b'The Digital Twin | Engineer Innovationwhen the guidance computer issued an 1201 alarm code" that the controllers had never seen before. After quickly determining that the error was indicating a computer overload that meant it might not be keeping up with its computing tasks, mission control called for the abort. This was the wrong decision, after conferring with the Massachusetts Institute of Technology (MIT) team that programmed the computer, guidance officer (GUIDO), Steve Bales later concluded that an 1201 code was a warning rather than a critical error and rewrote the mission rules just nine days before the eventual landing. If the final simulation hadnt prompted him to do that, its likely the actual Apollo 11 landing, the final minutes of which were plagued by a series of 1201 and similar 1202 alarms,Mission Control in Houston, moments before the explosion that would plunge the Apollo 13 mission into crisis. In the middle of the shot is White Team Leader, Flight Director Gene Kranz, would also have been aborted. Thewhose team was responsible for defining the strategies to bring the crippled spacecraft safely Eagle would not have landed. home. Image credit: NASADuring preparations for Apollo 10, mission controllers were tested in aInternet of Things, NASA did use simulation which involved the failure ofstate-of-the-art telecommunications the spacecrafts fuel cells as ittechnology to stay in touch with its approached lunar orbit, a scenariospacecraft. That data was ultimately which is staggeringly similar to theused to modify the simulators in order Apollo 13 explosion. Controllers tried toto reflect the condition of the crippled evacuate the astronauts into the lunarspacecraft. module, using it as a life raft, but did not manage to get it powered up inIn the audio transcripts of the Apollo 13 time, killing the virtual crew. Althoughflight controller loops, most of the many NASA insiders rejected theimmediate discussion is about multiple failures of that scenario asmaintaining data connections with the unrealistic it inspired the controllersspacecraft (such as executing roll involved to develop procedures thatmaneuvers to better align the main would allow the lunar module to beantenna array with ground tracking). used as a lifeboat, even with a crippledOne of the unsung heroes of the command module. incident was the Integrated Communications Officer (INCO), Gary Although the simulators did not play aScott who calmly kept the data key role in the design of the spacecraft,communications stream running, while they did play an essential role inalmost everything else was falling defining its operating parameters. Thisapart. illustrates one of the key purposes of the digital twin: to test the asset, and itsAlthough for some people the Apollo 13 systems and procedures, over a widestory begins with commander Jim range of possible operating conditions.Lovells ominous Houston we have a problem announcement (actually Connected twins Houston weve had a problem), Most modern digital twins involve amission control was immediately aware remote physical asset which isthat something had gone wrong connected to the digital model throughthrough telemetry even before Lovells a continuous stream of data. Thisvoice report (delayed by 3 seconds by connection is used to update thethe transmission distance), as the computer models in response toguidance officer calmly announces changes in the real-life object. AlthoughWe\'ve had a hardware restart. I don\'t Apollo 13 obviously didnt use theknow what it was, and then seconds 13'