Historic Crew Dragon flight concludes with Atlantic splashdown
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Crew Dragon splashes down in the Atlantic Ocean. Credit: NASA
The historic Crew Dragon Demo-1 mission has come to a conclusion with a successful splashdown in the Atlantic Ocean not far from where its mission began six days ago.
Following a five-day mission attached to the International Space Station, the unpiloted Crew Dragon autonomously undocked at 07:32 UTC March 8, 2019, and began moving to a safe distance. The spacecraft left the vicinity of the outpost about 20 minutes later.
“From Houston, we would like to congratulate the amazing teams from around the world who comprise of international partnerships and a great team at SpaceX for bringing Crew Dragon to the International Space Station,” spacecraft communicator Leslie Ringo radioed from Mission Control in Houston to the outpost. “We wish this new asset to human spaceflight fair winds and following seas as it returns to Earth for its splashdown in the Atlantic. You have all made us proud today.”
Aboard the ISS, Expedition 58 Flight Engineer and NASA astronaut Anne McClain replied saying she and her fellow crew members—Canadian Space Agency astronaut David Saint-Jacques and Russian cosmonaut and station Commander Oleg Kononenko—wanted to take the opportunity to thank the SpaceX team and recognize the milestone and accomplishment that marks the inaugural mission of the Commercial Crew Program, which formally began in 2010.
“Fifty years after humans landed on the Moon for the first time, America has driven a golden spike on the trial to new space exploration feats through the work of commercial partner SpaceX and all the talented and dedicated flight controllers at NASA and our international partners,” McClain said. “It won’t be long before our astronaut colleagues are aboard Crew Dragon and Boeing’s Starliner vehicle, and we can’t wait. Let us continue to be united by our insatiable curiosity to go beyond what is known to do what has never been done.”
Launching from Kennedy Space Center’s Space Launch Complex 39A, a Falcon 9 rocket sends the Crew Dragon Demo-1 spacecraft into orbit. Credit: NASA
Crew Dragon Demo-1 launched at 07:49 GMT March 2, 2019, from Launch Complex 39A in Kennedy Space Center, Florida. It was the same launch pad that hosted the start of the Apollo 11 mission to the Moon in July 1969 as well as nearly all human lunar missions through 1972 and many Space Shuttle flights between 1981 and 2011.
Inside the unpiloted commercial spacecraft was an anthropomorphic test device named Ripley (after Ellen Ripley in the Alien film series) in a SpaceX pressure suit. Also inside was a zero gravity indicator in the form of an Earth plush and some 180 kilograms of crew supplies and equipment for the Expedition 58 crew.
Once in orbit, SpaceX’s Crew Dragon began a 27-hour trek to the International Space Station, docking with the outpost at 10:51 UTC March 3.
Hatches between the spacecraft and station were opened just under 2.5 hours later at 13:07 UTC. The crew ingressed and had a welcoming ceremony.
Over the next several days, the crew emptied the minimal cargo in the capsule before loading it with some 150 kilograms of return equipment and experiments.
The Expedition 58 crew bid farewell to Crew Dragon beginning on March 7 when the closed the hatch to the spacecraft. Hatch closure took place at 17:39 UTC. Several hours later, the spacecraft was ready for departure.
The undocking sequence itself took several minutes. It involved the hooks between the docking adapter and spacecraft unlatching. Once released, a quick 1.5-second thruster burn pushed Crew Dragon away at a leisurely 0.15 meters per second.
Less than a minute later, a second 1.5-second thruster firing doubled its departure rate.
From there, four departure burns were performed: One not long after undocking and a second some 5 minutes after separation. This pushed the spacecraft out of the space station’s “keep out sphere,” which is a 200-meter imaginary bubble around the outpost.
Once outside the keep out sphere, the next major milestone was leaving the approach ellipsoid, which occurred about 17 minutes after undocking.
Credit: SciNews
Dragon kept drifting away for another 30 minutes before performing a third departure burn. This lowered the spacecraft’s orbit to begin flying underneath the outpost. A fourth burn occurred about 100 minutes after undocking to place the vehicle in a co-elliptical orbit with the ISS.
Several orbits later, Crew Dragon was set to perform its deorbit burn. First, the trunk separated at about 12:48 UTC. This was followed by a roughly 15-minute burn using the spacecraft’s Draco thrusters to drop the vehicle out of orbit.
After that, the nose cone, which protects the docking adapter and guidance equipment during launch, was retracted and closed for re-entry.
Entry interface occurred at 13:33 UTC while the capsule, protected by its PICA-X heat shield, was flying about 100 kilometers over the Midwestern United States on a descending node across the continent.
For several minutes, Crew Dragon entered a communications blackout, as the ionization from the atmospheric heating caused interference. This is typical for re-entering spacecraft.
About 8 minutes later, the spacecraft had slowed down enough and was low enough in the atmosphere for a series of parachutes to open, culminating in four main chutes. This allowed the capsule to gently descend toward a staging area in the Atlantic Ocean off the coast of Florida and Georgia. Splashdown took place at 13:45 UTC.
This was the first time a spacecraft intended for humans had splashed down in the Atlantic Ocean since Apollo 9 on March 13, 1969.
The next steps will be for the SpaceX recovery teams to retrieve the spacecraft and place it on a recovery ship to be brought back to Port Canaveral, Florida. There, its cargo will be offloaded and the spacecraft inspected, refurbished and then readied for its next mission as the capsule to be used for an in-flight abort test, likely sometime between April and June.
SpaceX and NASA will analyze data for both the Demo-1 mission and the in-flight abort to ensure everything will be safe for humans when the spacecraft is officially certified for people. Only then will the Demo-2 mission fly with NASA astronauts Doug Hurley and Bob Behnken.
Right now, SpaceX and NASA are hoping for that flight to occur as early as July 2019.
Credit: SciNews
