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Space Elevator

neal.fun

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Re: Space Elevator

#181

Post by mjmsmith »

marstall wrote: post #63
once_inc wrote: post #43

Earlier quoted context omitted.

That is mostly because the international space community works with metric, so the Karman line is at 100km above earth, and converting to imperial units would be forced. Remember, there are only three countries that use imperial units; two third-world counties, and a global superpower.

it just detracts a bit from the "wow so high! 10 miles! factor" for the luddites among us

12,875 metres high, and when you touch down

You'll find that it's stranger than known

Re: Space Elevator

#182

Post by joemi »

csomar wrote: post #62

Couple of things I learned from this: 1. Some birds go really high into the sky. Not sure how they evolved to tolerate such a hostile environment. But it seems that Duck-like birds are able to handle very high altitude. 2. There are lots of cool spaceships that man has made. But it seems most of these were made in the 1950-1990 era. It's a shame that we are no longer doing that.

I think there are still a lot of cool ones, but not as many sexy ones. Rocket planes like the X-15 were incredibly sexy, IMO, though in many ways not as cool and useful as current rockets.

Re: Space Elevator

#183

Post by barbs »

byhemechi wrote: post #132
JoBrad wrote: post #85

Earlier quoted context omitted.

That’s not entirely true. The UK and Australia use Imperial measurements quite frequently, especially for speed.

hi, i’m australian, the only time i ever use imperial is if i work with hydraulic hoses or (rarely) tell someone my height we pretty much only use metric, unlike the uk

Also Australian, can confirm although TV/monitor screen sizes are also usually expressed in inches.

We also haven't made the switch to metric time yet ;)

Re: Space Elevator

#185

Post by sph »

ilikehurdles wrote: post #176

I don't usually complete these little "fun internet" experiments but I thoroughly enjoyed this journey from start to end, and learned a bit on the way. My mind was blown a few times checking on the scrollbar thinking it's always over only to see we've barely just begun. Excellent.

It's not the first time I happen upon Neal's fun experiments, and I always love them.

As soon as I see the domain neal.fun, it is a must click.

Re: Space Elevator

#186

Post by jonas-w »

Moissanite wrote: post #24

FYI, this crashed my browser with extreme prejudice; I can't remember one other time when I've had to force-stop the application. (Firefox on Android)

Using firefox on android and it worked perfectly fine.

Re: Space Elevator

#187

Post by marcosdumay »

MilStdJunkie wrote: post #170
marcosdumay wrote: post #130

Earlier quoted context omitted.

> In the long term, a space elevator is inevitable There are plenty of zero-fuel launch possibilities and a few very high-ISP ones. On the long term one of them is inevitable, but it's pushing it a bit to claim that it will be the space elevator.

Space elevator is by far the most efficient though . . right? Stuff that's on the end of the cable has enough angular velocity to get flung all across the inner system. Lunar orbit could be reached with release at 50,960 km. At the end of a 144,000 km cable you could get to Jupiter. I dunno what sort of other zero fuel launch techniques are getting considered though - there's no doubt a space elevator is just out of…

The zero fuel options all sit around the same efficiency possibilities. A launch-loop won't get you as far as a GEO space elevator, but it can get farther than a non-stationary one. A sky hook can in theory get you a larger delta-v than a GEO elevator. A space fountain can do GEO, but no further...

And the very high ISP options are all on the same category in that they can save you more fuel than the zero fuel ones, but only if you want enough delta-v.

None of those are viable today, but most are in a "we can make all parts, but it's a fucking big machine that we can't assemble", while the elevator is still missing parts.

Re: Space Elevator

#188

Post by midasuni »

outworlder wrote: post #140
midasuni wrote: post #93

Earlier quoted context omitted.

Getting to 100km or even 200km is easy. Staying there is hard. 80% of the energy in a rocket goes to adding sideways motion. An elevator upto GEO adds enough energy (taken from the earths rotational energy) to your payload to get it into orbit. If you let go lower down you need to add sideways velocity. In LEO you on an elevator would be travelling about 1,400mph and need to get to 18,000 to get into orbit. Sure ther…

> In LEO you on an elevator would be travelling about 1,400mph That's a pretty significant speed already and it helps that you are already in space. See how tiny a Pegasus rocket is, and that one is launched from aircraft, slower, and nowhere near as high as what we are discussing. https://www.northropgrumman.com/space/pegasus-rocket/ Getting to 100km from ground requires beefy first (even second) stages because you…

Launching from the equator starts you at 1100mph though

(Haven’t done the exact maths, I suspect the delta is even closer than 300moh)

Re: Space Elevator

#189

Post by midasuni »

jutrewag wrote: post #172
midasuni wrote: post #90

Earlier quoted context omitted.

If your bad guys can get high enough to sever your cable, they can get high enough to do a kinetic or powered bombardment and cause magnitudes more damage.

A bomb on wheels that rides the cable before exploding.

I can’t take a tube of toothpaste on a plane. How am I going to pack a bomb large enough to cause that much damage. Why don’t people blow up planes with that method today?

Re: Space Elevator

#190

Post by throwawaymobule »

kbelder wrote: post #121
jackcviers3 wrote: post #104

Earlier quoted context omitted.

It exploded when trying to orient for the first stage separation. And it appeared to have 5 of the 33 engines out during the first stage flight. This launch gave me very "Don't Look Up" ending vibes.

Just the opposite. This is engineer-driven testing.

it's amazing how well this works for them. I think this is the main reason they can crank through development so fast. Wish this sort of development was more common.
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