Combining Solar Electric Propulsion and chemical propulsion for crewed missions to Mars
This paper documents the results of an investigation of human Mars mission architectures that leverage near-term technology investments and infrastructures resulting from the planned Asteroid Redirect Robotic Mission (ARRM), including high-power Solar Electric Propulsion (SEP) and a human presence in Lunar Distant Retrograde Orbit (LDRO). The architectures investigated use a combination of SEP and chemical propulsion elements. Through this combination of propulsion technologies, these architectures take advantage of the high efficiency SEP propulsion system to deliver cargo, while maintaining the faster trip times afforded by chemical propulsion for crew transport. Evolved configurations of the Asteroid Redirect Vehicle (ARV) are considered for cargo delivery. Sensitivities to SEP system design parameters, including power level and propellant quantity, are presented. For the crew delivery, liquid oxygen and methane stages were designed using engines common to future human Mars landers. Impacts of various Earth departure orbits, Mars loiter orbits, and Earth return strategies are presented. The use of the Space Launch System for delivery of the various architecture elements was also investigated and launch vehicle manifesting, launch scheduling and mission timelines are also discussed. The study results show that viable Mars architecture can be constructed using LDRO and SEP in order to take advantage of investments made in the ARRM mission.
Space launch system and solar electric propulsion: Comparing payload to Earth escape from different initial Earth orbits
The Space Launch System (SLS) is being built as the launch vehicle to enable crewed exploration of destinations beyond Low Earth Orbit. One significant piece of cargo that SLS will deliver is the Deep Space Transport (DST), a combination deep space habitat and transit module that will carry crew beyond Earth's sphere of influence. The proposed propulsion system for the DST includes both high thrust chemical propulsion and low thrust electric propulsion elements. Initial estimates of the size of the DST are larger than the projected future capability of the SLS launch vehicle, so additional propulsive capabilities will be required to deliver the DST to the Deep Space Gateway (DSG). The goal of this paper is to explore the trade space between the potential initial orbits that SLS can deliver the DST to and the DST propulsion systems, in order to maximize the final delivered mass of the DST to the DSG.
Small Body Rendezvous Mission Using Solar Electric Ion Propulsion: Low Cost Mission Approach and Technology Requirements
Abstract This paper shows that existing solar electric ion propulsion (SEP) technology can deliver substantial payloads to important small bodies for an effective cost. SEP, using hardware being validated by the NASA SEP Technology Application Readiness (NSTAR) program, can deliver significantly more mass in a dramatically shorter period of time than a chemical propulsion system launched from the same Delta II launch vehicle. Analysis of three rendezvous missions shows that NSTAR hardware can deliver a payload (spacecraft with science) of 364 kg to asteroid Vesta, 280 kg to the outer main belt asteroid Ceres, and 291 kg to comet Kopff. The paper begins with a discussion of why SEP is now ready for space science missions, the NSTAR program, benefits of ion propulsion, the range of SEP applications, a detailed SEP mass breakdown, and the cost and other considerations of using an ion propulsion system. A discussion of SEP navigation and a new start development schedule concludes the paper.