explain xkcd - User contributions [en]

1992: SafetySat

2018-05-13T14:17:14Z

Rowhamma time: /* Explanation */ changed faulty seal to volitile epoxy seal

{{comic
| number = 1992
| date = May 11, 2018
| title = SafetySat
| image = safetysat.png
| titletext = During launch, in the event of an unexpected sensor reading, SafetySat will extend prongs in all directions to secure itself and any other cubesats safely in the launch vehicle until the source of the problem can be determined.
}}

== Headline text ==
[http://www.example.com link title][[File:Example.jpg]]==Explanation==
{{incomplete|Created by a CubeSat so dangerous, I corrupted the image file and crashed the server (the first image upload was corrupt)- Maybe expand it a little? Some of the individual items need more explaining. Do NOT delete this tag too soon.}}

{{w|CubeSat}} is a standard format for small satellites that can fit in a 10×10×10 cm format with a mass of less than 1.3 kg. They have been widely used by academics for research satellites, and by both small and large companies.

CubeSats are often launched as a additional payload on commercial launches but also deployed from the {{w|International Space Station}} at the {{w|Kibo (ISS module)|Kibo-Module}} or other airlocks. All these satellites are orbiting the Earth in a low orbit and since they have no propulsion system they are also become a part of {{w|space debris}} when they are out of control. And eventually they will reenter earth's atmosphere without any further hazard.

Only a few days before this comic was released the first interplanetary CubeSats called {{w|Mars Cube One}} were launched together with NASA's probe {{w|InSight}} aiming to the planet {{w|Mars}}.

There are multiple safety rules to ensure that the CubeSat cannot damage the primary payload. However, the joke in this comic is that [[Randall]]'s design seeks to break as many rules as possible.

Items counterclockwise from bottom left:

;Americium corners
:{{w|Americium}} is a very dense and radioactive substance. Depending on the amount of americium involved, this alone could shoot the mass over the 1.3 kg mass limit. The isotope <sup>241</sup>Am is used in smoke detectors but also proposed for use in {{w|Radioisotope thermoelectric generator|radioisotope thermoelectric generators}} in spaceflight.

;Guncotton
:A form of {{w|nitrocellulose}}; an explosive.

;{{w|Crude Oil}}
:{{w|Exxon Valdez oil spill}}, {{w|Deepwater Horizon explosion}}... need we say more? Of course the leakable volume would not be near those levels, but plenty dangerous nonetheless if it were to leak though a volitile epoxy seal... And this is not helped by the fact that it is in orbit or if it leaks during launch...

;Volatile Epoxy Seal
:When this goes, everything gets coated in flammable crude oil.

;Celebratory Firework
:Explosive fire source that can hit other satellites in the vicinity.

;CFCs/Ozone-depleting CFC Spritzer
:{{w|Chlorofluorocarbons}} (CFCs) are fully halogenated paraffin hydrocarbons that contain only carbon, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane. {{w|Freon}} is a common example of a CFC, and the use of CFCs has been linked to a depletion of the Earth's {{w|ozone layer}} leading many countries to ban their use. So spritzing CFCs in an area closer to the Ozone layer sounds like a good idea?

;Laser Pointer (Hubble-Seeking)
:Aiming a red laser at a visible light telescope is really bad for the telescope in question and its optics. This is because the laser will be focused by the lens directly onto the sensor. This can heat up the pixels to the point where they overheat and break. A particularly high powered laser might even break the lens' glass. {{Citation needed|reason=Not obvious to non-experts why visible-light laser is damaging to a telescope designed to read visible spectrum, disruptive perhaps?|date=May 2018}}.

;Laser Pointers (Fixed)
:These three laser points will effectively point in 3 different random directions, which is not safe for other objects around this Cubesat. It depends on the power of the laser pointers but, in general a laser over 5 mW can heat up and damage things given enough time.{{Citation needed|reason=Why is a laser pointer dangerous?|date=May 2018}}.

;SDR/{{w|Software-Defined Radio}} (Code Editable via Public Wiki)
:A radio which can be programmed to broadcast and receive in a range of frequencies, and formats. Since anyone could change the radio's instructions; the radio could interfere with other satellites, or with the launch vehicle. This counts as a huge security risk, as ''anyone'' could edit it.

;BIC Mini-Lighter
:Fire source, resting on the can of crude oil. The pressurized butane could also make the lighter burst, but in space without oxygen the lighter never would ignite. And even if the inside of the CubeSat contains some oxygen in weightlessness a flame would go out very soon.

;Rare-Earth Magnets
:{{w|Rare-earth magnets}} are very powerful magnets that have a high likelihood of messing up the electronics on nearby electronics, like other CubeSats. Might also stick to other satellites.

;Wet Sand Dispenser
:Possible reference to the {{w|Kessler syndrome}}, which refers to a hypothetical situation wherein there are enough objects floating around in low earth orbit that collisions between objects might result in a "domino effect," each collision causing more collisions and breaking objects into smaller pieces of space debris, which increase the likelihood of further collisions.

;Batteries (eBay)
:The quality of batteries bought on the auction site can vary widely, and certain batteries exposed to conditions outside their design specifications can {{w|Battery_(electricity)#Explosion|explode or leak corrosive acids}}. These batteries might also be connected to the adjacent spark plug.

;Solar Panel (Found)
:The quality of the solar panel and the power it produces would have to be investigated thoroughly before being cleared for space flight.

;Spark Plug
:Fire source, if it was connected to electricity. Excess mass if not.

;Title text
:{{Wiktionary|prong|Prong}}s that extend in the event of an unexpected sensor reading at launch could damage the rocket and/or nearby CubeSats/payloads. Along with this, it is not unlikely that this CubeSat might be the source of any internal problem that might arise; in such a situation, having such a dangerous CubeSat further secure itself would be counterproductive.

==Transcript==
:[A prototype for a small cube-shaped "CubeSat" satellite, with labels on various components.]

:[Labeled on top:]
:Rare-Earth Magnets
:Bic Mini Lighter
:Software-Defined Radio (code editable via a public wiki)

:[Labeled on right:]
:Laser Pointers (fixed)
:Laser Pointer (Hubble-seeking)
:Ozone-Depleting CFC Spritzer

:[Labeled on bottom:]
:Celebratory Firework
:Volatile Epoxy Seal
:Filler (Guncotton)

:[Labeled on left:]
:Americium Corners
:Spark Plug
:Solar Panel (found)
:Batteries (eBay)
:Wet Sand Dispenser

:[Labeled from within drawing in white text on top of a black rectangle:]
:Crude Oil

:[Caption below the panel:]
:My CubeSat proposal was the first to be rejected for violating every design and safety requirement simultaneously.

{{comic discussion}}

1992: SafetySat

2018-05-12T09:39:23Z

Rowhamma time: /* Wet Sand Dispenser */ corrected some grammer

{{comic
| number = 1992
| date = May 11, 2018
| title = SafetySat
| image = safetysat.png
| titletext = During launch, in the event of an unexpected sensor reading, SafetySat will extend prongs in all directions to secure itself and any other cubesats safely in the launch vehicle until the source of the problem can be determined.
}}

==Explanation==
{{incomplete|Created by a CubeSat so dangerous, I corrupted the image file and crashed the server (the first image upload was corrupt)- Maybe expand it a little? Some of the individual items need more explaining. Do NOT delete this tag too soon.}}

{{w|CubeSat}} is a standard format for small satellites that can fit in a 10×10×10 cm format with a mass of less than 1.3 kg. They have been widely used by academics for research satellites, and by both small and large companies.

CubeSats are normally launched as a secondary payload often beside a deployment to the international space station. There are multiple safety rules to ensure that the CubeSat cannot damage the primary payload. However, the joke in this comic is that [[Randall]]'s design seeks to break as many rules as possible.

Items counterclockwise from bottom left:

====Americium corners====
{{w|Americium}} is a very dense, highly radioactive substance. Depending on the amount of Americium involved, this alone could shoot the mass over the 1.3 kg mass limit.

====Guncotton====
A form of {{w|nitrocellulose}}; it is explosive.

====Crude Oil====
{{w|Exxon Valdez oil spill}}, {{w|Deepwater Horizon explosion}}... need we say more? Of course the leakable volume would not be near those levels, but plenty dangerous nonetheless if it were to leak though a faulty seal... And this is not helped by the fact that it is in orbit or if it leaks during launch...

====Volatile Epoxy Seal====
When this goes, everything gets coated in flammable crude oil.

====Celebratory Firework====
Explosive Fire Source that can hit other satellites in the vicinity.

====CFCs/Ozone-depleting CFC Spritzer====
{{w|Chlorofluorocarbons}} (CFCs) are fully halogenated paraffin hydrocarbons that contain only carbon, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane. {{w|Freon}} is a common example of a CFC, and the use of CFCs has been linked to a depletion of the Earth's {{w|ozone layer}} leading many countries to ban their use. So spritzing CFCs in an area closer to the Ozone layer sounds like a good idea?

====Laser Pointer (Hubble-Seeking)====
Aiming a red laser at a visible light telescope is really bad for the telescope in question and its optics{{Citation needed|reason=Not obvious to non-experts why visible-light laser is damaging to a telescope designed to read visible spectrum, disruptive perhaps?|date=May 2018}}.

====Laser Pointers (Fixed)====
These three laser points will effectively point in 3 different random directions, which is not safe for other objects around this Cubesat{{Citation needed|reason=Why is a laser pointer dangerous?|date=May 2018}}.

====SDR/{{w|Software-Defined Radio}} (Code Editable via Public Wiki)====
A radio which can be programmed to broadcast and receive in a range of frequencies, and formats. Since anyone could change the radio's instructions; the radio could interfere with other satellites, or with the launch vehicle. This counts as a huge security risk, as ''anyone'' could edit it.

====BIC Mini-Lighter====
Fire source, resting on the can of crude oil. The pressurized butane could also make the lighter burst, allowing the sparkp lug to ignite the volatile butane gas.

====Rare-Earth Magnets====
{{w|Rare-earth magnets}} are very powerful magnets that have a high likelihood of messing up the electronics on nearby electronics, like other CubeSats. Might also stick to other satellites.

====Wet Sand Dispenser====
Possible reference to the {{w|Kessler syndrome}}.

====Batteries (eBay)====
The quality of batteries bought on the auction site can vary widely, and certain batteries exposed to conditions outside their design specifications can {{w|Battery_(electricity)#Explosion|explode or leak corrosive acids}}. These batteries might also be connected to the adjacent spark plug.

====Solar Panel (Found)====
The quality of the solar panel and the power it produces would have to be investigated thoroughly before being cleared for space flight.

====Spark Plug====
Fire Source, if it was connected to electricity. Excess mass if not.

====Prongs (title text)====
Prongs that extend in the event of an unexpected sensor reading at launch could damage the rocket and/or nearby cubsats/payloads. Along with this, it is not unlikely that this cubesat might be the source of any internal problem that might arise; in such a situation, having such a dangerous cubesat further secure itself would be counterproductive.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A prototype for a small cube-shaped "CubeSat" satellite, with labels on various components.]

:[Labeled on top:]
:Rare-Earth Magnets
:Bic Mini Lighter
:Software-Defined Radio (code editable via a public wiki)

:[Labeled on right:]
:Laser Pointers (fixed)
:Laser Pointer (Hubble-seeking)
:Ozone-Depleting CFC Spritzer

:[Labeled on bottom:]
:Celebratory Firework
:Volatile Epoxy Seal
:Filler (Guncotton)

:[Labeled on left:]
:Americium Corners
:Spark Plug
:Solar Panel (found)
:Batteries (eBay)
:Wet Sand Dispenser

:[Labeled from within drawing in white text on top of a black rectangle:]
:Crude Oil

:[Caption below the panel:]
:My CubeSat proposal was the first to be rejected for violating every design and safety requirement simultaneously.

{{comic discussion}}

1992: SafetySat

2018-05-11T22:15:28Z

Rowhamma time: Added Kessler syndrome under wet sand dispenser.