02280nam a2200361Ma 4500011444049MiAaHDL20141009010000.0m d cr bn ---auaua100203s1961 dcua b f000 0 eng dsdr-uiuc6401617(OCoLC)646588338AD#STFUIUUNAS 1.14:D-5923NASA-TN-D-5923Weyers, Vernon J.Site accessibility and characteristic velocity requirements for direct-descent lunar landings.Vernon J. Weyers.Washington, D.C. :National Aeronautics and Space Administration :[For sale by the Office of Technical Services, Dept. of Commerce],[1970]24 p.:ill. ;26 cm.NASA technical note ;NASA TN D-5923Prepared at Lewis Research Center."July 1970."--Cover.Major NASA subject terms: Descent trajectories, lunar landing, lunar landing sites, velocity, cryogenics, lunar topography, mission planning, specific impulse, storable propellants.Includes bibliographical references (p. 24).A direct descent is one in which the main descent propulsion system burns continuously from lunar approach to touchdown. The characteristic velocity requirement for direct lunar descents is presented as a function of the landing site location relative to the normal impact point. Results are included for translunar trip times of 60, 75, and 90 hours, for specific impulses representative of both Earth storable and cryogenic propulsion systems, for landing sites located anywhere on the lunar surface, and for ignition thrust-to-Earth weight ratios between 0.12 and 10.0. The data presented are useful in determining approximate performance capability and in evaluating tradeoffs during preliminary mission planning studies.Mode of access: Internet.Trajectories.Low temperature engineering.Lunar landing sites.Speed.Lewis Research Center.United States.National Aeronautics and Space Administration.01144404920101109123849.020141009010000.020141112165512.02025-01-02T19:12:19Z2025-01-02T18:30:02ZSDR-UIUCUNKNOWNloader.pl-003-020BKsdr-uiuc6401617uiugSDRUIUCuiug.30112106879635UIU6401617UIUUIUC20250102googleuiug.301121068796351961pdbibUS fed doc