Cargo ship brings supplies, science gear and holiday treats for space station crew
An unpiloted SpaceX Dragon cargo ship caught up with the International Space Station and glided in for a smooth docking on Tuesday — Election Day across the U.S. — bringing 3 tons of supplies, science gear and other equipment to the lab, including holiday treats for the crew.
The Dragon's Falcon 9 rocket blasted off from historic launch pad 39A at the Kennedy Space Center at 9:29 p.m. EST Monday, lighting up the night sky for miles around as it climbed away atop 1.7 million pounds of thrust.
After boosting the rocket out of the dense lower atmosphere, the first stage, making its fifth flight, peeled away, reversed course and headed back to an on-target landing at the Cape Canaveral Space Force Station while the second stage continued the climb to space.
The landing marked SpaceX's 57th successful booster recovery at the Florida Space Force station and its 363rd overall, including California flights and droneship landings.
Just under 10 minutes after liftoff, the vacuum-optimized engine powering the Falcon 9's second stage shut down and one minute later, the Dragon was released to fly on its own.
Running slightly ahead of schedule, the cargo ship executed a series of rendezvous rocket firings, catching up with the space station from behind and below before looping up to docking at the lab's forward port at 9:52 a.m.
"Welcome aboard, Dragon," astronaut Barry "Butch" Wilmore radioed from inside the station. "Nice to have you aboard." Station commander Sunita Williams, referring to the successful docking in general and the food on board in particular, added: "Just want to say thank you to SpaceX, the International Space Station program, the Commercial Crew program for bringing us... honey."
One of the first items on the agenda is a test Friday to determine the Cargo Dragon's ability to boost the space station's orbit slightly using its aft-facing thrusters. The ISS is routinely re-boosted by Russian Progress freighters and Northrop Grumman Cygnus cargo ships, but Friday's test will be a first for SpaceX.
The California rocket builder is under contract to NASA to build a powerful space tug of sorts that can be used to safely drive the ISS back into the atmosphere when the lab complex is retired in the 2030 timeframe. The vehicle is needed to make sure the station breaks up over a stretch of ocean well away from populated areas and shipping lanes.
During the test Friday, the Cargo Dragon's aft thrusters will fire for about 12 minutes.
"The data that we're going to collect from this reboost and attitude control demonstration will be very helpful, informing SpaceX analyses on how the system performs," said Jared Metter, SpaceX director of flight reliability. "This data is going to lead to future capabilities, namely the US de-orbit vehicle."
Reboost aside, the Cargo Dragon is loaded with slightly more than 6,000 pounds of equipment and supplies, including 2,022 pounds of science gear, 2,119 pounds of crew clothing, food and other supplies, 377 pounds of spacewalk equipment, 525 pounds of space station hardware and 44 pounds of computer equipment.
One of the more unusual payloads: Lignosat, a small wooden satellite using a framework of magnolia panels built by researchers at Kyoto University in Japan and the Tokyo-based logging company Sumitomo.
"While some of you might think that wood in space seems a little counterintuitive, researchers hope that this investigation demonstrates that a wooden satellite can be more sustainable and less polluting for the environment than conventional satellites," said Meghan Everett, the ISS deputy project scientist.
"The main objective here is to determine whether wood can be used in space, and to do this, researchers will measure the temperature and strain of the wooden structure and see how it might change in the vacuum environment of space with atomic oxygen and radiation conditions as well."
As with all station-bound Dragon cargo ships, the crew supplies include fresh food and special treats for holiday meals.
Bill Spetch, ISS operations and integration manager, said the "food kit" includes "citrus, apples, sweet onions, blueberries, radishes, etc," along with lobster, crab and quail for holiday meals. A variety of cheeses is on board as well as fresh coffee and personal items requested by each crew member.
Mounted in the Dragon's unpressurized trunk section is the Coronal Diagnostic Experiment, or CODEX, an instrument that will be mounted outside the space station to learn more about how charged particles in the solar wind are heated to millions of degrees and accelerated to enormous velocities, affecting Earth's space environment and the rest of the solar system.
Inside the station, the astronauts will have a variety of new experiments and instruments to operate and monitor, including one called ARTEMOSS that will examine how Antarctic moss tolerates the space radiation and microgravity environment to learn more about how plants might be used in future life support systems.
The European Space Agency is sending up a space exposure experiment to learn more about how high-tech materials respond to prolonged exposure to the weightless environment and another experiment to study how organic samples degrade when exposed to unfiltered ultraviolet light from the sun.
And in an experiment that could be particularly useful to future astronauts, a small device known as Nanolab Astrobeat, provided by the Malta College of Arts, Science and Technology, will test cold welding technology that could prove useful for repairing leaks or other damage from inside a spacecraft.
The Cargo Dragon is expected to remain docked at the space station for about a month before it returns to Earth with station components needing refurbishment, trash and other no-longer-needed items.