Putting Challenger Back in Orbit with Starry Night

Challenger as seen in Starry Night
Challenger, as depicted in Starry Night Pro 6.4.3 [full size]

For the past dozen years or so, on each anniversary of the Challenger accident, I've been putting the space shuttle Challenger back in orbit, using my desktop planetarium program, Starry Night. It's sort of been my own personal tribute and remembrance of Challenger and her crew.

Starry Night makes this easy to do this by letting users add satellites and spacecraft to its database. All that is needed is a photograph of the spacecraft (well, one that can be given a transparent background for the current version of Starry Night -- I use Photoshop for that). Fortunately, there are photos of Challenger taken while in orbit that can be used for this. During the STS-7 mission in 1983, Challenger was photographed by the SPAS-01 satellite, deployed from her cargo bay and later retrieved. Once you have a usable image, next you need a two-line orbital element set (TLE) to actually put the satellite or spacecraft in orbit -- two strings of numbers that describe its orbit -- that Starry Night will use to plot its position in the sky at any given time.

What I wanted to use for my tribute, however, was the TLE for what should have been Challenger's first orbit during mission 51-L. Since it was not available anywhere online, that wasn't going to be easy. However, with the help of some friends far more knowledgeable about orbits than I, we came up with a TLE giving a pretty good approximation of what would have been Challenger's first orbit during 51-L. It was adapted from the TLE for the first orbit of STS-29, which carried and deployed the replacement TDRS satellite lost in the Challenger accident, as well as a generic TDRS mission first orbit. I wish I could remember all those who helped me so I could properly credit them here. [I suspect Dr. T. S. Kelso (@TSKelso on Twitter) of Celestrak.com was the source of the orbit-1 TLE from STS-29.]

I had shared all this with other owners of Starry Night at the time on my AOL FTP but, sadly, AOL deleted all it's members' web pages a few years ago. With this being the 25th anniversary of the Challenger accident, it's time to remedy that. If any of you have Starry Night or a similar planetarium program (I hope these work for other programs) and would like to add Challenger to it's skies on January 28 yourselves, as I will be doing, here is the image I'm currently using:

Challenger.png
Download full-size: Challenger.png
[If this PNG does not work for you, here's an image of
Challenger
taken during STS-7 you can use to create your own.]



And here is the Challenger 51-L orbit-1 TLE:

Challenger 51-L
1 12886 860051-L 86 28.68110000 .00000516 00000 1 74863-6 0 15
2 12886 28.4602 212.0000 0007712 248.6964 111.2824 15.91256639 06



Finally, here is my saved Starry Night Pro file, for those who have Starry Night and would like download that, too, set up to start as in the YouTube animation, below. However, I don't know if it will work for everyone:

Challenger_Jan_28_1986.snf.zip


For those who don't have Starry Night, the clip below shows my "virtual" Challenger in orbit, using the TLE above, racing to meet-up with the point where 51-L would have had main engine cutoff during its ascent. It begins the moment 51-L was launched, with Starry Night set to 11:38:00 AM, EST (16:38:00 UT), on January 28, 1986. It reaches the point of MECO at end of the animation, where, if I let it Starry Night continue running, it would begin what should have been Challenger 51-L's orbit-1. The time of the animation is 17X normal (to reduce the size of the file uploaded to YouTube). It runs about 31 seconds but roughly 8 minutes, 30 seconds actually elapses.




For the next 90 minutes following where this animation ends, Starry Night will follow the Challenger 51-L orbit-1 path in real time, passing over the very same oceans, continents, islands and cities Challenger should have on that fateful day twenty-five years ago.

Jim Cook