Talk:1461: Payloads

Explain xkcd: It's 'cause you're dumb.
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It's possible he's talking about this comic. 07:20, 17 December 2014 (UTC)

I think he used horses as a reference to the unit of work, horse power, but in this case instead of being the 550 foot pounds per second, it is the force required to put a horse at that altitude 08:10, 17 December 2014 (UTC)

The top one clearly says "Spacecraft mass" and the bottom says "Capacity" (which is normally either the mass or volume something can hold), so I don't think either refers to force. 08:32, 17 December 2014 (UTC)

Horses might also be used as a length unit... I am wondering if this is somehow related to the size of SRBs [1] ;-) -- Ld75 (talk) (please sign your comments with ~~~~)

There is the famous tail (no pun intended) of how the width of the Space Shuttles SRBs are related to the width of a horses, er, um, butt -- which apparently is not true. However, similarly to the "Upgoer Five", Randall may just be trying to relate a very difficult to grasp concept (weight of a huge object) to something that with which a large number of people may be familiar. Jarod997 (talk) 14:34, 17 December 2014 (UTC)

A few mass calculations: (All masses from wikipedia)

  • ISS - 450,000 kg / 932 Horses = 483 kg/Horse
  • Skylab - 77,088 kg / 171 Horses = 450 kg/Horse
  • Mir - 129,700 kg / 286 Horses = 453 kg/Horse
  • Shuttle Payload - 24,400 kg / 54 Horses = 452 kg/Horse
  • Compton GRO - 17,000 kg / 38 Horses = 447 kg/Horse

It looks like Randall probably used 450kg as a standard horse, which seems like a fairly average weight for a horse. --Pudder (talk) 09:06, 17 December 2014 (UTC)

Curious: the Atlas-Centaur rocket is listed as lifting Centaurs, not horses. 09:11, 17 December 2014 (UTC)

Plus the Pegasus rocket is labelled as lifting one (mythical, horse-sized?) Pegasus. I took this as synchronicity, but currently someone (who missed the Centaur reference in the part of the main text about "joke additions/deviations") who edited the the main text seems to think that it's purely a mythical reference. 13:27, 17 December 2014 (UTC)

The Keyhole captions are wrong; assuming 450 kg/horse, 40 horses for the Keyhole 7 would be around 18,000 kg. Documents declassified a couple of years ago give the mass as around 2,000 kg. The Keyhole 3 was even smaller. The mass and dates are about right for Keyhole 11 satellites but I don't know where the 3 and 7 have come from (the dates are wrong for the third and seventh Keyhole 11s) 09:43, 17 December 2014 (UTC)

Initially I thought that the position of 'T Rex' along the X axis (approx 1985) may be a link to the band T.Rex, but according to wiki that was 1967-1977. I guess it could be a random date, but thats not usually Randall's style... --Pudder (talk) 10:51, 17 December 2014 (UTC)

The T Rex "Sue" was discovered in August 1990. Not quite right, either. 11:10, 17 December 2014 (UTC)
Perhaps a reference to the date of 'Jurassic Park'? Not sure exactly when that came out but I think it's in the right range. 14:55, 17 December 2014 (UTC)
Hadn't thought of that.. Though after checking, Jurassic Park was released 1993, and I believe set in 1990. Still doesn't seem to tie up.. --Pudder (talk) 15:22, 17 December 2014 (UTC)
I never knew there was ever a space craft called "T-Rex". Learn something new everyday! ;)

The Oldsmobile is probably a reference to the movie Mom and Dad Save the World. The title characters' station wagon was from around that era -- and it did go into space in the movie. --Aaron of Mpls (talk) 11:47, 17 December 2014 (UTC)

Terrastar may be referring to TerreStar-1, with a launch mass of 6,910 kg, divided by 15 horses is about 460 kg/Horse. This is consistent with the above calculations. Jarod997 (talk) 14:23, 17 December 2014 (UTC)

Based on that and its accurate position on the X axis, I would agree with you. I've added it to the table, with a note below. --Pudder (talk) 14:38, 17 December 2014 (UTC)

Thor may be referring to the Thor-Able launch vehicle. First flight of 1958 (good position on the graph), and payload of 120 kg is about 40 kg / dog -- that's a bit high for an average, but depending on the breed it could be accurate. Jarod997 (talk) 14:58, 17 December 2014 (UTC)

Yes, I believe that is correct. Added to tables. --Pudder (talk) 15:22, 17 December 2014 (UTC)

Based on horse payload, location on X-axis (time of first launch?), and some general wikipedia browsing, I believe the unlabeled launch vehicle on the bottom is a Delta IV Medium. According to Wikipedia, it was first launched on 11 March 2003, which fits the location on the timeline. It had an LEO payload capacity of 9,420 kg, which equates to 20.9333333 horses at the estimation of 450kg/horse. For reference, all my information was pulled from Screamsquad (talk) 16:20, 17 December 2014 (UTC)

Certainly seems a likely candidate..--Pudder (talk) 17:08, 17 December 2014 (UTC)
Title Text Calcs

I did some calculations on the title text, though I'm not sure how correct they are. We can use our standard horse at 450kg, and assuming 9.81m/s2 gravity (neglecting the slight drop in gravity as it moves up the space elevator), the formula I've used is:

1 Watt = 1 Newton raised 1 Metre in 1 Sec
Power[Watts] = (450[kg] * 9.81[m/s<sup>2</sup>]) * LEO[m] / Time[s]

A large power station is a pretty vague measure, but I would guess we are looking at around 1GW. I found a 30 acre solar farm (in the not-so-sunny UK) with an output of 5MW, scaled linearly (which may well not be valid) a 0.6 acre (2500m2 back yard could yield 93.5kW. Using these power guesstimates, we can calculate the altitude at which the 500 horses/year and 10 horses/minute converge. It works out at roughly 1350km. Depending on where you look, LEO is classified as anything under 2000km.

Now I know there are a lot of assumptions in there, and really the whole formula is backwards, but hey... its a starting point! --Pudder (talk) 17:05, 17 December 2014 (UTC)