Tough Choices for NASA Put Shuttle, Crew and Mission At Risk

Dec. 19, 2006 — -- The mission management team at NASA made the choice to do a final inspection of the Space Shuttle Discovery on Thursday and land on Friday or Saturday at the first available and weather-friendly landing site -- the Kennedy Space Center, Edwards Air Force Base or White Sands New Mexico.

The managers had faced a tough decision as to which was the bigger risk: skipping the late inspection to see if Discovery was damaged by a micrometeorite while it was docked with the International Space Station during the past week? Or running out of time to land Discovery safely when the shuttle's fuel reserves are close to empty?

The space shuttle has a failure rate of less than 1 in 50, having lost two orbiters in 116 missions. Some analysts argue it's a reasonable statistic because launching the space shuttle, or any other model of "booster," is inherently dangerous. These launches stretch existing technology to the limit. When you do that, it is unreasonable to expect zero failures.

The tough choice came as a result of a fourth spacewalk, which was added to an already packed mission. The spacewalk demonstrated that the Apollo 13 "failure is not an option" spirit continues to thrive at NASA.

In just two days, a plan was drawn up for a spacewalk the astronauts had not trained for, with tools that were already on-board. The tools were wrapped in insulating tape to keep astronaut Robert Curbeam from being electrocuted as he worked on fixing the solar array that would not retract.

The fourth spacewalk, however, took away the weather contingency day that mission managers like to build into every mission, just in case weather is bad at the three landing sites in the United States.

And weather doesn't look good for the landing sites on Friday and Saturday, so the mission management team struggled with the decision before ultimately choosing to complete the inspection Thursday.

Spaceflight is risky. Landing is risky. Anyone involved in the space program will tell you space is a risky business.

NASA prefers not to land at the Edwards Air Force Base in California or at White Sands in New Mexico because there are risks the shuttle is exposed to when it is ferried back to the Kennedy Space Center in Florida.

There is also pressure to finish the International Space Station.

Space station Program Manager Mike Suffredini is painfully aware that there is little room for error in the next 13 flights needed to finish the space station by 2010, when the space shuttle will stop flying.

"It'll be a challenging four years for us," he said. "There's very little wiggle room. We've got a set number of shuttle flights. You will find, as we talk over the next four years, every flight is very full, very busy. There are a handful of flights that we have options to carry failed ORU [Orbital Replacement Unit]. From a smaller ORU perspective, I'm pretty flexible. From a large ORU perspective, it's going to be more difficult with less flights, all of them very full. Every single shuttle flight is very busy. We already know that every flight has got a number of EVA tasks -- transfer tasks -- planned. A major problem with one of the elements will cause us a major change in the final configuration of the ISS."

NASA Administrator Michael Griffin is well aware of the consequences of another shuttle accident.

"I think in fairness, given our history now with the shuttle, that the future of the shuttle depends on every single flight that we do," Griffin said. "We cannot have any more bad flights on the shuttle."

Mission specialist Nick Patrick has been primarily responsible for much of the complicated robotics critical to the success of this mission. He told ABC News before his flight last month that the risk was not an issue for him.

"Spaceflight will always be risky business," explained Patrick. "It was a risky business before Columbia as well, it is just, as you say, we weren't quite as aware of it. I think the rewards are huge, both personal and national.

"Everybody gets something out of spaceflight. I don't worry about the risks at all. I think what I worry about actually is whether I will remember what I am trained to do right when I need to remember them. I think the rewards make the risks seem worthwhile."

Trisha Mack, the flight director for the spacewalk, had to balance the risks of coming up with a spacewalk on short notice.

"What is challenging is doing it, having only a few days to come up with an entire EVA on the end of a shuttle robotic arm, normally we train for a year and a half, but this entire EVA was put together over the course of a couple of days," she said.

"On an EVA time is always ticking, I can't ask, 'Can you give me another hour?'" she said. "There are consumables, we all knew we had to get the crew in at 6 hours 30 minutes, we always have that time pressure."

Earlier this year, space shuttle program manger Wayne Hale told ABC News that the Columbia accident has raised his awareness of the risks.

"We know so much more about the risk we are all going to be a little bit more apprehensive because we understand more fully what we are doing," said Hale. "Capt. John Young, one of our legendary heroes, went to the moon twice, commanded the first shuttle mission, he had a saying that he always told all of us new engineers, 'If you aren't a little scared, you don't understand what is really happening.' I find that to be true."

When the Discovery crew said goodbye to their colleagues on the international space station, there were hugs all around, the hatch was closed and now Discovery's crew is waiting to see when they come home: Thursday, Friday or Saturday.

They do know this, however: They will be home for Christmas.