The demanding nature of space station expeditions is one reason that NASA continues to recruit astronauts, maintaining a head count of 55, even though the opportunities to fly are limited. The training is so complex and demanding that it lasts from two and a half to three years. So at any given time, there are a dozen astronauts training to fly to and work on the station in what NASA calls “lines,” one for an astronaut who can qualify as a Soyuz second-seater or flight engineer, the other as a backup for a Russian, European, Japanese, or Canadian scheduled for the third seat.
Half a dozen more astronauts are in preliminary training for these assignments—brushing up on their language or spacewalking skills, for example. Still, that adds up to only around 20. What are the rest doing? What astronauts have done since the Mercury program: helping to develop the hardware and systems they will operate in space.
Astronauts are assigned to one or more of five branches in the astronaut office. The Station branch deals with support for current and future missions, medical issues, and ISS crew operations. The EVA/Robotics branch choreographs spacewalks and schedules tasks that require use of the station’s robotic arm. The Training branch oversees the new astronaut candidates. The Soyuz branch involves astronauts in design reviews of the vehicle, as it continues to evolve. And the Exploration branch—the largest—focuses on the cockpit design, habitability, and operations of the commercial spacecraft and Orion capsule, as well as the engineering requirements for the new Space Launch System. The chief, deputy, and branch chiefs add another dozen astronauts to the total.
Some positions in the branches are filled by astronauts who also have management positions outside the astronaut office, and that complicates the head-counting, as does the fact that most astronauts have several jobs. Randy Bresnik, for example, has a primary assignment in the Exploration branch as the astronaut rep for SpaceX, but he has additional duties in the EVA/Robotics branch, and recently took part in tests to see how spacesuited astronauts fit inside a mockup of the CST-100. In addition, he just gave up public astronaut appearances in order to train as a capcom (capsule communicator) for the station.
Robert Hanley’s major area is station systems integration, “where we deal with utilization of the station—science, experiments, crew procedures, and operations. I also have capcoms, IT, and a few other areas. There isn’t really a complete separation between me and Eric Boe, the [astronaut office] deputy chief. We cover for each other.”
The chief of the astronaut office is Robert Behnken, a 43-year-old Air Force flight test engineer who became an astronaut in 2000 and has made two visits to the space station as a shuttle mission specialist. His philosophy is simple: “Astronauts should be flying.”
The First Shall Be First
Several years ago, the JSC flight crew operations directorate studied astronaut staffing in light of flight opportunities and training requirements as well as mission support and even career and lifestyle issues, and a 2011 National Academy of Sciences panel confirmed its findings. For the next five years or so, the two bodies concluded, the ideal number of astronauts is 55. With 47 active astronauts and the eight newly selected candidates, that is just what NASA has now.
How many missions will be divided among them depends in part on what mode of transportation the astronauts will take to the station. There is the “rental car” mode, in which NASA buys a mission from a company and crews the flight entirely with astronauts; and there is the “taxi,” in which NASA buys a flight and assigns three to four astronauts, but uses company employees for the two pilots. “You can guess which one is most popular around here,” jokes Robert Hanley, Behnken’s technical deputy.
Once that’s worked out, the chief of the astronaut office will determine the order of flight assignments. “Management quite rightly wants to get unflown astronauts into space,” Ross says, “which also lengthens the line for the veterans.”
And if you’re a woman, the line is even longer. NASA’s standards for cumulative radiation exposure are 20 percent more stringent for women than for men, mostly because of their additional risk of getting breast, ovarian, or uterine cancers. That means women will fly only 45 to 50 percent of the missions men will fly, former chief astronaut Peggy Whitson told an Institute of Medicine workshop last July. “I think that the current standards are too confining for exposure limits...because I think it limits careers more than necessary,” she told the workshop. With astronaut careers projected to allow for, at most, two flights over the next decade, that’s a serious loss of flight opportunities.