Orbital elements of USA 21
| Launched | 11 February 1987 |
| Flight ended | – |
| Launch site | Air Force Western Test Range, California, USA |
| Owner | United States |
| NORAD ID | 17506 |
| Date fetched |
Epoch osculation |
Inc. [°] |
Ecc. | RA asc node [hr] |
Arg Peri. [°] |
Mean anom [°] |
Mean motion [rev/day] |
Abs. mag |
| Date fetched |
Epoch osculation |
Inc. [°] |
Ecc. | RA asc node [hr] |
Arg Peri. [°] |
Mean anom [°] |
Mean motion [rev/day] |
Abs. mag |
| 2026 Mar 03 18:56 | 2026 Feb 14 03:28:01 | 62.9671 | 0.72756 | 18.2112 | 278.0632 | 12.4511 | 2.01483 | – |
| 2026 Mar 02 18:57 | 2026 Feb 14 03:28:01 | 62.9671 | 0.72756 | 18.2112 | 278.0632 | 12.4511 | 2.01483 | – |
| 2026 Mar 01 18:57 | 2026 Feb 14 03:28:01 | 62.9671 | 0.72756 | 18.2112 | 278.0632 | 12.4511 | 2.01483 | – |
| 2026 Feb 28 18:56 | 2026 Feb 14 03:28:01 | 62.9671 | 0.72756 | 18.2112 | 278.0632 | 12.4511 | 2.01483 | – |
| 2026 Feb 27 19:05 | 2026 Feb 14 03:28:01 | 62.9671 | 0.72756 | 18.2112 | 278.0632 | 12.4511 | 2.01483 | – |
| 2026 Feb 26 20:45 | 2026 Feb 14 03:28:01 | 62.9671 | 0.72756 | 18.2112 | 278.0632 | 12.4511 | 2.01483 | – |
| 2026 Feb 05 18:58 | 2026 Jan 27 06:38:59 | 62.9610 | 0.72853 | 18.3843 | 277.9712 | 12.4511 | 2.01483 | – |
| 2026 Feb 04 18:57 | 2026 Jan 27 06:38:59 | 62.9610 | 0.72853 | 18.3843 | 277.9712 | 12.4511 | 2.01483 | – |