What bothers me is I often read they are using the planet’s gravity to gain speed. Whatever speed an objet may gain while entering orbit should be lost when exiting it, right ?
So I guess it’s the cinetic energy of the planet that is actually fuelling the spacecraft, isn’t it ?
Whatever speed an objet may gain while entering orbit should be lost when exiting it, right ?
That is true from the frame of reference of the planet. From the frame of a 3rd distant object that you want to accelerate towards, it appears you have gained momentum.
So I guess it’s the cinetic energy of the planet that is actually fuelling the spacecraft, isn’t it ?
Yes, but the mechanism for ‘extracting’ the kinetic energy from the planet is by using ‘gravity’, hence the name, “Gravitational Slingshot”.
Yes. If the planet was stationary in space, it wouldn’t work. Approach from ‘behind’ the planet and you get a boost, approach from the ‘front’ and you hit the brakes.
What bothers me is I often read they are using the planet’s gravity to gain speed. Whatever speed an objet may gain while entering orbit should be lost when exiting it, right ? So I guess it’s the cinetic energy of the planet that is actually fuelling the spacecraft, isn’t it ?
That is true from the frame of reference of the planet. From the frame of a 3rd distant object that you want to accelerate towards, it appears you have gained momentum.
Yes, but the mechanism for ‘extracting’ the kinetic energy from the planet is by using ‘gravity’, hence the name, “Gravitational Slingshot”.
Yes. If the planet was stationary in space, it wouldn’t work. Approach from ‘behind’ the planet and you get a boost, approach from the ‘front’ and you hit the brakes.