Who decides the upward direction in an artificial satellite?

Two satellites of masses $m$ and $3\,m$ revolve around the earth in circular orbits of radii $r$ and $3r$ respectively. The ratio of orbital speeds of the satellites respectively is:

$A$ satellite of mass $M$ is revolving in a circular orbit of radius $r$ around the Earth. The time period of revolution of the satellite is:

$A$ satellite of mass $m$ is revolving around the Earth of mass $M$ in an orbit of radius $r$. The angular momentum of the satellite about the centre of the orbit will be:

$A$ satellite of the earth is revolving in a circular orbit with a uniform velocity $V$. If the gravitational force suddenly disappears,the satellite will

An artificial satellite is moving around the Earth in a circular orbit with a speed equal to one-fourth the escape speed of a body from the surface of the Earth. The height of the satellite above the Earth's surface is ............ ($R$ is the radius of the Earth). (in $R$)