During the Apollo program, astronauts spent a third of their training time using hardware simulators for training purposes. Simulators allowed crewmembers to not only rehearse and master their mission but also build resilience by understanding where things could potentially go wrong.
Flight Director Gene Kranz quickly assumed that when his guidance computer displayed 1201 code, this indicated a system overload and ordered an abort. Later he would come to understand otherwise.
The Model Board
This photo shows the Model Board from the spacecraft simulator where astronauts trained prior to Apollo 11. Astronauts would manipulate flight controls of their lunar module on this model board to simulate moving through the Sea of Tranquillity and onto the Moon’s surface, and to train for reduced gravity of lunar surface and assess how their spacesuits would perform in low gravity environments.
The model board represented a digital twin of the real Apollo Command Service Module (CSM) and Lunar Module (LM). Each piece of simulated CSM was controlled by a separate computer to represent aspects of mission operations; astronaut input would cause these computer systems to respond like real spacecraft control systems would. This digital twin system played an invaluable role in the success of Apollo missions.
One simulation involved astronauts facing an imminent threat when their CSM’s battery power had run dangerously low and all systems might shut down in mere minutes if all systems weren’t quickly and accurately simulated by simulations to provide crucial information in time to save their crew from certain demise. Simulations provided accurate simulation of this problem with data that helped protect all parties involved from impending danger.
One of the more difficult problems simulated by these early models was jettisoning of lifeboat LM and crippled service module while plunging through Earth’s atmosphere at precisely the right moment, in order to avoid burn-up or skimming out into a reentry trajectory that would crash-land. This maneuver was repeated many times using Apollo simulators – and successfully accomplished nine days into actual Moon landing!
NASSP is currently developing Project Apollo for Orbiter’s open-source app that will let users relive this momentous history in 3D. This add-on provides an accurate simulation of actual spacecraft as well as accurate 3-D models of Saturn V rocket and CSM/LM modules.
Start off by tapping View Missions, which will bring up a list of major Apollo mission milestones chronologically ordered. By tapping an event you can then move through its 3D simulations.
The Lunar Module
NASA app title suggests, the lunar module is at the heart of this historic journey. As its title indicates, this structure was home to astronauts living quarters and most life support during a 10-day stay on space missions – including fuel cells for energy supply and radiators to keep cool temperatures under control. Subsequent Apollo missions featured spacecraft fitted with SIM bays which enabled additional experiments to be conducted during their stay in space.
The lunar module was an advanced spacecraft with intricate controls simulated fully in simulations. These early digital twins could be updated in real-time to reflect any information collected by its actual counterpart, enabling mission control to make critical go/no-go decisions that directly impacted its success in flight.
One key part of the simulator was a mockup of an actual command module, with astronauts entering this simulated spacecraft to train for all of the various tasks they would need to perform during missions – from landing to ascent, rendezvous and docking – as part of their missions. Though part of its purpose was training crew members for these activities, its simulator also proved useful in simulating other problems encountered on missions.
At Apollo 13, one of these simulations proved vital in saving the crew. When readings from their crippled spacecraft showed that its main engine in its service module was leaking oxygen, it became clear that time was quickly running out for their return home safely.
As the astronauts prepared to jettison LM and its crippled service module before reentry, they used simulators to run through their maneuver. These helped determine the optimal way to position their craft for reentry as well as ways to mitigate any possible fires or explosions during its return.
The Full Mission Tab replays the Apollo mission at 300 times faster than real-life speed for an entertaining overview of its experience. Other tabs allow you to select milestones and view different perspectives of its spacecraft; should it disappear for any reason it simply entered Earth or lunar shadow and will soon reemerge again.
The Command Module
NASA needed a way to train astronauts for the complexities of space travel when designing its Apollo program, so they developed the Lunar Module Simulator as an innovative training device. It accurately replicated a real lunar landing spacecraft. Consisting of three parts – cone-shaped Command Module carrying astronauts into Earth orbit from their Earth orbit in, cylindrical Service Module which provided oxygen, power and rocket engines necessary for return, and spider-shaped Lunar Module housing two astronauts during landing and living on lunar surface – they provided astronauts with everything necessary for successful lunar surface landing and life on surface.
Simulators allowed them to practice the complex procedures they would need to implement should there be issues during a mission. When readings indicated that the Command Module’s Service Module had lost its fuel cells, flight controllers needed a plan for getting it back home again while sparing any available power and activating only essential systems. Astronauts Ken Mattingly and Fred Haise used an Apollo simulator with just enough battery power remaining for one more test run of this scenario – learning that turning on any unnecessary system could further deplete their supplies faster than anticipated.
Today, this simulation provides a great way to gain an insight into what life was like for astronauts as they journeyed towards the Moon. The tabs across the top allow you to select different aspects of the mission, while the Time Flow control enables you to alter how quickly time passes (by default, 300x faster). Furthermore, you can pause, rewind and switch perspectives – it’s loads of fun! Expect no realistic LM or CM control panels to appear on your computer screen — the software was not created that way. Instead, this serves as a useful reminder that successful digital twins must adapt quickly and precisely to ever-evolving circumstances – especially when your problem takes a twist you weren’t prepared for or expected.
The Flight Control Room
After Neil Armstrong took his one small step on July 20, 1969, millions gathered around their television sets to witness Apollo 11’s landing on July 21. While many remember this iconic momentous occasion as an unforgettable event, few realized that their astronauts weren’t alone as they ventured off their module and onto lunar surface, thanks to support provided by Houston Flight Control Room or Mission Control Center or MCC in Houston.
MCC was home to a team of individuals whose sole mission in life was operating a manned spacecraft into orbit. These men and women were the only people on earth at that time with this singular responsibility as their primary job function.
These individuals were committed to their work, not only trained in the fundamentals of controlling a spacecraft but also developed a culture of competence and toughness ingrained into their characters. It became an extremely close-knit community they all felt proud to belong to.
There were ten front room controllers plus several backroom controllers who could provide extra analysis or assistance as necessary. This team represented some of the brightest minds and knowledge available worldwide about what it meant to take an astronaut on such a long journey into outer space and back again.
The MCC housed several individuals responsible for overseeing space exploration: Flight Director Gene Kranz, Lunar Module Pilot (LMP), Command Module Pilot (CM), an avionics engineer responsible for its complex Apollo Guidance Computer system; as well as Public Affairs officer to handle communications between astronauts and media representatives.
The MCC simulators could be networked together using 256kilobytes of shared memory to form one large simulation, covering either all or parts of an Apollo spacecraft. Two scenarios simulated during training directly affected successful resolution of issues during real Apollo 13 mission, marking a remarkable success rate for something that began as training exercise.