SpaceX’s Falcon 9 rocket sent a robotic Dragon cargo capsule into orbit today from Florida to deliver 5,600 pounds of supplies and experiments to the International Space Station, just two days after a different Falcon 9 launched 64 satellites from a pad across the country.
The primary mission was an undeniable hit, but this time around, SpaceX’s attempt to have the Falcon 9’s first-stage booster touch down on a landing pad was a miss.
Today’s liftoff from Cape Canaveral Air Force Station might have come even sooner if it weren’t for some moldy mouse food.
The mold contamination was discovered on some of the food bars that were packed aboard the Dragon for a zero-gravity rodent experiment in preparation for a Tuesday launch opportunity. Changing out the bad chow forced a 24-hour postponement of the launch, which came off right on time today at 1:16 p.m. ET (10:16 a.m. PT).
Forty mice will live aboard the space station in specially designed habitats as part of a study focusing on how microgravity affects bone density, muscle mass and internal organs. After their stints in space, the mice will be euthanized so that their tissues can be compared with samples from earthbound mice.
Rodent Research-8, the latest in a long-running series of experiments, is just one of the payloads packed on the Dragon. Other scientific payloads will provide high-resolution laser ranging observations to assess forest ecosystems and their role in Earth’s carbon cycle, analyze crystals of antioxidant protein that will be grown in zero-G, serve as antioxidants, and test a system for refueling spacecraft in orbit.
Yet another payload, known as SlingShot, is being brought up on a Dragon for eventual installation on a different type of commercial robotic cargo craft, Northrop Grumman’s Cygnus capsule. The apparatus is designed to deploy up to 18 nanosatellites after a Cygnus spaceship leaves the station.
In addition to the experimental payloads, the Dragon is carrying food (including Christmas turkey and the fixings) plus other supplies for the six humans on the station’s crew.
Today’s launch marked the second flight for this particular Dragon capsule, which was flown to the space station and back last year. Its ride to orbit was trouble-free, and it’s scheduled to rendezvous with the station on Saturday for a monthlong stay.
The ride wasn’t as smooth for SpaceX’s pristine Falcon 9 first-stage booster. After stage separation, the booster was supposed to fly itself back to a touchdown at Landing Zone 1, a pad set up on land near the launch site. But on the way down, one of the booster’s titanium steering grids failed to work properly. As a result, the booster went into a spin, veered away from the pad and splashed down about 2 miles offshore instead.
SpaceX’s vice president of mission assurance, Hans Koenigsmann, said the booster was programmed to fly itself into the sea if it experienced loss of control.
“The vehicle kept well away from anything where it could pose even the slightest risk to population and property,” he said during a post-launch briefing. “So public safety was well-protected here.”
SpaceX CEO Elon Musk explained what happened via Twitter:
Grid fin hydraulic pump stalled, so Falcon landed just out to sea. Appears to be undamaged & is transmitting data. Recovery ship dispatched.
— Elon Musk (@elonmusk) December 5, 2018
Can be reused once fished out ?
— Maurizio Ibba (@Dragonmaurizio) December 5, 2018
We may use it for an internal SpaceX mission
— Elon Musk (@elonmusk) December 5, 2018
Is there one pump for all fins (Presumably with backup).
— Scott Manley (@DJSnM) December 5, 2018
Pump is single string. Some landing systems are not redundant, as landing is considered ground safety critical, but not mission critical. Given this event, we will likely add a backup pump & lines.
— Elon Musk (@elonmusk) December 5, 2018
Engines stabilized rocket spin just in time, enabling an intact landing in water! Ships en route to rescue Falcon. pic.twitter.com/O3h8eCgGJ7
— Elon Musk (@elonmusk) December 5, 2018
Tracking shot of Falcon water landing pic.twitter.com/6Hv2aZhLjM
— Elon Musk (@elonmusk) December 5, 2018
The Falcon 9 that was launched on Monday from California’s Vandenberg Air Force Base fared much better. It became the first SpaceX booster to be sent into space and back successfully three times. During that mission, 64 satellites were successfully deployed in sun-synchronous orbit for the customers of Seattle-based Spaceflight, which handled pre-launch arrangements.
Update for 2:40 p.m. PT Dec. 8: The Dragon cargo craft arrived at the space station early Dec. 8, as planned, and after ground controllers coped with a glitchy communications link, the robotic spacecraft was grappled by the station’s robotic arm at 4:21 a.m. PT. A little more than three hours later, the Dragon was installed onto the station’s Harmony module in preparation for unloading. Once the Dragon is emptied, it will be filled up again with more than 4,000 pounds of cargo destined for return to Earth next month.
