Speaker
Description
Background of the study
The possibility of a 6-month round-trip mission to Mars using a propellantless propulsion system termed plasma surfing is investigated. The technique is based on the idea that a spacecraft interacting electromagnetically with the solar wind can generate a lifting force perpendicular to the apparent direction of the wind. The lift-generating mechanism extracts power from the flow over the vehicle in the apparent wind direction, which is then used to accelerate the surrounding medium in the transverse direction, generating lift at the expense of drag. The proposed implementation uses two plasma magnets to stroke the solar wind, extracting power in the process, while acceleration of the surrounding medium is achieved by launching plasma waves propagating at low group velocity. The concept for extraction of power from the solar wind via plasma magnets was previously established by Greason (JBIS, 2019), and the use of the extracted power to launch transverse plasma waves for lift was developed by Larrouturou et al. (Frontiers in Space Technologies, under review). In this presentation, we will apply this technology to realizing a rapid-transit, round-trip mission architecture for human exploration of Mars.
Methodology
In the trajectories investigated here, the lift generated is used to gain or lose orbital velocity to transfer from one orbit to the other. The simulations are done via numerical integration in a simplified planar, circular concentric model of the sun-Earth-Mars system. Transferring from Earth orbit to Mars orbit can be achieved relatively easily by first increasing orbital velocity to overtake Mars, and second losing excess velocity to rendezvous. The return transit (Mars to Earth) is more challenging, since it is problematic for the spacecraft to sail upwind. Therefore, for the return trip the spacecraft has to lose orbital velocity by directing the lift vector against the orbital direction (canceling orbital velocity) and then switch off the plasma interaction to accelerate toward the Sun under gravitational attraction alone. Once the Earth has been passed, the plasma interaction is turned back on and the spacecraft’s orbital velocity increases and turns to match Earth’s velocity. The lifting flight trajectory is optimized numerically to identify launch windows and to maximize duration on the Martian surface.
Results
In the numerical trajectory simulations incorporating orbital mechanics and plasma interactions, the ability to transfer from one orbit to another without the use of propellant has been demonstrated. The ability to use plasma surfing for round trip transits to and from Mars with a total trip time of six months is seen to be feasible, minimizing the risk to the crew posed by galactic cosmic rays and coronal mass ejection events.
Conclusion
The ability to perform a round-trip Mars mission of the same duration and radiation exposure of a typical ISS stay would greatly enable human exploration of Mars. The fact that the system is ideally propellantless provides the possibility for an economical, scalable, and robust infrastructure for interplanetary transportation.
