Launches of satellites forming the Iridium
constellation
showing launch identities and catalog numbers
For a summary of the current situation, see my Iridium Constellation Status page.
The Iridium satellites operate in near-polar orbits at an inclination of 86.4° to the equator, and in are grouped into 6 orbital planes at approximately 31.6° separation, leaving a smaller gap of around 22° at the "seams" between plane 6 and plane 1 where the satellites in adjacent planes are travelling in opposite directions.
The satellites were launched in groups of 2, 5 or 7:
Launch Orbital Launch Date Plane Id A B C D E F G
1997/05/05 4 97020 8 7 6 5 4
24792 24793 24794 24795 24796
1997/06/18 5 97030 14 12 9 10 13 16 11
24836 24837 24838 24839 24840 24841 24842
1997/07/09 6 97034 15 17 20 18 21
24869 24870 24871 24872 24873
1997/08/21 2 97043 26 25 24 23 22
24903 24904 24905 24906 24907
A demonstration launch of two dummy Iridium satellites took place in September 1997:
1997/09/01 97048 24925 24926 (these dummy satellites are omitted from my status table)
1997/09/14 3 97051 29 32 33 27 28 30 31
24944 24945 24946 24947 24948 24949 24950
1997/09/27 4 97056 19 35 36 37 34
24965 24966 24967 24968 24969
1997/11/09 6 97069 43 41 40 39 38
25039 25040 25041 25042 25043
1997/12/08 6 97077 42 44
25077 25078
(this launch completed the intended complement of 11 plus 1 spare in orbital plane 6)
1997/12/20 2 97082 45 46 47 48 49
25104 25105 25106 25107 25108
1998/02/18 5 98010 52 56 54 50 53
25169 25170 25171 25172 25173
(this launch completed the intended complement of 11 plus 1 spare in orbital plane 5)
1998/03/25 4 98018 51 61
25262 25263
(this launch completed the intended complement of 11 plus 1 spare in orbital plane 4)
1998/03/30 3 98019 55 57 58 59 60
25272 25273 25274 25275 25276
(this launch completed the intended complement of 11 plus 1 spare in orbital plane 3)
1998/04/06 1 98021 62 63 64 65 66 67 68
25285 25286 25287 25288 25289 25290 25291
1998/05/02 2 98026 69 71
25319 25320
(this launch completed the intended complement of 11 plus 1 spare in orbital plane 2)
1998/05/17 1 98032 70 72 73 74 75
25342 25343 25344 25345 25346
(this launch completed the intended complement of 11 plus 1 spare in orbital plane 1)
At this stage, the originally intended full complement of 66 satellites plus 6 in-orbit spares had been launched. However, by this time, a number of satellites had failed, so further launches were needed to replace the failures and to supplement the spares.
1998/08/19 2 98048 3 76
25431 25432
1998/09/08 6 98051 82 81 80 79 77
25467 25468 25469 25470 25471
1998/11/06 5 98066 2 86 85 84 83
25527 25528 25529 25530 25531
1998/12/19 2 98074 11a 20a
25577 25578
1999/06/11 1 99032 14a 21a
25777 25778
Eurockot conducted a demonstration launch of two dummy satellites in May 2000. While not specifically part of the Iridium program, the inclination of the target orbit matches with the Iridium constellation:
2000/05/16 00026 26365 26366 (these dummy satellites are omitted from my status table)
Even after the Iridium system was rescued, it was a considerable time before further launches took place to replenish the on-orbit spares.
2002/02/11 3 02005 90 91 94 95 96 (but note designation change made on January 1, 2006)
27372 27373 27374 27375 27376
(Iridium 90 was later moved to oribital plane 5, Iridium 94 was later moved to orbital plane 2, and Iridium 96 was later moved to orbital plane 4)
2002/06/20 4 02031 97 98
27450 27451
(note that Iridium 98 was later moved to oribital plane 6)
Iridiums 11a, 14a, 20a and 21a listed above are now known as
11, 14, 20 and 21 respectively, the second (replacement)
satellites known by those names (see below).
The original Iridiums 11, 14, 20 and 21 listed above later failed
and are now known as 911, 914, 920, and 921 respectively.
Note that the identities of various members of the Iridium
constellation have been confused at various times in the past.
Some interchanges of identities seems to have become permanent:
Iridium 24 is tumbling, and correctly labelled by Spacecom as
Iridium 24, and correctly tracked, but under 25105 (1997-082B)
which are the catalog number and launch identifier which
originally belonged to Iridium 46.
Iridium 46 is operational, and correctly labelled by Spacecom as
Iridium 46, and correctly tracked, but under 24905 (1997-043C)
which are the catalog number and launch identifier which
originally belonged to Iridium 24.
Iridium 11 is operational, and is now correctly labelled by
Spacecom as Iridium 11, and correctly tracked, but under 25578
(1998-074B) which are the catalog number and launch identifier
which originally belonged to (the second) Iridium 20.
Iridium 20 is operational, and is now correctly labelled by
Spacecom as Iridium 20, and correctly tracked, but under 25577
(1998-074A) which are the catalog number and launch identifier
which originally belonged to (the second) Iridium 11.
SPACECOM exchanged the labelling of Iridium 90 and Iridium 91 on January 1, 2006. The object being tracked under catalog number 27372 (spare in orbital plane 3 until brought into operational use to replace Iridium 33) is now known as "Iridium 91" rather than "Iridium 90", while the object with catalog number 27373 (migrated from orbital plane 3 to orbital plane 5) is now known as "Iridium 90" rather than "Iridium 91". This evidently addressed a long-standing mislabelling of these objects to bring the designations in line with those used by the operators of the Iridium system.
At the Iridium Satellite LLC press conference call on 12
December 2000
(see http://www.ee.surrey.ac.uk/Personal/L.Wood/constellations/iridium/conference-call-Dec-2000.html),
plans were announced to launch further spare satellites for the
constellation:
"We'll be launching seven more in the next year or so.
We have the first launch scheduled for next June, June of 2001.
That will be a Delta 2 launch; we'll be putting five spare
satellites into orbit. The following spring, roughly March of
2002, we'll be launching two more and in that case we'll be using
the Russian rocket. So we will inject seven more spares into the
system, so we'll have more than two spares in each orbit, and
that will give us the life that we believe is there."
These launches were in fact delayed until 2002.
The original Iridum satellites launched in 1997 to 2002 maintained the constellation until 2017, at which time it was reported that 64 of them still remaimed in operational service.
Iridium Next
The next generation Iridium Next launches started in 2017. These satellites were mostly launched in batches of 10.
Launch Orbital Launch Date Plane Id A B C D E F G H J K
2017/01/14 6 17003 106 103 109 102 105 104 114 108 112 111 (note that Iridiums 105 and 108 were moved to orbital plane 5 before entering service)
41917 41918 41919 41920 41921 41922 41923 41924 41925 41926
2017/06/25 3 17039 113 123 120 115 118 117 126 124 128 121 (note that Iridiums 113, 120 and 115 were moved to orbital plane 2 before entering service)
42803 42804 42805 42806 42807 42808 42809 42810 42811 42812 (note that Iridium 124 was moved to orbital plane 1 before entering service)
(note that Iridium 128 was moved to orbital plane 4 before entering service)
2017/10/09 4 17061 133 127 122 129 119 107 132 136 139 125
42955 42956 42957 42958 42959 42960 42961 42962 42963 42964
2017/12/23 2 17083 135 138 116 130 151 134 137 141 153 131 (note that Iridium 153 was moved to orbital plane 1 before entering service)
43070 43071 43072 43073 43074 43075 43076 43077 43078 43079
2018/03/30 1 18030 144 149 157 140 145 146 148 142 150 143 (note that Iridium 148 and Iridium 144 exchanged identities on 01 May 2018)
43249 43250 43251 43252 43253 43254 43255 43256 43257 43258 (note that Iridium 142 and Iridium 150 exchanged identities on 01 May 2018)
2018/05/22 6 18047 161 152 147 110 162 (launch was shared with 2 GRACE-FO satellites)
43478 43479 43480 43481 43482
2018/07/25 5 18061 160 166 158 165 155 154 163 156 164 159
43569 43570 43571 43572 43573 43574 43575 43576 43577 43578
2019/01/11 3 19002 180 176 168 173 169 172 175 171 170 167 (note that Iridium 169 was moved to orbital plane 4)
43922 43923 43924 43925 43926 43927 43928 43929 43930 43931
Note that the Iridium Next satellites are not expected to produce flares from the Main Mission Antenna in the same way as the original Iridum satllites.