How is the free-flight sweep angle computed?

Sum of true anomaly between injection and lunar intercept

Product of true anomaly between injection and lunar intercept

Difference between true anomaly between injection and lunar intercept

Square of difference between true anomaly between injection and lunar intercept

Correct Answer : Difference between true anomaly between injection and lunar intercept

Explanation : We know that the geocentric angular travel ψc is arbitrarily chosen whereas free-flight ψff is selected based on the initial injection conditions. This free-flight is just difference between true anomaly between injection and lunar intercept.

Recently Updated in Spaceflight Mechanics Questions

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