notes.

“Providing more frequent imaging will not only improve our situational awareness when a hurricane forms, [but also] provide information to models that help us determine how a storm is changing over time,” Karen St. Germain, director of NASA’s Earth Science Division, said in a statement. 

NASA selected Rocket Lab in November to launch the remaining four members of the constellation. The first two of those reached orbit on May 7 following launch aboard an Electron rocket flying from New Zealand’s Mahia Peninsula.

The final pair of Tropics cubesats is expected to be launched aboard another Rocket Lab Electron rocket in about two weeks.

A pathfinder Tropics satellite was launched in 2021. The Tropics mission is led by Bill Blackwell with the Massachusetts Institute of Technology’s Lincoln Laboratory.