Ask HN: Why don't we use ICBMs for transportation?
13 comments
> Seeing the progress of spacex's VTOL rockets has made me wonder what's stopping us from using rockets to move things and people (if they don't mind the g-forces) around the planet.
People, and very many things, definitely "mind the g-forces".
> I believe I read somewhere recently that you can move an ICBM between any two points on the planet in less than an hour.
You cannot.
You can use an ICBM to deliver a payload between any two points on the planet in that time, which is considerably different than moving the ICBM.
> Seems like there are things - and people - we'd pay a big premium to move around the planet that quickly.
Part of the "that quickly" is that, well, impacting at multiple km/s. There's not a lot of things or people that would survive being delivered in that manner.
> Is there some fundamental reason that makes this not work?
As covered elsewhere in the thread: cost (ICBMs aren't cheap), fragility of most of the things you'd want to deliver (and most of the places to which you might want to deliver them), and the fact launching ICBMs is a good way to start a war?
People, and very many things, definitely "mind the g-forces".
> I believe I read somewhere recently that you can move an ICBM between any two points on the planet in less than an hour.
You cannot.
You can use an ICBM to deliver a payload between any two points on the planet in that time, which is considerably different than moving the ICBM.
> Seems like there are things - and people - we'd pay a big premium to move around the planet that quickly.
Part of the "that quickly" is that, well, impacting at multiple km/s. There's not a lot of things or people that would survive being delivered in that manner.
> Is there some fundamental reason that makes this not work?
As covered elsewhere in the thread: cost (ICBMs aren't cheap), fragility of most of the things you'd want to deliver (and most of the places to which you might want to deliver them), and the fact launching ICBMs is a good way to start a war?
At $7 million per message (Minuteman per-unit cost) I doubt that there is a large demand - a slower but cheaper option is better for most deliveries, unless you want to deliver a nuke to someplace that doesn't want it.
I think the Russians get a bit twitchy when we start firing off ICBMs.
Also, they cost about seven million dollars each and one use only.
Also, they cost about seven million dollars each and one use only.
Assuming you could find a practical use for spending that much money, the United States and Russia are watching to shoot down or retaliate against exactly this kind of vehicle, 24/7.
https://en.wikipedia.org/wiki/Launch_on_warning
https://en.wikipedia.org/wiki/1983_Soviet_nuclear_false_alar...
https://en.wikipedia.org/wiki/Launch_on_warning
https://en.wikipedia.org/wiki/1983_Soviet_nuclear_false_alar...
The rocket equation. Your missile would have to be able to slow down when it arrived, which means carrying a lot of fuel. That makes it very heavy, which means you need more fuel for the launch, and you end up with a monster rocket that's far more expensive than an ICBM.
Not sure I am ready for the first FedEx branded rocket heading into Memphis.
Something like that was tried before, with limited success. http://en.wikipedia.org/wiki/Rocket_mail
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Besides the expense, I can think of two reasons:
- It has to be able to slow down before impact.
- To other countries it would look a lot like a nuclear missile.
- It has to be able to slow down before impact.
- To other countries it would look a lot like a nuclear missile.
Cost.
Similar to why we don't move people with the teleporter in star trek. It kills you ripping apart the atoms in your body then reassembles your now dead body at the destination.
For one, an ICMB gets there in an hour by hitting the ground at a couple thousand miles per hour. Sub-optimal for cargo. :-)
I believe I read somewhere recently that you can move an ICBM between any two points on the planet in less than an hour. Seems like there are things - and people - we'd pay a big premium to move around the planet that quickly.
Is there some fundamental reason that makes this not work?