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Alternate Space. For All Mankind: Part Three.

By Andy Cooke


Snoopy is heading to the Moon.

Picture courtesy Wikimedia Commons.


This is part 3 of an in-depth look at For All Mankind. Parts 1 and 2 can be found here. (Technically, there, I guess).



Snoopy Has Landed


In the last article, I referred to the three main areas needed for a narrative to which people will pay attention: world, character, and plot.


The first article covered the POD that kicked off the world of For All Mankind. The second article looked at some of the key characters at the start of the series.


It seems appropriate that this article will look at one of the key drivers of the plot at that same time.


When it comes to space AH, we naturally like to look at the space aspects. A crucial plot point in the first couple of episodes (other than the original Soviet lunar landing, already covered, and a minor, throwaway line about a Senator cancelling his proposed trip to Chappaquiddick) surrounds the flight of Apollo 10.


Apollo 10

We learn that Apollo 10 (with its Lunar Module crewed by Ed Baldwin and Gordo Cooper) flew more than a month before the Soviet landing, and orbited the Moon in a “dress rehearsal" for the upcoming landing of Apollo 11. That NASA officially claimed it was too heavy to land and return, which was why they hadn’t taken the opportunity to land and win the Space Race on the spot – but we now learn that Ed Baldwin disagreed. He thought that while the safety margins were narrower, it was achievable, and that it was merely NASA’s post-Apollo 1 tragedy’s safety-first mentality that precluded this. And even that he’d considered taking the LM down in defiance of orders, anyway, but he’d chosen to adhere to the mission plan in the end.


How much of this is based in reality?

Well, in OTL, Apollo 10 did indeed orbit the Moon in May 1969 in a dress rehearsal of the lunar landing (albeit crewed by Tom Stafford and Gene Cernan instead of the fictionalised astronauts in the series).


It demonstrated separation and descent along the planned Apollo 11 trajectory to an altitude of 50,000 feet above the lunar surface (in an elliptical orbit with the highest point at the altitude of the Command Module and the low point at 50,000 feet), scouted the Apollo 11 landing site on the Sea of Tranquility from close range, tested the landing radar (a critical test), before separating the ascent module from the descent module and practicing the crucial ascent and rendezvous phase while actually flying around the Moon.


And, yes, the Lunar Module (Snoopy) was indeed physically a little overweight compared to later ones (like Eagle) – a near-desperate campaign to further reduce the mass of the Lunar Module had been under way in the factory (called “scrape” and the “SWIP”, for Super Weight Improvement Programme) and had resulted in Eagle having its empty descent stage more than 100kg lighter than Snoopy’s. NASA did indeed publically say that Apollo 10 was too heavy to land – partially to see off pressure for a landing attempt on that mission.

Apollo 10 Command Module as viewed from the Lunar Module.

Picture courtesy Wikimedia Commons.

But was Ed Baldwin right? Could Apollo 10 have landed?

Yes. If we consider just weight, fuel, and delta-vee (the amount of velocity change a spacecraft can carry out – the crucial calculation for orbital changes, landings, and take-offs), then yes it could. Easily.


That may seem a rather airy assertion, but the landing delta-vee available to the descent phase of Apollo 10 was greater than that available to the same phase of Apollo 11’s flight. Looking at the raw figures, I make it more than 13% greater.


The sting in the tail is that it couldn't get back. That greater landing delta-vee was because it was carrying much less fuel; the lower mass of fuel gave it much more landing delta-vee. They'd just be stranded down there.

At least, that's how it looks at first glance. And, indeed, second glance. But there may be a crack in that certainty, which I'll cover later. But just running the figures on a theoretical launch back from the surface and running the ascent stage's tanks dry, its delta-vee capacity was barely 60% that of Apollo 11's fully-fuelled Eagle.

Yes, there was a safety margin (to which Baldwin alludes, asserting he'd not have needed that margin). but that safety margin wasn't that huge.


Maybe if they’d fully fuelled the descent stage, they’d have been able to do it after all? Ah – but the descent stage would have to carry all of the mass of that extra fuel, eroding its delta-vee budget. However, to partially offset that, as Apollo 10 wasn’t intended to land, it didn’t carry the lunar surface experiments and other such equipment that Apollo 11 did (the weight difference of which ended up offsetting two thirds of the Scrape and SWIP reductions).


Add the same quantity of fuel in the ascent stage, upweight the equipment carried on the descent stage for the surface – and Apollo 10 would have had 99.1% of the delta-vee landing budget of Apollo 11. Very close indeed.


Would that have been enough?

Well, in OTL, Apollo 11 came perilously close to running out of fuel in its descent stage . At the time, they believed they had only 17 seconds of fuel left (as it was sloshing, it turned out to be 45 seconds – which isn’t exactly a massive margin, anyway). This was because it was a little off course and had to pilot itself around a field of boulders.


Was Ed Baldwin good enough to land quicker and more efficiently? He certainly believes so. It was therefore possible to land – if they’d fully fuelled the ascent stage prior to launch. But during the first landings, the commanders found it difficult to fully trust their altitude above the Moon (with its different diameter causing a closer horizon) and hesitant to fully trust the new landing radar, so they followed a “stair-step” descent, wasteful of fuel. It wasn’t until Apollo 15 that Dave Scott, learning from their experience, forced himself to trust the radar and descended more cleanly and efficiently. Would Ed Baldwin really have done that much better?


Of course, if they were intent on landing prior to launch, they could have gone without the lunar surface experiments, reducing landing weight and increasing the delta-vee budget to 99.9% that of Apollo 11 – but it would have made the landing even more of a stunt than it was. Or they could have swapped out Apollo 10’s LM for that of Apollo 11, which would only have delayed the mission by one month (and in the show’s timeline, would have flown within a couple of days of the Soviet one).


So why didn’t they (in the show’s timeline or in OTL)?

It was seriously suggested within NASA. And, yes, it was safety concerns that stopped them. That was because the mission would have become extremely challenging in terms of the unknowns it had to negotiate.


The trajectory people didn’t understand the Moon’s gravitational field properly. It was lumpy and bumpy, for some reason – there appeared to be mass concentrations (“Mascons”) under the surface in random locations that changed the gravitational field, pulling orbital spacecraft slightly to left or right, or accelerating or decelerating them. Not by much, but enough to cause disaster in some circumstances. What if the LM was pulled off course away from the landing area into a hazardous location (with ground too steep or too bumpy, or covered in boulders)? What if the Command Module’s orbit was skewed so they couldn’t get back?


They had yet to determine how well they’d be able to communicate with two separate spacecraft at lunar distances. Would the landing radar work perfectly first time? What things would crop up that they couldn’t anticipate? Apollo 9’s first test of a LM in Earth Orbit had shown that the ascent stage’s rocket needed baffles, because theirs had burned holes in its insulation when used. What else didn’t they yet know?


No, if there was a desperate need, they might try it (as the Soviets did in the show’s timeline), but it would be hugely dangerous – and Apollo 11 was due to fly just over eight weeks later, with two further opportunities after that before the end-of-decade deadline.


As it was, one unknown did spring up that nearly caused disaster. It turned out that a single mis-set switch could cause the ascent module to tumble uncontrollably after the separation-and-engine-fire was triggered.


This led to a complaint from a member of the public, who complained about Cernan’s involuntary shout of “Son of a bitch!” when this happened. I’m on Cernan’s side. Unexpectedly tumbling out of control just over the surface of the Moon would probably get me swearing a lot worse.


Apollo 10 scoped out the Apollo 11 landing site, and in OTL (and we can assume in the show’s timeline) noted that it looked pretty good, especially at the near end. If they ended up landing long for whatever reason, though, there was a boulder field and Armstrong and Aldwin would need plenty of fuel to fly around and find a landing spot.

Apollo 10 scoped out the Apollo 11 landing site

Picture courtesy Wikimedia.

As it happened, an unexpected mascon threw out the descent orbit of Apollo 11 so that it was accelerated downrange by about two miles and they were indeed sent into the boulder field, but had just enough fuel to land even longer and avoid the boulders.


The proviso

So, if they had been willing to take a huge series of risks and also erode safety margins, they could have landed on Apollo 10. But let's go back to Ed Baldwin’s assertion that he could have landed and returned from the situation he was in when flying over the Moon’s surface. That's got to be impossible. Right?

Maybe not. There were some emergency scenarios (some already planned out, others not considered) that he could have had in mind.

As covered above, in OTL, the key factor was that the ascent stage was only half fuelled – all it needed to get from that low elliptical orbit back up to the Command Module’s orbit, plus a safety margin. But there was a contingency plan if the ascent engine had a problem on this mission: the Command Module could come and get them. As long as it was in some sort of orbit.

The Command Module had sufficient fuel to descend into that same elliptical approach orbit and rendezvous with them before firing its own engine again for the return to Earth. In fact, later missions (the “J-Class” uprated science missions) involved the Command Module descending into an elliptical orbit as standard so that the LM could land and return with less fuel, allowing for more experiments and samples.

So the question becomes: could that half-fuelled ascent stage get them into any lunar orbit from the surface?

The ascent stage of Apollo 10 viewed from the Command Module.

Picture courtesy Wikimedia.

Not quite. There’s a famous sci-fi short story called The Cold Equations whose lesson is simply this: if you fall short of the numbers, you’re short of the numbers. No skill or wanting hard enough will pull you past them.


Skipping past the maths and just comparing numbers: with only half the fuel in the ascent stage, they had a delta-vee budget of just about 1500 m/s. The absolute cold equations minimum you need to orbit the Moon – at the altitude of just above the surface (not recommended; those pesky mountains, ridges, and hills get in the way, but this is the lowest possible number) is just under 1600m/s. Including necessary fuel to fight gravity and get some altitude until reaching orbital velocity will mean you won’t have much change from 1700 m/s.


Sorry, Ed – you’re at least 200 m/s short (in OTL’s version of the fuelling). But...


If you nail the landing, you’ll have spare fuel in the descent stage. Snoopy's descent stage had 300-400 m/s delta-vee budget more than did Apollo 11. That's more than the difference between the delta-vee budget in the ascent stage and the shortfall in the Cold Equations.


No, you can’t transfer fuel between the stages – but you can relight the descent engine – IF you skip a couple of irrevocable steps in the post-landing checklist (vent fuel and vent oxidiser). Not recommended, but possible.


If you land well, with spare fuel (even if you do exactly as well or bad as did Apollo 11, you’d have over 300 m/s of leftover delta-vee, and probably closer to 400), you could – in theory, and after amending the landing checklist on the fly – relight the descent stage to take off. Burn it for altitude and towards orbital velocity until it runs dry (you’ll have to go manual for all of this; there’s no software package designed for this, because it’s barking mad), hit the abort button (without mis-setting the AGS/PNGS switch – which we know the Baldwin/Stevens crew successfully avoided doing in the show’s TL, unlike the Stafford/Cernan crew in OTL, because we saw the separation on screen), separate the stages in flight in abort mode (which was something in the Apollo 10 mission plan, anyway), burn the fuel in the ascent stage into a lower and elliptical orbit than planned, and the Command Module pilot could then follow a recognised emergency procedure to drop down and pick them up.


All right – the landing software wasn’t ready. Ed would bet on himself to pull it off.


The ascent stage was underfuelled. Okay, there was a way around that (albeit one that was barking mad), and the manual setting was available for that, too. Just remember not to vent the fuel and oxidiser in the landing checklist.


The ascent stage couldn’t jettison the equipment it did have on it, because it wasn’t designed to come off as it was for deployment on the surface in landings. Sure, but there should be enough to get into the elliptical emergency retrieval orbit.


And yes, they didn’t know the answers to all the unknowns they needed to uncover. Fine; he’d play it by ear – if they’d really needed to, and this had been the one shot before decade’s end, they’d have asked him to try, right?


He could get down. And he could get back. Maybe. In his mind, that “maybe” would be “probably” and he’d bet on himself. The cold equations could be warmed up just enough to pull it off.


I have, though, just rewatched the second episode, and seen that Baldwin claims that the ascent stage was nearly fully fuelled after all (he conveniently specifies the quantity of fuel in pounds, allowing for a comparison: according to Ed Baldwin in the show, Snoopy was actually fuelled to nearly the level of Eagle in OTL. Rather different from how it was in reality – and it’s a bit hard to understand why they felt the need to do this in the show’s timeline. Nevertheless, I’m leaving the analysis above for two reasons: Firstly, most discussions on whether or not Apollo 10 could have landed will focus on the possibility in OTL, and secondly, because Ed may have misspoken.

And thirdly, because having done all of the above analysis and realising that there was a way for OTL Snoopy to land, I wanted to mention it. I was tempted to pretend that I hadn’t heard that line and see if anyone picked me up on it...

However, I'll just revisit the bit earlier about whether they could have landed fully fuelled and run through the cold equations. If Ed was speaking accurately and, for some reason, they had lugged a lot more fuel to the Moon than they ever intended on using on the ascent stage, then Snoopy would have been very slightly under-fuelled in comparison to Eagle, and slightly heavier. He said: “A hair under 18,000 pounds in the descent stage and 5000 pounds in the ascent stage,” and confirmed it was slightly less than Eagle (which had 18,184 lbs in the descent stage - versus 18,219 for Snoopy in OTL - and 5,238 lbs in the ascent stage - versus 2,631 for Snoopy in OTL. Let's take Ed's words as having about 17,950 lbs in the descent stage of the show’s Snoopy and exactly 5,000 lbs in its ascent stage (less descent fuel than in OTL to partly offset the increase in ascent fuel). He also confirmed that Snoopy was slightly heavier; I’ll go with OTL’s figures on that.

This gives him a bit over 99% of the descent delta-vee that Eagle had, and 97% of the ascent delta-vee. The ascent is therefore fine – well within the real safety margin (even if outside of NASA’s at the time) and with the contingency possibility of the Command Module picking them up from a lower orbit, not really too much of an issue. Whilst, though, 99% (and a hair more) of the descent delta-vee might look ample, remember that the landing software wasn’t yet fully written. Ed would have had to fly fully manually, and remember the issues mentioned earlier about the differences in the horizon distance on the Moon tending to throw off all instincts learned by pilots on Earth, pushing them to follow a fuel consumption-heavier “stair-step” descent.

With that said, though, and even bearing in mind that Eagle almost ran out of fuel (with 17 seconds indicated left in the tank and a real level of 40 seconds left), it turns out that Snoopy would have had around 10 seconds indicated and 30 seconds in reality had Ed followed the exact landing pattern followed by Armstrong in OTL (although in the show, Armstrong cut it even finer - but for that, see the next article).

However, with the fuel light warning glowing brightly and aware he was entering the death zone, would Ed have aborted? It could have been almost a worst-case scenario for him – defying orders and the mission plan and then having to abort anyway. But the real worst-case scenario would have been for Snoopy to crash and explode.

But let’s say he pulls it off. It’s actually possible.

Apollo 10 mission profile.

Picture courtesy Wikimedia.

What else?

It’s what else would have happened. The Flight Director and all his staff would be utterly shocked. They weren’t ready to support it – they’d have tried when it became apparent he was going for it (hurriedly rewriting the STAY portion of the checklist). NASA wouldn’t have had TV slots prepared or setup worldwide broadcasting. I expect the news channels would have dumped everything to try to cover it, however.


They would have accomplished no science on the surface, and wouldn’t have picked up any samples (maybe a single rock as the contingency sample). They’d probably be on the surface for only minutes – every minute that live descent engine sat there was another minute they’d have worried.


If it had worked, and if they had got home, their careers would have been finished. Mutiny against direct orders and the mission plan to this degree would have been terminal to their chances of ever flying again.


But they’d have walked on the Moon, and been the first humans to do so. As it turned out, neither Armstrong or Aldrin ever flew again, anyway; Armstrong retired and Aldrin was kept busy making public appearances. Ed and Gordo, at the time of the beginning of the series, still smarting from their being overtaken on the finish line by the Soviets, would probably say it would have been worth it.


If they had pulled it off. And that’s still a really big “If”.




Discuss this article Here.


Andy Cooke is a very prolific author. His books range from political punditry to ending the world. These include the series The End and Afterwards and The Fourth Lectern [4], which predicted the rise of UKIP on the British political scene. He has also written the portal fantasy series for young adults, The Shadowlands Chronicles , and Skyborn [6], a post-apocalypse story with airships.




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