2804: Marshmallow

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Marshmallow

Title text: The increasing number of graham crackers and chocolate bars in orbit has created a growing risk of Kessler s'mores.

Explanation

This explanation may be incomplete or incorrect: Created by a CELESTIAL S'MORE - Please change this comment when editing this page. Do NOT delete this tag too soon. If you can address this issue, please edit the page! Thanks.

This comic shows the atmospheric re-entry process of a capsule similar to that used in the Apollo moon landing program in the late 1960s and early 1970s. This capsule features a fictional Reentry Marshmallow Toasting Module, with a marshmallow on a deployable stick, which is exposed to airflow during reentry.

During reentry, the capsule would presumably be going at orbital speeds, which for Earth are in excess of 8 km/s. This high velocity heats up the air around the capsule as the kinetic energy is dissipated.^{[actual citation needed]} This has the effect of heating the marshmallow. Additionally, reentry heating effects typically look like flames covering the bottom of the reentering object. This is very similar to a common practice on the Earth's surface of holding a marshmallow on a stick over a static fire on the ground, like a campfire, which also heats the marshmallow, improving its taste^{[citation needed]}.

At the start of the panel, the capsule is approaching atmospheric entry, so any aerodynamic forces would not have begun yet. "All systems nominal" is an aerospace phrase that means all systems (including life support, navigation and stability systems) are performing as expected. However, once the atmospheric effects begin then something goes wrong.

Having a long, thin extension to the airflow will disrupt the aerodynamics, as air starts pushing up against the roasting stick, creating an unbalanced torque that pushes the marshmallow further back into the airflow, rotating the entire capsule. This angular acceleration continues until the aerodynamic design of the rest of the capsule plays a significant factor, rotating the capsule back to its original position, and starting the uncontrollable cycle of oscillations anew. Hence, the astronaut on board reports some oscillations to Houston.

This prompts the unnamed astronaut to tell his colleague, Smith, to put away the marshmallow roaster. This would clean up the aerodynamic profile and stop the oscillation. This is met with resistance that the marshmallow is not cooked yet. This may be expected, as due to the design of the module, it appears as though the marshmallow has been on the outside of the capsule for the entire journey, exposed to the vacuum of space. In this situation, it would have radiated all its heat energy away, reaching temperatures near absolute zero (approximately -273.15 degrees Celsius, the absolute coldest temperature physically achievable). A very brief moment of shock heating from atmospheric effects may not have bought the marshmallow up to a consumable temperature, or even affected the internals of the marshmallow at all. The goal of roasting marshmallows is often to melt the inside of a marshmallow completely, so if this is still frozen, that defeats the entire purpose of the module.

Houston is a city in Texas, United States, where Mission Control for NASA is established. Astronauts in space would communicate with "Houston", as the specific person on the other end would vary with which shift was working. These communications are established via radio. During reentry, the superheated air forms a plasma phase and disrupts radio wave signals. Hence, it is doubtful that Mission Control would have received this communication from the capsule, and it is very unlikely Mission Control would have received further updates from the capsule until the reentry process was largely finished. This would make the Mission Control operators very concerned over the success of the reentry.

The caption for the panel muses that maybe the concept of the module was a mistake, which is a fair assessment given the number of flaws in the design. It would indeed be far better to have two such units, set upon opposing sides of the module and operated in conjunction, to balance rotational forces. Or even three of them, set 120° apart from each other, perhaps automatically and independently actuated to tune out all other undesired aerodynamic effects – with the added advantage of simultaneously preparing snacks for all three of the astronauts that typically inhabit an Apollo capsule, not just Smith.

The title text refers to a popular snack of s'mores, made by placing a marshmallow roasted over a fire with some chocolate between two crackers, similar to a sandwich. It also refers to a problem in rocketry known as Kessler syndrome, where vast amounts of space junk in low earth orbit reduce the chance of successful rocket launches, as new launches may crash into existing space junk, causing a rapid unplanned disassembly. These two concepts are combined in a ridiculous way, whereby instead of space junk, it is Graham crackers and chocolate bars that are polluting space. These, combined with the marshmallow from the toasting module, would create celestial s'mores, a novel and frankly whacky concept, as our space program does not primarily consist of chocolate and Graham crackers.

Transcript

This transcript is incomplete. Please help editing it! Thanks.

[as follows, left to right, top to bottom]

[Capsule begins reentry.]

Smith: We're approaching atmospheric entry.

Smith: All systems nominal.

Fwip

[Marshmallow roasting rod deployed]

Smith: Houston, we're experiencing some oscillations. Vehicle is becoming difficult to control.

Mission control: Smith, retract that stupid arm.

Smith: No! It's not ready yet!

[Caption below the panel:]

In retrospect, the reentry marshmallow toasting module was a mistake.

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Discussion

Made a start, not sure if the heating up science is completely correct though MrCandela (talk) 13:54, 19 July 2023 (UTC)

Because I'm a nitpicker, I kind of want to see some mention in this blurb about how reentry is usually a communications blackout period, due to the plasma sheath blocking all radio waves and so talking with Houston *during* reentry is unrealistic. I strongly suspect Randall knew this, though and ignored it for the sake of the joke. Trimeta (talk) 14:08, 19 July 2023 (UTC)

In the case of the space shuttle it was possible to circumvent the problem of radio blackout by relaying the radio through satellites (the plasma blocks the radio waves downwards, but there was be a window upwards). https://en.wikipedia.org/wiki/Communications_blackout#Spacecraft_reentry Rps (talk) 15:39, 19 July 2023 (UTC)

The current explanation suggests that Mission Control would be concerned by the lack of communication from the capsule, but given that they would be aware of the effects of reentry, there's no particular reason why this should cause them concern.141.101.99.134 15:58, 19 July 2023 (UTC)

Some things that should probably be added: The comic was likely published in anticipation of the 54th anniversary of the first moon landing on the 20th of July 1969 In reality, the marshmallow, exposed to the vaccum of space, would expand due to the internally trapped gasses until its structural integrity failed https://youtu.be/MYAmPRQ4eWo?t=285 The title text should probably direct reference to Kessler syndrome, in which a single collision of orbiting objects causes a chain reaction filling low earth orbit with debris, in this case, tasty stacks 162.158.155.71 14:30, 19 July 2023 (UTC)

The phrase "rapid unplanned disassembly" in the explanation of the Kessler syndrome, however, is inspired! RAGBRAIvet (talk) 11:02, 20 July 2023 (UTC)

IMO, "Reentry Marshmallow Toasting Module" refers only to the Marshmallow arm and any necessary associated parts (covers, actuators, etc.), not the whole spacecraft (as the way it is currently written suggests). That is, as for instance, Apollo had a command module, a service module, etc.(?) in this case, there is this extra module. I think it is not unusual to have experiments or sensors piggy-backing in a existent spacecraft or probe. Rps (talk) 15:55, 19 July 2023 (UTC)

Agreed - I'd just amended the article to that effect before coming down here and reading this. :o) 141.101.99.134 15:59, 19 July 2023 (UTC)

"the marshmallow has been on the outside of the module for the entire journey, exposed to the vacuum of space. In this situation, it would have radiated all its heat energy away, reaching temperatures near absolute zero" I think this is incorrect: the side of the spacecraft in the shadow gets quite cold, although probably not ~3ºK (cosmic background temperature), since in low-earth orbit you have a warm body (the Earth) radiating some heat some (most?) of the time. But the sun side gets quite hot. Apollo used "Passive Thermal Control" (informally, it was called “barbecue roll”) to even out the temperature. Rps (talk) 16:11, 19 July 2023 (UTC)

I wonder if Randall played Outer wilds recently. Fabian42 (talk) 17:00, 19 July 2023 (UTC)

I don't think the specific choice of graham crackers is a reference to anything scientific. That's the usual cracker used to make s'mores. Barmar (talk) 02:35, 20 July 2023 (UTC)

I completely agree. I'm sure that the S'mores Randall is familiar with would have been made with Graham crackers and that's what he's referring to. MAP (talk) 04:46, 20 July 2023 (UTC)

I had to look up s'mores. I don't think they are common in the UK.--172.70.251.40 15:04, 20 July 2023 (UTC)

Also agreed, graham crackers are the normal recipe for s'mores, there's no reason to expect any reference to Graham's number. I'll remove that from the explanation.PotatoGod (talk) 05:05, 20 July 2023 (UTC)

An Apollo capsule returning from a lunar mission would be traveling at approximately escape velocity. If you think about it, how would it lose all the velocity it gained falling from lunar orbit, except by atmospheric friction? (Luna is at approximately infinity in terms of velocity needed to reach L1. Nitpicking (talk) 02:55, 20 July 2023 (UTC)

Space is not zero kelvin, the CBC is some degrees above that. Also as we are close to the Sun and Earth, and the marshmallow might have been exposed to sunlight/Earth light so there is no reason to believe it is frozen. But any water could have evaporated. Furthermore it may have been deployed from inside shortly before reentry. It looks normal in the picture, so it could be presumed it is a fresh marshmallow only just put outside when reentry begins. --Kynde (talk) 13:07, 20 July 2023 (UTC)

And, contrary to current explanation (indicating that it'll end up salty and wet), the de-deployment process might allow the snack ...once 'done'... to be brought back in whilst still undergoing descent (perhaps once they're on 'chutes). But I definitely think there should be three such equidistant modules, for a more fair/timely availability of snacks. ;) 172.71.242.190 14:51, 20 July 2023 (UTC)

AT 8 km/s, once they hit the atmospheric interface, how long would Smith reasonable have before the marshmallow (then the stick) were instantly vapourised? I'm guessing maybe 5-10 seconds. I've always said that good timing is essential to good cooking. 172.68.66.60 01:56, 21 July 2023 (UTC)Beechmere

I have to mention this prior art on atmospheric reentry marshmallow toasting, and I regret to say Randall's idea is inferior, because this one has cats: https://www.youtube.com/shorts/LKb5LjZTEYY 172.71.178.64 07:24, 21 July 2023 (UTC)