The events of the last two Saturdays have stunned NASA in a way the space agency could never anticipated.
Mark Kelly, Endeavour's commander for the space shuttle mission in April, found himself on the way to Arizona where his wife, Rep, Gabrielle Giffords, was critically injured in a shooting. Kelly, at his wife's bedside while she fights for recovery, asked NASA to name a backup commander, Rick Sturckow, for Kelly's mission.
This past weekend, astronaut Tim Kopra was injured during a bicycle ride. The extent of his injuries has not been released, but they are serious enough to have mission managers scrambling to consider who could take his place on the STS 133 mission, Discovery's oft-delayed final flight, which is tentatively scheduled to launch next month.
NASA's choices: Wait for Kopra to heal from his injuries, or replace him on the mission. Kopra has been training for his two spacewalks for well over a year -- his mission was originally scheduled to fly in September 2010 and it was once the last space shuttle flight before the fleet was retired.
Astronauts give up anything risky when they start training for a flight -- no car racing, no sky diving, no scuba diving, no mountain climbing. Drew Feustel, who flew on the last mission to repair the Hubble Space Telescope, had to indulge his love for fast cars on the sidelines, watching his sons' race. Scott Parazynksi climbed Mount Everest only after he retired from the astronaut corps.
The training for a space mission is intense, so intense the astronauts become a second family.
Their commander for this next mission, Steve Lindsey, told ABC News working as a team is critical to the success of the mission. "You have to know that you can count on each other when things don't go as planned, and in contingency situations knowing that you have a team you can count on is important."
Al Drew is the other spacewalker on the mission. He admires Kopra not only for his spacewalking skill, but for his impish sense of humor. They are both members of the same rookie class of 2001, known as the bug class in honor of Y2K.
"Five of the six of us on the crew joined the same class, 10 years ago, the bug class, and Steve [Lindsey] is an honorary bug so we have been together since August of 2001 living and working together as long as many families have quite honestly."
Kopra's sense of humor was obvious during a shuttle evacuation training session. Astronaut Nicole Stott's young son came to watch his Mom rappel down the side of a shuttle. Tim reached over during a break, held up his forefinger and said, what's this? It's a tickle monster!
Many at NASA hope the tickle monster makes it on this next space shuttle mission.