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Hoffman, Steve

Publications and source records attributed to Hoffman, Steve.

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

The Moon as a Stepping Stone to Human Mars Missions

As we venture back to the Moon with a longer term goal of future Mars missions, lunar missions can provide an important testbed for technologies, systems and operations that directly feed forward to future Mars needs. Gateway missions can provide good in-space transportation feed forward to human Mars missions. Modest operations on the Moon such as the GER (Global Exploration Roadmap)-class missions, can provide key Mars human performance and surface mission capability development and risk reduction. A human return to the Moon can, if done correctly, serve as an excellent down payment to Mars.

Connolly, John F.↗
NASA NTRS2018

The Moon as a Stepping Stone to Human Mars Missions

Human space mission designers stretching back to von Braun and beyond have envisioned the moon as a waypoint to the more challenging missions to Mars. The moon is seen as a potential proving ground for technologies, equipment and operations, and a venue upon which to learn the art of surface exploration. Mars missions are years in duration with very limited Earth return opportunities, but the moon provides the opportunity to perfect exploration concepts while being only a few days from Earth. Though the environment and gravity differ from Mars, and will thereby not provide a perfectly analogous environment, the remoteness, limited logistics, and harsh conditions on the Moon provide an environment that can be used to stress many systems that will be used or will be extensible to hardware and operations that will be used on Mars. This paper begins by describing the systems, or options for systems, that together comprise a human Mars architecture. With this human Mars operational concept as a basis of comparison, each of these systems is analyzed in the context of a range of potential exploration missions that first targets lunar exploration experience, examining how the lunar experience can be best used to prepare for the eventual human mission to Mars. The paper concludes with a concise summary of specific areas that have the strongest applicability between exploration experience on the lunar surface and extensibility to human Mars exploration.

Connolly, John F.↗
NASA NTRS2018

Advantages of a Modular Mars Surface Habitat Approach

Early crewed Mars mission concepts developed by the National Aeronautics and Space Administration (NASA) assumed a single, large habitat would house six crew members for a 500-day Mars surface stay. At the end of the first mission, all surface equipment?including the habitat--would be abandoned and the process would be repeated at a different Martian landing site. This work was documented in a series of NASA publications culminating with the Mars Design Reference Mission 5.0 (NASA-SP-2009-566). The Evolvable Mars Campaign (EMC) explored whether re-using surface equipment at a single landing site could be more affordable than the Apollo-style explore-abandon-repeat mission cadence. Initial EMC assumptions preserved the single, monolithic habitat?the only difference being a new requirement to reuse the surface habitat for multiple expedition crews. A trade study comparing a single large habitat versus smaller, modular habitats leaned towards the monolithic approach as more mass-efficient. More recent work has focused on the operational aspects of building up Mars surface infrastructure over multiple missions, and has identified compelling advantages of the modular approach that should be considered before making a final decision. This paper explores Mars surface mission operational concepts and integrated system analysis, and presents an argument for the modular habitat approach.

Rucker, Michelle↗
NASA NTRS2017

Human Mars Mission Design - The Ultimate Systems Challenge

A human mission to Mars will occur at some time in the coming decades. When it does, it will be the end result of a complex network of interconnected design choices, systems analyses, technical optimizations, and non-technical compromises. This mission will extend the technologies, engineering design, and systems analyses to new limits, and may very well be the most complex undertaking in human history. It can be illustrated as a large menu, or as a large decision tree. Whatever the visualization tool, there are numerous design decisions required to assemble a human Mars mission, and many of these interconnect with one another. This paper examines these many decisions and further details a number of choices that are highly interwoven throughout the mission design. The large quantity of variables and their interconnectedness results in a highly complex systems challenge, and the paper illustrates how a change in one variable results in ripples (sometimes unintended) throughout many other facets of the design. The paper concludes with a discussion of some mission design variables that can be addressed first, and those that have already been addressed as a result of ongoing National Aeronautics and Space Administration (NASA) developments, or as a result of decisions outside the technical arena. It advocates the need for a 'reference design' that can be used as a point of comparison, and to illustrate the system-wide impacts as design variables change.

Connolly, John F.↗
NASA NTRS2012

Is Mars Sample Return Required Prior to Sending Humans to Mars?

Prior to potentially sending humans to the surface of Mars, it is fundamentally important to return samples from Mars. Analysis in Earth's extensive scientific laboratories would significantly reduce the risk of human Mars exploration and would also support the science and engineering decisions relating to the Mars human flight architecture. The importance of measurements of any returned Mars samples range from critical to desirable, and in all cases these samples will would enhance our understanding of the Martian environment before potentially sending humans to that alien locale. For example, Mars sample return (MSR) could yield information that would enable human exploration related to 1) enabling forward and back planetary protection, 2) characterizing properties of Martian materials relevant for in situ resource utilization (ISRU), 3) assessing any toxicity of Martian materials with respect to human health and performance, and 4) identifying information related to engineering surface hazards such as the corrosive effect of the Martian environment. In addition, MSR would be engineering 'proof of concept' for a potential round trip human mission to the planet, and a potential model for international Mars exploration.

biohazards↗