Updated 2:30 p.m. EDT.
WASHINGTON — A SpaceX Falcon 9 rocket suffered a failure more than two minutes after liftoff June 28 on a mission to deliver cargo to the International Space Station, an accident that may have repercussions on both space station operations and the debate about funding for NASA’s commercial crew program.
The Falcon 9 lifted off on schedule at 10:21 a.m. EDT Sunday after a problem-free countdown, and in good weather conditions. The launch appeared to be going well until a little more than two minutes after liftoff, when the first stage plume became irregular and, seconds later, the rocket appeared to disintegrate.
“The first stage flight was successful until 139 seconds into that flight. We experienced an anomaly that led to the failure of the mission,” SpaceX President Gwynne Shotwell said at a NASA press conference nearly three hours after the failure.
Video of the launch showed the anomaly started about 2 minutes and 19 seconds after launch, with a cloud forming near the top of the vehicle. It was not initially clear if that was the cause of the failure, or an effect of another problem with the rocket. “Falcon 9 experienced a problem shortly before first stage shutdown,” SpaceX Chief Executive Elon Musk tweeted shortly after the failure. “Will provide more info as soon as we review the data.”
Falcon 9 experienced a problem shortly before first stage shutdown. Will provide more info as soon as we review the data.
— Elon Musk (@elonmusk) June 28, 2015
Musk later tweeted that the problem was an “overpressurization event” of the liquid oxygen tank in the rocket’s second stage. “Data suggests counterintuitive cause,” he said, without elaborating.
There was an overpressure event in the upper stage liquid oxygen tank. Data suggests counterintuitive cause. — Elon Musk (@elonmusk) June 28, 2015
“We do not expect this to have been a first stage issue,” Shotwell said at the briefing. “We saw some pressurization indications in the second stage, which we’ll be tracking down and following up on there.” She said she didn’t have additional data about the second stage issue, and declined to speculate on the cause of the failure.
The mission was considered a commercial launch, and licensed by the Federal Aviation Administration’s Office of Commercial Space Transportation. Pam Underwood of the FAA said at the briefing that SpaceX would lead what is officially termed a “mishap” investigation, with oversight of the FAA.
Neither Shotwell nor Underwood said how long the investigation would last, or its effect on SpaceX’s launch schedule. “It certainly isn’t going to be a year,” Shotwell said of the length of the investigation. “I imagine a number of months or so.”
NASA officials expressed their disappointment in the failure, but said they continued to support SpaceX and emphasized that the failure would not have an immediate effect on ISS operations.
“We are disappointed in the loss of the latest SpaceX cargo resupply mission to the International Space Station,” NASA Administrator Charles Bolden said in a statement issued two hours after the launch failure. “However, the astronauts are safe aboard the station and have sufficient supplies for the next several months.”
“The space station crew is fine on orbit,” William Gerstenmaier, NASA associate administrator for human exploration and operations, said at the June 28 briefing. There are enough supplies on the station now to support the ISS crew through October, with a Progress cargo spacecraft slated for launch July 3 and a Japanese H-2 Transfer Vehicle cargo mission planned for August.
The failure is the first in 19 launches for the Falcon 9, which first launched five years ago. It is the first failure of a SpaceX launch vehicle since the third launch of its initial Falcon 1 small launch vehicle in August 2008.
The launch was the seventh in a series of cargo missions to the ISS under a SpaceX contract with NASA. The Dragon was carrying 1,950 kilograms of cargo for the station, including a docking adapter to allow future commercial crew vehicles to dock with the station. Also on board were supplies for the crew and a series of experiments.
The failure is the third involving an ISS cargo mission in eight months. An Orbital Sciences Corp. (now Orbital ATK) Antares rocket failed seconds after liftoff in Oct. 28 from Wallops Island, Virginia, destroying a Cygnus cargo spacecraft. A Progress spacecraft launched April 28 was placed in the wrong orbit by its Soyuz launch vehicle and reentered in May without docking at the ISS.
“We expected through the commercial cargo program that we would lose some vehicles,” said Gerstenmaier. “I didn’t think we’d lose them all in a one-year timeframe, but we have.”
The failure also comes as both NASA reviews proposals from several companies for follow-on ISS cargo delivery contracts, and seeks full funding for its commercial crew program for fiscal year 2016. Appropriations bills in the House and Senate both fall short of the agency’s request of $1.243 billion for the program, with the House bill providing $1 billion and the Senate bill $900 million. The Senate bill in particular was critical of what it perceived as delays in the development of crewed vehicles.
Eric Stallmer, president of the Commercial Spaceflight Federation, remained optimistic about both SpaceX and overall commercialization efforts. “I think we just move forward,” he said in a June 28 interview. “I think SpaceX will make adjustments and continue to fly.”
He acknowledged that the failure will heighten skepticism about NASA’s commercial crew efforts on Capitol Hill. “I know there will be debate, and questions raised, but I do believe you have to stay the course,” he said. “We need to figure out what went wrong and continue to move foward and shoot for that 2017 date” when NASA anticipates those vehicles entering service, he said.
Bolden was also optimistic. “SpaceX has demonstrated extraordinary capabilities in its first six cargo resupply missions to the station, and we know they can replicate that success,” he said in his statement. “Today’s launch attempt will not deter us from our ambitious human spaceflight program.”