All eyes on upcoming space station supply mission

The U.S. space shuttle program was always an impressive reminder of America's technical prowess, even if the flights took astronauts only to Earth orbit, and even if the main purpose of some was to ferry frozen dinners, Pop-Tarts and toilet paper to the International Space Station.

The space shuttles, of course, are now museum pieces. And today's supply missions to the orbiting space lab - whether they carry science experiments, technical equipment or basic provisions - are done by private contractors whose smaller rockets draw little attention because no one's on board.

But after three recent efforts to get supplies to the station have gone up in flames, there will be far more eyes than usual Thursday evening on the launch of the next supply mission, officially known as CRS-4. While those living on the station are not in danger of starving, the pressure is on to deliver.

"Spaceflight does carry risks, and sometimes those are realized," said Frank DeMauro, head of human spaceflight operations for Orbital ATK, the company tasked with the latest supply venture. "We don't treat any mission as routine, but we feel very confident that we're ready to get back to delivering cargo to the space station."

Last October, an Orbital resupply effort with 5,000 pounds of cargo exploded just seconds after liftoff from a NASA facility in Virginia. As shocking as the launch failure was, eight months later it happened again, this time with a Space X Falcon 9 rocket loaded with 4,000 pounds of food, scientific experiments, and station hardware. Liftoff went well, but the rocket exploded about two minutes into its flight. In between those mishaps, a Russian cargo vessel was lifted into space aboard a Soyuz rocket but failed to reach proper altitude and eventually fell back to Earth.

"There's no commonality across these events other than the fact that it's space and it's difficult to go fly," said William Gerstenmaier, NASA's associate administrator of Human Exploration and Operations, shortly after the Space X failure. "We are essentially operating systems at the edge of their ability to perform and operate. … This is a blow to us. We lost a lot of important research equipment on this flight."

Losing confidence?

Space station managers did not panic, nor did NASA executives. After all, Space X had successfully flown six resupply missions before the ill-fated one, and Orbital, too. There also are periodic visits from other non-U.S. cargo vessels, including one from Japan and one from Europe within the past year. In all, the space station receives eight or so cargo vessels a year, so the station had adequate supplies and scientific work to do.

But should problems persist with American rockets, confidence in the young companies might be imperiled. It may not be like the old days, when launch failure was too horrifying to accept. Lives are not in jeopardy. Yet for space missions to cross the threshold into normal human activity, or even to keep getting significant political support, the days of rockets blowing up must become past tense.

For Orbital's CRS-4, the outlook for this week's mission certainly is promising. Instead of trying again with its Antares rocket, along with its refurbished old Russian engine, the Cygnus cargo spacecraft will be lifted into orbit on an Atlas V rocket manufactured by United Launch Alliance, a joint venture of Lockheed Martin and Boeing.

The Atlas V has had only one launch incident, that occurring in 2007 when a leaky valve allowed fuel to escape from the rocket's upper stage. That meant the engine shutoff came four seconds early and the satellite payload was short of its desired orbit.

Orbital plans to use an Atlas rocket for its next resupply mission as well. One built-in advantage of the Atlas is greater lift capacity, which meant Orbital had no issues with its new and enhanced Cygnus vessel, which can contain about 53 percent more cargo, a total of almost 7,700 pounds. The company intends to go back to Antares with new Russian engines once testing is complete.

"We've had a long history of successfully launched missions," DeMauro said. "We are very confident in the work we have done."

As crushing as the launch mishap was for the 200 or so employees involved with the resupply program, the desire to go back to work and figure out the problem was even stronger, DeMauro said. Orbital ATK had already planned to change engines in the Antares in order to lift the heavier second-generation Cygnus, but the engine failure created a sense of urgency.

"Our team really loves this program because it has an attachment to human spaceflight," DeMauro said. "It has a very special meaning for them."

Garbage vessel, too

NASA allows for the possibility of resupply failures in its planning for the space station. About six months worth of supplies are in reserve. But when several missions in a short period go bad, it can make for a lack of replacement parts or perhaps fewer menu options.

Even more of a concern with the American mishaps was the loss of a new water filtration system. The system is crucial because packaged water is in limited supply - the station relies on filtering urine for daily crew needs.

Besides the science experiments, many of them years in the planning, and the standard supplies, newly arrived cargo vessels contain fresh food, a welcome treat. This particular "crew care package" will contain some special holiday fare.

When all the new stuff is taken off of Cygnus, the vessel changes roles and becomes a large trash can. Once full, it is undocked and booted back toward Earth, where it will burn up on re-entry.