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Drake, Bret

Publications and source records attributed to Drake, Bret.

11 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 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 NTRS2017

Human Mars EDL Pathfinder Study: Assessment of Technology Development Gaps and Mitigations

This paper presents the results of a NASA initiated Agency-wide assessment to better characterize the risks and potential mitigation approaches associated with landing human class Entry, Descent, and Landing (EDL) systems on Mars. Due to the criticality and long-lead nature of advancing EDL techniques, it is necessary to determine an appropriate strategy to improve the capability to land large payloads. A key focus of this study was to understand the key EDL risks and with a focus on determining what "must" be tested at Mars. This process identified the various risks and potential risk mitigation strategies along with the key near term technology development efforts required and in what environment those technology demonstrations were best suited. The study identified key risks along with advantages to each entry technology. In addition, it was identified that provided the EDL concept of operations (con ops) minimized large scale transition events, there was no technology requirement for a Mars pre-cursor demonstration. Instead, NASA should take a direct path to a human-scale lander.

Lillard, Randolph↗
NASA NTRS2017

Achieving And Sustaining Human Exploration of Mars The Fourth Community Workshop (AM IV)

About a half decade ago, several professionals working mainly in industry on scenarios for initial human exploration of Mars exploration together recognized that, under generally similar assumptions, there was a fair degree of similarity among these scenarios. Moreover, opportunities should be sought for greater community input into NASAs own scenario-building for the future of human space flight. A series of focused community workshops were considered to be effective to critically assess the increasingly sophisticated scenarios. Explore Mars, Inc. the American Astronautical Society agreed to support them. Four workshops to date each involve about sixty professional scientists, engineers, technologists, and strategists from NASA, academia, aerospace corporations, the National Academies, consulting organizations, and potential international partners. Each workshop produced a series of presentations and reports briefed to NASA leadership and other stakeholders.

Achieving Sustaining Human Exploration of Mars The↗
NASA NTRS2013

A Combined Solar Electric and Storable Chemical Propulsion Vehicle for Piloted Mars Missions

The Mars Design Reference Architecture (DRA) 5.0 explored a piloted Mars mission in the 2030 timeframe, focusing on architecture and technology choices. The DRA 5.0 focused on nuclear thermal and cryogenic chemical propulsion system options for the mission. Follow-on work explored both nuclear and solar electric options. One enticing option that was found in a NASA Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) design study used a combination of a 1-MW-class solar electric propulsion (SEP) system combined with storable chemical systems derived from the planned Orion crew vehicle. It was found that by using each propulsion system at the appropriate phase of the mission, the entire SEP stage and habitat could be placed into orbit with just two planned Space Launch System (SLS) heavy lift launch vehicles assuming the crew would meet up at the Earth-Moon (E-M) L2 point on a separate heavy-lift launch. These appropriate phases use high-thrust chemical propulsion only in gravity wells when the vehicle is piloted and solar electric propulsion for every other phase. Thus the SEP system performs the spiral of the unmanned vehicle from low Earth orbit (LEO) to E-M L2 where the vehicle meets up with the multi-purpose crew vehicle. From here SEP is used to place the vehicle on a trajectory to Mars. With SEP providing a large portion of the required capture and departure changes in velocity (delta V) at Mars, the delta V provided by the chemical propulsion is reduced by a factor of five from what would be needed with chemical propulsion alone at Mars. This trajectory also allows the SEP and habitat vehicle to arrive in the highly elliptic 1-sol parking orbit compatible with envisioned Mars landing concepts. This paper explores mission options using between SEP and chemical propulsion, the design of the SEP system including the solar array and electric propulsion systems, and packaging in the SLS shroud. Design trades of stay time, power level, specific impulse and propellant type are discussed.

Mercer, Carolyn R.↗
NASA NTRS2013

Human Expeditions to Near-Earth Asteroids: An Update on NASA's Status and Proposed Activities for Small Body Exploration

Over the past several years, much attention has been focused on the human exploration of near-Earth asteroids (NEAs). Two independent NASA studies examined the feasibility of sending piloted missions to NEAs, and in 2009, the Augustine Commission identified NEAs as high profile destinations for human exploration missions beyond the Earth- Moon system as part of the Flexible Path. More recently the current U.S. presidential administration directed NASA to include NEAs as destinations for future human exploration with the goal of sending astronauts to a NEA in the mid to late 2020s. This directive became part of the official National Space Policy of the United States of America as of June 28, 2010. The scientific and hazard mitigation benefits, along with the programmatic and operational benefits of a human venture beyond the Earth-Moon system, make a mission to a NEA using NASA s proposed exploration systems a compelling endeavor.

Abell, Paul↗
NASA NTRS2011

Human Exploration of Near-Earth Objects Accessibility Study

Key questions addressed: How short can the trip times be reduced in order to reduce crew exposure to the deep-space radiation and microgravity environment? Are there options to conduct easy, early missions?. What is the affect of infusion of advanced propulsion technologies on target availability When do the departure opportunities open up, how frequent and how long are they? How many launches are required to conduct a round trip human mission to a NEA? And, based on the above, how many Near-Earth Asteroids are available

Abell, Paul↗
NASA NTRS2010

Exploration Roadmap Working Group (ERWG) Data Collection, NASA's Inputs

This slide presentation reviews four areas for further space exploration: (1) Human Exploration of Mars Design Reference Architecture (DRA) 5.0, (2) Robotic Precursors targeting Near Earth Objects (NEO) for Human Exploration, (3) Notional Human Exploration of Near Earth Objects and (4) Low Earth Orbit (LEO) Refueling to Augment Human Exploration. The first presentation reviews the goals and objectives of the Mars DRA, presents a possible mission profile, innovation requirements for the mission and key risks and challenges for human exploration of Mars. The second presentation reviews the objective and goals of the robotic precursors to the NEO and the mission profile of such robotic exploration. The third presentation reviews the mission scenario of human exploration of NEO, the objectives and goals, the mission operational drivers, the key technology needs and a mission profile. The fourth and last presentation reviews the examples of possible refueling in low earth orbit prior to lunar orbit insertion, to allow for larger delivered payloads for a lunar mission.

Drake, Bret↗
NASA NTRS1998

Mars Human Exploration Reference Mission

This presentation proposes the next steps for human exploration of Mars. The presentation reviews the reasons for human exploration of Mars. Two different trajectories are proposed: (1) for a long stay mission, and (2) for a short term mission, which could also include a swing by Venus. A reference mission scenario is investigated, which includes forward deployment of two cargo missions, followed by a human piloted mission. The power needs of such a mission include nuclear thermal propulsion, and the possible use of Mars in situ resources. The exploration will require electric propulsion, stationary power source, and a mobile power source. The trajectories required for electric propulsion of earth are shown, and the engineering of a Mars Transportation Habitat are reviewed.

Drake, Bret↗