In which of these orbits is the Global Positioning System situated?

Low Earth Orbit

High Earth Orbit

Medium Earth Orbit

Equatorial Low Earth Orbit

Correct Answer : Medium Earth Orbit

Explanation : GPS is placed at an altitude of 20,200 km which is the medium-earth orbit. The orbital time-period of GPS is about 12 hours. Most of the navigation satellites are placed in the medium- earth orbit.

Recently Updated in Spaceflight Mechanics Questions

Which of these is not a type of an impulsive maneuver?

Energy change

Simple plane change

Adjustment of perigee and apogee height

Combined change of apsis altitude and plane orientation

Correct Answer : Option (A) : Energy change

Explanation : There are four types of single impulse maneuver-Adjustment of perigee and apogee height, simple rotation of the line of apsides, simple plane change and combined change of apsis altitude with plane orientation. There is no change in energy involved by applying single impulse.

What does non- impulsive maneuver mean?

Rockets with instantaneous bursts

Rocket fire short bursts for required delta-v

Maneuvers which are analyzed by Lambert�s equation

Rocket fires long bursts for long time for the required delta-v

Correct Answer : Option (D) : Rocket fires long bursts for long time for the required delta-v

Explanation : When the thrust applied by the rocket is done over a longer period to obtain the required delta-v, it is known as the non-impulsive maneuver. Unlike impulsive maneuver it does not involve applying impulse over a short period.

When the change in velocity represents a change in direction, what kind of maneuver is it called?

Pumping maneuver

Orbital raising maneuver

Cranking maneuver

Orbital lowering maneuver

Correct Answer : Option (C) : Cranking maneuver

Explanation : Each impulsive maneuver results in a velocity change of the spacecraft. This velocity change yield both magnitude and direction change of the velocity vector. When Δv represents a change in direction it is referred as a cranking maneuver.