US: Spire, the developer of CubeSat constellation, has raised $40 million to complete work on the satellites and begin launching them later this year. Spire is developing three-unit CubeSats equipped with sensors to collect weather data using a technique called GPS radio occultation. The sensors observe the GPS signals as they pass through the atmosphere, measuring refraction from which temperature and humidity profiles can be derived. This information can be incorporated into weather forecasting models to improve their accuracy. Spire plans to start launching the satellites in September as secondary payloads on other missions, with a goal of placing 20 satellites into orbit by the end of 2015.
Source: Military Technologies