HyMS-IOD

HyMS-IOD [Spire Global]

HyMS-IOD (Hyperspectral Microwave Sounder – In-Orbit DemonstratOR) is a UK-led microsatellite mission built by Spire Global (Spire Space Services Ltd., SFL) to demonstrate the HyMS hyperspectral microwave sounding instrument in orbit. The satellite supports the proposed future Earth observation mission HYMS CONCAM (Hyperspectral Microwave Sounder Constellation of Nanosatellites for Climate Change and Mitigation).

The mission objective is to validate a compact, space-ready hyperspectral microwave sounder designed for atmospheric sounding and numerical weather prediction (NWP). HyMS-IOD is intended to demonstrate the ability to provide high–spectral resolution microwave radiance measurements that enable improved retrievals of atmospheric temperature, humidity, and precipitation, contributing to better understanding of weather system formation and evolution in near real time.

HyMS represents a first-of-its-kind hyperspectral microwave mission implemented on a small satellite platform. Operating in the millimetre-wave regime, the instrument is designed to deliver detailed vertical information on the internal structure of the atmosphere, including through cloud cover, addressing key gaps in existing microwave sounding capabilities.

The satellite is based on Spire Global’s 16U CubeSat bus. It carries the HyMS instrument as its primary payload. HyMS is implemented as a crosstrack scanning radiometer incorporating ultra-sensitive radiometers and a wideband, high-resolution spectrometer. Key subsystem technologies meeting system requirements have been demonstrated prior to flight.

The mission is conducted in collaboration with the UK Science and Technology Facilities Council (STFC), with RAL Space contributing significant heritage in microwave sounding technology. RAL Space has provided microwave instrument receivers for MetOp Second Generation missions, including MWS, MWI, and ICI, as well as the ground calibration rig for the MetOp-SG Microwave Sounder (MWS). This heritage underpins the HyMS instrument design and calibration approach.

HyMS-IOD serves as a pathfinder for a potential future operational constellation of small satellites providing global atmospheric monitoring using hyperspectral microwave observations. The long-term objective is to deploy the HYMS CONCAM constellation to support weather forecasting, climate monitoring, and mitigation applications.

The HyMS-IOD satellite was launched on a CubeSat (16U) platform provided by Spire Global as an in-orbit technology and mission demonstrator.