Is it possible at all to go faster in an orbit around the earth?

In summary, there are several methods for moving around the Earth faster, including applying radial thrust or changing the orbit to a lower altitude. However, these methods may not always be practical due to fuel and energy constraints. Ultimately, any maneuver will require a burn and the most efficient way to travel in space is still through orbital mechanics.
  • #1
vjk2
90
0
My understanding is that generally with space flight, when you accelerate in the direction of orbit, you don't go around the Earth any faster but instead ascend to a higher orbital plane, which arguably has a longer period of orbit.

Is there any manuver method that let's you move around the Earth faster?
 
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  • #2
You can apply radial thrust as well.
 
  • #3
Accelerate in the opposite direction of motion. That reduces the size of the orbit and the satellite takes less time to orbit the Earth.

That's an almost intentionally confusing way to look at things, though.

You either add energy to the orbit, making it bigger and increasing the time it takes to complete an orbit ... or you subtract energy from the orbit, making it smaller and decreasing the amount of time it takes to complete an orbit.

Until transporters are invented allowing us to say, "Beam me up, Scotty!", kinetic energy is the only type of energy we can add or subtract - and that's what you're really doing: adding or subtracting kinetic energy.

When the energy is subtracted, and the orbit gets smaller, the potential energy is less. Some is gone because you subtracted energy from the orbit and some of it is converted to kinetic energy. So, while the speed of the spacecraft may have increased, it lost more potential energy than it gained in kinetic energy.

And just the reverse when you add energy to the orbit. Some of the kinetic energy is converted to potential energy, plus you've added energy. The speed winds up decreasing, but it gained more potential energy than it lost in kinetic energy.
 
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  • #4
Simon Bridge said:
You can apply radial thrust as well.
This. If thrust and fuel is not an issue, you can ignore orbital mechanics and just head to any position you like. In (current) space travel, thrust and fuel are relevant, so you have to look for cheap transitions between orbits. In that case, the quickest way to go around Earth is the lowest possible orbit, at a height of ~200km (everything below that quickly falls down to Earth due to friction).
 
  • #5
Oh, of course. Yes, you should be able to just ignore it all and use thrust to go fast. It would be tremendously expensive though.
 
  • #6
The question, as stated, does allow that [radial thrust] as a serious answer.
Indeed, the preamble to the question appears to suggest that an orbit-radius change is not desired: OP knows about that but wants another way. The only other way is radial thrust (or finding a new law of physics).

But the question could be more closely defined than that - if the object, for example, is to end up at the same spot after going around the Earth exactly once by the fastest route then ... changing to an elliptical orbit? Everything will require a burn. As mentioned, manouvers are usually strongly constrained by energy availability.

Oh I suppose you could make your vessel dumbell shaped and spinning so that each end will spend part of the orbit faster and part slower... I don't think that's what is meant either somehow :D

I can only think of similarly "throwaway" answers :/
 

FAQ: Is it possible at all to go faster in an orbit around the earth?

1. Is it possible for an object to go faster than the speed of light in an orbit around the Earth?

No, it is not possible for an object to exceed the speed of light in any scenario, including in an orbit around the Earth. This is due to the laws of physics, specifically Einstein's theory of relativity.

2. What is the maximum speed an object can achieve in an orbit around the Earth?

The maximum speed an object can achieve in an orbit around the Earth is known as the orbital velocity. This velocity is dependent on the altitude of the orbit and the mass of the Earth, and is typically around 7.8 kilometers per second.

3. Can an object increase its speed while in orbit around the Earth?

Yes, an object in orbit can increase its speed by using external forces, such as a rocket engine, to propel itself. However, this increase in speed must be carefully calculated to maintain a stable orbit and avoid crashing into the Earth's atmosphere.

4. How does the Earth's gravity affect the speed of an object in orbit?

The Earth's gravity is the primary force that keeps an object in orbit. As the object moves faster, the pull of gravity keeps it from flying off into space. However, if the object's speed becomes too great, it can escape the Earth's gravity and leave orbit.

5. Is there a limit to how fast an object can travel in an orbit around the Earth?

Yes, there is a limit to how fast an object can travel in an orbit around the Earth. This limit is determined by the orbital velocity, as well as other factors such as the strength of the object's propulsion system and the friction of the Earth's atmosphere. Overall, it is not possible for an object to continuously increase its speed in orbit without external forces.

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