Video: Liftoff of Atlas 5 rocket with Mexico’s Morelos 3

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.

What began as a concept scribbled on a cocktail napkin in a Tucson bar 12 years ago — sending a spacecraft to an asteroid and retrieving a pristine sample to bring back to Earth for study — becomes reality Thursday with the launch of NASA’s OSIRIS-REx mission.

Two days after blasting off from Virginia’s Eastern Shore, Orbital ATK’s Cygnus supply ship reached its destination Tuesday. The automated spacecraft packed with 3.7 tons of supplies and experiments was captured by the International Space Station’s robotic arm at 5:04 a.m. EST (1004 GMT).