These pages complement the paper Critical issues related to registration of space objects and transparency of space activities (Jakhu, Jasani and McDowell 2018, Acta Astronautica) (Link to published article) and provide an updated list of satellites which have NOT been registered with the United Nations.
See also my UN Registration analysis page
The tables assign and categorize (suspected) reasons that each unregistered satellite is not registered. For launches up to 2016 Dec 31, considering only registrations up to 2017 Dec 1:
| Payloads launched | 7575 | ||
| Registered payloads | 7106 | 93.8 percent | |
| Unregistered payloads | 469 | 06.2 percent | (409 launched prior to 2016) |
| Tabulated by country |
List of unregistered satellites. The list gives for each payload the country that I think should have registered it, the international designation, launch vehicle, launch date, and assigns a category for each failure to register.
Summary table of unregistered satellites by category:
Figure 1 (a) (Upper panel): Total payloads per year, registered (white) and unregistered (solid); (b) (Lower panels): payloads for USA, USSR/Russia, and others (unregistered payloads shaded).
Figure 2: Distribution of orbit types - low, geostationary and other - for registered satellites whose orbital data is NOT provided in the registration.