SINGLE LAUNCH, DIRECT EARTH RETURN MSR MISSION

摘要

The standard Mars Sample Return mission profile implies two launches (one orbiter and one lander) and a rendezvous in Mars orbit before returning the sample to Earth. This paper explores the possibility to combine an improved cryogenic upper stage of ARIANE 5 using VINCI engine, an orbital propulsion module using cryogenic propellants, associated with active refrigeration for interplanetary cruise or a combination of electric propulsion provided by Hall effect Thrusters (PPS 5000) with chemical propulsion, either cryogenic or earth storable bipropellant. The mass provided by these combinations is sufficient to land several tons on Mars surface. This enables a large increase of the lander mass. It is therefore possible to return the samples directly to Earth without Mars orbit rendezvous (required Delta V ～ 6 km/s) The payload gain comes from three factors: 1. The direct payload gain from VINCI engine and its re-starting capability for interplanetary missions. 2. The use of electric propulsion where it is the most efficient: for orbit transfer around a celestial body (e.g. from "GTO like" to highly elliptical orbit) instead of being used during interplanetary flight. 3. The use of chemical propulsion where it is the most effective: for impulsive injection into interplanetary orbit by firing at perigee (conversely by firing the chemical engine on an hyperbolic trajectory to insure planetary capture).