Watch live as Elon Musk unveils his vision for missions to Mars

SpaceX chief executive Elon Musk on Tuesday outlined an ambition to send humans to Mars with methane-fueled reusable spaceships and the largest rocket ever built, an effort he said will likely require government support and initially cost billions of dollars to develop and test.

NASA awarded Northrop Grumman a contract worth as much as $84.5 million earlier this month to supply rocket motors for a first-of-its-kind launch vehicle to fire a capsule of rock samples off of Mars on a journey back to Earth.

Mission managers will be closely monitoring the weather for the first launch of astronauts aboard SpaceX’s Crew Dragon spacecraft, not just around the Kennedy Space Center, but along a corridor stretching thousands of miles across the Atlantic Ocean in case the crew capsule has to escape from its Falcon 9 rocket during the climb into orbit.