Initiating an Interplanetary He-3 Economy with Lunar Propellant Generation and In-Situ Resource Exploration

Introduction: We present the initial development of an integrated space transportation and energy architecture of a self-sustaining interplanetary economy based on extraction of Helium-3 (He) for fusion power and propulsion. While no single element of this architecture is entirely new, our contribution is the synergistic space transportation and energy architecture, shown in Figure 1, which provides a practical and sustainable path to a revolutionary D-He powered future on earth and in space. In this talk, we will progressively focus our vision from spanning the Solar System and centuries of time to recommended payloads for the first lunar landing missions of this epoch of Exploration, in the years 2010-2012. Lunar Resources Enable This Architecture: The Moon is the key to this architecture, as it is for the Exploration Vision in general, since 1. The Moon contains enough He in adequate concentration to supply initial demand for terrestrial power generation and justify the resources to develop He reactors. 2. The Moon is 2000x closer to Earth than the other reservoirs of He, the outer planets, vastly simplifying repair, resupply, and rescue operations. 3. The Moon has LOX/LH2 resources for propellant for high thrust/mass (>1 ms) transportation needed to move cargo to and from the lunar surface. The He Extraction Architecture Implies Goals for Near-Term Robotic Lunar Exploration: While elements of this economy are in the distant future, the first steps are within the planning horizon of lunar exploration, between now and 2020: 1. Locate highest concentrations of 3He, hydrogen, and oxygenic minerals. Polar ice deposits would be a windfall but are not necessary 2. Field-test extraction methods The next step, building a positive mass flow lunar H2O economy, is analyzed with a detailed mass flow model connecting mining operations, lunar bases, the lunar Lagrange point, LEO, and the Earth’s surface to show a reduction of launch mass by a factor of 4 or more. Robotic Lunar Exploration Goals Lead to Site Selection, Measurement Objectives, and Payloads for the First Lunar Landers: In pursuit of lunar water, we identify and discuss landing sites near Shackleton Crater which meet the requirements of 1. Solar illumination for >60 days during Solstice 2. Line of Sight to Earth for communication >14 days 3. Adjacent to cold traps which may contain water. 4. Less than 15 degree slope for landing. We discuss a notional payload suite to characterize the cold trap and adjacent regions, including a waterdetection instrument (“Water Boy”) which can be shot out of a mortar from the lander in sunlight to the regions of interest in perpetual darkness. Based on the work of Vasavada et al. [1], this distance can be as small as 2 km. “Water Boy” payloads may also be delivered from a magazine aboard an orbiting bus, as described by Van Cleve and Mitchell [2]. Finally, we discuss searching for 3He on subsequent landed missions using active neutron spectroscopy. References: [1] Vasavada A. R. et al. (1999), Icarus 141, 179 [2] J. E. Van Cleve and S. Mitchell (2005), AAS 05144[JVC1].