Linked Questions

19 votes
6 answers
9k views

What artificial satellite has the farthest orbit around the Earth?

What is the furthest Earth orbiting satellite? What is its speed and purpose?
  • 1
13 votes
4 answers
16k views

How to obtain UTC of the epoch time in a satellite TLE (two line element)?

I want to convert the epoch time of a TLE to UTC. At this moment I am less interested in explanations and history - I just want to know quantitatively, with certainty, how to convert. I'm confused ...
  • 148k
9 votes
4 answers
1k views

Is there a database for space junk beyond Earth orbit, and is Roadster in it?

After a bit of low drama I've come to accept that Roadster is space junk and agree with this answer. After reading this answer about space junk in orbit around Earth, I'd like to ask if there is a ...
  • 148k
4 votes
2 answers
1k views

Why has no TLE been published for the DSCOVR satellite and the Falcon 9 R/B?

So, usually a few days after every launch, I go out and check out the published TLE data for each satellite, made public courtesy of CelesTrak. It generally includes all the orbital parameters for ...
  • 8,715
6 votes
2 answers
2k views

Differences between SGP8 and the standard SGP4? Is it ever used in practice?

The Wikipedia article Two Line Element Set says: The SGP4 model was later extended with corrections for deep space objects, creating SDP4, which used the same TLE input data. Over the years a number ...
  • 148k
4 votes
3 answers
817 views

Is the amount of accurate information in a TLE equal to that of a single state vector?

My question is basically regarding whether there is orbital information "lost" when converting from a Two Line Element set (TLE) to a state vector. Given that the following are true: I have a TLE, ...
  • 43
5 votes
2 answers
1k views

How do SDP4's "Deep space" corrections to SGP4 account for the Sun's and Moon's gravity?

The Simplified Perturbations model SGP4 is used to calculate Earth satellite state vectors (position and velocity) using standard ephemeris data encoded as TLEs (Two Line Elements). According to ...
  • 148k
4 votes
2 answers
859 views

Tesla Roadster new orbital elements [closed]

Has a TLE been posted somewhere for the Tesla Roadster in its new orbit out past Mars? I was hoping to paste it into SN7. Thanks
  • 43
6 votes
1 answer
301 views

Is TESS really lost? What does Celestrak mean exactly?

From this answer to the question What artificial satellite has the farthest orbit around the Earth?: I found the following "far out" spacecraft: TESS (Transiting Exoplanet Survey Satellite)...
  • 148k
1 vote
2 answers
426 views

Does the James Webb Telescope have a Two Line Element set?

How do you track the position of the James Webb telescope? Does it have its own TLE, or...?
3 votes
2 answers
217 views

Why can n2yo somehow interpret this TLE but Skyfield can't? Why does it return nans and zeros for position?

@Rafa pointed out that there is at least one officially released TLE for the JWST mission after it left Earth orbit, and here's the latest one at n2yo.com: ...
  • 148k
0 votes
0 answers
46 views

Did 18 SPCS issue two TLEs for JWST when it was not bound to Earth nor orbiting it? Is this a spaceflight first?

spacetrack.org lists two TLEs for 2021-130A with epochs of 21359.67 and 21362.00 I think that for at least the second one, JWST was well on it's way to it's Sun-Earth L2 halo orbit traveling at least ...
  • 148k