Soyuz in French Guiana

Soyuz in Guiana, a risk for health?

A newspaper account of a Russian study on the impact of space activity at Baikonur on the health of local populations has raised questions about the installation of the Soyuz launcher in French Guiana to which CNES has responded.

Generally speaking, the protection of life, property and the environment is an absolute priority for the CNES/CSG and any rocket launched from the Guiana Space Centre has to comply with French regulations under the supervision of the authorities. The launches of all mission from the Guiana Space Centre point towards the sea. This is one of the main reasons why the site was chosen, in order to comply with CNES/CSG range safety objectives.

The characteristics of the Soyuz launcher in Guiana

The Soyuz launcher mainly uses liquid oxygen (about 183 tonnes) and kerosene (about 74 tonnes) for its propulsion as they do not involve any intrinsic toxic risk. The combustion products are identical to those automobile or aircraft engines (carbon monoxide, carbon dioxide, hydrogen and oxygen, etc.)

Only the upper FREGAT stage uses storable propellant: an oxidizer (nitrogen peroxide, about 3.8 tonnes), a fuel (UDMH, dissymmetric dimethylhydrazine, about 2.35 tonnes) and hydrazine (about 70 kg). The motor is ignited beyond an altitude of 150 Km and these propellants thus do not have any impact on the environment. Finally, satellites also use storable propellants of the same kind (derived from nitrogen peroxide and hydrazine derivatives) which are used during their life in orbit.

Range safety rules at the Guiana Space Centre

The toxic nature of this propellant has been carefully studied and the conclusions taken into account when defining range safety rules for all situations: storage and handling phases on the ground, nominal flight and also for in-flight accidents.

The toxic risk during the launch phase is controlled by defining trajectory constraints (based on the notion of an authorised flight corridor) and constraints on acceptable weather conditions (wind conditions) for the launch.

These precautions guarantee the protection of people both for nominal and accident situations.

The stages fall back into the sea 350 km away and are equipped so that they can be neutralised with no risk of contamination for people and also sunk in order to avoid any floating wreckage.

The unpublished study which led to the press coverage appears to refer mainly to the Russian PROTON launcher which is different to the Soyuz launcher.

The very nature of the launchers, the launch modes and the choice of site (with a wide opening towards the ocean) as well as the rules which are applied at the CSG for protecting life, property and the environment, enable us to assert that the conclusions of this study, as reported, do not apply to the Soyuz project in Guiana. Furthermore surveillance of the environment on the base is undertaken with independent organisations,