Rocket landing overshadows SpaceX Dragon's return to flight

An experimental new type of module is among the fresh supplies headed to the International Space Station in SpaceX's first Dragon cargo launch in nearly a year - punctuated by a heart-stopping at-sea landing of the rocket's first stage.

The Falcon 9 blasted off into the clear blue Florida skies just before 5 p.m., pushed toward the heavens by a column of flame nearly as long as the rocket itself. Minutes later, it was out of sight, but long-range cameras tracked the separation of the rocket booster and its perilous plunge.

SpaceX video showed the booster extend its landing legs as it angled towards the converted barge, righting itself at only the last moment and touching down delicately as cheers erupted from coast to coast. Spectators at the launch site in Florida applauded while employees at SpaceX's California mission control broke into cheers of "USA! USA!" as the smoke cleared, showing the booster upright and intact.

PHOTOS: Falcon 9 launch from Cape Canaveral

"The rocket landed instead of putting a hole in the ship, so we're really excited about that," SpaceX CEO Elon Musk said with a chuckle afterwards.

Indeed, four previous ship landings came close but ended in spectacular crashes -- each due to a different failure -- though a landing attempt on a pad back at Cape Canaveral was successful back in December. Eventually, the company hopes to make the first-stage landing a routine part of missions, allowing them to reuse boosters and save money.

Meanwhile, the Dragon capsule continued on into orbit, where astronauts will use the station's grappling arm to grab the capsule on Sunday. That moment will mark another first, this time for NASA - the first time that each of the agency's commercial cargo suppliers will have a craft docked at the space station simultaneously. An Orbital ATK Cygnus capsule launched last month and is several weeks into its mission at the station.

The scenario was hard to envision as recently as last summer after both SpaceX and Orbital suffered catastrophic launch failures that left both of their respective rockets - and capsules - grounded.

Orbital's craft have been hitching rides on Atlas rockets to keep supplies flowing to the orbiting outpost, while SpaceX has had several successful commercial flights since last year's accident - including that dramatic first-stage return and landing at Cape Canaveral - but this is the company's first Dragon mission to the station since the failure.

The Dragon capsule provides a unique ability to launch larger pieces of cargo in its unpressurized 'trunk,' and a first-of-its-kind expandable habitat is riding in that space on this flight. Astronauts will install the Bigelow Expandable Activity Module (BEAM) and fill it with air, adding over 500 cubic feet of livable space - the first significant addition to the station since the shuttles stopped flying back in 2011.

BEAM will spend two years attached to the station's Tranquility node while NASA evaluates its durability for long-term flights, like those to Mars. Such expandable modules, which lack heavy, rigid structural panels, could reduce the weight and cost of future spacecraft.

The Dragon is scheduled to spend a month at the space station. Before it leaves, astronauts will pack a malfunctioning spacesuit inside. NASA hopes to study it to figure out how a dangerous water leak happened during a spacewalk earlier this year.

Back in Florida, tugboats are expected to guide the ship - with its new cargo aboard - back to land within a few days.

"It should arrive Sunday, then we're going to do some test-fires," Musk added. "If things look good, we'll qualify it for reuse and launch. We're hoping to re-launch on an orbital mission in June."