NASA’s 2001 Mars Odyssey is ready for a Saturday liftoff, as long as the Sun cooperates. Solar activity is churning out higher than normal doses of protons — high-energy particles that can wreak havoc with microelectronics on satellites, as well as rocket boosters. These energetic protons can zap equipment causing “single-event upsets” — glitches in computers that can then send out faulty signals to hardware.