| 1963-043A | I-2B 1 |
| 1964-019A | I-2B 2 |
| 2008-039A | I-4 Americas |
| 2005-009A | I-4 Asia-Pacific |
| 2005-044A | I-4 EMEA |
| viz. | IA [=Intelsat Americas] |
| 1996-032C | IAE |
| 2008-051A | IBEX |
| 1991-031B | IBSS |
| 2009-002A | Ibuki |
| 1978-079A | ICE |
| 2003-002A | ICESat |
| 2001-026A | ICO F-1 |
| 2008-016A | ICO-G1 |
| 2002-021B | Idefix |
| viz. | IDCSP |
| viz. | IDSCS |
| 1964-051A | IE-A |
| viz. | IGS |
| 2010-020E | IKAROS |
| 1999-051A | Ikonos |
| 1999-051A | Ikonos 2 (Ikonos) |
| 2000-017A | IMAGE |
| viz. | IMEWS |
| 1992-002A | IML-1 |
| 1994-039A | IML-2 |
| viz. | IMP |
| viz. | Improved Midas |
| viz. | Improved Samos |
| 2005-031B | INDEX |
| 1997-071B | Indostar 1 |
| 1991-006A | Informator 1 |
| viz. | Injun |
| viz. | Inmarsat |
| viz. | Insat |
| 1997-058D | Inspektor |
| 1974-089C | Intasat |
| viz. | Intelsat |
| 2002-048A | INTEGRAL |
| 1995-039A | Interball 1 |
| 1996-050C | Interball 2 |
| 1996-050C | Interball Aurora |
| 1995-039A | Interbol 1 |
| 1996-050C | Interbol 2 |
| 1996-050C | Interbol Avroral'nyj Zond |
| viz. | Interkosmos |
| 1969-099C | Intrepid |
| viz. | Ionosphere |
| 2005-028A | Ipstar 1 |
| 1965-093A | IQSY |
| 1983-004A | IRAS |
| 2000-009B | IRDT/Fregat |
| viz. | Iridium |
| 2006-005A | IRIS |
| 1968-041A | IRIS-1 |
| 2009-049C | IRIS/Fregat |
| 1984-088B | IRM |
| 1996-017A | IRS B3 |
| viz. | IRS |
| 1984-011C | IRT |
| 1971-063D | IRW |
| viz. | IS [=Iridium Satellite] |
| viz. | IS [=Intelsat] |
| viz. | ISEE |
| viz. | ISIS |
| 1981-065C | Iskra 1 |
| 1982-033C | Iskra 2 |
| 1982-033AD | Iskra 3 |
| 1995-062A | ISO |
| 1990-090B | ISPM |
| viz. | ISS [=Indian Scientific Satellite] |
| viz. | ISS [=International Space Station] |
| viz. | ISS [=Ionosphere Sounding Satellite] |
| viz. | Italsat |
| 1993-061F | Itamsat |
| viz. | ITOS |
| viz. | ITSO [=International Telecommunication Satellite Organization] |
| 2009-051E | ITU-pSAT-1 |
| 1985-114A | ITV-1 |
| 1985-114B | ITV-2 |
| 1978-012A | IUE-1 |