Supplementary material to “Science in NASA’s Exploration Strategy”

Bradley L. Jolliff, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri

Citation:
Jolliff, B. L. (2007), Science in NASA’s exploration strategy, Eos Trans. AGU, 88(29), 294. [Full Article (pdf)]

The NASA Advisory Council hosted a workshop February 27–March 2, 2007 in Tempe, Arizona, examining science associated with and enabled by a return to the Moon. This workshop follows the precedent set in 1965 by the meeting in Falmouth, Massachusetts, that considered science objectives to be accomplished during the Apollo Program. The Tempe workshop provided the science community, through the Science Subcommittee advisory structure, a means to make recommendations on science activities and priorities associated with the lunar exploration architecture. The workshop was the beginning of an ongoing, iterative process of discussion between the science community and the exploration architecture developers at NASA and was a key part of the plan to advise NASA on science associated with the Vision for Space Exploration (VSE).

Workshop participants included members of NAC Science committee and subcommittee members, the Lunar Architecture Team, an Outreach Committee, personnel from NASA’s Science and Exploration Systems Mission Directorates, and experts representing the space science disciplines. NASA Administrator Dr. Michael Griffin described the role of NASA’s return to the Moon within the context of the VSE. NASA officials described a human-tended lunar outpost with a notional landing site near the south pole as the current NASA architectural model, beginning with the “seventh lunar human landing” in 2020. The architecture uses the Ares/Orion launch system, with its first manned launch planned for ~2015. Subsequent heavy lift capabilities allow for a gradual accumulation of surface infrastructure at a single outpost site. The notional architecture maximizes access to nearly constant sunlight and maintains flexibility to launch unmanned cargo missions and human sorties to alternate locations for exploration, science, and resource utilization. The exploration architecture also allows for commercial and international cooperation.

Breakout sessions were aligned with the five Science Subcommittees: Astrophysics, Earth Science, Heliophysics, Planetary Protection, and Planetary Science. Discussions focused on identifying and prioritizing key objectives of science activities associated with a lunar return. The Subcommittees assessed science activities within their disciplines and considered how they would fit within the architecture. They considered technology developments, science programs, and feasibility studies that are needed to enhance the return on potential science activities.

Concerns common to all the Subcommittees include the need to access more than one lunar location, surface mobility, transportation infrastructure to deliver payloads and to return materials to Earth, and adequate crew training and time on the surface to devote to specialized science experiments and in-situ resource utilization. Participants stressed the need for a robust robotic precursor program to support scientific exploration and prepare the way for human missions. A mix of human and robotic exploration, space hardware design, orbiting and landed laboratory science payloads is needed to maximize the science return. A summary of issues addressed by the science subcommittees follows.

Astrophysics

Many promising astrophysics projects are enabled by the architecture for returning humans to the Moon. A simple yet scientifically useful study probes gravity by laser ranging, using retroreflectors or transponders. A concept of interest is the creation of radio observations of the sky, eventually observing the red-shifted 21-cm hydrogen line from the early universe. Competitively selected small payloads were considered, not only for surface deployment, but also for deployment on lunar orbiters or as secondary payloads from launch vehicles. Future, large observatories—likely deployed to the Earth-Sun L2 libration point—may utilize the lifting capacity developed for the lunar program. A suite of activities was identified to enable astrophysics capabilities, including carrying small (100 kg) packages to the lunar surface with landers, flying small packages on lunar orbiters, deployment of payloads of all sizes across large areas of the lunar surface, utilization of larger volume fairings for Ares V, and the eventual assembly/service of high-value assets with robots or humans.

Heliophysics

The Heliophysics community identified many topics that are scientifically exciting as well as useful to lunar exploration. This community can take advantage of the opportunities afforded by the journey to and exploration of the Moon. Heliophysics science topics related to lunar exploration are grouped in four themes:

  1. Heliophysics Science of the Moon—investigating fundamental space-plasma processes using the Moon and its environment as a natural laboratory,
  2. Space Weather; Safeguarding the Journey—understanding the drivers and dominant mechanisms of plasma-dust, radiation, and space environment that affect the health and productivity of human and robotic explorers,
  3. Moon as a Historical Record—seeking knowledge of the history and evolution of the Sun and Solar System as captured in the lunar regolith,
  4. Moon as a Heliophysics Science Platform—exploring possibilities of establishing remote-sensing capability on the lunar surface to probe Geospace, the Sun, and the Heliosphere.

Planetary Protection

Current NASA and COSPAR Planetary Protection policies do not constrain operations on the Moon, thus the Moon is an ideal location to investigate contamination associated with human exploration, including in-situ analyses. Forward and back contamination must be understood prior to sending astronauts to Mars, including improved space-suit designs and sample-return capabilities that prevent back contamination. Lunar exploration will allow high-fidelity tests of technologies and procedures required for Mars missions. Equipment to perform organic and microbial monitoring will be needed. Understanding the potential for forward contamination will be important in the scientific investigation of lunar volatiles in polar deposits.

Planetary Science

Much remains to be learned about the Moon and about Solar System processes and history recorded on the Moon’s surface. The geologic record of early events in planetary evolution has all but vanished from the Earth and is at least partially erased from other planetary bodies. The Moon, however, provides a record of its formation, early evolutionary processes, and the forces under which the Earth-Moon system evolved. For example, the remnants of one of the basic mechanisms of early planetary differentiation, a magma ocean, are preserved on the Moon. The impact- and solar-flux history of the Earth-Moon system, fundamental to understanding the origin and evolution of life on Earth, is also found in the lunar geologic record. Investigation of lunar surface processes, including effects of exploration on its exosphere, are applicable to more distant airless objects such as Mercury and asteroids. Earlier lunar missions resulted in shifts in fundamental appreciation of processes and timescales functioning in the Solar System, yet these missions were restricted to a limited region of a heterogeneous Moon. Fulfilling many of the highest priority scientific objectives facilitated by a return to the Moon requires access to unvisited lunar terrains by both robotic and human missions, the return of samples from those terrains, and development of a global geophysical network.

Earth Science

Although much of the current data needed for NASA’s Earth Science research is collected by low Earth orbiting (LEO) and geostationary (GEO) satellite-based instruments, useful observations could be made from a lunar outpost. During the workshop, two questions were addressed:

  1. What unique/complementary set of observations could be made from the Moon that would significantly enhance data from LEO or GEO satellites?
  2. Could those measurements be made from the proposed outpost on the rim of Shackleton Crater?

Discussion focused on lunar-based Earth observatories, solid-earth science, atmospheric composition, and Sun-Earth interactions. The notional outpost location would offer only a limited view of the Earth, thus mobility to gain access to a suitable location for Earth observing or a different outpost location would be needed. A phased approach is envisioned, with an Earth Observatory eventually located at a lunar outpost or at Earth-Moon L1. Both could offer unique, stable, serviceable platforms for global, continuous, full-spectrum views of the Earth to address a range of Earth Science questions such as the monitoring of hazards, and atmosphere/ecosystem dynamics.

Cross-cutting topics

Several topics were addressed that cut across disciplines. Exploration Science addressed investigations associated with lunar resource utilization, operating in the lunar environment, and issues with feed-forward to Mars exploration. Sun-Earth interactions combined Earth Science and Heliophysics to consider how observations from the Moon could be used to better monitor and understand how solar activity affects Earth’s environment and climate change. A session on lunar dust science addressed the characteristics of lunar dust, how it behaves in the plasma environment at the lunar surface, and what investigations are needed to conduct sustained operations safely within the lunar dust environment. Understanding and defining the roles of astronauts in the exploration architecture and related science activities was stressed, along with the need for a program to provide field geoscience training to astronauts and support personnel, and experience conducting operations with modern field analytical methods and robotic assistance.

Summary

The Tempe Workshop was a pivotal meeting of representatives of diverse science communities and NASA’s Science and Exploration Mission Directorates gathered together to discuss potential science activities, assess priorities, and identify common issues and challenges. Results of the workshop will feed into continued efforts by NASA to develop the lunar exploration architecture. The Tempe Workshop began the process of collaborative teaming between NASA and the science community that will lead to a robust, scientifically productive, and successful return-to-the-Moon program.

Presentations made at the workshop and white papers submitted for the workshop are posted at a web site hosted by the Lunar and Planetary Institute: http://www.lpi.usra.edu/meetings/LEA/.

Workshop Synthesis Committee:

Contact:

Bradley L. Jolliff
Department of Earth and Planetary Sciences
Washington University
Campus Box 1169
One Brookings Drive
St. Louis, MO 63130
Phone: +1 314 935 5622
Fax: +1 314 935 7361
E-mail: blj@levee.wustl.edu