the quality of data anticipated, reflight of comparable instruments is required in order to acquire data that will address items in column (a).
Column (c) provides examples of the type of materials that would specifically benefit the different science concepts through sample return and analyses in Earth-based laboratories. Analytical capabilities improve with each technology advancement, continually expanding the value of the sample-return investment.
Column (d) highlights an array of landed experiments, instruments, and rovers that will contribute substantially to exploration of the Moon in specific terrains. In situ activities are fundamental to detailed scientific understanding.
Initial human activities on the Moon fall within the timeframe of this report, and column (e) provides examples of human fieldwork to be undertaken for each science concept. These are activities that specifically benefit from the abilities of humans present to carry out integrated or challenging tasks. Well-designed human-robotic partnership will be central to the success of the activities.
The actual implementation of individual options within NASA’s VSE requires an integrated partnership between universities, NASA and government centers, industry, and the private sector. If the United States wishes to take a leadership role in this activity, then sustained commitment must be made to involve each of these partners in the effort and to maintain and build on strength and experience developed in the U.S. science and engineering communities. In addition, it is clear that an expanding group of space-faring countries will continue to play a central role in exploration of the Moon, and ultimately in how lunar resources are used in human society. Developing the appropriate balance and interaction between U.S. participants and foreign partners/collaborators will be a challenge as well as an opportunity.
The lunar exploration activities of the recent past and the near future are pervasively international in scope. The European Space Agency (ESA) launched Small Missions for Advanced Research in Technology (SMART)-1 to the Moon in September 2003 on a technology-demonstration mission to validate solar-electric propulsion systems. After a long journey, SMART-1 entered orbit around the Moon and began limited studies of the lunar surface with a suite of small, innovative instruments. SMART-1 scheduled a successful end-of-mission impact on the lunar nearside along with coordinated observations during the fall of 2006. A new image mosaic from the farside of the Moon obtained by SMART-1 is shown in Figure 4.1.
The Japanese Aerospace Exploration Agency has planned two missions for near-term implementation, Lunar A and SELENE. Lunar A is designed to study the lunar interior using seismometers and heat flow probes deployed by penetrators, but technical difficulties during testing put the mission on hold and it was later cancelled. SELENE, however, is a mature orbiter prepared for launch in 2007 for a 1-year nominal mission. The goals of SELENE are to study lunar origin and evolution and to develop technology for future lunar exploration. It carries an array of modern remote sensing instruments for the global assessment of surface morphology and composition. SELENE also carries two subsatellites that will enable the gravitational field of the farside to be measured accurately.
The Chinese National Space Administration formally announced its Chang’e lunar program in March 2003. Chang’e 1, a lunar orbiter with a broad complement of modern instruments, is prepared for launch in 2007. Chang’e 1 carries several remote sensing instruments to study surface topography and composition as well as the particle environment near the Moon. In addition, Chang’e 1 carries a four-wavelength microwave sounder to probe the regolith structure. Future elements being planned for the Chang’e program include a lander/rover and a sample-return mission as precursors to human exploration.
The Indian Space Research Organization will launch its Chandrayaan-1 spacecraft in 2008 on a 2-year orbital mission to perform simultaneous composition and terrain mapping using high-resolution remote sensing observations at visible, near-infrared, x-ray, and low-energy gamma-ray wavelengths. This spacecraft will carry two sophisticated instruments from the United States to characterize and map mineralogy using near-infrared spectroscopy and to map the shadowed polar regions by radar. It will also carry three ESA instruments, two of which were prototypes on SMART-1. In addition to the remote sensing experiments, the Chandrayaan-1 spacecraft will also carry an instrumented probe that will be released and targeted for a hard surface landing.