What is an apse line?

Minor axis

Imaginary line connecting the apsides of circular orbit

Imaginary line connecting the apsides of ellipse

Line tracing the direction of movement of satellite in the orbit

Correct Answer : Imaginary line connecting the apsides of ellipse

Explanation : Apse line is the imaginary line that connects the two extreme apside points in the orbit. It is only defined for elliptic parabolic or hyperbolic orbits as the circular orbit has an eccentricity of 0. For the Non-Hohmann transfer, the two orbits share a common apse line.

Recently Updated in Spaceflight Mechanics Questions

Where does the smallest possible transfer ellipse occur for a Hohmann transfer?

Equator

Only apogee of the final orbit

Only perigee of the final orbit

Perigee and apogee of the final orbit

Correct Answer : Option (D) : Perigee and apogee of the final orbit

Explanation : When there is a Hohmann transfer, the smallest possible transfer ellipse occurs when the transfer takes place at either apogee of perigee of the final orbit which is at a point opposite to the terminating point.

When both initial and final orbits are circular, what is the maneuver known as?

Chase maneuver

Bi- elliptic transfer

Hohmann transfer

Phasing maneuver

Correct Answer : Option (C) : Hohmann transfer

Explanation : When the initial and final orbits are circular, the optimal maneuver is called a Hohmann transfer. This transfer consists of two tangential velocity impulses which I applied at the initial and final radius.

In which case is the minimum velocity impulse achieved for coplanar maneuver?

When impulse is applied radially

When impulse is applied at 45 deg

When impulse is applied tangential

When impulse is applied perpendicularly

Correct Answer : Option (C) : When impulse is applied tangential

Explanation : For a coplanar maneuver, multi-impulse maneuver is very efficient. The minimum velocity impulse is achieved when the impulse is applied in the same direction of initial and final velocity vector. This is known as tangential impulse.