Space station - tension of the structure

AI Thread Summary
The discussion focuses on calculating the tension experienced by a space station in low Earth orbit, which has a length L and uniformly distributed mass M. The tension is derived from the weight of the mass at the bottom of the station, with the equation f = M R / 2 g L representing the tension based on the station's dimensions and gravitational effects. The contributor also notes that differential thermal expansion between the sunlit and shaded sides of the station could significantly impact structural integrity, potentially more than gravitational differences. The calculations suggest a specific relationship between the station's length, mass, and the forces acting on it. Overall, the tension analysis highlights the complexities of structural dynamics in space environments.
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There is a space station of the length L and uniformly distributed mass M on the low Earth orbit. One side of it always faces the Sun. Which tension will the structure experience?

long_space_station.png


My attempt of the solution: bottom of the station is L/2 meters below the stable orbit at that velocity. Therefore, the mass of the bottom of the station has some weight. In fact, any small mass m at the bottom of the station will weight:

(L/2) / R = m / fg

where:
L - length of space station
m - test mass
R - orbit radius
f - tension or weight
g – acceleration of free fall at the height of the orbit

m is one quarter of total space station weight. Proof: the bottom half of the station has mass M/2. The weight of an object at the height of L/4 will be half of those at the bottom of the station. Therefore, weight M/2, uniformly distributed over bottom half of the station, is equivalent to M/4 at the bottom of the station (in regards to tension).

After solving the equation, I have got:

(L/2) / R = M / 4fg
L / 2R = M / 4fg
L / R = M / 2fg
f = M R / 2 g L


Right or wrong?
 
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In reality I would have thought the differential thermal expansion between the hot and cold side would be more than the gravitational field difference.
 
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