Why can the entire surface of the Earth be viewed with the help of a polar satellite?

$A$ satellite is orbiting just above the surface of a planet of density $\rho$ with a periodic time $T$. The quantity $T^2 \rho$ is equal to ($G=$ universal gravitational constant).

Consider a star of mass $m_2 \ kg$ revolving in a circular orbit around another star of mass $m_1 \ kg$ with $m_1 \gg m_2$. The heavier star slowly acquires mass from the lighter star at a constant rate of $\gamma \ kg/s$. In this transfer process,there is no other loss of mass. If the separation between the centers of the stars is $r$,then its relative rate of change $\frac{1}{r} \frac{dr}{dt} \ (\text{in } s^{-1})$ is given by:

The Sun revolves around the galaxy with a speed of $250 \, km/s$ and its radius is $3 \times 10^{4} \, \text{light years}$. The mass of the Milky Way is:

$A$ $10\; kg$ satellite circles Earth once every $2\; hours$ in an orbit having a radius of $8000\; km$. Assuming that Bohr's angular momentum postulate applies to satellites just as it does to an electron in the hydrogen atom, find the quantum number of the orbit of the satellite.

Does a satellite require fuel to orbit around the Earth?