Having just toasted the 50th anniversary of the Apollo 11 moon landings, I see them in a new, more relevant light now than I did when I was younger. On my visit to Kennedy Space Centre, at age 11, I spent time looking at “all the cool rockets”, but my preteen mind wasn’t quite ready to fully embrace the magnitude of what they signified.
Listening to recent podcasts, and the live feed of what happened on 16 July 1969, though, I feel like I’ve shared what Neil, Michael and Buzz went through. And it told me something vivid, and that we can all relate to: to understand the significance of a Check Engine light, you’ve gotta take a trip to The Moon.
Imagine for a moment that you’re skimming the surface of the moon in a module built from tinfoil, looking for a safe spot to put down. Years of training has prepared you for this, and your instincts have been honed to turn this into just another landing, in just another experimental aircraft.
The Eagle
Eagle is different, though – while the state of the art in late ’60s aeronautical engineering sees it that no variable goes unaddressed in supersonic flight, lunar flight is another matter. You might have grown the necessary third arm that enables you to manipulate multiple controls at once, and your senses may be capable of processing several visual indicators at once, but it would still be all to easy to upset your equilibrium.
An alarm tone, for example, that you’re not expecting, backed up by a fault code that you’ve never seen before. Just seconds before the Eagle landed, Neil Armstrong’s attention was grabbed by a “1201” warning on the guidance computer, and neither he or Buzz Aldrin had any clue what it meant. With fuel fast running out and a hand hovering over the abort button, this was the last thing these lunar pioneers needed.
It’s rather less dramatic when you’re driving along and your ‘check engine’ light comes on, but, in fact, the premise is pretty similar. You’re on a journey, your family’s on board and you’ve a destination firmly in mind. When, out of the blue, your dashboard throws a ‘check engine’ warning up, you suddenly have to make a decision, based on having no information at hand whatsoever.
What’s wrong?
All you know is that ‘something isn’t right’ with your engine. Do you immediately re-route to the nearest workshop and have it checked out? Do you get it checked when you reach your destination? Do you abort the mission, head home and pick up a car that – touch wood – isn’t afflicted by the orange dash light of doom?
A check engine, or engine management light (EML) can be triggered off by any number of variables falling outside set parameters, and unless your car has sophisticated onboard diagnostic circuits, or you happen to be carrying a fault code reader with you (which, these days, isn’t actually much of a hardship), you’ll have no idea what the warning actually signifies. Of course, the standard advice is to curtail your journey until you know it’s safe to continue. But, again, imagine you were on your way to The Moon. Failure is not an option.
As with an EML, the 1201 alarm, as with the 1202 alarms that had sounded multiple times in an earlier phase of the landing, signified that something wasn’t working properly – but didn’t tell the vehicle’s crew anything more than that. Fortunately, the Eagle was linked to NASA by live telemetry – assuming continued reception – where CAPCOM could monitor every crucial variable. Even they, though, had no instinctive idea what to do with a 1202 alarm.
Work it out
So they looked it up. On the back of simulation experience and previous test missions, Flight Controller Gene Kranz had previously demanded that a list be made of all possible computer warning codes, and what they meant. It was of the utmost importance that any code be judged for what it meant, and whether it was safe to continue with the flight. John “Jack” Garman did just that, and it was that list that ultimately saved the landing from being aborted.
What the warnings amounted to in effect was a stack overload. The navigation computer was being asked to write cheques that its processing power couldn’t cash – notably when Neil Armstrong requested that the DisKey (keyboard display) show Verb 16 Noun 68 (rate of descent) data. What with all the maths that the computer was trying to juggle at the time, his request was the straw that broke the camel’s back.
Thing is, being that the alarm was local to the Lunar Module’s computer, it likely wasn’t transmitted to CAPCOM, and the first thing they knew of it was Neil Armstrong’s remarkably calm announcement. A few seconds later, Garman had referenced the code, and advised that it could be ignored if it didn’t come up too often. “We’re go on that alarm”, and the mission continued.
Await Advice
With hindsight, perhaps it might have been an idea if such alarms were automatically relayed directly to CAPCOM, with perhaps an ‘await advice’ light on Eagle’s panel. The problem was not something Neil or Buzz themselves could deal with, after all – all it did was add to their workload at a critical moment.
One might say the same about an EML, which is the only warning light on your dashboard more vague than ‘door ajar’. It might signify anything from an increase in NOX emissions to imminent explosion – it would be rather nice to know which end of the spectrum you’re facing, wouldn’t it?
These days, I’m sure it wouldn’t be too hard for cars to have sufficient on-board diagnostics to offer a little more advice than a panicky-looking amber dashboard light can provide. In fact, in these connected times, over-air diagnostics ought not just be possible, but the norm. Should a fault code arise, it can be transmitted to a technical centre, interpreted and, if non-critical, reset, with communications remaining open should the fault reoccur on the same journey.
AR Diagnostics in the future?
As an ex warranty administrator, I can see how the reduction in ‘no fault found’ workshop traffic would be appreciated, and there’s little doubt that motorists would welcome the added certainty that augmented diagnostics would bring. In fact, I suspect that such technology is already in development, leaving only the question of why it’s taken so long.
The ‘check engine’ and EML warnings should have only been a step towards something more useful, ergo a car that can actually tell you what’s wrong, rather than merely that something is wrong. On Apollo 11, they were limited by an absence of alphanumeric display – “insufficient memory” is rather less cryptic than “1202”, as well as being less sinister in its ambiguity. There is literally no point in being given a vague warning. All it does is erode your happiness.
It’s much better for journey’s end to be a Sea of Tranquility than an overcrowded workshop.
(Copyright RoadworkUK / Hooniverse 2019. All images from Wikipedia.)
Leave a Reply