Which of these assumptions are not employed for using patched�conic approximation for a selenocentric orbit?

The Earth is fixed in space

The Moon is fixed in space

The eccentricity of the Moon orbit around the Earth is neglected

The flight of the space vehicle takes place in the Moon orbital plane

Correct Answer : The Moon is fixed in space

Explanation : There are various assumptions employed for using patched–conic approximation for a selenocentric orbit. Out of these, the assumption that is invalid is that the moon is not fixed in space.

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What kind of trajectory is obtained if the satellite is launched from a place whose latitude is 30 deg

Arc trajectory

Co-axial trajectory

Coplanar trajectory

Non-coplanar trajectory

Correct Answer : Option (D) : Non-coplanar trajectory

Explanation : Coplanar trajectory only occurs when the launch is at a suitable condition where launch latitude matches the moon’s orbital inclination. This is a rare condition which occurs only at Cape Kennedy whose latitude for launch is 28.5 deg. When launches are done at any other location or when the suitable conditions is not met, it results in non-coplanar trajectory.

Which of these is not a constraint on lunar trajectories?

Phase of the moon

Accuracy tolerance

Launch site location

Rotation speed of the earth

Correct Answer : Option (D) : Rotation speed of the earth

Explanation : There are several constraints which carrying out lunar missions. These include-launch site location, accuracy tolerance, limited range of injection conditions, phase of the moon determining the lighting condition, direction of launch from a site.

What is the right ascension of launch point equal to?

Synodic time

Local sidereal time

East longitude

Greenwich sidereal time

Correct Answer : Option (B) : Local sidereal time