The flight was an almost complete success , marred only by a heater that had inadvertently been turned off prior to liftoff and that allowed the inside temperature to drop to 50 ° F ( 10 ° C ) , a bout of space sickness , and a troublesome re-entry when the reentry module failed to separate cleanly from its service module .
Problems included not turning on a heater which meant the temperature dropped to 50 ° F ( 10 ° C ) , a period of space sickness , and problems on re-entry when the reentry module failed to separate cleanly from its service module .