Spaceship Design

[Turtle]

Originally Posted by Jay-qu

How is that supposed to create acceleration towards the sun? The sail works because of the solar wind yes? I dont see any way possible for it to go 'upstream' without outside help

Perhaps by tacking & jibing just as sail boats on water do? Galaxy Cup Regatta anyone?

[Jay-qu]

Originally Posted by Turtle

Perhaps by tacking & jibing just as sail boats on water do? Galaxy Cup Regatta anyone?

but the solar wind doesnt flow around behind the sail like air does, you would be unable to create a lower pressure on the sun side of the sail.. oh wait you where joking, turtle you old dog you

[Turtle]

Originally Posted by Jay-qu

but the solar wind doesnt flow around behind the sail like air does, you would be unable to create a lower pressure on the sun side of the sail.. oh wait you where joking, turtle you old dog you

Mmmmm...I didn't mean to joke, but if it is funny and I don't know it, it is still fine to laugh. Is it sure the solar wind does not eddy behind a large solar sail? Does that even matter in regard to tacking & jibing?

[CraigD]

Originally Posted by Jay-qu

How is that supposed to create acceleration towards the sun?

A solar sail (light sail) can’t produce an acceleration toward the sun. It can produce an acceleration directly away from the sun, and lower accelerations approaching 90° from directly away from the sun.

I dont see any way possible for it to go 'upstream' without outside help

By light pressure itself, a light sail ship could not. However, such a ship also has mass, so is accelerated by gravity, just as any massive object is. This is “outside help”, but of a kind not only available, but unavoidable.

A light sail ship may be made to accelerate toward the sun by reducing its angular velocity around the sun, placing it in a more elliptical “transfer” orbit. When this orbit approaches the desired distance from the sun, the sail is used to increase its angular velocity, placing it in a more circular orbit at that distance.

If the sail is used to reduce the ship’s angular velocity to zero, then turned or retracted to produce no acceleration, the ship will fall directly toward the sun.

Solar sail ships can take advantage of planets and moons for “gravity assist” acceleration, just as conventional rocket ships do.

The sail works because of the solar wind yes?

No.

In principle, such a sail could be designed, but to date, most solar sails designs don’t “catch” solar wind protons and heavier nuclei sufficiently to gain much force from them. Instead, they gain their force from the very slight “pressure” due to reflecting photons.

Analogies relating light sails in outer space to wind sails on boats floating of bodies of water on Earth are inexact. Light doesn’t flow in a laminar way over light sails, and there’s no equivalent of a sailboat’s hull an keel’s “grip” on the water. However, the best analogy I can think of is: light sail ship is to sail boat as light is to wind as gravity is to water pressure.

[Kayra]

Originally Posted by Jay-qu

ohh I understand now I can see many troubles with this design, one slight miscalculation and we are all fried!

That was the reason for sending the energy out from the sun in a 1 KM wide beam. Nothing so concentrated that it would cause problems.

The only danger is at the point of focusing the energy, and i suppose that might have it's risks.

Most events would likely cause the reflector to lose shape and no more concentrated sunshine.

The amount of power that I am beaming is ridiculously large for our needs as well. Might want to beam most of that to earth, and releay what is needed to the spaceship.


The 4 updraft towers should be able to generate a combined power of at least 400 Mghr of power.

[Jay-qu]

so how do you get around the fact that something in a closer orbit to the sun will have to orbit faster, so at times it will be inaccesible to our ship? multiple beaming towers?

[Kayra]

Originally Posted by Jay-qu

so how do you get around the fact that something in a closer orbit to the sun will have to orbit faster, so at times it will be inaccesible to our ship? multiple beaming towers?

Good question

Actually, there is very little inside the orbit of mercury (where I suggested the collector be placed)

Since the device is in a polar orbit, it can be set to always have an eyeball on the ship. (imagine looking at the sun, and seeing the collector circling around the outside edge of it.)

[Jay-qu]

ahh now that is a good idea eccentric orbit

as for the big scoop that collects particals from the vacuum of space - I hear the average particle density is 10^-3 particles per cm cubed, but this sounds wrong - because then even if you had a scoop of cross-sectional area of 100m^2, would only take in 9.6x10^-7 between here and pluto... am I missing something?

[GAHD]

You would need a minimum of 6 such satilites in opposite orbits (2 in each axis) if my geometry is up to par, depends on where you were in the other axies vs where it is the sun could obscure it. so 6 smaller ones where 3-4 could focus at oncewould seem to be a better system. They'd need a lot of refueling though.

[Kayra]

Originally Posted by GAHD

You would need a minimum of 6 such satilites in opposite orbits (2 in each axis) if my geometry is up to par, depends on where you were in the other axies vs where it is the sun could obscure it. so 6 smaller ones where 3-4 could focus at oncewould seem to be a better system. They'd need a lot of refueling though.

More headaches is it? (cracks a beer)

I was visualizing a single platform going from pole to pole in a non-eliptical orbit. The only time it would be obscured is if a planet (not the sun) was between it and the reciever.

Personally, I like the redundancy in multiple smaller systems though.

What would cause the high fuel load on the collector?