# Could people fly on the moon? **URL:** \ **Category:** Factual Questions\ **Created:** [January 8, 2009, 4:38pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389 "2009-01-08T16:38:24Z")\ **Posts on this page:** 14\ **Page:** 3
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [January 9, 2009, 6:46pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/41 "2009-01-09T18:46:47Z")
There is a big difference in flying and lifting. We have all gone off in the flapping our gu… er… arms direction. Evolutionary changes in muscle growth etc. Seen the Jetwing dude pictures/video’s? Fly in a high pressure dome at 1/6 G, piece of cake… ---
**Author:** ![WF\_Tomba](https://avatars.discourse-cdn.com/v4/letter/w/d9b06d/32.png) [@WF\_Tomba](https://boards.straightdope.com/u/WF_Tomba)\ **Post date:** [January 9, 2009, 6:47pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/42 "2009-01-09T18:47:43Z")
Missed the edit window: Also, we don’t need to be able to hover. I am envisioning birdlike flight–most birds can’t hover at all. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 9, 2009, 6:56pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/43 "2009-01-09T18:56:38Z")
> [@WF\_Tomba](#): > > You can’t assume that a helicopter is a model of efficient powered flight. How many horsepower do you think a condor puts out? Make some assumptions. Quote/use some physics/aerodynamics. Make some calculations. Show where I am terribly wrong. Is it remotely possible? Perhaps, if you squint at the problem and cross your fingers. Is it going to be where the average joe straps on something that looks like wings, casually flaps his wings every few seconds in near silence and soars like a bird? Hell no IMO. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 9, 2009, 7:00pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/44 "2009-01-09T19:00:15Z")
> [@GusNSpot](#): > > Seen the Jetwing dude pictures/video’s? > > Fly in a high pressure dome at 1/6 G, piece of cake… Yes. Look fun as hell ! And probably as noisy. Are you aware the Jetdude has MANY times more power available to him than even the most fit human is capable of putting out ? ---
**Author:** ![WF\_Tomba](https://avatars.discourse-cdn.com/v4/letter/w/d9b06d/32.png) [@WF\_Tomba](https://boards.straightdope.com/u/WF_Tomba)\ **Post date:** [January 9, 2009, 8:11pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/45 "2009-01-09T20:11:44Z")
> [@billfish678](#): > > Make some assumptions. > > Quote/use some physics/aerodynamics. > > Make some calculations. > > Show where I am terribly wrong. OK. Check out this site: > **[Power Curve for Bird Flight](http://lavica.fesb.hr/~slap/pcurve/)** If you plug in the numbers for a 12.5 kilogram bird with a 3 meter wingspan, and a velocity range of 1-10 m/s, you will see that it needs about 3 horsepower for very slow flight, and less than 1 horsepower to fly at human running speed. So I think I’m justified in dismissing your helicopter analogy. ---
**Author:** ![WF\_Tomba](https://avatars.discourse-cdn.com/v4/letter/w/d9b06d/32.png) [@WF\_Tomba](https://boards.straightdope.com/u/WF_Tomba)\ **Post date:** [January 9, 2009, 9:02pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/46 "2009-01-09T21:02:59Z")
Also, have a look at this information from the site [ornithopter.com](http://ornithopter.com) : > [@](#): > > Schmid constructed an ornithopter, weighing 60 kilograms and having a wingspan of 12.6 meters. From the sides of the fuselage emerged smaller flapping wings, each 3.2 meters long. The flapping wings were arranged to move in a circular motion instead of straight up and down, perhaps imitating the upstroke wingspan reduction utilized by birds. Although some have objected to Schmid’s combination of fixed and flapping wings, birds too have a substantial fixed lifting surface in the body and tail. It is only by the thrust of the flapping wings that these fixed surfaces are able to produce lift. > > . . . Schmid next installed an engine in the ornithopter. This provided far more power than what the pilot’s muscles could furnish. With a 3 hp Sachs motorcycle engine, and presumably wheels added, the ornithopter was able to take off unassisted from the ground. It made a quiet 15-minute flight at about 60 kilometers per hour. Then a 6 hp engine was installed, increasing the speed to 80 kph. This was in the 1940s, by the way. I also found accounts of a supposedly successful (though short) human-powered ornithopter flight in 2006. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 9, 2009, 11:05pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/47 "2009-01-09T23:05:58Z")
> [@WF\_Tomba](#): > > Also, have a look at this information from the site [ornithopter.com](http://ornithopter.com) : > > This was in the 1940s, by the way. I also found accounts of a supposedly successful (though short) human-powered ornithopter flight in 2006. I call BS on this one. The 40’s part, not the 06 part. So, in 06 somebody (maybe) pedaled like hell and got airborn for a very short period of time. Still a FAR cry from flying anything like a bird. ---
**Author:** ![Icerigger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/icerigger/32/432_2.png) [@Icerigger](https://boards.straightdope.com/u/Icerigger)\ **Post date:** [January 9, 2009, 11:20pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/48 "2009-01-09T23:20:15Z")
Ben Bova’s book “Welcome to Moonbase” has his guests flying by muscle power in large pressurized spaces. I wonder if this could be an incentive for tourists going to the moon in the future. How much would someone pay for the reality of personal flight? ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 9, 2009, 11:28pm UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/49 "2009-01-09T23:28:05Z")
> [@WF\_Tomba](#): > > OK. Check out this site: > > [Power Curve for Bird Flight](http://lavica.fesb.hr/~slap/pcurve/) > > If you plug in the numbers for a 12.5 kilogram bird with a 3 meter wingspan, and a velocity range of 1-10 m/s, you will see that it needs about 3 horsepower for very slow flight, and less than 1 horsepower to fly at human running speed. So I think I’m justified in dismissing your helicopter analogy. So 12 kilograms times 6 (lunar gravity advantage) equals 72 kilos, or about 160 pounds. So, a fit person, and absolutely NO weight for the equipment. Lets say thats AOKAY anyway. You are STILL talking 1 to 3 HP to fly on the moon. I Repeat. Even very fit humans can NOT put out that amount of power for very long, if ever. For any extended period of time? Forget it. And thats not even considering that to “fly like a bird”, you’d want your energy to come from flapping arms, not flailing/pedaling legs. Arms put out a fraction of the power legs do. As someone noted above thread, the factor isnt EVEN 6 but square root of 6 (2.5 or so). If you assume ALL the following: Really dense atmosphere… Really efficient flapping or whatever…which I aint believing Very powerful human… Equipment that weighs very little… Some updrafts or large/tall structure to launch from… You can just possibly maybe fly on the moon. ---
**Author:** ![NoCoolUserName](https://avatars.discourse-cdn.com/v4/letter/n/5fc32e/32.png) [@NoCoolUserName](https://boards.straightdope.com/u/NoCoolUserName)\ **Post date:** [January 10, 2009, 12:07am UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/50 "2009-01-10T00:07:42Z")
Note that, in _The Moon is a Harsh Mistress_, Mr. Heinlein also had Mannie (Manuel Garcia O’Kelly) say\*: “He even talked about the possibility of flying. Thought he had tripped his safeties.” (Quote from memory, I don’t seem to have a copy on the shelf.) - Mannie and the Prof are on Earth, attempting to convince groundhogs that living on the moon is a good thing. Prof does most of the talking. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [January 10, 2009, 12:52am UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/51 "2009-01-10T00:52:55Z")
> [@billfish678](#): > > You can just possibly maybe fly on the moon. So people could fly on the moon. Glad that’s settled. ---
**Author:** ![John\_H\_1](https://avatars.discourse-cdn.com/v4/letter/j/e9bcb4/32.png) [@John\_H\_1](https://boards.straightdope.com/u/John_H_1)\ **Post date:** [January 10, 2009, 2:41am UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/52 "2009-01-10T02:41:29Z")
> [@Xema](#): > > If you change that guess to 1/sqrt(6) you’d be right. Surely for lifting a given thing with 1/6th the force of gravity 1/6th the work is done. I can not see how a bird weighing 10,000 times as much as normal would need to do only do 100 times the work to fly. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 10, 2009, 3:03am UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/53 "2009-01-10T03:03:08Z")
> [@John\_H\_1](#): > > Surely for lifting a given thing with 1/6th the force of gravity 1/6th the work is done. I can not see how a bird weighing 10,000 times as much as normal would need to do only do 100 times the work to fly. Remember To fly you are “throwing” air down in order to stay up. Keep air density and other variables constant (besides gravity itself) and it does NOT surprise me that it is non-linear. ---
**Author:** ![WF\_Tomba](https://avatars.discourse-cdn.com/v4/letter/w/d9b06d/32.png) [@WF\_Tomba](https://boards.straightdope.com/u/WF_Tomba)\ **Post date:** [January 10, 2009, 6:26am UTC](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389/54 "2009-01-10T06:26:35Z")
> [@billfish678](#): > > I call BS on this one. > > The 40’s part, not the 06 part. On what grounds? Physics hasn’t changed since the 40s. Anyway, we’re almost agreed. I just don’t agree that flapping wings are necessarily a less efficient way to power flight than rotors or fixed wings. (I really have no idea how efficient they are, but I don’t see the reason to assume that they’re very inefficient.) I said above that I thought a very strong person might be able to do this with very well engineered wings, but not an average person. [Previous page](https://boards.straightdope.com/t/could-people-fly-on-the-moon/480389.md?page=2)