11 votes

Object slowest at periapsis - despite correct position calculation

If I understand correctly, your $p, q$ are essentially cartesian coordinates, and you're trying to get the velocity components in those two orthogonal directions. However, you're taking the derivative ...
uhoh's user avatar
  • 149k
10 votes
Accepted

In circle orbit, give a delta V to a satellite, how to find final orbit altitude?

To calculate how high your satellite will go, you forgot 1 major thing. The hohmann transfer. I am going to show you how to calculate the transfer from a 600 km circular orbit to another circular ...
The Rocket fan's user avatar
9 votes
Accepted

Object slowest at periapsis - despite correct position calculation

As uhoh said, the velocity is the derivative of the position w.r.t. to time, not true anomaly. I.e., if we denote time by $t$, the components of the velocity vector are $\left(\frac{dp}{dt}, \frac{dq}{...
Litho's user avatar
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9 votes

In circle orbit, give a delta V to a satellite, how to find final orbit altitude?

A single application of all of the allotted delta V will result in an elliptical orbit with a perigee equal to the original altitude. What you want to do instead is to apply a delta V at the start and ...
David Hammen's user avatar
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5 votes

In circle orbit, give a delta V to a satellite, how to find final orbit altitude?

In addition to the great answers you have already got, beware of what happens in the extreme case! The cost of a Hohmann transfer increases by altitude, but only up to a point. After that, the cost ...
SE - stop firing the good guys's user avatar
5 votes

Transform ECI to ECEF

I know this is a old/dead post but I essentially took on the same challenge and when I googled the answer I kept being brought here. I wanted to add some information here so anyone in the future who ...
Dylan's user avatar
  • 151
4 votes

In circle orbit, give a delta V to a satellite, how to find final orbit altitude?

Matlab's symbolic toolbox is very helpful to solve this problem. Below, I wrote expressions for $\Delta v$ from initial circular orbit to Hohmann transfer orbit and from Hohmann transfer orbit to ...
spaceguy1997's user avatar
3 votes

sun pointing coordinate system design

For a real mission, there would probably be more pointing constraints than just sun-pointing (likely for communication, thermal, or power reasons). However, for your purposes, you could do this: ...
Erin Anne's user avatar
  • 10k
2 votes

In circle orbit, give a delta V to a satellite, how to find final orbit altitude?

I used my Hohmann Spreadsheet inputting 600 km into periapsis for earth orbit and adjusting by trial and error the apoapsis for earth orbit. I look at the sum of the apoapsis and periapsis ...
HopDavid's user avatar
  • 15.6k
2 votes

sun pointing coordinate system design

To orient the ship to face the sun steadily, try the vector of the ship to the sun, and cross that with the velocity vector of the earth relative to the sun (not the ship relative to earth). ...
cubetronic's user avatar
1 vote

Using today's technology, is interstellar navigation possible?

Answer: Interstellar navigation is possible using today's technology. Interstellar navigation can use X-rayPulsar-based navigation, technology which has been demonstrated by XPNAV-1 spacecraft and ...
Woody's user avatar
  • 17.6k

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