quick question (but I've spent half an hour not answering it via Google)

[tamaranth]

how many satellites are in geosynchronous orbit (and in other orbits) around the Earth? (Let's exclude space junk and bits that've fallen off other satellites.)

Context: throwaway line in piece about Clarke's 'Extraterrestrial Relays' paper, published 60 years ago ...

Comments

[nwhyte]

If you find out, let me know - I remember arguing with Ken MacLeod about this on a panel at Worldcon...

[pigeonhed.livejournal.com]

The UN has a registry of Space Objects but its complex and hard to wade through to find actual totals.

http://www.oosa.unvienna.org/OSOIndex/

OR the Satellite Encyclpedia apparently list over 2500 unmanned satellites

http://www.tbs-satellite.com/tse/online/

[pigeonhed.livejournal.com]

Thinking about this, I seem to remember a figure of about 4,000 being tossed around some while ago. 2,500 doesn't actually seem that many does it?

[sbisson.livejournal.com]

Here's a list of commercial Clarke orbit satellites: http://www.geo-orbit.org/default.html

It's a little out of date, but seems fairly comprehensive. There are fewer than you might think - obsolete birds are usually de-orbited as prime real estate is getting pretty crowded.

[major-clanger.livejournal.com]

The always excellent Jonathan's Space Report (http://www.planet4589.org/space/jsr/jsr.html) has a list of everything that's ever been in geosync orbit (http://planet4589.org/space/book/LOGS/logindex/geo.html). Importing the index file into a spreadsheet gives 1035 objects up to March last year.

JSR also has a full list of NORAD catalogued items (up to last year); importing this and filtering on 'in orbit' gives 9451 objects, although a lot of those are described as 'debris' or 'parts'.