[Rhodes22-list] How Much Energy To Launch A Payload Into Space?

[Roger Pihlaja]

Ron,

Man, now we are talking about one SERIOUS bank of capacitors!  Man made
lightening bolts indeed!

Roger Pihlaja
S/V Dynamic Equilibrium

----- Original Message -----
From: "Ronald Lipton" <rlipton at earthlink.net>
To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
Sent: Wednesday, January 19, 2005 11:59 AM
Subject: Re: [Rhodes22-list] How Much Energy To Launch A Payload Into Space?


> The reason Roger's number is so high is that he is computing the power
> needed during launch.  The reactors supply countinuous power, so the
> comparison to reactor power is only valid if you are launching waste
> continuously.  You would have to multiply by the launching duty factor,
> (and then get serious about how you store and deliver the power when
> needed, conversion efficiency, friction ...) to get a more valid estimate.
>
> Ron
> ----- Original Message -----
> From: "Michael Meltzer" <mjm at michaelmeltzer.com>
> To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> Sent: Wednesday, January 19, 2005 8:11 AM
> Subject: Re: [Rhodes22-list] How Much Energy To Launch A Payload Into
Space?
>
>
> > Are you sure, seems a couple of orders of magnum off, The "standard"
> > rocket lunches the finial payload in that range(10 ton), but lunch
> > weight is many times that, mostly the need to lift the fuel to get is to
> > the next level, the rail gun does not take the fuel along, were the moon
> > rockets in that energy level??? as a crosscheck?, what about the probes
> > they send out they are not using that type of energy budget?
> >
> > MJM
> >
> >
> > Roger Pihlaja wrote:
> >
> > >Gentlemen,
> > >
> > >I don't think you folks appreciate how much energy it requires to lift
a
> payload into space.  Just for snicks and grins, I did the following rough
> calculation:
> > >
> > >Suppose we want to be able to shoot 10 tons (9091 kg) off the earth
into
> the sun.  To do this, we must somehow accelerate the mass from rest up to
> so-called escape velocity.  Escape velocity from the earth is about 25000
> mile/hr (11176 m/s).  Suppose we build a "rail gun" up the side of a
> mountain.  Now, once per day, the earth's rotation will have our rail gun
> pointed in the correct direction to shoot a payload into the sun.  Let's
say
> we can build our rail gun 10 km long.  For the sake of simplicity, we will
> assume the acceleration in the rail gun will be constant over the entire
10
> km and there are no losses due to friction, magnetic coupling, electrical
> resistance, etc.  How much power do we have to feed this rail gun?
> > >
> > >The required acceleration is 6245 m/s^2 or about 637 g's!  The payload
> will have to withstand this acceleration for 1.79 seconds.  The energy
> required is 5.677E11 joules and the power is 3.172E11 watts.  That's 31720
> megawatts!  Keep in mind that a big nuclear power plant is typically rated
> at around 1500 megawatts.  So, our rail gun facility needs about 211 world
> scale nuclear power plants all operating at rated capacity to supply it
with
> sufficient power to launch one 10 ton payload per day into the sun.
> > >
> > >The power requirement for an explosive powered cannon is similarly
> astronomical!
> > >
> > >Yeah I know, I need to get a life. :)
> > >
> > >Roger Pihlaja
> > >S/V Dynamic Equilibrium
> > >__________________________________________________
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> > >
> > >
> > >
> > >
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