Space Elevator

[csomar]

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.

[jackmott42]

List of cool spaceships being worked on now or recently:

* The Falcon 9, the first partially reusable spaceship that actually costs less than not re-using anything

* Terran R - a fully reusable space ship in the works by relativity space

* RocketLab Electron - an active rocket that is unique in its use of electric turbo pumps, 3d printed engines, and advanced composites use

* RocketLab Neutron - in the works, a larger rocket with the aim to be partially re-usable ala Falcon 9 but with a cheaper expendable 2nd stage and simpler design

* SpaceX Starship - in the works, (test flight today!) a large heavy lift vehicle with the aim to be fully reusable

* Blue Origin - working on a ship similar to starship

there are others!

[O5vYtytb]

I have to wonder what you mean we're no longer making cool spacecraft? The SpaceX starship is about to launch in an hour, it's very cool.

[ZeljkoS]

Regarding 1, wikipedia about Rüppell's vulture (highest-flying bird) explains the adaptation: "The birds have a specialized variant of the hemoglobin alphaD subunit; this protein has a great affinity for oxygen, which allows the species to absorb oxygen efficiently despite the low partial pressure in the upper troposphere. A Rüppell's vulture was confirmed to have been ingested by a jet engine of an airplane flying over Abidjan, Ivory Coast on 29 November 1973 at an altitude of 11,300 m (37,000 ft)." https://en.wikipedia.org/wiki/R%C3%BCppell%27s_vulture

[brvsft]

To your 2nd point, I'd venture an uneducated guess that the reason we were doing this was largely a part of the arms race between USA and USSR during that period.

[mcv]

Swans and geese may not look like the greatest flyers when they're on the ground, but they're among the highest flying birds. But why? Is it their size and strength? Why do people have trouble breathing at that altitude, but birds don't?

[Xenoamorphous]

I wonder how they estimated the flying altitude of pterodactyls.

[joemi]

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.

[hobo_in_library]

I was shocked to see a butterfly above the cloud level

[nojs]

3. The temperature gradient is weird, and doesn’t just get colder the higher you go.

[codethief]

> It's a shame that we are no longer doing that.

"We" have built a lot of spaceships since then but they simply went higher up than "just" 100km, so don't show up in the OP.

[swader999]

I think there's a lot of craft we just don't know about.

[davidhyde]

At 74km/h you would reach space (100km karman line) in an hour and a half but you would need to keep going for another 20 days at that speed reach geostationary orbit in order to not fall back to earth when you exit the space elevator.

[philwelch]

Yeah, I wish this went on as far as an actual space elevator would, perhaps with extra visualizations of the heights of various orbits. The top would be slightly above geostationary orbit, since you would need the center of mass to be at the geostationary point in order to work.

[midoridensha]

The other problem people seem to forget is radiation. The Van Allen belts expose people to a lot of radiation; normally it's not a problem, because either people stay under the belts (as in stations like the ISS which are at LEO), or for the few times humans went beyond LEO, to the Moon, they blasted through the belts very quickly and thus had negligible cumulative radiation exposure. But if you're sitting on a space elevator taking days to go through the VA belts, you'll probably get a fatal dose.

Wikipedia has an article that touches on this here: https://en.wikipedia.org/wiki/Space_elevator_safety

[LeanderK]

but do you need to reach geostationary? couldn't you just switch to a rocket at this stage? Maybe a small one to bridge the gap? I would have thought that the first kilometres are the ones where you have to invest the most work so if you just bridge them using the space elevator it would be still an improvement.

Maybe for cargo the 20 days are not really important

[NoMoreNicksLeft]

Can the speed be safely increased once you leave the atmosphere and there is no (appreciable) drag? With such a system in place, are there no other interesting places to stop along the way to geosync?

[nivenkos]

At that point gravity will act slower though, so it might be enough to take up a small liquid fuel craft too.

Rockets will have abandoned solid fuel boosters long before then.

[hanselot]

I love this. Reminds me of a thread I perused once re Orbital Ring Space elevator concept, and how it seems not only possible, but almost disgustingly cheap (in terms of the gains) with current technology. Not only would such an endeavor restore some aspect of pride to humanity, but the benefits are quite numerous.

To name a few low-hanging fruit:

The research done to make it possible, would definitely advance several fields.

The ability to access photons from outside of the atmosphere should vastly improve how much energy we could capture from the sun. Pair this with transparent solar tech designed to pass through the wavelengths that are useful to plants, and we can factory farm crops in space using fully automated systems. This could also lead to exploration of engineered crops that can withstand (and potentially absorb radiation), that may serve as a biological wall for the humans.

Obviously, it would be a given that asteroid mining would become vastly more simplified, and autonomous robotic space construction and perhaps even asteroid mining would become a fantastic way to profit from it (or/and dilute the value of existing rare earth minerals/metals).

Obviously, this would also make intra-solar travel orders of magnitudes cheaper.

Maintaining and cleaning up space debris would become substantially simpler.

Building planetary defense mechanisms (against extinction level events) would become more feasible if we have this in place.

There are obviously an enormous number of things that could go wrong with a project like this, but given a CERN or Manhattan Project level of funding and cooperation, I think we could build this in a couple decades.

This is the kind of future I would want to be a part of. The cost estimate I think was somewhere in the trillions, but even so, the potential benefits are so vast that it just doesn't make sense not to do it, right?

In case you don't want to google the wiki page: https://en.wikipedia.org/wiki/Orbital_ring

Don't even take my word for it. Go question ChatGPT about it.

[xg15]

"Above this altitude is known as the 'death zone', because there isn't enough oxygen for human life."

whooper swan casually floats by

[virtualritz]

This is great.

I just wish there was one way to switch all units. The temp. can be switched between F/C by tapping on it.

The height is metric and seems fixed and then stuff in text bubbles is again imperial (e.g. mph instead of kph).

[once_inc]

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.

[elbigbad]

I’m a simple hacker news lurker. When I see a post that links to Neal.Fun I click. Always such high quality work

[gsanderson]

Me too! They are always great.

[adlpz]

That was absolutely fantastic. I just left a pretty rough meeting and came to HN for some healthy procrastination.

Really made my day.

[ilikehurdles]

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.

[sph]

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.

[ilikehurdles]

Correction: almost* not always.

[paxys]

Amazing visualization. The most interesting part to me is the weird fluctuation in temperature. You'd think it would trend in a single direction. What causes all the frequent ups and downs?

[wonrax]

At 17446m mark:

> Unlike the troposphere, the temperature in the stratosphere increases the higher you go.

[seabass-labrax]

Ah yes, I thought, scrolling past the Learjet 45, the de Havilland Vampire, the Caproni Ca.161, all high-tech jet aircraft of the space age... hang on, the Ca.161?! I must say I'm sceptical that such a single-engined biplane could reach 50000 feet. The most advanced piston-powered aircraft, the four-engined Lockheed L-1649 Starliner, had a cruising altitude of no more than 30000 feet.

[gibolt]

A key point with space elevators is that they aren't limited to Earth. The solar system has plenty of celestial bodies that could benefit (us) from having one.

It may not be as significant as the impact of an Earth-based one, but any propellant savings is a win.

[philwelch]

Some of those celestial bodies are even small enough that we could build the elevators with existing materials, too.

[lastangryman]

A martian space elevator is explored in Kim Stanley Robinson's Red Mars trilogy, definitely worth a read.

[mcv]

I thought it would go all the way up to the anchor of the space elevator, so I expected to have to scroll up for another couple of hours. I guess the creator wisely decided that was a bit too much.

Amazing how high the F-104 Starfighter could fly, by the way.

[debesyla]

> Congratulations! You have made it 0.01% to the moon.

Okay, haha, now that gives a nice perspective how far is the Moon.

[ronyfadel]

I’m impressed with how high planes and rockets built almost 100 years ago got.

[jimmySixDOF]

Slightly tangential, slightly more achievable (?) , but I was just listening to a BBC Worldservice Radio Podcast on Space based Solar farms that would beam concentrated energy back down to earth [1]. By no means a new idea but they wrap up current thinking in 30min.

[1] https://www.bbc.co.uk/sounds/play/w3ct5bjt

[d_burfoot]

I used to think that the space elevator is a great and necessary concept for building a space-based civilization. How else can we get enough raw physical material into space? There's no way rockets can scale up to the enormous tonnages that will be required.

Now I think the solution is to build an industrial base on the moon. The lunar factories and mines (mostly run by robots) will harvest the necessary material, do some initial refining, and then fling the products into space using mechanical techniques (something like SpinLaunch, or a giant catapult). Lifting off from the moon is far easier than getting off the Earth (think of that tiny lander that the Apollo astronauts used).

[archibaldJ]

This is beautiful. I cried. And then I bought Mr Neal a coffee.

the space elevator.. it is a story of human progress .. it is something we will get to build one day

[ibdf]

The space elevator music was particularly good.

[runlevel1]

Time of useful consciousness would be another interesting number to add. Here's a table of average times published by the FAA for a gradual ascent:

- 18,000 ft; 5,500 m: 20-30 min

- 22,000 ft; 6,700 m: 10 min

- 25,000 ft; 7,600 m: 3-5 min

- 28,000 ft; 8,550 m: 2.5-3 min

- 30,000 ft; 9,150 m: 1-2 min

- 35,000 ft; 10,650 m: 30-60 sec

- 40,000 ft; 12,200 m: 15-20 sec

- 43,000 ft; 13,100 m: 9-12 sec

- 50,000 ft; 15,250 m: 8-10 sec

Here's a demonstration of the effects of hypoxia and time of useful consciousness done in a hyperbaric chamber by SmarterEveryDay: https://www.youtube.com/watch?v=kUfF2MTnqAw

[1]: https://en.wikipedia.org/wiki/Time_of_useful_consciousness

[blkhawk]

As cool as space elevators are - I wish all the other "easier" to build options would be more mainsteam. Say orbital hooks or maybe some of the more sedate active support structures like orbital rings or lauch loop variants.