An Assessment of the Navigation and Course Corrections for a Manned Flyby of Mars or Venus

The guidance law, schedule, propulsive requirements, and expected guidance accuracy for typical manned flybys to Mars or Venus are described. Navigation is based upon sightings taken by the crew with a sextant which has an accuracy of 10 seconds of arc. Injection errors at the beginning of the interplanetary leg are based upon those expected with today's inertial guidance. Midcourse corrections are selected from a study in which the benefit (in terms of decreased position error at the target planet) was traded against an increasing ΔV requirement. A total of only 300 feet per second velocity correction (3σ) is required for the entire flyby mission.