Small satellite sensor set to transform weather forecasting

Above: HyMS technology in the lab at RAL Space. 
Credit: STFC RAL Space

The shoebox-sized sensor was developed by Spire Global Ltd in collaboration with STFC RAL Space.

The Hyperspectral Microwave Sounder (HyMS) in-orbit demonstrator lifted off from Vandenberg Space Force Base in California on 11th January 2026 aboard SpaceX’s Twilight mission.

Building on technology from STFC RAL Space’s Millimetre-Wave Technology Group, Spire Global Ltd led the development to engineer the flight payload for HyMS, integrating it into a small satellite and developing the ground processing capability.

This represents a major breakthrough in more frequent and higher-resolution atmospheric monitoring.

Transforming what’s possible in weather forecasting
Accurate weather forecasting relies on measuring atmospheric temperature and moisture, but cloud cover makes this hard to do consistently from space.

Microwaves can penetrate clouds to gather this data, making them one of the most valuable tools in meteorology.

HyMS is designed to make these measurements more frequent and more detailed than ever before.

More frequent atmospheric sampling
Traditional meteorological satellites are very large and expensive to develop and launch.

They typically revisit the same location once daily, limiting their ability to track fast-moving, high-impact weather events such as tropical storms.

HyMS offers higher frequency resolution in a much smaller and more affordable package, opening the possibility of deploying multiple sensors for far more frequent atmospheric sampling.

From laboratory to orbit
HyMS began life as a concept within RAL Space, developed through early-stage funding from the Science and Technology Facilities Council (STFC) Innovations team and the UK Space Agency.

Spire Global then licensed the technology and took on the engineering challenge of turning it into a space-ready product.

The two organisations brought complementary expertise to the project. STFC RAL Space supplied the receivers, calibration target and thermometry, while Spire led mission design, operations and instrument control.

Together, they are now developing the first operational satellite.

Delivering a step change in weather forecasting
Professor Peter Huggard, Millimetre-Wave Technology Programme Leader at STFC RAL Space, said: "After years of development by teams at RAL Space and Spire, we’re tremendously proud to see the first HyMS in space.

"The receiver and calibration technology our team has provided will play a critical part in helping Spire Global deliver a step change in weather forecasting.

"This first demonstrator heralds the beginning of a new era, as when HyMS is deployed across multiple satellites, it will dramatically improve how we can track and predict the increasingly variable weather, with benefits for society and the economy."

Global benefits ahead
This launch is the first step in a broader ambition. Spire plans to roll out HyMS across a fleet of future satellites.

They plan to make these measurements available more frequently and to more agencies around the world, including in remote regions like oceans where observational data is currently scarce.

Most impactful model worldwide
Theresa Condor, CEO of Spire Global, said: "Microwave sounding is one of the most impactful satellite observations for weather forecasting models worldwide, alongside radio occultation profiles.

"This area represents a multi-billion-dollar global atmospheric sounding need, driven by the essential role these observations play in delivering accurate temperature and moisture profiles, particularly in cloudy conditions.

"With the successful launch of our Hyperspectral Microwave Sounder demonstrator, we are proud to strengthen our ability to support global forecasting agencies and further enable efficient and effective private sector participation in the global observing system."