Suppose a nut becomes loose and gets detached from a satellite

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Discussion Overview

The discussion revolves around the scenario of a nut detaching from a satellite in low Earth orbit and explores how an astronaut might influence its trajectory to land on Earth. The conversation includes considerations of orbital mechanics, drag effects, and methods of altering the nut's velocity vector.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant suggests that the nut will continue in its orbit due to inertia and questions how an astronaut could make it land on Earth.
  • Another participant argues that the nut cannot be made to land on Earth as it will experience significant drag relative to its mass, likely resulting in it burning up in the atmosphere after falling from low Earth orbit.
  • It is noted that drag is dependent on altitude and air density, and changing the nut's velocity vector toward Earth is necessary for it to descend.
  • A question is raised about the effectiveness of throwing the nut toward Earth to change its trajectory, with uncertainty expressed about whether it would continue to follow its orbital path.
  • One participant proposes that throwing the nut down or behind the astronaut could alter its orbit, leading to a potential crash into Earth.
  • Another participant suggests that the optimal method to deorbit the nut would be to throw it opposite to its orbital direction, although practical limitations of such an action are acknowledged. They explain that canceling the nut's orbital velocity would result in a straight descent, while partial cancellation would lead to a lower orbit.
  • It is mentioned that throwing the nut behind the astronaut would maximize energy loss and minimize the distance of closest approach to Earth.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of making the nut land on Earth, with some asserting it is impossible while others discuss methods to influence its trajectory. The discussion remains unresolved regarding the effectiveness of various proposed methods.

Contextual Notes

Participants highlight the complexities of orbital mechanics and the influence of drag, indicating that assumptions about the nut's behavior depend on its initial conditions and the astronaut's actions.

zorro
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Suppose a nut becomes loose and gets detached from a satellite revolving around the earth.
The nut will continue in its orbit due to its inertia. My question is how can an astronaut make it land on earth?
 
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An astronaut can't make the nut land on earth. Because such a small object will have a much greater drag compared to its mass, the nut will likely fall back from low Earth orbit in weeks, but will then burn up in the upper atmosphere.
 


Drag depends on altitude, i.e. air density. To make a nut fall to earth, change its velocity vector to point toward earth.
 


How can we change its velocity vector towards earth? If the astronaut throws the nail towards earth, will it land on earth? Or after leaving the satellite, it again follows the orbit due to inertia?
 


Throw it either down or behind him.

Small disturbances will change the orbit radius, until ultimately it will crash into the earth.
 


The best way to deorbit the nut is to throw it opposite the orbital direction - though in practice one couldn't throw it enough, one would instead perform a de-orbital burn.

IF one totally canceled out the orbital velocity of the nut, it'd fall straight down. Without a total cancellation, it'll still enter a lower orbit.

If you restrict yourself to actually "throwing" the nut, you probably won't make a huge difference in its orbit no matter what you do, but you'll maximize the energy loss and minimize the distance of closest approach to the Earth by throwing it behind you, against the direction of orbital motion.
 

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