# Orbits -- radial verses perpendicular orbits & energy

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• Albertgauss
In summary, if a spacecraft wants to thrust perpendicular to the orbital solar system plane, it would require more energy than flying only in the orbital solar system plane. If the spacecraft does thrust perpendicular to the orbital solar system plane, the sun's gravity will try to bring the ship back into the orbital solar system plane.

#### Albertgauss

Gold Member
Does anyone know where I can find information about how to calculate how much extra energy is required of a spaceship to try to thrust perpendicular (or at some angle) to the orbital plane verses flying completely/only in the orbital plane when moving outwards in our solar system? If the spaceship does thrust perpendicular to the orbital solar system plane, will the sun's gravity try to bring the ship back into the orbital plane?

Albertgauss said:
Does anyone know where I can find information about how to calculate how much extra energy is required of a spaceship to try to thrust perpendicular (or at some angle) to the orbital plane verses flying completely/only in the orbital plane when moving outwards in our solar system? If the spaceship does thrust perpendicular to the orbital solar system plane, will the sun's gravity try to bring the ship back into the orbital plane?
No, gravity is symmetrical in all directions. The only reason that it would be easier to travel along the orbital plane is because your launch point is also traveling along that plane so you already have some momentum. It's the same reason that all launches happen as close to the equator as possible and always go in the same direction that the Earth is rotating.

Once in orbit, you should not require any fuel no matter how you are oriented in regards to the solar system.

The planets are all in a plane because they formed from a spinning blob of dust that formed the sun 4.6 billion years ago. The self-interaction of that gas cloud and spinning motion of it formed it into a disk. Much further out, objects orbit in all lots of different obits. The Oort cloud is theoretically spherical.

Oh, I see. Just a check on my logic: Thus, if there was a satellite or comet orbiting at an oblique angle with respect to the orbital plane for some reason and no space gas, the satellite or comet should then stay in that orbit. Is this correct?

Albertgauss said:
Oh, I see. Just a check on my logic: Thus, if there was a satellite or comet orbiting at an oblique angle with respect to the orbital plane for some reason and no space gas, the satellite or comet should then stay in that orbit. Is this correct?
For all practical purposes: yes. Once in orbit, it will stay there. There are some known comets that have orbits like that.

If it's in the solar system, the gravity of Jupiter (and the rest of the planets to a less degree) will pull anything towards the plane of the planets, but it'd have to be out there for millions of years to be noticeable.

Albertgauss said:
Does anyone know where I can find information about how to calculate how much extra energy is required of a spaceship to try to thrust perpendicular (or at some angle) to the orbital plane verses flying completely/only in the orbital plane when moving outwards in our solar system? If the spaceship does thrust perpendicular to the orbital solar system plane, will the sun's gravity try to bring the ship back into the orbital plane?
If by "orbital plane" you mean the Sun's equatorial plane, Then you should be made aware of the fact that none of the planets actually orbit exactly in that plane. Mercury orbits closest to this plane. The ecliptic, or the Earth's orbital plane, is tilted by some 7.25 degree to the Sun's equatorial plane. Relative to the ecliptic the other planets have inclinations that vary from 0.77 to 3.39 degrees (Pluto's orbit is at 17.15 degrees to the ecliptic.) The main body of the asteroid belt includes objects with as much as 30 degree inclinations.

Okay, I got it. Thanks for your help everyone. I'm good to go now.

## 1. What are radial and perpendicular orbits?

Radial and perpendicular orbits refer to the path or trajectory that an object takes around another object in space. In a radial orbit, the object moves in a straight line towards or away from the center object. In a perpendicular orbit, the object moves at a right angle to the center object.

## 2. What determines the type of orbit an object takes?

The type of orbit an object takes is determined by the initial velocity and direction of the object, as well as the gravitational pull of the center object. If the initial velocity is perpendicular to the center object, the orbit will be perpendicular. If the initial velocity is directed towards the center object, the orbit will be radial.

## 3. How do radial and perpendicular orbits differ in terms of energy?

In a radial orbit, the object's kinetic and potential energy will vary throughout its orbit, with the highest energy at the closest point to the center object. In a perpendicular orbit, the object's kinetic and potential energy will remain constant throughout its orbit.

## 4. Which type of orbit requires more energy?

Perpendicular orbits require more energy than radial orbits. This is because in a perpendicular orbit, the object must constantly change direction and overcome the gravitational pull of the center object, resulting in a higher energy requirement.

## 5. Can an object change from a radial to a perpendicular orbit?

Yes, an object can change from a radial to a perpendicular orbit, or vice versa. This can occur through the influence of other objects or forces, such as gravitational interactions with other celestial bodies or the application of external forces such as thrust from a spacecraft's engines.