SAN FRANCISCO — Members of a congressional panel questioned the wisdom of NASA’s plan to rely on two commercial companies to handle the critically important job of ferrying cargo to the international space station after the space shuttle concludes its final flight scheduled for July.

During a May 26 hearing of the House Science, Space and Technology space and aeronautics subcommittee, Rep. Ralph Hall (R-Texas) accused NASA of “gambling the future of space station on the success of two very new launch systems.”

Hall, chairman of the House Science, Space and Technology Committee, said NASA’s original plan to encourage companies to develop commercial launch capabilities and then award space station logistics contracts through competition was reasonable. When NASA began that program, plans called for the agency to also deploy its own means of transporting crew and cargo to the orbiting facility.

Under the current approach, NASA is entirely reliant on two companies, Orbital Sciences Corp. and Space Exploration Technologies Corp. (SpaceX), that are developing commercial logistics capabilities with the aim of beginning regular cargo runs to the space station in 2012. This is risky, Hall said, because NASA has no backup vehicle if the companies encounter technical challenges or schedule delays.

By the end of 2011, the space agency will have spent more than $1.25 billion for development of commercial transportation vehicles and the purchase of cargo flights, according to the subcommittee’s hearing charter. From 2011 through 2016, the space agency’s budget plan includes more than $5 billion for commercial cargo flights, according to the hearing charter.

“In spite of optimistic projections and even the success of the SpaceX Falcon 9 launch and Dragon capsule recovery, NASA’s commercial cargo partners have yet to demonstrate the ability to safely deliver cargo to the international space station,” said Rep. Steven Palazzo (R-Miss.), chairman of the space and aeronautics subcommittee. SpaceX and Orbital are well behind their original schedules for demonstrating their respective cargo delivery services.

NASA officials, however, “see no reason to doubt” that SpaceX and Orbital will be successful, William Gerstenmaier, associate administrator for NASA’s Space Operations Mission Directorate, told members of the subcommittee. Both companies have experienced the types of technical challenges and schedule setbacks that often occur during the development of new spacecraft, he said. Further challenges are likely to arise as the companies complete testing and attempt to establish a regular pattern of cargo flights to the space station, he said.

To accommodate the delays in the commercial cargo program, NASA will utilize the final space shuttle mission, a congressionally mandated flight now scheduled for July 8, to deliver additional supplies to the space station. By doing so, NASA will be able to maintain station operations for approximately one year with minimal resupply efforts, Gerstenmaier said. “That allows some of these [cargo] flights to move around without having an immediate impact on us,” he said.

In December 2010, the Falcon 9 rocket built by Hawthorne, Calif.-based SpaceX carried the company’s Dragon cargo capsule into Earth orbit for the first time. The capsule made two orbits before splashing down in the Pacific Ocean, where it was recovered by SpaceX employees. The next Falcon 9/Dragon demonstration is scheduled to occur later this year, SpaceX President Gwynne Shotwell told the panel. “If all goes as planned, it will berth with the international space station, deliver cargo and return cargo to Earth,” she said.

SpaceX has proposed berthing with the space station on Dragon’s upcoming mission, but NASA has yet to approve the idea.

Orbital is scheduled to conduct the first test flight of its Taurus 2 rocket in October from NASA’s Wallops Flight Facility in Virginia. Two months later, the company plans to demonstrate the Taurus 2’s ability to send the Cygnus cargo capsule to berth with the international space station, said Frank Culbertson, senior vice president and deputy general manager of Dulles, Va.-based Orbital.

Lawmakers asked Gerstenmaier how much money NASA plans to spend to send 1 pound (0.45 kilograms) of cargo to the space station aboard the new commercial rockets. The subcommittee staff calculated that NASA would pay $26,770 per pound using the commercial cargo vehicles, compared with $21,268 per pound aboard the space shuttle and $18,149 per pound aboard the Russian Progress vehicle, said Rep. Mo Brooks (R-Ala.).

Gerstenmaier said there was no simple way to verify the accuracy of those calculations. To provide a valid comparison, NASA would have to determine how many flights would be conducted by each spacecraft and what vehicle development costs were factored into each equation. Gerstenmaier said his staff would complete that analysis and provide its answers to the subcommittee after the hearing.

Shotwell said the subcommittee’s numbers were erroneous because they are based on the minimum amount of cargo the companies are contractually required to deliver in a specified number of flights. “The fact is that NASA has bought 12 flights from SpaceX,” with a minimum cargo delivery requirement of 20 metric tons, she said. “We can take much more than 20 metric tons to orbit on those flights. We do not charge NASA extra for anything above the 20 metric tons as long as we are still doing the 12 flights.”

Lawmakers also asked Gerstenmaier to address safety concerns with commercial cargo vehicles approaching the space station. “We have stringent visiting vehicle requirements for station to make sure a vehicle not only gets there safely, but if it has to abort its mission that it won’t do any damage,” Gerstenmaier said.

NASA officials are evaluating the capabilities of the SpaceX and Orbital spacecraft to meet those requirements. In approximately one month, when space agency officials complete those safety reviews, they will schedule meetings with their international partners to show them “why we think it is safe and prudent for us to allow these vehicles to come to the space station,” Gerstenmaier said.



NASA Seeks To Ease Doubts About Commercial Crew Support

NASA Raises Bet on Commercial Cargo

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...