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: Near term missions on the journey to mars
A human mission to Mars has long been an exploration goal of the United States and the international community. To achieve this goal, NASA is developing the Orion crew capsule and Space Launch System (SLS) as key elements in the eventual architecture for the Evolvable Mars Campaign (EMC). Both elements are designed to advance human spaceflight beyond Low Earth Orbit (LEO) for the first time since the Apollo missions with the eventual goal of landing humans on Mars. This aggressive goal is complicated by the need to optimize the use of government resources during a period when budgets are challenged. Defining and prioritizing the technology and hardware needed is crucial to achieving the goal of landing humans on Mars. This paper will discuss potential near term missions that leverage Orion and SLS. A unique feature of the SLS/Orion system is supporting co-manifested payloads along with launching crews beyond LEO. Doing so provides new flexibility in achieving human exploration, operations, and science objectives on any given mission. Utilizing this co-manifest capability, a number of potential near term missions have been identified that will mature the elements needed for an eventual Mars mission, develop long duration mission operations techniques necessary for the Mars mission, refine life support systems, and conduct science investigations that were previously impractical. This paper will discuss a possible roadmap of missions that could be conducted over the next decade to place humans on the path to Mars.
300-kW Solar Electric Propulsion System Configuration for Human Exploration of Near-Earth Asteroids
The use of Solar Electric Propulsion (SEP) can prov ide significant benefits for the human exploration of near-Earth asteroids. These benefit s include substantial cost savings ‐ represented by a significant reduction in the mass required to be lifted to low Earth orbit ‐ and increased mission flexibility. To achieve these benefits, system power levels of 100’s of kW are necessary along with the capability to store and process tens of thousands of kilograms of xenon propellant. The paper presents a conceptual design of a 300-kW SEP vehicle, with the capability to store nearly 40,000 kg of xenon, to support human missions to near-Earth asteroids.