Analysis of spacecraft entry into Mars atmosphere
Abstract
The effects on a spacecraft body while entering the Martian atmosphere and the resulting design constraints are analyzed. The analyses are conducted using the Viking entry phase restriction conditions and a Mars atmosphere model. Results from analysis conducted by the Program to Optimize Simulated Trajectories (POST) are described. Results obtained from the analysis are as follows: (1) flight times depend greatly on lifttodrag ratio and less on ballistic coefficients; (2) terminal landing speeds depend greatly on ballistic coefficients and less on lifttodrag ratios; (3) the dependence of the flight path angles on ballistic coefficients is slightly larger than their dependence on lifttodrag ratios; (4) as the ballistic coefficients become smaller and the lifttodrag ratios become larger, the deceleration at high altitude becomes larger; (5) small ballistic coefficients and low lifttodrag ratios are required to meet the constraints of Mach number at parachute deployment and deployment altitude; and (6) heating rates at stagnation points are dependent on ballistic coefficients. It is presumed that the aerodynamic characteristics will be 0.2 for the lifttodrag ratio and 75 kg/sq m for the ballistic coefficient for the case of a Mars landing using capsules similar to those used in the Viking program.
 Publication:

Future Space Activities Workshop
 Pub Date:
 July 1991
 Bibcode:
 1991fsa..workU....N
 Keywords:

 Aerodynamic Characteristics;
 Flight Mechanics;
 Hypersonic Reentry;
 Mars (Planet);
 Mars Atmosphere;
 Mars Landing;
 Mars Probes;
 Space Exploration;
 Spacecraft Reentry;
 Aerodynamic Heating;
 Atmospheric Density;
 Atmospheric Models;
 Atmospheric Temperature;
 Dynamic Pressure;
 Flight Paths;
 Flight Time;
 Mariner Space Probes;
 Viking Orbiter Spacecraft;
 Spacecraft Design, Testing and Performance