I would like to know how many satellites are physically able to be in place, at the same time, orbiting the earth. Lets ignore which Nations need or use the most satellites (area in space above them) and assume an even distribution. My understanding is each satellite is inline with a degree on earth (longitude), but there are only 180 of these. Would you then be able to line up satellites on each degree of latitude for each degree of longitude? So 180 x 180 = 32400? Or is there more to this? Could you put a satellite either further or nearer to the earth so they would almost overlap to make room for more?
[Physics] the limit to how many satellites can orbit the earth
orbital-motionsatellitesspace
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Best Answer
This is actually quite a complex problem. At large numbers of satellites, gravitational effects need to be considered. A real answer would need values such as 'every satellite has the same mass and volume' etc. Basically you can keep adding satellites until Earth becomes a black hole. Satellites are very dense since they have lots of metal (which is a dense material) In my opinion, a great 'answer' to this question would be a fun computer simulation.
If we just use the values given by Phil H, we fit in satellites between 2000 km and 35786 km altitudes. $R_E$, the radius of the Earth is 6371km. So we calculate the volume: $V_{total}=\frac{4}{3} \pi [(d_2+R_E)^3-(d_1+R_E)^3]=\frac{4}{3}\pi (42157^3-8371^3)=9.341\times10^{14}\,\text{km}^3$
We assume that all the satellites have mass of $m_s = 800\,\text{kg}$ (note that this is a 'fantasy' problem so we don't really need to follow real world statistics) and volume $V_s=4.8 \,\text{m} \times 4.8 \,\text{m} \times 5.5 \,\text{m} = 1.267 \times 10^{-7} \, \text{km}^3$
Thus, the total mass of the orbiting satellites will be $M_{total} = \frac{m_s}{V_s} V_{total}= 5.90 \times 10^{24}\,\text{kg}$
Now let's compare that to the mass of the Earth, $M_E=5.97\times 10^{24} \,\text{kg}$.
Notice how $M_{total} \approx M_E$, though this is just due to some values which we chose and does not arise from some values which arise from nature.