Video: SpaceX launches first mission of 2020 (members only)

China’s heaviest rocket has rolled to its launch pad for liftoff Thursday with the country’s first Mars landing mission, an ambitious attempt to place an orbiter around the Red Planet and a robotic rover on the Martian surface in early 2021.

During a visit to Cape Canaveral this week, NASA astronauts Doug Hurley and Bob Behnken strapped in to the SpaceX crew capsule they will ride into orbit as soon as mid-to-late May. Next week, the astronauts will be in Houston to continue training for an extended stay on the International Space Station that could last two-to-three months.

After calling a hold less than a minute before liftoff Friday, SpaceX launched the Maxar-built SXM 7 radio broadcasting satellite for SiriusXM Sunday. A Falcon 9 rocket lifted off from pad 40 at Cape Canaveral at 12:30 p.m. EST (1730 GMT).