SpaceX has successfully completed its 16th resupply mission launch and its Dragon cargo ship is on its way to the International Space Station (ISS) on behalf of NASA. The ship is carrying 2.5 tons of supplies, experiments, and provisions for the astronauts.  

“It was an incredible launch,” Joel Montalbano, NASA's deputy ISS program manager, said in a statement. “This was the fourth launch in three weeks to the space station.”

A little blemish on this launch was the rocket's re-entry and landing. The first stage of the rocket was supposed to secure an upright landing on the ground in Cape Canaveral, but a malfunction made it spin. Despite the issue, it made it all the way back to Earth and ended up in the Atlantic Ocean in one piece.

"Grid fin hydraulic pump stalled, so Falcon landed just out to sea. Appears to be undamaged and is transmitting data. Recovery ship dispatched," SpaceX CEO Elon Musk said on Twitter. "Engines stabilized rocket spin just in time, enabling an intact landing in water! Ships en route to rescue Falcon."

In a following tweet, Musk shared an incredible video of the rocket approaching the surface of the sea and actually landing, before crashing sideways. This is the first failed landing on solid ground by a SpaceX rocket. The previous 12 were all successful. The company has also landed rockets on automated ocean barges, a much trickier job, 20 times so far.

The launch had to be postponed on Tuesday after it was discovered that a supply of mouse food had gone moldy. Mice are being used on the ISS to investigate the effects of microgravity on the immune system.

Two of the science experiments currently being carried to the space station are particularly interesting. The first is the Robotic Refueling Mission Phase 3 (RRM3), which will demonstrate the storage and transfer of cryogenic liquid in space. RRM3 will see the first ever transfer of cryo-fluid (liquid methane) in space. This investigation will be critical for propulsion and life support systems in orbit.

The second is the Global Ecosystem Dynamics Investigation or GEDI. The experiment will make high-quality laser ranging observations of Earth’s forests and topography. Scientists expect to learn a lot more about the carbon and water cycles with the data collected using this instrument.