After five years of NASA training, two science teachers are about to rocket into space to attempt multiple spacewalks — the most dangerous job in orbit.
It is the first time for two one-time teachers to enter space together, and the men will be in space for two week with their five crewmates, military pilots and rocket scientists.
The crews will deliver and install a final set of solar wings for the space station.
The launch of the Discovery has been delayed a month due to concerns about hydrogen gas valves in the engine compartment but NASA has now deemed the spacecraft safe to fly.
It was only a year and a half ago teacher astronaut Barbara Morgan went to space. Morgan had been the backup in for schoolteacher Christa McAuliffe who died in the space shuttle Challenger explosion on Jan. 28 1986.
"It definitely had an impact when you look at the sacrifices that she (McAuliffe) made and the importance that NASA put on it," said Acaba, 41, who was a freshman at the University of California at Santa Barbara when the explosion occured.
Because of the disaster, he said stepping up " really made you feel like you were doing something worthwhile."
Arnold, 45, was recently out of college at the time of the accident and living in Washington. His wife-to-be was a student-teacher.
It was not only because of their profession as teachers that the two were paired up by NASA. Both worked in the space station branch at Johnson Space Center in Houston dealing with hardware and technical issues.
Acaba and Arnold will be interviewd during the flight with questions coming from students' submissions Channel One News, a newscast for teenagers.
Despite all his intensive training, Arnold, who has taught worlwide, says he still identifies more as a teacher than an astronaut.
"Teachers have to think on their feet. They have to adjust all the time, and I think that's part of what we do" Acaba said. As astronauts, "We train for specific things, but you never really know what's going to happen."