SpaceX's Crew Dragon splashes down in the Atlantic bringing its first crucial test flight to an end

Completing an end-to-end uncrewed flight test, Demo-1, SpaceX’s Crew Dragon departed the International Space Station at 2:32 a.m. EST Friday, March 8, 2019, and splashed down at 8:45 a.m. in the Atlantic Ocean about 200 nautical miles off the Florida coast. Credits: NASA Television 

On Friday morning, SpaceX Crew Dragon capsule successfully splashed down in the Atlantic Ocean after spending nearly a week at the International Space Station. With the splashdown, SpaceX has proved that its capsule can survive the harrowing journey to space and back, and that means the company has just made a significant leap in its quest to put people on the Crew Dragon someday. 

SpaceX’s #CrewDragon on its journey back to Earth, including its deorbit burn and splashdown in the Atlantic Ocean. Credit: NASA 

The splashdown marks the last major milestone of SpaceX Demonstration-1 or DM-1 mission - a critical test flight required for NASA's Commercial Crew Programme. This is an initiative of the US space agency aimed at sending astronauts to space on private Spacecrafts. 

SpaceX has been developing the Crew Dragon as new passenger vehicle for the program. But before the vehicle can carry people, NASA wanted to see the Crew Dragon prove itself in space without anyone on board. So, DM-1 was created as a way for NASA to evaluate the Capsule's performance and figure out what needs changing before astronauts can board. 

After much anticipation and numerous delays, DM-1 finally got off the ground this month, sparking a whirlwind trip to the orbit. The flight began on Saturday when the capsule lifted off from Kennedy Space Center in Florida on top of one of SpaceX's Falcon 9 rockets at 2:49 AM ET. About a day later, the Crew Dragon met up with the ISS and docked by itself to a port outside the station. Such a docking maneuver was something that SpaceX had never performed before.

Both the launch and docking were major hurdles that SpaceX needed to clear from DM-1 to be a success, but perhaps the biggest challenge of the mission occurred when the Crew Dragon returned to earth.

SpaceX needed to demonstrate that the capsule could plunge through our planet's atmosphere and make it to the ocean in one piece while protecting any cargo inside.

At 2:32AM ET in the morning, Crew Dragon undocked from the Space Station and distanced itself from the lab in preparation of its decent to earth. Just before making the plunge into the planet's atmosphere, the vehicle jettisoned its trunk, a cylindrical structure attached to the base of the capsule that provides power and temperature control during the flight. Crew Dragon then ignited its onboard thrusters for about 15 minutes in order to take the capsule out of the orbit. That initiated the final fall to the earth.

The Crew Dragon then dove to the ground at a speed more than that of sound, experiencing intense heating. There was a concern that this portion of the return may cause the vehicle to roll because of its asymmetrical shape. However, Crew Dragon made it through this part of the decent. After this intense experience, the capsule then deployed its four main parachutes to slow itself down and touch down gently in the Atlantic Ocean off the coast of Florida. A SpaceX recovery boat called Go Searcher then randezvous with the capsule and hoist it out of the ocean in order to bring it back to the shore.

Though the Crew Dragon didn't have any living crew member on board, it did carry a smart dummy named Ripley. The manequinn was equipped with sensors to measure the forces and accelerations the human body might experience while riding inside the Crew Dragon. The capsule also carried 330 pounds of cargo and research from the ISS.

It'll be a while before NASA fully assesses how this flight went, but SpaceX and NASA representatives agreed after landing that the mission ran smoothly. "The vehicle really did better than we expected", said Steve Stich, the deputy manager of flight development and operations for commercial crew, on NASA's live stream following the splashdown.

In months ahead, SpaceX will perform another test flight - the one designed to try out the Crew Dragon's emergency abort system. This is the system that will help save a crew during flight, in case the rocket carrying the capsule experiences a major failure. Engines embedded on the outside of the vehicle can ignite during the ascent to space, carrying the capsule away from disintegrating rocket. SpaceX will test out this process during a launch from Florida, which is currently targeted for April. The company will use the same Crew Dragon capsule that just finished this week's mission.

If that goes well, it'll be time to put people on the Crew Dragon. Two NASA astronauts, Bob Behnken and Doug Hurley, are scheduled to fly on the capsule for the first time, during the vehicle's final test flight. That mission is scheduled to occur in July, though it's unclear if that date will hold. However, the NASA representatives were confident that the flight could occur in 2019. "I don't think we really saw anything in the mission so far - and we've got to do the data reviews - that, you know, would preclude us having the crewed mission later this year", said Stich.