Training becomes more rigorous once the astronaut begins focusing more on Space Shuttle operations. This phase of training begins by studying manuals and computerized lessons before proceeding to simulators. The Single System Trainer familiarizes astronauts with the operations of each Orbiter subsystem while the Shuttle Mission Simulators provide training on each stage of flight. Once assigned to a specific mission, the training becomes more specialized and includes the actual software to be used during the flight. The astronauts also train with flight controllers in mission control. The total time spent training in the simulators for a specific mission is about 300 hours.
Sustained human exploration begins with the International Space Station. The station begins a new era of permanent operations in space. NASA's experience during the Shuttle/Mir program provides many answers to the question of sustaining a long-term operation in space.
While the International Space Station will be permanently crewed, the crews will rotate during crew exchange flights. As an incoming crew prepares to replace the outgoing crew there will be a 'handover period'. The current space station crew will communicate by telecon to the crew on Earth any situations not planned for during training, new techniques or any topic necessary for life aboard the space station. Once the new crew arrives onboard the space station the outgoing crew will brief them on safety issues, vehicle changes and payload operations.
Besides being the most advanced laboratory for research and science, the International Space Station will be a launching point to destinations across the solar system. For instance, after sustaining autonomous space operations for 30 days explorers will be able to leave the space station for a journey to the moon and possibly set up a lunar outpost. After autonomous space station operations for 3 years explorers will be able to journey to Mars.
Habitable, pressurized volume on the International Space Station will be 43,000 cubic feet. That is about the volume of three average American houses, each one containing about 2,000 square feet with a 7 foot ceiling for a total of around 14,000 cubic feet. The pressurized volume will be roughly equivalent to the interior of a 747 jumbo jet.
Astronaut Candidate Training
Astronaut candidates receive training at JSC near Houston, Texas. They attend classes on shuttle systems, in basic science and technology: mathematics, geology meteorology, guidance and navigation, oceanography, orbital dynamics, astronomy, physics, and materials processing are among the subjects. Candidates also receive training in land and sea survival training, scuba diving, and space suits.
As part of the Astronaut Candidate training program, Astronaut Candidates are required to complete military water survival prior to beginning their flying syllabus, and become SCUBA qualified to prepare them for the extravehicular activity training. Consequently, all Astronaut Candidates will be required to pass a swimming test during their first month of training. They must swim 3 lengths of a 25M pool in a flight suit and tennis shoes. The strokes allowed are freestyle, breast, and sidestroke. There is no time limit. They must also tread water continuously for 10 minutes.
Candidates are also exposed to the problems associated with high (hyperbaric) and low (hypobaric) atmospheric pressures in the altitude chambers and learn to deal with emergencies associated with these conditions. In addition, astronaut candidates are given exposure to the microgravity of space flight. A modified KC-135 jet aircraft produces periods of weightlessness for 20 seconds. During this brief period, astronauts experience the feeling of microgravity. The aircraft then returns to the original altitude and the sequence is repeated up to 40 times in a day.
Pilot astronauts maintain flying proficiency by flying 15 hours per month in NASA's fleet of 2-seat T-38 jets; they build up jet aircraft hours and also practice Orbiter landings in the Shuttle Training Aircraft, a modified corporate jet aircraft. Mission specialist astronauts fly a minimum of 4 hours per month.
Astronaut Formal Training
The astronauts begin their formal space transportation system training program during their year of candidacy by reading manuals and by taking computer-based training lessons on the various Orbiter systems ranging from propulsion to environmental control.
The next step in the training process is the single systems trainer (SST). Each astronaut is accompanied by an instructor who helps in the learning process about the operations of each Orbiter subsystem using checklists similar to those found on a mission. The checklists contain information on normal system operations and corrective actions for malfunctions. The astronauts are trained in the SSTs to operate each system, to recognize malfunctions, and to perform corrective actions.
Following the SST portion of the training program, the astronauts begin training in the complex Shuttle Mission Simulators (SMSs). The SMS provides training in all areas of shuttle vehicle operations and in all systems tasks associated with the major flight phases: prelaunch, ascent, orbit operations, entry and landing. The orbit training includes payload operation, payload deployment and retrieval, maneuvers, and rendezvous. Two additional simulators, a fixed base and a motion base, are used to train the astronauts.
The fixed base crew station is used for both specific mission/payload training and launch descent and landing training. It is the only trainer with complete fore and aft consoles, including an RMS console. A digital image generation system provides visual cues for out-the-window scenes of the entire mission, e.g., the Earth, stars, payloads and the landing runway. Missions can be simulated literally from launch to landing.
The motion base crew station is used to train pilots and commanders in the mission phases of launch, descent, and landing. Motion cues are provided by the 6-degrees-of-freedom motion system which also allows the flight deck to be rotated 90 degrees to simulate lift-off and ascent.
Astronauts begin their training in the SMS using generic training software until they are assigned to a particular mission, approximately 10 months before flight. Once they are assigned to a flight, astronauts train on a flight simulator with actual flight-specific training software.
During this last 11 weeks, the astronauts also train with the flight controllers in the Mission Control Center (MCC). The SMS and MCC are linked by computer in the same way the Orbiter and MCC are linked during an actual mission. The astronauts and flight controllers learn to work as a team, solving problems and working nominal and contingency mission timelines. Total hours in the SMS for the astronauts, after flight assignment, is about 300 hours.
In parallel with the SMS training there are several other part-task trainers that are used to prepare astronauts for shuttle missions. These trainers are in varying degrees of fidelity and each serve a particular purpose.
The Sonny Carter Training Facility, or Neutral Buoyancy Laboratory (NBL), provides controlled neutral buoyancy operations in the facility water tank to simulate the zero-g or weightless condition which is experienced by the spacecraft and crew during space flight. It is an essential tool for the design, testing and development of the space station and future NASA programs. For the astronaut, the facility provides important pre-flight training in becoming familiar with planned crew activities and with the dynamics of body motion under weightless conditions.
Several full-scale mockups and trainers are also used to train astronauts. The full fuselage trainer is a full-sized plywood Orbiter mockup with nonfunctional mid-deck and flight deck, and full-scale payload bay. It is used for onboard systems orientation and habitability training. Astronauts practice meal preparation, equipment stowage, trash management, use of cameras, and experiment familiarization. This trainer is also used for emergency egress training after shuttle landings.
The crew compartment trainer is a mockup of the forward section of the Orbiter crew station, without a payload bay, that can be tilted vertically. It is used to train for on-orbit habitability procedures and also emergency pad egress and bailout operations. The crew stations of both trainers are similar. The manipulator development facility is a full-scale mockup of the payload bay with full-scale hydraulically operated RMS, the mechanical arm on the Orbiter which is used to move payloads in and out of the payload bay. Mission specialists use this trainer to practice deploying and reberthing of payloads into the Orbiter.
Pilots training for a specific mission receive more intensive instruction in Orbiter approach and landing in Shuttle Training Aircraft (STA), which are four Gulfstream II business jets modified to perform like the Orbiter during landing. Because the Orbiter approaches landings at such a steep angle (17-20 degrees) and high speed (over 300 miles per hour), the STA approaches with its engines in reverse thrust and main landing gear down to increase drag and duplicate the unique glide characteristics of the Orbiter. Assigned pilots receive about 100 hours of STA training prior to a flight, which is equivalent to 600 shuttle approaches. In between training sessions, the crew members continue to keep themselves up-to-date on the status of the space craft and payloads for their assigned mission. In addition, the astronauts study flight rules and flight data file procedures, and participate in mission-related technical meetings. They also participate in test and checkout activities at the NASA Kennedy Space Center in Florida, the launch site for the space shuttle.
The months of preparation pay off and the mission is a success; the actual mission will have far fewer contingencies than were practiced for. The accuracy of the simulations and training is remarkable. Astronauts often comment that only the noise and vibration of launch and the experience of weightlessness are missing from the practice sessions; everything else in training accurately duplicates the space experience.