Accession Number : AD0718405

Title :   Fuel-Optimal Retrothrusted Soft Landing Through an Atmosphere,

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : Juncosa,M. L.

Report Date : DEC 1970

Pagination or Media Count : 33

Abstract : A simple analysis of the problem of achieving a soft landing for airdrop by fitting the payload with retrorockets, and a direct iterative numerical procedure for determining the switch-on point for minimal fuel consumption, in terms of either time or altitude. Through appropriate reversals of sign, the formulas may also be used for ascent trajectories of full-thrust, vertically boosted rockets where the assumption of a constant gravity field is acceptable. Since the unretrothrusted portion of the descent is identical with free fall, the dynamical equations are integrable in closed forms. For a constant atmosphere, closed form analytic solution is also obtained for the retrothrusted descent. For an exponentially varying atmosphere, however, one cannot escape a numerical integration of the dynamical equations. (Author)

Descriptors :   (*DESCENT TRAJECTORIES, MATHEMATICAL MODELS), (*AIR DROP OPERATIONS, SOFT LANDINGS), RETRO ROCKETS, FUEL CONSUMPTION, OPTIMIZATION, NUMERICAL ANALYSIS, GRAVITY

Subject Categories : Military Aircraft Operations
      Military Operations, Strategy and Tactics

Distribution Statement : APPROVED FOR PUBLIC RELEASE