Gemini 4 Press Kit - heroicrelics Mirror

- 91 -ORBITS - REVOLUTIONSDuring long-duration Gemini flights the spacecraft'scourse in space may be measured in either orbits or revolutions.Orbits are space referenced and take into account Earthrotation.Gemini 4 is a planned 97-hour-and-fifty-minute flight.The planned orbital period is about 90 minutes or 16 orbitsevery 24 hours.Revolutions will be measured each time Gemini 4 passesover 80 degrees west longitude, about once every 96 minutes.This method of measurement results in about 15revolutions per day, or less revolution than orbits.The longer time for revolutions is caused by the retationof the Earth. As the spacecraft orbits, the Earth turnsunderneath it so that on each ascending pass across theeqaator the spacecraft regresses about 22.5 degrees, aboutsix minutes in time.- end -