Rapid Acquisition and Return of Mercury Polar Ice Samples

To this date only two missions have visited Mercury, with a third currently on its way. None of these have touched down on the surface, leaving Mercury the least studied of the inner planets. Preliminary results suggest that there may be water ice in the permanently shaded regions of craters near Mercury’s north pole, which holds many interesting implications for the formation of the planet and history of the early Solar System. It is the goal of the High-speed Extraction and Retrieval for Mercury’s Extraterrestrial Samples mission, or HERMES, to make the journey to Mercury and retrieve accreted polar ice samples so that scientists on Earth may unlock its secrets. To accomplish this, HERMES will have to act quickly in order to carry out its task, as the extreme conditions on and around the surface of Mercury make long-term operations difficult. After entering a polar orbit, a lander will descend to the surface, collect samples, load them into a cryocooler, and launch an ascent vehicle to rendezvous with an orbiter, all within the span of about two hours. This would make HERMES both the first mission to the surface of Mercury, as well as the first mission to return samples to Earth from another planet, containing a wealth of information about the composition and formation of Mercury’s polar ice.