Apogee and Perigee
Understanding the high and low points of every orbit - from the International Space Station's careful dance with Earth's atmosphere to the extreme ellipses that take satellites to the edge of space and back.
DMSP 5D-2 F11 (USA 73) (21798)
COSPAR: 1991-082A | Alt Name: DMSP F-11
Image
Additional Sources
Launch Details
Launch Date
November 28, 1991
Launch Site
AFWTR
Launch Pad
SLC3W
Launch Vehicle
Atlas E
Orbital Elements
NORAD ID
21798
International Designator
1991-082A
Epoch
Sat, 04 Jul 2026 03:31:20 GMT
Apogee
Calculating...
Perigee
Calculating...
Inclination
98.69°
Right Ascension
213.04°
Eccentricity
Calculating...
Argument of Perigee
217.93°
Period
101.59 min
Mean Motion
14.17 rev/day
Latitude
Calculating...
Longitude
Calculating...
Altitude
Calculating...
Velocity
Calculating...
Polar Plot
3D Visualization
Basic Satellite Info
Name
DMSP 5D-2 F11 (USA 73)
Alternative Name
DMSP F-11
Type
Payload
Status
Non-operational
Owner
AFSSD2
Country
United States
Constellation
N/A
Related Satellites
Major Events
N/A
Latest TLEs
1 21798U 91082A 26185.14676144 .00000061 00000-0 51627-4 0 9994
2 21798 98.6899 213.0365 0011675 217.9256 142.1098 14.17452695787539
Source: Celestrak
Summary
DMSP 5D-2 F11 (USA 73), also known as DMSP F-11, is a meteorological satellite launched on November 28, 1991, from AFWTR using an Atlas E launch vehicle from SLC3W. It was manufactured by GEEW and has a TIROS-N Bus configuration with dimensions of 3.4 meters in length, 1.2 meters in diameter, and a span of 5 meters. The satellite has a dry mass of 749 kilograms and is equipped with a deployable solar array and batteries for power generation. Its mission was meteorology, and it used the DMSP Block 5D-2 S-12 payload. Operated by AFSSD2, DMSP 5D-2 F11 was designed for a five-year lifetime but reached an operational lifespan of 22 years as the fourteenth satellite in its series. The satellite's shape is described as "Box + Pan," and it has a radar cross-section (RCS) value of 3.5425.
Physical Characteristics
Length
3.4
Diameter
1.2
Span
5
Dry Mass
749
Launch Mass
749
Shape
Box + Pan
Radar Cross Section
3.5425
Visual Magnitude
Unknown
Color
Unknown
Material Composition
Unknown
Technical Details
Payload
DMSP Block 5D-2 S-12
Purpose
Meteorology
Mission
Meteorology
Manufacturer
GEEW
Life Expectancy
5 years (design); 22 years (reached, #14)
Bus
Block 5D
Configuration
TIROS-N Bus
Motor
Star 37S
Equipment
see above
Power System
Deployable solar array, batteries
ADCS
Unknown
Transmitter Frequency
Unknown
Map
Next Pass
Azimuth Elevation Time (Local)
Start Azimuth
Max Elevation
Stop Azimuth
Time Until
Pass Duration
Satellite Articles
View All Posts »Learn more about satellites and other related topics.
Falcon 9 Lands in Bahamas for 2nd Time, Reentry Pollution Measured | KeepTrack X Report
SpaceX lands Falcon 9 in The Bahamas for the second time ever during Starlink 10-34 mission. Scientists measure rocket reentry air pollution in real-time for the first time.
Space Brief 16 Jan 2025
Explore today's pivotal news in space with highlights on record government space budgets, military satellite developments, and significant industry shifts.
Space Brief 30 May 2025
Today's brief highlights significant advancements in satellite launches, new defense contracts, and technological integrations between major firms in the space sector.
X Report 9 Feb 2025
SpaceX prepares for another Starlink launch while facing potential C-band spectrum challenges.
Space Brief 16 Sep 2025
Today's brief highlights the impact of military spending and technology competition on the space economy, new satellite connectivity partnerships, and defense spending pledges in Europe.
Space Brief 9 Apr 2025
Today's brief covers Blue Origin’s new defense launch contracts, the ISS launch of a Navy SEAL astronaut, Sierra Space’s GPS security advancements for the U.S. Space Force, and the Space Force's 'Orbital Watch' initiative.
Space Force Plans to Double Active-Duty Force by 2030 | KeepTrack Space Brief
Space Force confirms plan to double active-duty Guardians by 2030, targeting faster response to satellite anomalies and adversary maneuvers in space domain awareness operations.