Title text: The increasing number of graham crackers and chocolate bars in orbit has created a growing risk of Kessler s'mores.
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 leads to air in front of the capsule compressing and heating up as it absorbs its kinetic energy (see Atmospheric entry for more details on ways of heating at work). 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.
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 their 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 the radio callsign for NASA Mission Control, located in Houston, Texas. During reentry, the superheated air forms a plasma phase and disrupts radio 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. But as orbital mechanic and spaceman extraordinaire Scott Manley has discussed the feasibility of roasting a turkey by dropping it from space (and Randall has himself addressed the issue of cooking steaks), the astronauts featured in this cartoon are not straying too far from accepted marshmallow roasting techniques and should not be reprimanded by NASA.
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. However, if there is no way to retrieve the marshmallows without exiting the capsule, they would likely be somewhat salty and waterlogged after the time the capsule splashes down and the astronauts can "enjoy" their cooking.
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 Graham crackers, similar to a sandwich. It also refers to a problem in rocketry, known as Kessler syndrome. Kessler syndrome is a scenario where the density of space junk in low Earth orbit is so high that pieces of space junk crash into each other, breaking apart into smaller pieces. This increases the amount of space junk in orbit, setting off a cascade that could render low earth orbit unusable. 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 wacky concept, as the United States space program does not primarily consist of chocolate and Graham crackers.
- [A space capsule beginning reentry into Earth's atmosphere is shown. There are four versions of this as it moves deeper and deeper into the atmosphere, but shown in a single panel.]
- [The first version is shown to the left with just a bit air resistance shown with thin dotted lines around and behind it. The capsule looks pretty standard with the broad bottom with the heat shield pointing forwards, and the capsule above it narrowing in a pyramid shape. There are a circular shapes (windows?) and some other lines indicating either doors or access panels. The one special feature is on the left, a stick is held back along the edge of the capsule from a extrusion near the bottom of the capsule. At the top of the stick a white square is located. From inside the capsule one of the unseen astronauts is speaking, possibly with ground control. All speech texts are located in rectangular frames with jagged arrows pointing towards the capsule.]
- Astronaut voice: We're approaching atmospheric entry.
- Astronaut voice: All systems nominal.
- [In the second version air resistance has increased a lot, with many more and thicker lines indicating the air resistance. At this point the arm with the white square turns on its pivot so it is now sticking straight out from the capsule far outside the heat shield below. Two lines indicate the circular movement and the release of the stick makes a loud noise:]
- [In the third version air resistance continues to increase, but now also the stick and particular the white square at the end begins to heat up, smoke coming of from the white square. Two small lines on either side of the top of the capsule indicates it is shaking.]
- [In the forth version the air resistance is about the same, but there are now six larger lines at the top of the capsule, two on either side and two above indicating more violent shaking of the capsule. The white square on the stick seems to be burning.]
- Astronaut voice: Houston, we're experiencing some oscillations. Vehicle is becoming difficult to control.
- Astronaut voice: Smith, retract that stupid arm.
- Astronaut Smith's voice: No! It's not ready yet!
- [Caption below the panel:]
- In retrospect, the reentry marshmallow toasting module was a mistake.
add a comment! ⋅ add a topic (use sparingly)! ⋅ refresh comments!