NASA is calling off its next mission to Mars because there isn't enough time to fix a leaky seal on a key science instrument. The InSight spacecraft was set for launch in March. The problem is with a protective pouch around the lander's seismometer, which was designed to measure ground movement on the red planet. NASA managers and French designers of the instrument said Tuesday they must now decide whether the pouch's vacuum seal needs to be repaired, redesigned or the mission scrapped. ...