Live coverage: Atlas 5 countdown and launch journal

With the SpaceX scrub earlier this week and the time needed to convert the Eastern Range over to the Delta 4, liftoff of that rocket carrying an internationally-purchased military communications satellite for the Air Force has been bumped to Saturday evening.

Scientists eager for answers to long-standing questions about the geology of Mars will get a lift Saturday with the blastoff from California of an Atlas 5 rocket with NASA’s InSight mission, a robotic landing craft that will take the pulse and temperature of the red planet.

The SMAP observatory to map soil moisture distribution from 426 miles in space and its workhorse booster have been cleared for launch Thursday morning from California.