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I realise this is a trite observation, but it never ceases to amaze me that it took just 22 years from the beginning of space exploration to walking on the moon
by Xophmeister 5y ago
I realise this is a trite observation, but it never ceases to amaze me that it took just 22 years from the beginning of space exploration to walking on the moon.
- crubier 5y agoThe delta-v from Earth Surface to Low Earth Orbit (beginning of space exploration) is 9km/s. The delta-v from Earth Surface to Moon is 15km/s. So basically once you learned to go to space, going to the Moon is "only" 60% harder, even thought the moon is 1000x further away.
- simonh 5y agoA full up Saturn V with LEM and the works looks a lot more complex and capable than a 60% improvement on a V2.
- HelloNurse 5y agoBut the additional complexity is mostly designing a suite of vehicles, not general rocketry advances.
- geocrasher 5y agoIncorrect. Orbital mechanics were not a part of the V2 era programs because they were sub-orbital with relatively simple parabolic trajectories. Getting a capsule back from LEO was not something that had been worked out mathematically until later.
- hoseja 5y agoV2 does NOT go into orbit.
- simonh 5y agoYet another reason why the comment I'm replying to was incorrect, thanks.
- crubier 5y agoNo, it’s actually the opposite. Re read. If you compare an actually LEO capable vehicle and a moon lander of the same payload, you’ll see that the difference is not that big. Saturn had a massive payload, hence the gap in difficulty. But my point anyway was that Saturn V is not 1000x larger than a soyouz, despite the moon being 1000x further away. Distance is not what counts in space.
- dmd 5y agoThe delta-v from Earth Surface to the bottom of the ocean is 0, so by your logic, going there is trivial.
- OJFord 5y agoWell when did you ever hear of a space agency bothering? Jokes aside, I hadn't heard the term before and from what I could guess/infer didn't see how it could be a measure between two places: https://en.wikipedia.org/wiki/Delta-v https://en.wikipedia.org/wiki/Delta-v
- crubier 5y agoIt’s a measure of the energy needed to move from one orbit to another.
- ustolemyname 5y agoI'm going to nit this for several reasons: 1. Walking on the moon implied a return trip which requires an extra ~3km/s. 2. Under the rocket equation the fuel requirements for more delta v grows superlinearly, which then awkwardly makes your rocket bigger, which requires more fuel... 3. 22 years prior a metal can went to space. The scale of a manned moon mission in comparison is absolutely nuts, even basic things like having rocket motors that can be relit is a large technical challenge.
- mhh__ 5y agoAddendum to point 3. It's not just a metal can, it's a metal can with some people in it. You have to keep them alive and useful for roughly a week, not just fling them at the moon.
- deleted 5y ago[deleted]
- TeMPOraL 5y agoThere's a filk song about Sputnik that makes this point as its punchline. https://www.youtube.com/watch?v=o-mZ9pKvCmk https://www.youtube.com/watch?v=o-mZ9pKvCmk - "Surprise!" Sputnik wore out and spiraled back to Earth On re-entry it burned up very soon Hail and good-bye to that goose in the sky... And in 12 more years a man walked on the Moon! I find it far from trite, I'm continuously amazed by this as well.
- nautilius 5y ago27 years; that's what the whole linked article on wikipedia is about.
- Xophmeister 5y ago> Exploration of space began in earnest in 1947 22, 27...either way it's incredible.