In addition to $\gamma$, the angle between the tangential direction and the velocity vector, there is $\beta$, the angle between the radial direction and the velocity vector. People often say "flight path angle" without saying which definition they're using. Confusing! (I just noticed that the diagram in Julio's answer also shows $\beta$)

2020年5月4日 · The flight path angle is simply the angle between the velocity vector and the vector perpendicular to the position vector. An easy way to visualise this: If the orbit was a circle, this angle would be zero. The angle is therefore due to the contribution of the inward/outward motion of the object away from the focal point.

There was really no difficulty in targeting the desired entry flight path angle, assuming that your thrusters were working. All of the Apollo lunar returns were within about a tenth of a degree of -6.5° (halfway between -5.3° and -7.7°), except for Apollo 13, which was within a quarter of a degree. $\endgroup$ –

2015年11月20日 · The flight path angle is always changing, whether you've hit the atmosphere or not, but there is only one entry flight-path angle per entry. For Apollo the entry interface was defined at 400,000 ft (about 122 km).

2022年10月29日 · the confusion arises because this is the inertial flight path angle (in Apollo documents "space-fixed" == "inertial") So sitting on the pad the vehicle in the "space-fixed" coordinates has a horizontal velocity of ~ half a km/s (due to the rotation of the Earth) and a flight path angle of 0.

2024年11月8日 · Listening to the "Think Like a Rocket Scientist" book by Ozan Varol, it is said that the angle during re-entry should be "just right" and that it could result in an overshoot where the craft bounces off the atmosphere or it burns into a crisp. I would like to know what the factors are in order to calculate the perfect re-entry angle in order ...

Invariably I end up with a final angle $\gamma$ (gamma) of about 39 degrees when checking the moment where C3 = 0, not 31 degrees. I'm doing a unitless calculation where GM = 1.0 and the period of an r=1.0 orbit is $2 \pi$.

2022年7月5日 · $\begingroup$ The angle of attack is the angle between the axis and air flow, for rockets this should always be almost zero. $\endgroup$ – GdD Commented Jul 5, 2022 at 9:01

Radial burns are usually not an efficient way of adjusting one's path - it is generally more effective to use prograde and retrograde burns. The maximum change in angle is always less than 90°; beyond this point the orbit would pass through the center of mass of the orbited body and the ship would traverse a slow spiral in towards the orbited ...

2020年1月20日 · Assuming that a defense system is capable of determining an object's flight path angle ($\gamma$), velocity (v), and radius (r), how could one differentiate between an ICBM, a satellite, or a solar probe? One could begin with the energy equation: $$\epsilon = \frac {v^2}{2} …