Total space tools

[OneSpeed]

This might not be the best place for it, but I'd like to start a topic for tools that might help people make their own estimates for orbital mechanics in general. To kick it off, here is a simple Windows C# app (requires the .NET Framework 4) for the rocket equation, and another slightly more complex one for the vis-viva equation.

The rocket equation example is for a 1335t Starship in LEO, with a 185t final mass, and an Isp of 356. It calculates that the available ΔV is about 6,900 m/s.

The vis-viva program calculates the orbital velocity for a range of gravitational parents (Earth, Mars, the Sun etc.) and a defined apogee, perigee, and altitude. It can also calculate the ΔV required to circularise the orbit, as well as the cost of a plane change at that altitude, and finally the ΔV required for a burn that combines both. The example here is for a Starlink launch out of Boca Chica, to a 180 x 440 km orbit at 33° inclination, and then a combined plane change of 20° and circularisation to 440 x 440 kms. The total ΔV requirement calculated is 2,634 m/s.

[Nydoc]

I have a few browser-based space calculators bookmarked. Some are rather elementary but here they are.

NASA tools:
Trajectory Browser - https://trajbrowser.arc.nasa.gov/traj_browser.php
RocketModeler III Version 1.2h - https://www.grc.nasa.gov/WWW/K-12/rocket/rktsim.html

ESA tools:
Orbit Reconstruction, Simulation and Analysis (ORSA) - http://orsa.sourceforge.net/

Other tools:
Delta-V Calculator - http://www.strout.net/info/science/delta-v/
Kepler's 3rd Law Calculator - http://www.1728.org/kepler3a.htm
Escape Velocity and Surface Gravity Calculator - http://www.1728.org/escvel.htm
Lagrange Point Finder - http://orbitsimulator.com/formulas/LagrangePointFinder.html
Kinetic Energy Calculator - http://www.endmemo.com/physics/kineticenergy.php
Centrifugal Force Calculator - http://www.endmemo.com/physics/centriforce.php
Centripetal Acceleration Calculator - http://www.artificial-gravity.com/sw/SpinCalc/SpinCalc.htm
Launch Vehicle Performance Calculator - http://www.silverbirdastronautics.com/LVperform.html
Gravity Simulator (simulates solar system orbital mechanics) - http://www.orbitsimulator.com/gravity/articles/simu.html
Introductory physics - how to calculate specific impulse - http://www.qrg.northwestern.edu/projects/vss/docs/propulsion/3-how-you-calculate-specific-impulse.html