In a few days, the SVOM (Space-based multi-band astronomical Variable Objects Monitor) space mission, a result of French-Chinese collaboration, will be launched from the Xichang base in China. This ambitious mission aims to study gamma-ray bursts, some of the most energetic and ancient cosmic phenomena in the Universe, resulting from massive star explosions, neutron star mergers, or black holes.
SVOM will observe these gamma-ray bursts from a low Earth orbit, at an altitude of 388 miles (625 kilometers). The satellite is equipped with four sophisticated instruments, including two developed by French teams: the ECLAIRs telescope, capable of detecting and locating gamma-ray bursts, and the MXT telescope, designed to observe soft X-rays. The Chinese instruments include the GRM spectrometer, which measures the high-energy spectrum of gamma-ray bursts, and the VT telescope, which detects visible light emitted after a gamma-ray burst.
Gamma-ray bursts are extremely brief events, lasting from a few milliseconds to a few tens of seconds, but their energy is colossal, equivalent to more than a quadrillion (one billion billion) suns. To observe them effectively, the SVOM satellite will quickly reorient itself after a gamma-ray burst is detected, allowing all its instruments to precisely target the event.
This mission will allow the exploration of phenomena dating back to the early Universe, with some gamma-ray bursts emitted when the Universe was less than a billion years old. The light from these events travels billions of light-years before reaching Earth, carrying valuable information about the history and evolution of the Universe. SVOM will analyze this data to better understand interstellar composition, the dynamics of galactic gas, and the host galaxies of gamma-ray bursts.
The collaboration between the National Centre for Space Studies (CNES) for France and the China National Space Administration (CNSA) has enabled the development of cutting-edge instruments, requiring several years of preparation. French and Chinese teams have been working since mid-May on the final technical interventions and necessary checks before the launch.
In addition to gamma-ray bursts, the reactivity of SVOM and its automated instruments will allow the observation of other transient cosmic phenomena, such as supernovae and gravitational wave sources. This ability to study ephemeral or variable objects makes it a particularly rich scientific mission.
The smooth progression of activities has led the CNSA to move up the launch date by 2 days. Initially scheduled for June 24, it will now take place on Saturday, June 22 at 9 a.m. (Paris time).
Article author: Cédric DEPOND