September 23, 2013
Space Exploration Technologies (SpaceX) is modifying its Dragon capsule to afford more payload capacity for NASA cargo runs to and from the International Space Station (ISS). But the improvements will push a planned December ISS mission into 2014, in which the company's crowded launch manifest is pending the delayed debut of the revamped SpaceX Falcon 9 rocket.
President Gwynne Shotwell says NASA needs SpaceX to make the Dragon enhancements in order to increase the reusable cargo vessel's cold-storage capacity for transporting research samples between Earth and the ISS.
“We're developing a major upgrade to Dragon to triple the amount of science that we carry up and back,” Shotwell said Sept. 10 at the World Satellite Business Week conference here, adding that the capsule's December mission is now scheduled for February.
Under the terms of SpaceX's $1.6 billion Commercial Resupply Services (CRS) contract with NASA, the company is supposed to deliver 20,000 kg (44,000 lb.) of food, supplies and science materials to the ISS by Dec. 31, 2015. Dragon's advertised payload capacity is for more than 3,300 kg of pressurized and unpressurized cargo to the space station and up to 2,500 kg on the return trip.
Since the December 2008 CRS contract was signed, however, Dragon has conducted just three trips to the ISS, delivering a combined 1,595 kg of pressurized cargo and returning a total of 2,120 kg to Earth.
NASA spokesman Joshua Byerly says no new requirements have been added to the SpaceX CRS contract, suggesting the upgrades are expected to fulfill a long-standing requirement to meet ISS cargo needs. But he says the work is taking longer than initially planned.
“The December launch date was chosen in cooperation with SpaceX and assumed the enhancements being implemented by SpaceX,” Byerly explains. “It is simply taking longer to get all the modifications completed, which is not unreasonable, given the nature of the enhancements.”