Accession Number : AD0837639

Title :   MULTIPLE SITE RETURN CAPABILITY OF SPACECRAFT FROM CIRCULAR AND ELLIPTICAL ORBITS.

Descriptive Note : Technical rept. Mar-Nov 67,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA EL SEGUNDO TECHNICAL OPERATIONS

Personal Author(s) : Chu, S. T. ; Davis, K. S.

Report Date : JUN 1968

Pagination or Media Count : 35

Abstract : The probability of spacecraft returning from circular or elliptical orbits to multiple sites is examined as a function of spacecraft cross-range capabilities and waiting time allowed in orbit. The analysis involves the determination of ascending nodes from which the spacecraft with a given cross-range capability could land at a specified site. The loci of these nodes form coverage belts along the equator. A procedure for determining the magnitude and locations of these belts is presented. The series of ascending belts generated by the waiting of spacecraft in orbit and the availability of multiple sites overlap in some of their coverages. A discrete set of regions of accessibility along the equator is thus created and, in turn, determines the probability of return. The concept of coverage belts and regions of accessibility is useful for missions in which the ascending node and the in-track position of the spacecraft are random at the time of recall. Sample results of return probability are presented. (Author)

Descriptors :   *DESCENT TRAJECTORIES), (*SPACECRAFT, (*LANDING, SITE SELECTION), ELLIPTICAL ORBIT TRAJECTORIES, CIRCULAR ORBITS, ATMOSPHERE ENTRY, PROBABILITY, TIME, LIFTING REENTRY VEHICLES, MANNED SPACECRAFT.

Subject Categories : Spacecraft Trajectories and Reentry
      Manned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE