[LUM#2] Nanosats, maxiperspectives

Designed by UM students, the nanosatellites of the university space center (CSU) at Montpellier could help us better anticipate "Mediterranean episodes", the frequency of which is set to increase.

September 29, 2014. The Mediterranean coast is on high alert. For several days now, the weather forecasters have been announcing the arrival of a "Mediterranean episode", a thunderstorm system typical of the area around the Gulf of Lion, born of the electrical encounter between an oceanic low-pressure system and warm currents from the Mediterranean. In just a few hours, the equivalent of several months' rainfall will fall on the Montpellier region. But when exactly? No one is in a position to say.

Weather freighters

This is where Robusta 3-A could come in, a small cube of technology floating in perfect tranquility several hundred kilometers away. Although the laws of physics prevent the nanosatellite from carrying the optical tools available to Météo France's satellites, it could provide other services. "Today, we need to improve forecasting over highly localized areas. This requires a dedicated system that Météo France doesn't have," explains Laurent Dusseau. Tailor-made, on the other hand, for nanosats.

The operation, scheduled for launch in 2018, will be divided into three phases. First stage: GPS signals from "traditional" satellites are collected by mini-weather stations aboard cargo ships at sea. " Depending on how these signals propagate in the atmosphere, we can assess the amount of water vapor present above the ship," sums up the CSU director. These data are then transmitted to the nanosat, which transfers them to a ground station, where they are used to develop predictive models. By acting as a relay, Robusta 3-A could contribute to the establishment of precise cartography, enabling more detailed and, above all, up-to-date monitoring of the disturbance.

A tropical Languedoc?

This concentrate of technology, measuring just a few centimetres on each side, has another quality: its price. A few hundred thousand euros: about a hundred times less than a large geostationary satellite. This is hardly surprising for a satellite designed entirely by students: "They manage projects from A to Z," explains Frédéric Saigné. From DUT to post-doctorate, each level of study is supervised by the level above," explains the director of the Van Allen Foundation.

A foundation that brings together manufacturers and major space agencies to take student projects to the stars. A consortium on a scale commensurate with the stakes involved in these Mediterranean episodes, which specialists predict will intensify, with rainfall reaching up to 1000 mm in a single day. Rainfall levels worthy of a tropical climate.

UM podcasts are now available on your favorite platforms (Spotify, Deezer, Apple podcasts, Amazon Music...).