SpaceX’s CRS-13 Dragon capsule departs ISS after 4-week stay
The first visiting vehicle activity at the International Space Station in 2018 concluded on Saturday, Jan. 13 with the unberthing, departure and splashdown of SpaceX’s CRS-13 Dragon cargo ship after it had spent nearly a month at the orbiting outpost.
This was the second time the Hawthorne, California-based company utilized a refurbished Dragon capsule. The pressure vessel first flew as part of the CRS-6 mission in April 2015. Additionally, the Dec. 15, 2017, CRS-13 launch was the first time NASA utilized a “previously-flown” Falcon 9 first stage core.
CRS-13 brought to the outpost some 4,861 pounds (2,205 kilograms) of food, supplies, experiments and equipment to the ISS. The Expedition 54 crew spent the last four weeks unloading the capsule and reloading it with unneeded equipment as well as experiments to be returned to Earth for data collection. According to NASA, approximately 4,100 pounds (1,860 kilograms) of cargo, science and technology demonstration samples were loaded inside Dragon for return.
Once the hatches between Dragon and the ISS were closed, ground-based robotics operators utilized Canadarm2—the stations 58-foot (17.6-meter) robotic arm—to unberth and move the capsule to a staging point some 33 feet (10 meters) below the Destiny laboratory. At 4:58 a.m. EST (9:58 GMT) it was released to begin a series of burns to safely move away from the space station.
While this was the first ground-controlled release of a visiting vehicle, NASA astronauts Joe Acaba and Scott Tingle—two of the six people residing aboard the ISS—monitored the departure inside the station’s cupola window. Would it have become necessary, the two could have taken over control of the arm. However, everything went according to plan.
Several hours later, SpaceX teams commanded the capsule to close its guidance, navigation and control bay door. This was expected at around 8:45 a.m. EST (13:45 GMT) with a 10-minute deorbit burn using Dragon’s Draco thrusters expected about an hour later at 9:43 a.m. EST (14:43 GMT).
Just before entry interface, the trunk of Dragon, which had the solar panels attached to it as well as a defunct external experiment that spent the last several years on the ISS, was jettisoned from the capsule. It was not designed to survive reentry and incinerated during the descent.
SpaceX confirmed via Twitter that the deorbit burn and trunk separation had occurred as planned.
Dragon's deorbit burn is complete and trunk has been jettisoned. Pacific Ocean splashdown in ~30 minutes.
— SpaceX (@SpaceX) January 13, 2018
After several minutes blazing through the atmosphere with its protective heat shield, Dragon slowed down enough for a series of parachutes to open up. Several minutes later, the vehicle performed a soft splashdown in the Pacific Ocean just off the coast of Baja California.
“Good splashdown of Dragon confirmed, completing the second resupply mission to and from the @Space_Station with a flight-proven commercial spacecraft,” SpaceX’s official Twitter account announced at 10:39 a.m. EST (15:39 GMT).
SpaceX employees are expected to recover the spacecraft via a ship and take it to Long Beach, California, just south of Los Angeles. There, time-sensitive cargo will be removed for an immediate return to NASA. After that, the capsule with the rest of the cargo will be transported to the company’s test facility in McGregor, Texas, where it will undergo final processing, according to NASA.
This was the 13th mission for SpaceX under NASA’s $1.6 billion Commercial Resupply Services (CRS) contract with the company. The only mission that did not arrive to the outpost was 2015’s CRS-7 mission, which was lost after the Falcon 9 carrying the rocket exploded some two minutes into ascent.
CRS-13 was the first of several additional missions added to the first phase of CRS, known as CRS 1. In 2016, NASA announced three companies and their spacecraft—SpaceX with its Dragon, Orbital ATK with its Cygnus, and Sierra Nevada Corporation with its Dream Chaser—were awarded a minimum of six missions to resupply the ISS beginning as early as late 2019 as part of the second phase of the commercial cargo program, CRS 2.
Video courtesy of NASA
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.
I am confused by the decision to use a ground command to release Dragon. Was this simply a detailed test objective or is it poised to become standard operating procedure on ISS?
If the presence of astronauts was required to oversee such a critical automated operation — as backups in this instance — then will they be required to standby everytime a U.S. cargo ship departs? In which case what is the point of astronauts being involved in the activity at all, especially if it was never really necessary?
I am aware Cygnus, Dragon and Japan’s Kounotori are berthed by MCC-Houston. So will the entire process — capture, berthing, unberthing and release — eventually become autonomous with virtually no crew oversight?