Abstract. Lunar orbit insertion LOI is a critical maneuver for any mission going to the Moon. Optimizing the geometry of this maneuver is crucial to the success of the architecture designed to return humans to the Moon. LOI burns necessary to meet current NASA Exploration Constellation architecture requirements for the lunar sortie missions are driven mainly by the requirement for global access and "anytime" return from the lunar surface. This paper begins by describing the Earth-Moon geometry which creates the worst case ∆V for both the LOI and the translunar injection (TLI) maneuvers over the full metonic cycle. The trajectory which optimizes the overall ∆V performance of the mission is identified, trade studies results covering the entire lunar globe are mapped onto the contour plots, and the effects of loitering in low lunar orbit as a means of reducing the insertion ∆V are described. Finally, the lighting conditions on the lunar surface are combined with the LOIand TLI analyses to identify geometries with ideal lighting conditions at sites of interest which minimize the mission ∆V.

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This study investigates the feasibility of using a heavy-lift variant of the Lunar Surface Manipulator System (LSMS-H) to lift and handle a 12 metric ton payload. Design challenges and requirements particular to handling heavy cargo were examined. Differences between the previously developed first-generation LSMS and the heavy-lift version are highlighted. An in-depth evaluation of the tip-over risk during LSMS-H operations has been conducted using the Synergistic Engineering Environment and potential methods to mitigate that risk are identified.The study investigated three specific offloading scenarios pertinent to current Lunar Campaign studies. The first involved offloading a large element, such as a habitat or logistics module, onto a mobility chassis with a lander-mounted LSMS-H and offloading that payload from the chassis onto the lunar surface with a surface-mounted LSMS-H. The second scenario involved offloading small pressurized rovers with a landermounted LSMS-H. The third scenario involved offloading cargo from a third-party lander, such as the proposed ESA cargo lander, with a chassis-mounted LSMS-H. In all cases, the analyses show that the LSMS-H can perform the required operations safely. However, Chariot-mounted operations require the addition of stabilizing outriggers, and when operating from the Lunar surface, LSMS-H functionality is enhanced by adding a simple ground anchoring system. Nomenclature = slew ½ angle = guy angle relative to the horizontal βR = LSMS length from shoulder to elbow = horizontal distance from the tipping fulcrum to the insipient tip over limit using chassis mount dd critical = horizontal distance from the tipping fulcrum to the CG of down-slope payloads du critical = horizontal distance from the tipping fulcrum to the CG of up-slope payloads F a, F c = reaction forces on the left or right of the tipping fulcrum F guy = force in the guy wire F groundanchor = force in the ground anchor g l = lunar gravity h cg = CG height h gm = ground mount height LSMS = Lunar Surface Manipulator System LSMS-H = Heavy-lift Lunar Surface Manipulator System LSS = Lunar Surface Systems l chariot = chassis length lp lsms = distance between LSMS and chassis when chassis-mounted M (element) = element mass m i , m j = mass of elements to left and right of tipping fulcrum R = maximum LSMS reach = LSMS shoulder height to reach ratio θ 1 = LSMS kingpost rotation angle θ 2 = LSMS shoulder rotation angle θ 3 = LSMS elbow rotation angle

<p>The 2017-2027 US National Academy of Sciences Decadal Survey for Earth Science and Applications from Space classified mass change as one of five designated observables having the highest priority in terms of Earth observations required to better understand the Earth system over the next decade.  In response to this designation, NASA initiated multi-center studies with an overarching goal of defining observing system architectures for each designated observable.  Here, we discuss the progress made and future plans for the Mass Change Designated Observable study. Progress includes the development of a Science and Applications Traceability Matrix, a tool that links science objectives to measurement techniques and accuracies,  for the 15 science and applications objectives listed in the Decadal Survey, as well as the definition of as many as three different architectural classes for which to achieve those objectives.  We will describe the Value Framework that is under way to assess and evaluate each observing system architectural option.  Preliminary results assessing the science value versus cost/risk of observing system architectures will be presented. In addition, future plans for the Mass Change Designated Observable Study will be discussed.</p>

Abstract-NASA's future human lunar campaign faces significant performance, cost and risk challenges. These include:o Providing the capability to access large portions of the lunar surface for expanded science and exploration within the performance constraints of the integrated transportation system; o Minimizing the annual cost of the lunar campaign; and o Minimizing operational risk including probability of loss of mission (PLOM) and probability of loss of crew (PLOC)Innovative lunar operations scenarios which address these challenges are potentially feasible based on the concept of dual, sequential missions utilizing a common crew and a single Ares I/Crew Exploration Vehicle (CEV). Dual mission scenarios possible within the scope of baseline technology planning include Outpost-based sortie missions, dual sortie missions, and enhanced Outpost deployment. Additional mission scenarios are potentially possible with the development of advanced capabilities. These include abort to the lunar surface options and Lander reusability options.