MyRTLE is a TLE browser application written in Go. Years ago, I created its sloppy predecessor while learning programming. I have decided to rewrite it from scratch according to my current knowledge of both the orbital mechanics and programming.

This application uses CelesTrack as the source of data and calculates all of the orbital elements from the downloaded set. Its command line interface uses the pterm module. Requires Go v1.19 or newer.

Two-Line Element set is a data format that contains the most essential parameters describing the position and motion of a satellite in orbit around Earth. Every set consists of three lines, the first of which is a title line. The next two hold the basic orbital elements of a body at a given moment in time (epoch).

Example TLE set for the International Space Station:

ISS (ZARYA)             
1 25544U 98067A   22014.20078024 -.00001581  00000+0 -20061-4 0  9991
2 25544  51.6452  19.1428 0006828  17.5887  10.3753 15.49476744321309

This information allows us to calculate the exact position and velocity of a body as well as predict changes due to various object-specific forces, such as atmospheric drag.

Orbital elements symbols and the display format mimic those seen on Orbit MFD in Orbiter Space Flight Simulator.

SMa    -  Semi-Major Axis
SMi    -  Semi-Minor Axis
PeR/A  -  Periapsis Radius/Altitude ASL
ApR/A  -  Apoapsis Radius/Altitude ASL
R/Alt  -  Radius/Altitude ASL
Ecc    -  Orbital Eccentricity
T      -  Orbital Period
PeT    -  Time to Periapsis
ApT    -  Time to Apoapsis
Vel    -  Orbital Velocity
Inc    -  Orbital Inclination
LAN    -  Longitude of Ascending Node
LPe    -  Longitude of Periapsis
AgP    -  Argument of Periapsis
TrA    -  True Anomaly
TrL    -  True Longitude
MnA    -  Mean Anomaly
MnL    -  Mean Longitude
EcA    -  Eccentric Anomaly

If ! appears by the eccentric anomaly's symbol it means that solution for Kepler's equation did not converge.

I would encourage users to build the application themselves. I have provided the scripts to do so. However, zipped releases are available. If you choose to use them, download the right one for your system and unpack it anywhere.

There are 4 commands that control the behavior of application:

• /b - go back to the previous page
• /e - exit application
• /f - go forward to the next page
• /h - display the list of commands and symbols

Search accepts the query phrase at least 3 characters in length and the following arguments:

• /c - search by object's catalogue number
• /n - search by object's name (default)

These commands format the values of orbital elements and can be passed when making a query:

• /a - display distance as altitude ASL
• /r - display distance as radius from the center of the dominant body (default)
• /p - display precise values
• /s - display shortened values (default)

The results page displays 20 found matches at a time. To skip to the next 20, use these commands:

• />[n] - go forward by n subpages
• /<[n] - go back by n subpages

1. Kelso, T., S. 1985. CelesTrak. [on-line] Available at https://celestrak.com [accessed on 15.01.2022] COMSPOC Corp. Exton, PA.

2. Kelso, T., S. 2019. Frequently Asked Questions: Two-Line Element Set Format. CelesTrak. [on-line] Available at http:https://celestrak.com/columns/v04n03/ [accessed on 15.01.2022] COMSPOC Corp. Exton, PA.

3. Murison, M., A. 2006. A Practical Method for Solving the Kepler Equation. [on-line] Available at http:https://murison.alpheratz.net/dynamics/twobody/KeplerIterations_summary.pdf [accessed on 15.01.2022] U.S. Naval Observatory, Washington, DC.

4. Pterm by Martin Wendt

5. Orbiter Space Flight Simulator by Martin Schweiger

This software is available under MIT License.