Worthless space launch stats

A bit closer to my background and my daily occupations (again info about myself!) I stumbled on a space launch “home-made” database.

It is the result of the parsing of a couple of very well-provided web sites (here and there). So, I got my hands on a database of about 5490 space launches from 1957 onward which put in space about 9080 man-made spacecraft (out of about 9853, considering also the failed launch attempts). Nothing particularly exciting thus far.

Putting aside the classical stats that can be made with such a kind of database (e.g. launch per year or number of launches per nation, etc…) I began daydreaming on the following three useless stats:

  • Is there any trans-country launcher? I.e. which are, if any, the launchers used by more than a single nation? Perfectly aware than each launcher usually serves the nation that developed it (a domestic affair based on “defence” reasons), I would have made a couple of guesses… To make this estimation I assumed that: 1) the nation operating a launcher is the nation where the main contractor belongs, 2) before and after 1991 Russia is always Russia (ex-urss, what is it?), 3) ESA (is ESA a Nation?) is always ESA (thus ELDO, UAE, etc., all authorities merged into ESA have always been some kind of “ESA branches”). Out of 355 catalogued launch vehicles, I found that only 11 have been used by two different national entities (none by three or more!). These launchers belong to 5 families: Zenit, Start, Soyuz, Scout and Kosmos.launchexXnatOf course this means that of the two nations, one (useless to say, US or Russia) developed and used the launcher as first and the other one just borrow the launcher. Do you see how many times Italy appears as “second user”?! A result of the San Marco project. The Soyuz launcher family (one of the launcher I expected to see in this list) results to be used by Russia and France and appears also with its -U version, the most-flown orbital launch system ever developed with about 750 flights. The Kosmos 11K65M is a russian liquid two stage launcher operated 446 times between 1967 and 2010 and also used by Japan (to be honest only once, but enough to be mentioned here). Italy is one of the major second-launcher-user since it operated 5 versions of the Scout rocket family: the first completely solid launcher developed in America and operated between 1961 and 1994. The Start-1 russian launcher has been used 3 times also by Japan (second placement as launcher-borrower). This launcher results to be used also by Israel, but it doesn’t appear in this stats since the prime operator of israeli launches remains Russia. The last launcher present in this multi-country-launcher-list is the Zenit S3L. 36 launches, 91.6% success mainly used for telecom satellite in Geostrationary Transfer Orbits. Actually used by the Cayman Islands British Overseas Territory, at that time HQ of the Sea Launch Company (i.e. UK appears only for jurisdictional reasons…).
  • Is there any month preferred for space launches? That’s a very stupid question since it does not take into account the mission target orbit, launch windows and so on; so it is a perfectly useless stats, good!
    fig2Well it seems that the Christmas time is rather appealing for watching (and reaching) the stars. Is it related to the run-to-invoicing of the New Year’s Eve? The second, third and fourth places are rather close (a sort of ex-equo second placement): April, June and October. The less appealing month for launching is January (it is hard re-starting the year…)
  • Is there a year with 100% of successful launches? Of course I would expect that the number of failed launches has been decreasing since 1957, but is this trend actually monotonically decreasing (given as percentage of the total launches in the year)? I would have never said.
    fig3Actually the worse year, with 71% of failed launches was the 1958, but the most surprising (only for me 🙂 ) data is that the 1984 is the only year ever with 100% of successful launches. Actually there is another zero in the plot, but the database, unfortunately, is not update with the 2015 Proton-M recent launch failure. Moreover it seems that after the 1984 there is a sort of sinusoidal trend in launch failures and the minimum should be right around 2015. Let’s see what comes in the next months (especially, useless to say, in December)…



Un pensiero su “Worthless space launch stats


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