After about a month berthed to the International Space Station (ISS), SpaceX’s eighth Commercial Resupply Services (CRS-8) Dragon was released from the outpost at 8:19 a.m. CDT (13:19 GMT) May 11. The capsule splashed down in the Pacific Ocean just before 2 p.m. CDT (19:00 GMT).
British astronaut Tim Peake was controlling the robotic Canadarm2 at the Robotics Workstation (RWS) in the station’s Cupola module. He gave the command to release Dragon.
“Dragon depart commanded,” Peake said. “Dragon spacecraft has served us well, and it’s good to see it departing full of science. We wish it a safe recovery back to planet Earth.”
The process to prepare the capsule for unberthing began yesterday when the hatch was closed at 11:20 a.m. CDT (16:20 GMT). Unbolting of the port connecting Dragon to the nadir port of Harmony began at 5:15 a.m. CDT (10:15 GMT) this morning. About 45 minutes later, it was maneuvered by Canadarm2 to its release position about 33 feet (10 meters) below the Destiny laboratory.
Three minutes after release, the first of three Draco thruster burns occurred to push Dragon safely away from the orbiting outpost. About a minute-and-a-half later, a second burn moved the capsule away faster.
About seven minutes after that, the third departure burn pushed Dragon out of the station’s Keep-Out Sphere (KOS)—an imaginary region measuring some 820 feet (250 meters).
The spacecraft continued to orbit Earth three times before conducting a 10-minute-long de-orbit burn at 1:01 p.m. CDT (18:01 GMT). About 5 minutes after the burn, the trunk separated. It will burn up at a safe distance from the re-entering capsule.
After Dragon entered the atmosphere and slowed to a safe speed, drogue parachutes deployed. About a minute later, at 1:45 p.m. CDT (18:45 GMT), the spacecraft’s three main parachutes deployed. This slowed the capsule to about 12 mph (20 km/h) in preparation for splashdown in the Pacific Ocean.
Dragon splashed down at about 1:51 p.m. CDT (18:51 GMT) approximately 261 miles (420 kilometers) southwest of Long Beach, California.
Returning with the capsule is more than 3,700 pounds (1,675 kilograms) of cargo and experiments, including the last of yearlong astronaut Scott Kelly’s biological samples. These include over 1,000 tubes of blood, urine, and saliva. Kelly returned to Earth on March 1 of this year.
Also packed inside the capsule for ground study and repair is Extravehicular Mobility Unity number 3011—the spacesuit that started accumulating water in NASA astronaut Tim Kopra’s helmet during an spacewalk conducted in January. No astronaut was in any danger, but the spacewalk was terminated.
SpaceX teams will have 25–26 hours to get the capsule to the dock at Long Beach to retrieve time-critical experiments. The rest of the cargo will be off-loaded when the capsule arrives at the company’s test facility in McGregor, Texas, before being transported to the Johnson Space Center in Houston.
CRS-8 launched on April 8 and brought much-needed cargo and equipment to the space station. The most notable item was, perhaps, the Bigelow Expandable Activity Module (BEAM). BEAM, the first expandable module to be added to the ISS, was taken out of the spacecraft’s trunk early last month and attached to the aft port of Tranquility. BEAM is currently scheduled to be expanded on May 26.
The next Dragon to launch to the ISS is planned for June 27. The CRS-9 mission will bring the International Docking Adapter-2 (IDA-2) to the orbiting lab.
Written by: Derek Richardson
Original source: spaceflightinsider.com