WASHINGTON — The cargo lost on a SpaceX Dragon spacecraft when its Falcon 9 launch vehicle failed June 28 range from a key piece of hardware for future commercial crew spacecraft to an experiment developed by middle school students, but NASA officials said none of the cargo was critical to the near-term operations of the International Space Station.
The Dragon, flying on the seventh mission under SpaceX’s Commercial Resupply Services contract with NASA, carried 1,867 kilograms of pressurized cargo intended for the ISS, a total that increases to 1,952 kilograms when the weight of the cargo’s packaging is included. That total included 676 kilograms of crew supplies, 461 kilograms of hardware for the ISS, and 529 kilograms of scientific investigations.
The largest, and perhaps most valuable, item lost on the Dragon was an International Docking Adapter (IDA), a 526-kilogram item transported as unpressurized cargo in the “trunk” section of the Dragon spacecraft. The IDA, one of two built by NASA, would have been attached to the station to serve as a docking port for future commercial crew vehicles and potentially other spacecraft.
“Our dream is to have one common docking system that all countries will use to give us commonality as we reach further and further into space,” said Michael Suffredini, NASA ISS program manager, discussing the IDA during a pre-launch briefing June 26 at NASA’s Kennedy Space Center.
NASA planned to install two IDAs on the station to allow for what Suffredini said June 28 were “direct handovers,” where two commercial crew vehicles would be docked to the ISS simultaneously as a new crew arrived before the old crew departed. That is not mandatory, he said, saying the ISS could operate with a single IDA once commercial crew vehicles are online.
There are spare parts available for a third IDA, built as part of the overall program that cost the agency approximately $100 million. “We’ll look to see how quickly we can assemble that,” he said.
Another key piece of hardware lost in the launch failure was an extravehicular mobility unit, or spacesuit used by astronauts to perform spacewalks outside the ISS. That suit was to replace one currently on the station that had a faulty pump, Suffredini said.
“I suspect we’ll have a conversation about just replacing the pump and keeping it on orbit a bit longer,” he said of the suit on the station. With three other suits currently on the station, “I suspect we’ll be fine with suits for a while” if the pump can be replaced.
The Dragon carried cargo to support more than 35 experiments on the ISS, as well as 30 student research investigations sponsored by the Center for the Advancement of Science in Space. Among the latter was an experiment developed by students at Bell Middle School in Golden, Colorado, to test if worms can compost in microgravity.
Heidi Smith, one of the students worked on that experiment, said at a June 27 NASA briefing that students worked all school year on the experiment. “It’s awesome that it’s so close to being launched,” she said.
The Dragon’s cargo also included eight cubesats for San Francisco-based Earth imaging company Planet Labs that were scheduled to be deployed from the airlock on the station’s Kibo module. It’s the second time the company has lost satellites in an ISS cargo mission failure: 26 of the company’s Dove satellites were on an Orbital Sciences Corp. Cygnus spacecraft lost in an October 2014 launch failure.
“This is a hard day for Planet Labs but we’ve experienced a launch failure before, and statistically, we will again,” Planet Labs Chief Executive Will Marshall said in a June 28 statement, referring to the Cygnus failure. He added that with plans to launch satellites on a quarterly basis, the failure would not deter the company’s long-term plans to deploy a constellation of satellites to provide daily images of the entire Earth.
NASA officials said that despite the lost supplies and hardware on the Dragon mission, ISS operations should not suffer any near-term problems. William Gerstenmaier, NASA associate administrator for human exploration and operations, said there were no plans to delay the launch of three new ISS crew members on a Soyuz scheduled for July 22.
“We’re good from a food and water standpoint. We also have a good amount of research on orbit,” he said. “At this point, we don’t see a need to slip it.”
Gerstenmaier and Suffredini said there are enough supplies on the ISS to support a crew at least through the end of October, even if no other resupply missions are launched. Russia plans to launch a Progress mission on July 3, the first such mission since a failed Progress flight April 28. A Japanese H-2 Transfer Vehicle is scheduled to launch in mid-August.
In addition, Orbital ATK is planning to launch its Cygnus spacecraft for the first time since last October’s failure on a United Launch Alliance Atlas 5. That launch is currently scheduled for December, based on the schedule of other missions, but Gerstenmaier suggested at the post-launch briefing that it could be moved up.
“The launch manifest kind of compressed us into December,” he said. “If we can advance a little bit from December, and the manifest lets us do that, we might want to do that as early as October.”
Suffredini said that none of the cargo lost on the Dragon was so critical that they would attempt to replace it on the Progress launching in five days. “I can’t think of anything off the top of my head that is so important that we would want to rush it to our Russian colleagues,” he said. “Overall, we’re in very good shape on orbit.”