2148: Cubesat Launch

|< < Prev Comic #2148 (May 10, 2019) Next > >|

Cubesat Launch

Title text: Luckily, the damages were partly offset by the prize money we got from accidentally winning the nearby water skiing championship tournament.

Explanation

This explanation may be incomplete or incorrect: Created by a Launch Accident Investigator. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon. If you can address this issue, please edit the page! Thanks.

A CubeSat (aka U-class spacecraft) is a miniature artificial-satellite with cubic dimensions of 10 cm × 10 cm × 11.35 cm (~ 4 in × 4 in × 4.5 in), and masses of about 1.33 kg (2.9 lbs) per unit. CubeSats are put into orbit from the International Space Station, or launched as secondary payloads. As of January 2019, at least 900 CubeSats have successively achieved orbit, and at least 80 have been destroyed in launch failures. They typically function as Earth observation satellites, amateur radio emitters as well as testing prototype small-satellite technology.

The comic begins with Megan telling Cueball that being officially part of a CubeSat launch is very expensive, but she has an idea for a much cheaper alternative: use a fishing line on a drone to attach to a rocket just before launch, with the cubesat attached to the other end of the fishing line so it gets pulled into space.

In reality, this plan would fail for multiple reasons.

1. Security would presumably prevent the drone from reaching the rocket.
2. The unshielded CubeSat would likely be destroyed by aerodynamic forces.
3. The drone would not be able to attach itself to the rocket in a way that would remain secure.
4. The fishing line would not hold - either the rocket exhaust would sever it, or the force from the cubesat, gravity, and the acceleration of the rocket, would become more than its tensile strength could withstand.
5. Precise weight is an EXTREMELY important number during launch. The extra weight of the drone, the fishing line, the air drag from the drone, and the cubesat all would combine to put more downward force on the rocket. This unexpected extra weight would not have been calculated during fueling of the rocket and the rocket would run out of propellant before achieving the planned orbit.

Upon realizing her plan, Cueball immediately responds with "uh-oh", indicating his concern, but Megan assures him that it will be fine, before piloting the drone towards the rocket. She successfully connects the drone to the rocket, and the rocket lifts off.

Whatever her plan was, it goes wrong almost immediately. The unexpected force on the rocket from the side causes it to tilt and go off course (implied that it's not due to the comparatively small force of the cubesat, but because Cueball is standing on the fishing line). Perhaps if the rocket's control software employed adaptive control techniques, it could have maintained control in the presence of this unexpected force. Megan and Cueball get tangled in the fishing line and are carried away. It is implied that the rocket crashes not long after. In reality, the unplanned attitude change of the rocket would likely activate the automatic termination sequence or result in manual activation of the destruction protocol.

Megan and Cueball miraculously survive and are brought to an investigative board to explain their actions. Megan attempts to defend herself using flawed logic: something was bound to go wrong sooner or later, so it's not her fault that she was the cause. This logic does not account for the fact that this particular rocket's chance to crash was greatly increased by the drone attempting to connect to it.

The title text describes that the supposedly huge damages they caused were partly covered by the earnings from a water skiing championship, which Cueball and Megan presumably won by being dragged across the water by the rocket.

Additionally, this is not the first comic to discuss CubeSats; they were also mentioned in 1866: Russell's Teapot and in 1992: SafetySat.

Transcript

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

[Megan and Cueball talking. Megan is holding a cube attached to a drone by string.]

Megan: A spot on a cubesat launch costs a lot, but you can get a drone and a spool of fishing line for cheap.

Cueball: Uh oh.

[A wide shot of Megan flying the drone.]

Megan: No no, watch. This is gonna go great.

[Wide shot of a rocket launch with drone and string approaching from the right.]

[Drone attached to rocket.]

Off-panel: Perfect!

[Vapor cloud at bottom of rocket.]

Foom

[Rocket taking off, tilting in the direction of the string.]

Off-panel: Should it be tilting already?

Off-panel: Hey, move your leg.

[Megan and Cueball struggling in tangle of string whilst holding cube.]

Megan: Ugh, let go, I can get-

Cueball: -No, lift your other arm-

[Three small panels of rocket tilting increasingly to the right and down as if pulled by the string.]

[Megan and Cueball flying through the air, attached to the string. Two onlookers flee.]

Aaaaaa

[A disheveled looking Megan and Cueball both with plaster casts on their arms stand before four members of an interview panel at a table labeled 'Launch accident investigation board'].

Megan: Listen. Space exploration is never going to be completely safe.

 add a comment! ⋅  add a topic (use sparingly)! ⋅  refresh comments!

Discussion

I have added an important point to the explanation regarding the impossibility of this plan - Mission Control should have scrubbed the launch as soon as someone noticed the drone anywhere near the rocket. The failure of this to happen means that Mission Control was negligent and they bear major responsibility for the failure than the mission, more so than Megan. I can't believe such an obvious point was missed by previous editors though - would you launch a rocket if you saw a drone near it?172.68.253.53 07:12, 11 May 2019 (UTC)

Ahh, yes kites! Or actually, that is a very strong kite with very strong thread. Must be nice to knock-off a spacecraft! - 162.158.231.24 15:29, 10 May 2019 (UTC) (P. S. Please don't interrupt ANY space launch, kids!)

To whomever edited the explanation to say the Megan is planning to board the Cubesat rocket: Cubesat rockets launch cubesats only. There is no place for astronauts. If Megan boarded the rocket, she would die from lack of air (among other things). 172.68.90.112 16:28, 10 May 2019 (UTC)SiliconWolf

This is weird. The first time I went to the page, I saw a bunch of conspiracy theory nonsense, but when I go back, all of that stuff has been deleted. I thank you, whoever did this, but who the heck made all that conspiracy theory stuff? -Spongepants Squarebob 172.68.38.64 (talk) (please sign your comments with ~~~~)

I believe there's one user who just keeps spouting random conspiracy theorist stuff on a few of the recent comics and who seems to go by the motto "Soon the truth will be revealed" or something. We usually revert all of their edits as soon as possible. (Also sign your comments!) Jason (talk) 18:44, 10 May 2019 (UTC)

Yeah...a while back, on comic 2133, someone edited it to say "This comic references the non-existent 'Event Horizon Telescope', an international project dedicated to deceiving the masses into thinking that black holes are real, in accordance with the whims of the Zionist conspiracy."

So...yeah. That happened. 172.68.143.144 20:24, 10 May 2019 (UTC)

Yeah, one anti-Semitic lunatic vandalizing explanations and talk pages, mostly focusing on the space related comics. We can't ban all IP editors, so the mods are blocking any user accounts he tries to make, which makes him have to type in a CAPTCHA (which can be quite annoying) every time he wants to vandalize a page. Plus we can just instantly revert his edits, making him waste his efforts. Sooner or later he'll get tired of this and leave. Herobrine (talk) 21:41, 10 May 2019 (UTC)

Do NOT blame that user for Explain XKCD using Cloudflare which makes ALL edits looking like being done by Cloudflare IPs. There is enough stuff he can be blamed for, no need to add something he can't influence. -- Hkmaly (talk) 22:16, 10 May 2019 (UTC)

??? What I was trying to say was that even though there's only one vandal doing this, Explain xkcd uses Cloudflare which makes edits looking like being done by Cloudflare IPs, so even though there are several IP vandals they're all the same person. I'm not blaming that vandal for Explain xkcd using Cloudflare. Anyways, I've removed that bit, sorry if it caused any misunderstanding. Herobrine (talk) 22:54, 10 May 2019 (UTC)

The explanation says the inclusion of the additional cubesat would cause the rocket to fail to reach its desired orbit. That is ridiculous. Yes, the unplanned for weight would have an effect, but given the overall weight of the rocket the weight of a single additional cubesat would be close to immaterial. CERTAINLY well within the safety margins. This isn't The Cold Equations." 162.158.107.55 05:26, 11 May 2019 (UTC)

I agree. The three pounds or so would be surely less than normal variation in loaded fuel mass, either due to measuring uncertainty during loading or evaporation while standing on the launch pad. I've added 'citation needed' but I am somewhat inclined to remove that point completely. -- Malgond (talk) 12:00, 13 May 2019 (UTC)

How does it work, you ask? CRYSTALS!!! HAHAHAHAHA - Dr. D

In addition to the problems already mentioned, there's yet another one. At best this scheme could attach a cubesat to the aerodynamical fairing around the rocket's payload. However the fairing is detached as soon as it's aerodynamically feasible to do so (ie. well below orbital altitude) both to save weight and to prevent the fairing from contributing to the orbital debris problem. So the cubesat wouldn't even get to space, much less to orbit. 162.158.238.166 08:13, 12 May 2019 (UTC)

Is the "Space exploration will never be completely safe" line a reference to this? https://yarchive.net/air/perfect_safety.html Tait marconi (talk) 15:39, 13 May 2019 (UTC)

I am VERY surprised that one of the "Reasons this is impossible and won't work" isn't "Even if this all worked as intended, Megan would be in space with no space suit, either freezing or suffocating to death." :) NiceGuy1 (talk) 03:03, 18 May 2019 (UTC)

My interpretation of the comic is that Megan is trying to launch the box that she is holding into space, rather than herself. Still, even though the incomplete banner has gone it doesn't mean that the explanation is definitive, so always feel free to add alternative explanations where appropriate. AlChemist (talk) 09:18, 18 May 2019 (UTC)

My first understanding was like that, but the very presence of the fishing line means she wants to go up with it. A drone is wireless, it doesn't need any sort of command connection. Her being tied to the rocket seems to be the intent. :) NiceGuy1 (talk) 04:13, 8 June 2019 (UTC)

Ah, had to reread. I had thought the cubesat was attached as part of the drone. I now recognize the "getting tangled in the fishing line" frame for what it is. Clarity achieved! LOL! NiceGuy1 (talk) 04:17, 8 June 2019 (UTC)