[LUM#2] Nanosats, maximum perspectives

[LUM Magazine] - Published on May 3, 2016 in Science-Society

Designed by UM students, the nanosatellites at the Montpellier University Space Center (CSU) in Montpellier could help to better anticipate "Mediterranean episodes," which are expected to become more frequent.

Read all articles in this issue

September 29, 2014. The Mediterranean coastline is on alert. For several days, the weather forecast has been predicting the arrival of a "Mediterranean episode," a stormy weather system typical of the Gulf of Lion area, caused by the electrical encounter between an oceanic depression and warm currents from the Mediterranean. In just a few hours, the equivalent of several months of rainfall will fall on the Montpellier region. But when exactly? No one can say for sure.

Weather cargo ships

This is where Robusta 3-A could come into play, a small cube of technology floating in perfect tranquility several hundred kilometers away. While the laws of physics prevent the nanosatellite from carrying the optical tools available to Météo France satellites, it could provide other services. "We now need to improve forecasting in very localized areas. This requires a dedicated system that Météo France does not have," explains Laurent Dusseau. However, nanosatellites are tailor-made for this purpose.

The operation, scheduled to launch in 2018, will be carried out in three phases. First step: GPS signals from "traditional" satellites are collected by mini weather stations carried on board cargo ships at sea. "Depending on how these signals propagate through the atmosphere, we can estimate the amount of water vapor present above the ship," explains the CSU director. This data is then transmitted to the nanosatellite, which transfers it to a ground station, where it will be used to develop predictive models. By acting as a relay, Robusta 3-A could help to establish accurate mapping, enabling more detailed and, above all, up-to-date monitoring of the disturbance.

A tropical Languedoc?

This technological marvel, measuring just a few centimeters across, has another advantage: its price. A few hundred thousand euros: about a hundred times less than a large geostationary satellite. This is not surprising for a satellite designed entirely by students: "They lead the projects from A to Z," explains Frédéric Saigné. " From technical degrees to post-doctorates, each level of study is supervised by the level above," adds the director of the Van Allen Foundation.

A foundation that brings together manufacturers and major space agencies to take student projects all the way up to the stars. A large-scale consortium capable of tackling the challenges posed by these Mediterranean episodes, which experts predict will become more intense, with rainfall reaching up to 1,000 mm in a single day. Precipitation levels worthy of a tropical climate.