4
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So the two I can think of are the ISS orbit and GEO. Are there any other orbits that consistently have 10+ launches a year?

For this question, when I say matching orbit, I mean eccentricity, semimajor axis, inclination, longitude of the ascending node, and argument of periapsis. So SSOs with different longitudes of the ascending node wouldn't count.

Perturbations and drag will also take satellite orbits away from being exact, so as long as they have the same intended orbit, they should count.

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  • $\begingroup$ Molniya orbits are likely in the running; I don't know how many actually go up in any given year, or if they should all be counted as the 'same' orbit by your criteria. $\endgroup$ – Roger Nov 13 '18 at 20:12
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    $\begingroup$ Does a graveyard orbit count? $\endgroup$ – DrSheldon Nov 13 '18 at 22:40
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    $\begingroup$ polar, and sun-synchronous are "popular" and do not apply to ISS's orbit. I have no idea how to count them per year though. $\endgroup$ – uhoh Nov 14 '18 at 1:58
  • $\begingroup$ "longitude of the ascending node" Should I edit this out of the question? It seems to be being ignored in comments and answers anyways. It also has occurred to me after some further reading that it can't really be applied to some orbits that aren't Keplerian such as SSO. My purpose is having it, is that in general, two orbits with the same inclination, but different longitude of the ascending node will still take a lot of delta V to reach each other. $\endgroup$ – Lex Nov 15 '18 at 3:20
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I made a quick pivot table based on the Union of Concerned Scientists Satellite Database data, which unfortunately only lists operating satellites (though it should be accurate for the last couple years of launches), I also assumed that satellites launched on the same day were on one launch (occasionally 2 or more rockets will launch on the same date).

In 2017 the most popular orbits were:

  • GEO - 28 Launches
  • LEO - Non-Polar Inclined, 18 Launches
  • LEO - Sun-Synchronous, 16 Launches
  • LEO - Other, 4 Launches
  • LEO - Polar, 4 Launches
  • Elliptical - Molniya, 2 Launches
  • MEO - Non-Polar Inclined, 2 Launches
  • LEO - Equatorial, 1 Launch
  • MEO - Other, 1 Launch

Full table:

+----------------------------------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+-------------+
|            Launch Type           | 1974 | 1988 | 1989 | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | Grand Total |
+----------------------------------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+-------------+
| Elliptical                       |      |      |      |      |      |      |      |      |      |      |    1 |      |      |      |      |      |      |      |      |      |    1 |      |      |      |      |    1 |    1 |      |    1 |    1 |      |      |           6 |
| Elliptical-Deep Highly Eccentric |      |      |      |      |      |    1 |      |      |      |      |      |      |    2 |    1 |      |    1 |      |      |      |      |      |    1 |      |      |      |      |      |      |      |      |      |      |           6 |
| Elliptical-Molniya               |      |      |      |      |      |      |      |      |      |    1 |      |      |      |    3 |      |      |      |    1 |      |    1 |    1 |    1 |      |    1 |    2 |    1 |      |    2 |    1 |      |    2 |      |          17 |
| GEO                              |      |    1 |    1 |    1 |    1 |      |    2 |    3 |    8 |   10 |   10 |    8 |   13 |   18 |   11 |   21 |   18 |   10 |   18 |   17 |   12 |   23 |   23 |   26 |   23 |   29 |   21 |   26 |   30 |   29 |   28 |   10 |         451 |
| LEO                              |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |    1 |    4 |    1 |           6 |
| LEO-Cislunar                     |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |    1 |      |      |      |      |      |      |      |           1 |
| LEO-Elliptical                   |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |    1 |      |      |      |      |      |      |      |    1 |      |    1 |      |      |      |           3 |
| LEO-Equatorial                   |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |    1 |      |      |      |      |      |      |      |      |      |    2 |      |      |    3 |      |    1 |      |           7 |
| LEO-Non-Polar Inclined           |      |      |      |    1 |      |      |    1 |      |      |      |    1 |    5 |    6 |    1 |    1 |    3 |    1 |    1 |    1 |    2 |    8 |    5 |    3 |    4 |    4 |    2 |    4 |    6 |    3 |   12 |   18 |    2 |          95 |
| LEO-Polar                        |    1 |      |      |      |      |      |      |      |      |      |    9 |   10 |    1 |      |    2 |    2 |    2 |    2 |    1 |    1 |    1 |    1 |    1 |    4 |    2 |    2 |   10 |    3 |    2 |    2 |    4 |    1 |          64 |
| LEO-Sun-Synchronous              |      |      |      |      |      |      |      |      |      |      |    1 |    1 |    4 |    1 |    3 |    1 |    5 |    6 |    5 |    7 |    7 |    6 |   14 |   10 |   12 |   11 |   15 |   20 |   12 |   16 |   16 |   12 |         185 |
| MEO                              |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |    1 |    2 |           3 |
| MEO-Equatorial                   |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |      |    1 |    2 |      |      |      |    1 |           4 |
| MEO-Non-Polar Inclined           |      |      |      |      |      |      |      |    1 |      |      |    1 |      |    1 |    3 |    1 |      |    3 |    3 |    2 |    3 |    4 |    1 |    2 |    3 |    5 |    4 |    1 |    8 |    4 |    6 |    2 |      |          58 |
+----------------------------------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+-------------+
| Grand Total                      |    1 |    1 |    1 |    2 |    1 |    1 |    3 |    4 |    8 |   11 |   23 |   24 |   27 |   27 |   18 |   29 |   29 |   23 |   28 |   31 |   34 |   38 |   43 |   48 |   49 |   52 |   54 |   67 |   57 |   67 |   76 |   29 |         906 |
+----------------------------------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+-------------+
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