Using the Suns gravity for propulsion

[Scaledriver]

Is it possible to use the sun to slingshot vehicles in order to achieve higher velocities?

 

[Orodruin]

Higher velocities relative to what? And starting from what?

 

[Scaledriver]

Higher velocities relative to what? And starting from what?

Relative to the Suns position starting from earth.

 

[Orodruin]

You can never do a slingshot relative to an astronomical body itself. The entire idea behind a slingshot is that the relative velocity between the slingshotting object and the slingshotted object is maintained (after the objects have become well separated). You can do slingshots using planets because they are moving relative to the Sun.

 

[Scaledriver]

I was curious if a parabolic course through the Suns gravity would produce any increase of velocity.

 

[Orodruin]

It does, of course, increase the velocity close to the Sun, but this has to do with how gravity works and the loss of potential energy, not with slingshotting. By conservation of energy (and ignoring other astronomical bodies) you will have the same velocity as your original velocity when you reach the radius you started at.

 

[Scaledriver]

The Earth is moving very fast relative to the sun. So initial velocity is high. Why can't that be used as a base to then vector off the Suns gravity and change that potential to a chosen vector?

 

[Scaledriver]

The Earth gives us the speed, the sun can be used to change the direction of the velocity.

 

[Orodruin]

Why can't that be used as a base to then vector off the Suns gravity and change that potential to a chosen vector?

It is unclear what you mean by this. Yes, the initial velocity relative to the Sun is high. It will still be high when something (like the Earth) returns to the same radius, but it is not a slingshot effect. The slingshot effect is using a large moving object to increase the velocity of a smaller object relative to the frame in which the large object is moving.

 

[Scaledriver]

I apologize I can envision this I just need to run some computer modeling to see the effects.

Thank you for your input.

 

[Drakkith]

If you haven't already, you should read this article: http://en.wikipedia.org/wiki/Gravity_assist

 

[Scaledriver]

If you haven't already, you should read this article: http://en.wikipedia.org/wiki/Gravity_assist

I have and its applicable.

 

[Scaledriver]

Compiling and running simulation. I'll let you know if it works.

 

[Scaledriver]

The "ship". Doesn't even need to have very much propulsion. Most is used for course correction. Human pilot is going to be needed though rf signals wouldn't be able to reach the area I'm going.

 

[Scaledriver]

This changes all my theories. Using this new data I can build a fully electric space vehicle. Solar powered.

 

[Scaledriver]

This changes all my theories. Using this new data I can build a fully electric space vehicle. Solar powered.

And, because you can also use the rotation of the Earth in the same manner I can take off from Earth and circle the sun and land again. if the craft is light enough. Which is possible with the current materials.

 

[Scaledriver]

six months with no gravity would be an issue. Need to recalculate.

 

[Orodruin]

Please note that Physics Forums is not a place for personal theories. The original question has been answered and the answer is "no". This thread is therefore closed.