3k views

### How close would the Tesla Roadster with Starman have to get to Earth in order to become attracted and fall on Earth?

In 2091 the Tesla Roadster is said to maybe get closer to Earth than the Moon is. At Starman's current speed, would its location in 2091 be sufficient for the Earth to re-attract the Starman to let it ...
574 views

### Can Keplerian elements from TLEs be used without SGP?

Are orbital elements in TLEs valid at the epoch? I want to predict an orbit without SGP, but I need some initial orbital conditions.
2k views

### TLE data conversion to osculating orbit elements [closed]

I got the latest TLE from www.celestrak.com for a satellite. How could I convert it to osculating elements? Please, share some links/references.
756 views

### Recreating the eccentricity value of TLE

I cannot confirm the eccentricity value of a TLE using corresponding position and velocity vectors. Let me go through an example, ISS, to explain the situation. Using this TLE for ISS, 1 25544U ...
1k views

### Keplerian Orbital Elements ↔ Cartesian ECEI with WGS84 Corrections

I'm trying to write code to go back and forth between equatorial KOE (Keplerian Orbital Elements) and ECEI (Cartesian). ECEI→KOE I found here: How to programmatically calculate orbital elements ...
491 views

### Orbit Maneuvering

I am working on a project of simulating orbit maneuvering. I have interfaced SGP4 with my current simulation code, however I realized that the orbit maneuvering cannot be done using SGP4. I am aware ...
700 views

### From osculating to mean equinoctial elements and back

I'm struggling with orbital elements... I'm trying, at the same time as finding a clear definition to them, to write a piece of code to switch from osculator elements to mean equinoctial elements. I'...
192 views

### Why does the eccentricity of Venus's (and other) orbits as reported by Horizons vary based on the frame origin and basis?

I did try to think this through before posting, but I am going to need some explanation. In my (perhaps naïve) view, an ellipse will have the same eccentricity no matter what frame it is in. In ...