Target NEO: Open Global Community NEO Workshop Report
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July 28, 2011 On behalf of the international near-Earth object (NEO) community, we are pleased to transmit the final report of the Target NEO: Open Global Community NEO Workshop, held at George Wash- ington University on February 22, 2011. This report has undergone extensive public peer review, and the summary of results has also been presented and refined at several conferences, including the 42nd Lunar and Planetary Science Conference on March 8, 2011 and the 2nd International Academy of Astronautics Planetary Defense Conference on May 11, 2011. The workshop was conceived and implemented by the community to ensure that the collective opinions of experts in fields pertinent to both the robotic and human exploration of NEOs were heard and documented. The workshop hosted nearly 200 attendees with representation from NASA Headquarters, seven NASA Centers, academia, industry, and other public agencies and international organizations. This report embraces the collective opinions of these participants and the rigor of subsequent peer review. The key question posed by the workshop was: What information about NEOs is still needed to support a robust, sustainable human exploration program? The attached report includes numerous recommendations prompted by this question, but a primary conclusion by the participants is the need for a space-based survey telescope to greatly expand the catalog of accessible targets for human exploration. This critical asset should be considered as part of the basic infrastructure to enable human exploration beyond LEO. Such an asset could be rapidly developed and would have cross-cutting benefits across multiple NASA directorates and international space agency interests. This report of the Target NEO workshop is hereby provided by the community in service to NASA and international space agencies in pursuit of our collective objectives for space exploration. Respectfully, Members of the Robotic and Human Exploration Communities Target NEO: Open Global Community NEO Workshop Report Brent W. Barbee, Editor July 28, 2011 George Washington University, Washington, D.C. February 22, 2011 Revision History Revision Date Notes Number 1 04/08/2011 Release of initial draft for public comment. 2 04/25/2011 Embedded all fonts; no content changes. Appended addendum summarizing the NEO activities coordination workshop held in Bucharest during May 3 05/24/2011 2011; expanded list of acronyms; added NEO orbit types figure; text re-worded in a few places for clarity. Listing B. W. Barbee as editor on title page; minor correction to formatting of NEO names in Figure 4 and switch to PDF graphics file; replaced Figure 1 4 07/28/2011 with modified PDF graphics file; cover letter added; updated NEO activities coordination workshop adden- dum and made it an appendix; revised Executive Sum- mary. Acknowledgments The session co-chairs, who authored this report, wish to extend their gratitude to all of the workshop panelists and participants, whose willingness to share their expertise made the workshop–and this report–possible. Introduction, Workshop Scope, Overview of Flexible Path Vision Moderator: Panel: JohnLogsdon,GeorgeWashingtonUniversity ThomasJones,Florida Institute for Human & Machine Cognition Scott Pace, George Washington University Dave Korsmeyer, NASA-ARC The NEO Population: Knowns and Unknowns Co-chairs: Panel: Andy Cheng, JHUAPL Tim Spahr, MPC Lindley Johnson, NASA-HQ Don Yeomans, JPL Scott Stuart, MIT Lincoln Laboratory Amy Mainzer, JPL Al Harris, Consultant Mission Design: Getting There and Back Co-chairs: Panel: Brent Barbee, NASA-GSFC Damon Landau, JPL Dan Adamo, Astrodynamics Consultant (NASA-JSC, ret.) Bret Drake, NASA-JSC Ron Mink, NASA-GSFC Josh Hopkins, Lockheed-Martin Space Systems Company Chel Stromgren, SAIC NEO Characteristics for Safe and Meaningful Human Exploration Co-chairs: Panel: Andy Rivkin, JHUAPL Patrick Michel, CNRS, Cote d’Azur Observatory Paul Abell, NASA-JSC Lance Benner, JPL Joe Nuth, NASA-GSFC Dan Scheeres, University of Colorado Mike Hess, NASA-JSC Mission Duration: Quantifying the Risks Co-chairs: Panel: Dan Mazanek, NASA-LaRC Craig Kundrot, NASA-JSC RobLandis,NASA-ARC/JSC JackStuster,AnacapaSciences,Inc. Ron Turner, ANSER Andy Thomas, NASA-JSC Affordable Options for Increasing the Accessible NEO Catalog Co-chairs: Panel: Rich Dissly, Ball Aerospace Andy Cheng, JHUAPL Ken Hibbard, JHUAPL Lynne Jones, University of Washington Ken Hibbard, JHUAPL Amy Mainzer, JPL Robert Arentz, Ball Aerospace NASA HQ Feedback on Workshop Discussions Co-chairs: Panel: James Garvin, NASA-GSFC Charles Gay, NASA-HQ Cheryl Reed, JHUAPL Sam Scimemi, NASA-HQ Benjamin Neumann, NASA-HQ i Table of Contents Executive Summary iii 1 Introduction 1 2 The NEO Population: Knowns and Unknowns 1 2.1 NEO Monitoring and Publication of Results . 2 2.2 The State of NEO Survey Activities . 2 2.3 Discovery of NEOs Potentially Accessible for Human Space Flight . 3 2.4 SummaryofKeyFindings................................ 4 3 Mission Design: Getting There and Back 4 3.1 The near-Earth object (NEO) Human Space Flight (HSF) Accessible Targets Study (NHATS) .......................................... 5 3.2 NEO Mission Design Challenges . 7 3.3 Impacts of NEO Detection and Observation Methods on Human Space Flight Op- portunities ......................................... 8 3.4 Mission Architecture Considerations . 9 3.5 SummaryofKeyFindings................................ 9 4 NEO Characteristics for Safe and Meaningful Human Exploration 10 4.1 NEO Population Diversity and Motivations for Exploration . 10 4.2 Characterization Information Relevant to Human Exploration . 11 4.3 Robotic Precursor Missions . 13 4.4 NEOProximityOperations .............................. 15 4.5 NEO Target Selection Considerations . 15 4.6 SummaryofKeyFindings................................ 15 5 Mission Duration: Quantifying the Risks 16 5.1 Acute and Long-Term Physiological Effects from Radiation . 16 5.2 Behavioral Health Support . 18 5.3 Micro-gravityEnvironment . 18 5.4 Habitation & Life Support . 19 5.5 Human Factors and Group Interaction Considerations . 20 5.6 Mission Support/Operations Considerations and Abort Options . 21 5.7 SummaryofKeyFindings................................ 23 6 Affordable Options for Increasing the Accessible NEO Catalog 24 6.1 SurveyOptions..................................... 25 6.2 SurveySimulationResults. 25 6.3 Survey Operations Considerations . 27 6.4 SummaryofKeyFindings................................ 28 Appendix I: NEO Activities Coordination Workshop Addendum 29 Acronyms and Abbreviations 32 ii Executive Summary The Open Global Community NEO Workshop was held on February 22, 2011, at George Wash- ington University in Washington, D.C., to bring together experts for a technical discussion of the key issues surrounding human exploration of near-Earth objects (NEOs). The workshop ad- dressed the following questions: Are there enough known, potentially accessible NEOs to support a robust, resilient, forward-looking, and affordable human exploration program beyond Low Earth Orbit (LEO) over the next two decades? What are the knowns and unknowns in the context of human exploration of NEOs? Is the missing information critical or optional? What is the timescale on which critical missing information must be acquired? What level of effort and what resources are necessary to resolve outstanding issues? And, finally, what is the community consensus regarding the costs and benefits of resolving these issues? The workshop consisted of five technical sessions in which expert speakers presented the latest research and results on the relevant topics and then participated in question-and-answer sessions during panel discussions. The speakers consisted of domestically and internationally recognized small body experts in both the robotic and Human Space Flight (HSF) communities, including small body scientists and related analytical and operational experts, mission designers, systems engineers, and experts in mission operations, safety, and human health factors such as radiation. The following is a summary of those proceedings. While ongoing ground-based surveys and data archives maintained by the NEO Program Office and the Minor Planet Center have provided a solid basis to build upon, a more complete catalog of the NEO population is required to inform a robust and sustainable HSF exploration program. Low change-in-velocity (∆v), short-duration HSF mission opportunities to currently known NEOs are few and far between. Also, it is envisioned that a target NEO will need to be discovered several years in advance to provide sufficient lead time to deliver robotic precursor missions, plan the human mission, and deliver the crew to the chosen destination. The paucity of viable candidate destination NEOs can be attributed to the fact that NEO observing assets are currently confined to Earth’s vicinity. Historical analysis of past trajectory opportunities to NEOs has shown that some were highly accessible during the timeframes of their discovery, because they had to closely approach Earth in order to be detected. Assuming that only a small percentage of the total NEO population accessible to HSF is currently known, a better return on investment is realized by a comprehensive NEO survey based in deep space, rather than augmenting HSF capability to access only the currently known NEOs. Analysis shows a dedicated NEO survey has the potential to increase the number of known HSF-accessible targets by at least an order of magnitude. To this end, there exist today multiple