A Brief History of Space Flight Training
As the design of NASA’s human space flight missions has changed over the decades, so has NASA’s space flight training design. For Apollo-era and Space Shuttle missions, astronauts were provided extensive practice for mission operations as an intact team training to detailed flight plans with a well-defined set of duties or tasks for their assigned mission roles (Weaver, Weaver, & Weaver, 2015; Woodling et al., 1973). For current International Space Station (ISS) Expeditions, astronauts are provided generic-task training to support the flexibility to perform across a wide range of tasks that may occur throughout a long ISS Expedition (National Research
Council, 2011). What has not changed since the beginning of space flight is that each of NASA’s space flight training programs has been primarily designed based on what we term a “system-siloed” training approach. That is, an approach in which training begins with vehicle system flows (e.g., an electrical power system training flow, a thermal control system training flow) and discipline flows (e.g., a robotics training flow, an inventory and stowage training flow), with training for mission operations being provided only after extensive training on vehicle systems and disciplines is completed. Additionally, the operational concepts for each of these programs have assumed that real-time expertise needed to respond to unplanned, complex technical problems or unforeseen medical issues would be provided by the flight control personnel in MCC, and a return to Earth within hours, or at most days, would always be an option.
In the early days of space flight, during the Mercury, Gemini, and Apollo programs, astronauts spent years learning the vehicle systems as they worked col- laboratively w'ith systems engineers on the vehicle designs. In fact, the selection criteria for the Mercury Seven included requiring candidates for NASA’s first group of astronauts to have an engineering background along with test pilot experience (Weaver et al., 2015). Mission objectives for these early space flights were clearly defined (e.g., placing a manned spacecraft into orbit around the Earth, demonstrating the rendezvous and docking capability needed for lunar missions, landing men on the moon and returning them safely back to Earth). According to Woodling et al. (1973), the mission-specific training requirements were that the astronauts could practice and demonstrate proficiency in the critical aspects of their mission. To support this training, NASA made tremendous engineering advancements in designing simulators that could mimic the various space flight environments the crew would encounter (e.g., neutral buoyancy simulators for extravehicular activities (EVAs, aka spacew'alks), motion-based simulators for ascent and entry, and reduced gravity simulators for lunar surface operations) allowing the astronauts to practice critical tasks planned for their missions (Weaver et ah, 2015; Woodling, et ah, 1973). Astronauts were assigned specific roles (e.g., commander, command module pilot) with unique job duties and provided numerous hours of individual and team training. Training took place in part-task trainers as well as in high-fidelity, full-task, fixed- and motion-based simulators. Astronauts practiced well-defined tasks based on detailed flight plans with MCC, averaging almost 1,000 hour of simulator time per crew'man per mission during the Apollo program (Woodling et ah, 1973). Skylab missions flown at the end of this era were longer in duration, but the pre-flight training remained the same in that the crew' were provided extensive training for planned tasks (Schneider, 1976).
Much like astronauts in NASA’s earlier programs, the first Space Shuttle astronauts learned the vehicle systems as they were being built. As the Space Shuttle program progressed, space flight training was formalized into lessons, w'here sets of lessons were designed into training flows, and training culminated in a series of simulations that provided crew'members practice or rehearsal of critical tasks in their mission timelines. While lessons and flows were sequenced to ensure prerequisites from one flow were trained prior to being needed in a different flow, the fundamental design approach was based on distinct vehicle system and discipline flows.
The most influential factor in NASA’s design was simple logistics - the instructors were grouped by system or discipline.
Newly hired Space Shuttle astronaut candidates (ASCANs) were provided 2 years of initial training, focused extensively on the vehicle’s systems, prior to being designated as “astronauts” qualified for flight assignment and ready for flight-specific training. Between the end of ASCAN training and being flight-assigned, astronauts had additional training opportunities. Space Shuttle mission objectives were clearly defined (e.g., servicing the Hubble Space Telescope, installing the Joint Airlock to the ISS), and detailed flight plans were built for missions lasting up to 17 days. Flight-specific training for Shuttle missions was typically 1 year long, although flight delays often extended this training time. Crewmembers were assigned roles (e.g., commander, pilot, mission specialist) with unique job duties, and provided intensive training focused on ensuring they could perform their assigned duties and tasks as per their mission timeline. The commander and pilot were required to demonstrate proficiency in piloting the vehicle for ascent, entry, and rendezvous, as well as in docking and vehicle operations. They were provided training on these tasks in training facilities ranging from part-task trainers to high-fidelity, full-task, motion-based simulators, as well as training in the Shuttle Training Aircraft, an aircraft modified to duplicate the handling of a Space Shuttle during approach and landing. Mission specialists were required to demonstrate proficiency in performing EVAs, robotics operations, and scientific operations and were provided training on these tasks in mock-ups and simulators of varying fidelity, including EVA training in a neutral buoyancy simulator. Although much of this flight-assigned training was provided to individual or pairs of crewmembers within system or discipline training flows, flight- specific simulations allowed the entire crew to practice ascent and entry, as well as practice challenging longer mission flight plan sequences such as satellite deployments or EVA tasks, integrated as a team with MCC. Space Shuttle astronauts averaged about 120-160 hours of flight-specific integrated simulation time with MCC per crewmember in fixed- and motion-based simulators.
Unlike Space Shuttle missions, ISS missions differ significantly from NASA’s previous missions in several important ways that impact the design of training. The ISS is a large, permanently-orbiting laboratory consisting of modules and elements provided by five international partners (NASA, Russia, the European Space Agency (ESA), the Japanese Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA)). The ISS was designed and built with the objective of supporting ongoing scientific research across a range of disciplines. Currently, astronauts travel to and from the ISS on the Russian three-person Soyuz spacecraft, and six crewmembers (two three-person Soyuz crews) are in space together for 6 months as an ISS Expedition crew'. ISS operations are ongoing, and detailed flight plans, or timelines, are developed real-time based on long-range plans. Although astronauts are assigned roles (e.g., commander, flight engineer), because of the nature of ISS missions and the need for flexibility in assigning tasks throughout the mission, they are all required to have the skills necessary to perform tasks across a wude range of job duties including EVA, robotics, scientific research, repair and maintenance, and responding to potential malfunctions and emergency situations (National Research Council, 2011). During training, each NASA astronaut is required to demonstrate these skills for tasks conducted in NASA modules, as well as demonstrate the skills needed to perform in each international partner module. They must also meet Russian language proficiency requirements, and Russian Soyuz training requirements. (International partner astronauts and cosmonauts have similar training requirements, including training on tasks in their modules.)
ISS training for NASA astronauts again begins with 2 years of ASCAN training, including extensive systems training on NASA modules, as well as initial discipline training for EVAs, robotics operations, medical operations, and science operations. While flight assignments can occur immediately after ASCAN training is completed, typically an astronaut is assigned office or mission support duties while waiting for a flight assignment. Pre-assignment training opportunities during this period may include some refresher training on ASCAN skills (e.g., ASCANs assigned as capsule communicators (CAPCOMs) receive refresher training on ISS emergency response), additional training on robotics operations in Canada, and training on new skills as part of assignments (including CAPCOM certification). There are also opportunities for team training in analog missions such as the NASA Extreme Environment Mission Operations project (NEEMO) conducted in the underwater Aquarius habitat operated by Florida International University (Landon, Slack, & Barrett, 2018), and such as the European Space Agency’s (ESA) Cooperative Adventure for Valuing and Exercising (CAVES) human behavior and performance skills course conducted in deep underground caves.
Flight-assigned training for ISS missions is approximately 2 years, and astronauts are provided portions of their training by each of the ISS international partners, requiring extensive international travel. NASA astronauts spend about one-third of their assigned training at NASA’s Lyndon B. Johnson Space Center (JSC), about one-third at Roscosmos in Russia, much of which is training for ascent and entry on the three-person Russian Soyuz vehicle, and the remaining one-third either at ESA, JAXA, on holiday and vacation, and traveling between the international partner centers. Flight-assigned training at JSC builds on ASCAN training and covers a wide range of vehicle system’s training, medical operations, robotics, EVA, in-flight maintenance and scientific research training, and also includes ongoing spaceflight readiness training in T-38N aircraft, Russian language training, team skills training, and physical training. Much of this flight-assigned training is provided to individual or pairs of crewmembers within vehicle system or discipline training flows, including generic two-person EVA training (mission-specific EVAs are not usually known prior to launch). Astronauts are also provided training as an intact three-person crew by Russia during Soyuz training, and by NASA during several operations simulations. Crews then practice typical tasks in a mission setting, as well as vehicle malfunction scenarios in which they practice responding to off-nominal conditions per published procedures. The only training astronauts are provided as a six-person ISS Expedition crew is for integrated emergency response. Because ISS timelines are developed real-time, very little training is to an actual timeline - the notable exception is Soyuz ascent and entry training.
Decades of successes in human space flight in low-Earth orbit and lunar missions have shown the effectiveness of NASA’s space flight training programs for these missions. However, to date, the flight control team in MCC has always been able to provide real-time expertise to the onboard crew as needed, and a return to Earth has always been an option in response to any unforeseen event. Now there is Mars. Earth’s closest planetary neighbor, but still up to 24 light-minutes away, and at times completely blocked by the Sun. A quick return to Earth will not be possible, and realtime expertise from MCC will no longer be available. The current “system-siloed” approach to the design of space flight training may not be able to adequately prepare future astronauts for their missions to Mars.