Key statistics
Satellite REX at a glance.
Uptime
12427
Days in orbit
Revolutions
≈ 14.2
Per day
Orbit
LEO
Low Earth Orbit
Inclination
89.5
Latest
Satellite identification and parameters
Extended collection of information and parameters for REX.
Object identification
Identified? True
Debris? False
Object name: REX
International designator: 1991-045A
Object number (NORAD): 21527
Object ID (CCSDS): 21527
Country: UNITED STATES OF AMERICA (US)
Current information (Y/N): Y
RCS size: MEDIUM
Orbital parameters
Period: 101.16 minutes
Inclination: 89.5293 deg
SMA: 7191.731 km
Apoapsis: 863.872 km
Periapsis: 763.319 km
RAAN: 278.8629 deg
Eccentricy: 0.0069909
Argument of periapsis: 39.2955 deg
Mean anomaly: 321.3281 deg
Mean motion: 14.23484121 rev/day
Mean motion (dot): 0.00000077 rev/day2
B* drag term: 0.000027226 1/REarth
Two-line elements (TLE)
Creation date: July 5, 2025, 10:46 p.m.
Reference frame: TEME
Reference center: EARTH
Epoch: July 5, 2025, 6:09 p.m. UTC
TLE line 0: 0 REX
TLE line 1: 1 21527U 91045A 25186.75684701 .00000077 00000-0 27226-4 0 9993
TLE line 2: 2 21527 89.5293 278.8629 0069909 39.2955 321.3281 14.23484121766057
Live tracking on map
Real-time ground track for satellite REX.
In-orbit conjunctions
A list of the most updated potential collisions computed for object REX.
Associated space launch
REX (Radiation Experiment) or ISES (Integrated Space Experiment System) was an Air Force Rome Laboratory ionospheric research satellite which tested the effects of the atmosphere on radio transmissions, and employed GPS for on-board navigation and attitude control.
REX was lifted into orbit during the mission ‘Scout G-1 | REX’, on board a Scout G-1 space rocket.
The launch took place on June 29, 1991, 2 p.m. from Space Launch Complex 5.
For more information about the launch, click the button.
Scout G-1 | REX
Agency: N/A
Status: Launch Successful
Launch date: June 29, 1991, 2 p.m. UTC
Rocket: Scout G-1
Launch pad: Space Launch Complex 5
Location: Vandenberg SFB, CA, USA
...
Latest news about this satellite
There are no fresh news available about this satellite. Check back as we update our databases every day.
Newsletter sign-up
Weekly statistics, charts and insights to help you stay on top of the space industry.
