The Gruithuisen region in northern Oceanus Procellarum on the Moon contains three distinctive domes interpreted as nonmare volcanic features of Imbrian age. A 4 d extravehicular activity (EVA), four-astronaut sortie mission to explore these enigmatic features and the surrounding terrain provides the opportunity to address key outstanding lunar science questions. The landing site is on the mare south of Gruithuisen 3 (36.22°N, 40.60°W). From this site, diverse geologic terrains and features are accessible, including highlands, dome material, mare basalts, multiple craters, small rilles, and a negative topographic feature of unknown origin. Preliminary mission planning is based on Clementine multispectral data, Lunar Prospector geochemical estimates, and high-resolution (0.5 m/pixel) stereo images from the Lunar Reconnaissance Orbiter Narrow Angle Camera. Science objectives for the mission include: (1) determining the nature of the domes, (2) identifying and measuring the distribution of any potassium, rare earth elements, and phosphorus (KREEP)- and thorium-rich materials, (3) collecting samples for age dating of key units to investigate the evolution of the region, and (4) deploying a passive seismic grid as part of a global lunar network. Satisfying the science objectives requires 7 h, ~20 km round-trip EVAs, and significant time driving on slopes up to ~15°.

In response to the need to develop science-conducive architectures for future human exploration of particularly interesting targets on lunar and planetary surfaces, we have developed scenarios for a geological expedition to Marius Hills within current constraints of week-long sortie missions. This area has a dense nest of volcano-tectonic features representing the range of mare volcanic structures, which is one of the reasons why it is so compelling. Two distinct episodes of flood basaltic volcanism are represented, along with volcanic shields, domes, cones, rilles, wrinkle ridges, floor fractures, and a magnetic swirl anomaly. We found two potential landing sites (constrained to 10 km radius) in the southwestern portion of Marius Hills that would allow access to examples of most of the features of interest. We describe the geological context, resulting investigations, daily traverses, and survey/sample sites along those routes, in detail, as well as the required tools, instruments, and surface activities. The resulting science requirements, for a minimum of two rovers plus a few hundred kilograms of science payload, along with implications for a science-conducive architecture, are considered.

The Schrödinger impact basin near the southern pole on the lunar farside (134°E, 75°S) is a young multiring impact basin, and it is well preserved and exposed for scientific study. A crewed sortie-reconnaissance mission to Schrödinger Basin would allow (1) collection of samples in order to obtain an absolute age date for the Schrödinger impact event and to constrain the ages of volcanic events, (2) detailed analysis of pyroclastic materials that mantle the basin's impact melt sheet, (3) study of lunar explosive volcanism mechanics, and (4) installation of a passive seismic array for study of interior activity. The region's diversity of geologic materials and features make it a prime target for human and robotic exploration. A landing site located within the pyroclastic deposit (139.6°E, 75.7°S) allows access to the volcanic vent and inner ring of the basin. Sampling the inner ring, which may be composed of South Pole–Aitken Basin uplift material, would allow absolute dating of the South Pole–Aitken Basin event. Engineering objectives necessary for extending surface stay time for sortie missions or a lunar outpost can be met at this locale. Pyroclastic material is optimal for in situ oxygen production. Demonstrating oxygen production and storage at the landing site would prove technologies for an outpost and leave a cache of consumables for use by future longer-term expeditions. Mission planning is based on Lunar Reconnaissance Orbiter , Lunar Orbiter , Clementine , and SELENE mission data. Extravehicular activities necessary for completing the science objectives require long traverses (24 km and 7.5 h per traverse) for a four-member crew over a 4 d mission.

The lunar south polar region (60°S–90°S) is being mapped at 1:2,500,000 scale using spacecraft data ( Lunar Reconnaissance Orbiter , Clementine , Lunar Prospector , and Lunar Orbiter ) to characterize geologic units, recognize contacts and structures, and identify impact craters (diameter [ D ] >2 km) for age dating. Most of the map area is located within the South Pole–Aitken basin, the largest (~2600 km) and oldest basin known on the Moon. At 18 km deep, South Pole–Aitken basin is believed to have exposed materials from the Moon's lower crust or upper mantle. Several large impact basins, such as Schrödinger basin ( D = 334 km), are superposed on the floor of South Pole–Aitken and may have excavated through the floor of the basin. Thus, the materials that form the primary basin structures (rim and peak-ring) of Schrödinger, as well as the materials that cover its floor, may be used as proxies for the ancient lunar crustal and/or upper-mantle materials. Characterization of the materials that constitute Schrödinger and geologic mapping of the basin have identified nine units within the Schrödinger assemblage organized into three groups: basin materials, the plains formation, and the volcanic formation. The volcanic and plains materials found on the floor of Schrödinger exhibit flat expanses with smooth to rough surfaces and are dissected by floor fractures. These materials are interpreted to consist of impact melt and/or were emplaced by effusive eruptions of mafic materials, and they are some of the youngest materials in the basin, ranging from early Imbrian to early Eratosthenian in age.