Hermian Exploration Researching Mercury, Excavating Samples (HERMES) Mission Architecture

Mercury is the closest planet to the Sun and is also the smallest in the Solar System. It is an intense world; one with extreme temperatures, riddled with craters and constantly bombarded by solar winds. Despite these extreme conditions, the planet is determined to have water in the form of ice at its poles. The evidence and study of frozen water from the poles will provide insight into the history of the planet and of how it may have evolved. Mercury Sample Return’s primary objective is to send a landing craft to the north pole of the planet, to collect ice core samples up to 1 m below the surface. The mission aims to accomplish the secondary goals of studying the subsurface makeup of Mercury, investigating the origin of its magnetic field and its interaction with solar winds. The proposed mission architecture consists of four main systems: the orbiting craft, landing module, sample collection rover, and sample ascent vehicle. The orbiter is launched as a payload from Earth, traveling along a trajectory consisting Earth, Venus, and Mercury gravity assist maneuvers resulting in a polar orbit around Mercury. The landing module then detaches from the orbiter, performing a thrusted descent, aiming for a crater on the Hermian pole. A differential drive rover is deployed after a landing in and using a core drill collects samples. The samples are returned to the landing craft and transferred to the ascent vehicle which is a two-stage bi-propellant rocket with cryocooled sample payload, launching from the planet and meeting with the orbiter in its polar orbit. After capturing the samples, the orbiter begins its return to Earth trajectory with the samples kept at cryogenic conditions.