ESTIMATES OF MINIMUM ENERGY REQUIREMENTS FOR RANGE-CONTROLLED RETURN OF A NONLIFTING SATELLITE FROM A CIRCULAR ORBIT
Abstract
Existing expressions are used to obtain the minimum propellant fraction required for return from a circular orbit as a function of vacuum trajectory range. Solutions for the parameters of the vacuum trajectory are matched to those of the atmospheric trajectory to obtain a complete return from orbit to earth. Results are restricted by assumptions of (1) impulsive velocity change, (2) nearly circular transfer trajectory, (3) spherical earth, atmosphere, and gravitational field, (4) exponential atmospheric density variation with attitude, and (5) a nonrotating atmosphere. Calculations are made to determine the effects of longitudinal and lateral range on required propellant fraction and reentry loading for a nonrotating earth and for several orbital altitudes. A comparison of the single- and two-impulse method of return is made and results indicate a trade off between propellant fraction required and landing-position accuracy. An example of a return mission from a polar orbit is discussed where the initial deorbit point is the intersection of the North Pole horizon with the satellite orbit. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1961
- Accession Number
- AD0266700
Entities
People
- Charlie M. Jr. Jackson
Organizations
- National Aeronautics and Space Administration