Editing 2624: Voyager Wires

{{comic
| number    = 2624
| date      = May 25, 2022
| title     = Voyager Wires
| image     = voyager_wires.png
| titletext = Also, they're getting increasingly worried that someone will accidentally hit the 'retract' button, and that the end of the cable thrashing around as it winds up could devastate the Earth's surface.
}}

==Explanation==
This comic claims that the {{w|Voyager program|Voyager probes}} communicate with NASA though ridiculously long copper wires. These wires would have to be continuously lengthened as the probes travel away from {{w|Earth}}. Supposedly, because of "high copper prices and budget constraints," they may not be able to afford to lengthen the wires much longer. If this occurred, they would have to either cut the wires or let them break, which would prevent any further communication with the probes. In reality [https://voyager.jpl.nasa.gov/mission/status/ they use radio waves], not long copper wires, so this doesn't actually happen.

If copper wires were dragged by the Voyager probes, assuming a 1 mm² thick cable, 550 tons of copper would be needed per hour and it would add 1 million {{w|ohm}} per hour to the cable resistance. At [https://www.moneymetals.com/copper-prices $8,720/ton], this would cost just over $42 billion dollars/year, which would be nearly twice [https://www.planetary.org/space-policy/nasas-fy-2022-budget NASA's entire annual budget].

The resulting wire would slow down the probes by drag unless the wire itself was actively suspended (i.e. accelerated) continuously as it was fed. The wire could not be used for any other mechanical purpose such as a {{w|Space elevator|space elevator}} for this reason. 

Since the Earth spins, the wires would also spool around the Earth, slowing the probes down even further. [https://what-if.xkcd.com/157/ Clearly, this is not a good idea.] This problem might be avoided if the wires reached Earth at one of the poles. Or perhaps they could go to an airplane that flies around Earth at exactly 15 degrees of longitude per hour, with periodic {{w|air-to-air refueling}}, so that it is always on the side of the Earth facing the probe.

Because the Voyager probes aren't in the plane of the Earth's orbit around the Sun, the Earth would not, in its rotation around the Sun, drag these copper wires through the {{w|Sun}}. If it did, the wires would melt, as copper melts at around 1360 {{w|kelvin|K}}, while the Sun's surface is approximately 5700 K.

The title text references the phenomenon seen with self-retracting cables, such as are commonly found on vacuum cleaners, where the free end of the cable, where the plug is, oscillates more and more wildly as the cable approaches full retraction, leading to the danger of a painful rap on the hand if it is not withdrawn in time. A planet-sized impact of this kind could cause severe damage.{{Citation needed}}

A few days before this comic was released, [https://voyager.jpl.nasa.gov/news/details.php?article_id=124 NASA had reported] receiving corrupted altitude data from the Voyager 1 probe.  The fact that they are receiving any data at all means that the altitude control system must be working (or else the antenna would not point at Earth), but they continue to investigate how that data could be corrupted after that point.

'''Spoiler alert'''

The consequence of a cable between a craft in space and a planetary location being suddenly retracted was recently imagined in the first episode of the Apple TV+ series ''{{w|Foundation (TV series)|Foundation}}'', wherein a {{w|space elevator}} tether was severed. [https://www.youtube.com/watch?v=huRmvG3zRpg It didn't end well for anyone other than the terrorists] who won the freedom of thousands of inhabited worlds which had formerly suffered under the jackbooted oppression of {{w|Trantor}}'s fascist galactic Empire regime.

Another illustration in fiction of a severed space elevator is in Red Mars, part of the {{w|Mars Trilogy}} by Kim Stanley Robinson.

[[Black Hat]] has previously severed a space elevator tether using a pair of scissors in an [[697: Tensile vs. Shear Strength|earlier comic]].

==Transcript==
:[In the bottom right corner is a space probe, with large satellite dish and long antenna. Behind it runs a long wire, that makes three loops before it is connected to North America  on the Earth in the top left corner. To the left of the Earth there is a second wire, which goes off-panel to the left.] 

:[Caption below the panel:]
:Sad news: Due to high copper prices and budget constraints, NASA may finally have to cut the wires that they've been spooling out to communicate with Voyager 1 and 2.

{{comic discussion}}

[[Category:Space probes]]