iss elements

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Real-time ISS Tracking in Orbiter

Realtime ISS

Real-time tracking

You can now use Orbiter to track the ISS realtime. Just download the scenario offered here, ISS Realtime track.scn. Then copy this scenario into your Orbiter scenario folder, then run the scenario and check ISS in the Atlantis map MFD. As long as you keep this scenario updated you shall find ISS right where the real one is in the sky this very moment. Be sure to come back here to get the latest ISS elements every so often.

The elements below are converted from NASA Two Line Elements
( TLE ) into Orbiter elements. NASA offers daily TLE for the ISS which are good for a few days to a couple weeks. The accuracy of the position prediction degrades as time goes by though. Therefore it is necessary for you update the elements and plug into the scenario for current ISS positions. Obviously you only need to do this when you care to.

Example for ***July 13, 2005 STS-114 Launch Date*** (not realtime)

NASA ISS TLE Vector Time (GMT): 2005/194/16:10:29.000
ELEMENTS 6732723.75466136 0.00029500 67.09874701 135.96619656 224.98658911 115.45918911 53564.66664349

Converted for Orbiter: ----------------------------------------------
Vector Time (GMT): 2005/198/16:10:29.000
ELEMENTS 6732428.87297400 0.00027420 60.56106069 119.31109333 219.98421855 93.18801855 53568.73625640

To update the ISS Realtime track.scn edit it in note pad by replacing the ELEMENTS line for ISS listed under the BEGIN_SHIPS section. Simple copy the complete ELEMENTS line from the OrbTrack.com website over your scenario ELEMENTS line. The Vector Time (GMT) is for your reference and is not needed in the scenario. However you may wish to paste it into the BEGIN_DESC section to keep tabs on how up to date your elements are. The OrbTrack.com website converts the TLE into Orbiter elements for you. It also provides the Orbiter elements for the Hubble Space Telescope.

Predictive tracking

You may set the scenario to open up at a particular launch time by adding the predicted date/time into the scenario. This is done by first converting the date/time you would like into Julian Date ( JD ) or Modified Julian Date ( MJD ) for Orbiter. Insert the JD or MJD into the scenario under the BEGIN_ENVIRONMENT section. As long as the date is within a few

days of the ELEMENTS Vector Time the ISS should be place at the proper location. Below is an example May 22.

BEGIN_ENVIRONMENT
System Sol
Date MJD 53512.7084338773
END_ENVIRONMENT

Converting TLE for Orbiter Yourself

You may convert your own ISS TLE for Orbiter as well as any other station or satellite you have the TLE for. Start by getting the Two Line Elements for any satellite at the celestrak website. Then use the TLE to Orbiter Converter tool by Alex Frost to get the elements converted into Orbiter format. Alex includes all the formulas with this tool in case you want to check the numbers for yourself. Also read the full explanation of Two-line Element Set Coordinate System by NASA. Lastly plug the converted elements into your Orbiter scenario for that station or satellite. Check your satellites for accuracy with ORBITRON - Satellite Tracking System by Sebastian Stoff a fine freeware product.

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