Collision course trajectory / velocity

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SUMMARY

The discussion focuses on calculating the velocities required for an orbiting body to follow circular, parabolic, and hyperbolic trajectories around a massive body, utilizing the equations v_{circular} = √(μ/r) and v_{parabolic} = √(2μ/r). The user seeks assistance in determining the velocity necessary for a collision trajectory, emphasizing the need to incorporate the radius of the bodies involved. The challenge lies in adjusting the existing formulas to account for the physical dimensions of the bodies rather than treating them as point masses.

PREREQUISITES
  • Understanding of gravitational parameters, specifically gravitational constant (G) and mass (M).
  • Familiarity with orbital mechanics concepts, including circular, parabolic, and hyperbolic trajectories.
  • Knowledge of basic calculus for manipulating equations involving square roots and ratios.
  • Experience with astrodynamics, particularly in calculating orbital velocities and trajectories.
NEXT STEPS
  • Research how to modify existing orbital velocity equations to include body radii for collision calculations.
  • Study the concept of effective potential in orbital mechanics to understand collision trajectories.
  • Explore numerical simulation tools for modeling orbital dynamics, such as MATLAB or Python with SciPy.
  • Investigate the principles of impact parameter and its role in collision course calculations.
USEFUL FOR

Astronomy students, aerospace engineers, physicists, and anyone involved in orbital mechanics or astrodynamics who seeks to understand collision trajectories and velocity calculations.

CarlosMarti12
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Hello everyone!

I have calculated the velocities required for an orbiting body to follow a circular, parabolic, and hyperbolic trajectory around another massive body, which are the following:

v_{circular} = \sqrt{\frac{\mu}{r}} = \sqrt{\frac{GM}{r}}
Geostat.gif


v_{parabolic} = \sqrt{\frac{2\mu}{r}} = \sqrt{\frac{2GM}{r}} = v_{circular} \times \sqrt{2}
Parabolic_orbit.gif


v_{hyperbolic} > v_{parabolic}
Hyperbolic_orbit.gif


An article about the different orbital trajectories can be found here: http://en.wikibooks.org/wiki/Astrodynamics/Orbit_Basics

I am now trying to calculate the velocity required for an orbiting body to follow a trajectory that leads to a collision with the massive body. Of course, we would now have to factor in the radius of the objects, since we could previously consider them point masses to calculate their trajectories. But bodies have extension (in this case, spherical would be sufficient), and their extension must be taken into account to calculate collisions. So we must add the radius of the objects, r_{body} into the equation... somehow.

I have failed to find a way to do this based on the parameters shown above (gravitational constant, mass, distance, radii), though I highly expect I'm missing something (perhaps something obvious). Does anyone know how to calculate the velocity required for an orbiting body to enter a crash course trajectory with a massive body?

Any help, as always, would be greatly appreciated!
 
Astronomy news on Phys.org
Use your calculation to get the minimum distance from the center of the massive object. If it is less than the radius you have a collision.
 

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