March 18, 2018

Commercial cargo craft splashes down in Pacific Ocean after station resupply run

The Dragon spacecraft is pictured soon after its release from the International Space Station on Saturday. Credit: Norishige Kanai/JAXA/NASA

A commercial cargo capsule owned by SpaceX concluded a month-long resupply trip to the International Space Station on Saturday, wrapping up the 13th round-trip flight to the station by a Dragon spacecraft with an on-target splashdown in the Pacific Ocean west of Baja California.

Bringing home 4,078 pounds (1,850 kilograms) of disused equipment, spacesuit gear and spacewalk hardware, and scientific specimens, the Dragon capsule splashed down in the Pacific Ocean at 10:37 a.m. EST (7:37 a.m. PST; 1537 GMT) after a blistering hot re-entry through Earth’s atmosphere.

Traveling northwest to southeast, the unpiloted spaceship plunged through the atmosphere protected by a heat shield surrounded by red-hot plasma as temperatures reached 3,000 degrees Fahrenheit (1,650 degrees Celsius).

Two drogue parachutes deployed to stabilize the Dragon capsule for its final descent, then three 116-foot-diameter (35-meter) orange and white main parachutes unfurled to slow the spaceship for a gentle splashdown at sea, where SpaceX recovery teams were waiting to approach the craft and hoist it aboard a boat to return to port in Southern California.

SpaceX confirmed the successful splashdown of the capsule on Twitter. The return marked the end of SpaceX’s 13th operational resupply flight to the space station under contract to NASA. Twelve of the missions have been successful, in addition to a round-trip test flight to the orbiting complex in 2012.

NASA has awarded SpaceX a contract for 20 cargo missions through the end of 2019 — with 13 now in the books — and the space agency has a follow-on agreement for at least six more Dragon resupply flights from 2020 through 2024.

Time-sensitive refrigerated specimens, such as blood and urine, and live rodents that returned to Earth inside Dragon for an experiment investigating muscle wasting in microgravity will be handed over to scientists in the next couple of days. The rest of the cargo will be unloaded from the Dragon’s pressurized module and turned over to NASA and research teams once the capsule travels to SpaceX’s test facility in McGregor, Texas, for post-flight processing.

Other items packed inside the Dragon by station astronauts included specimens from a plant growth experiment that studied how vegetation responds to reduced oxygen, which can occur in flooding on Earth.

The commercial company Made in Space also sent up a privately-funded technological experiment to study how optical fiber could be produced in orbit — perhaps with better quality than the silica-based fiber optic cables manufactured on Earth. The results were aboard Dragon on the trip home Saturday.

The Dragon capsule lifted off Dec. 15 aboard a Falcon 9 rocket from Cape Canaveral, and it arrived at the space station two days later with 2.4 tons of food, supplies and experiments.

The Dec. 15 launch was the first time NASA has entrusted cargo to launch on a previously-flown Falcon 9 rocket booster. The mission also used a recycled Dragon cargo module that first flew on a trip to the station and back in April and May of 2015.

A breakdown of the return cargo manifest. Credit: NASA

The Dragon spacecraft delivered a habitat containing research mice to study muscle atrophy, two commercial investigations from Budweiser that will study how the microgravity environment on the space station affects barley, and an experiment to examine how plants grow in partial gravity for the first time.

In late December, the station’s robotic arm pulled two payloads out of the Dragon’s aft cargo bay for placement on attach posts outside the complex.

The NASA-funded Total and Spectral Solar Irradiance Sensor, or TSIS-1, hosts two instruments to monitor the sun’s energy output, a key driver of Earth’s climate.

NASA’s Space Debris Sensor was also removed from the Dragon capsule’s trunk and attached to the European Space Agency’s Columbus laboratory module.

The Space Debris Sensor will register impacts with tiny pieces of space junk for at least two years, helping engineers and scientists better understand the population of untracked objects orbiting at the same altitude as the space station.

The Canadian-built robotic arm installed a failed weather instrument named RapidScat inside the Dragon’s external cargo bay for disposal in Earth’s atmosphere. The trunk section is designed to burn up on re-entry, while the primary module parachutes back to Earth.

The arm removed the Dragon capsule from its berthing port on the station’s Harmony module Friday in preparation for departure Saturday.

Using a command issued from the Canadian Space Agency’s control center, the robot arm released the Dragon spacecraft at 4:58 a.m. EST (0958 GMT) Saturday. It was the first time a visiting vehicle was released from the station via a ground command.

Astronauts Joe Acaba and Scott Tingle monitored the departure maneuvers, and the Dragon backed away with a series of three thruster firings to set up for a de-orbit burn at 9:43 a.m. EST (1443 GMT).

The de-orbit burn dropped the low point of the Dragon spacecraft’s orbit back into Earth’s atmosphere, low enough for it to be captured by aerodynamic drag and head for splashdown in the Pacific Ocean.

SpaceX’s 14th commercial resupply flight to the station is scheduled for launch April 2.

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