Space Brief 29 Nov 2025
Today's Space Brief covers a Soyuz launch mishap that damaged Baikonur pad, Varda Space's AFRL test flights, ION vehicles aboard SpaceX Transporter-15, and more.
SPACENET 4 (ASC 2) (21227)
COSPAR: 1991-028A | Alt Name: ASC 2
Image
Additional Sources
Launch Details
Launch Date
April 13, 1991
Launch Site
Launch Pad
LC17B
Launch Vehicle
Delta 7925
Orbital Elements
NORAD ID
21227
International Designator
1991-028A
Epoch
Fri, 03 Jul 2026 19:51:33 GMT
Apogee
Calculating...
Perigee
Calculating...
Inclination
13.77°
Right Ascension
13.73°
Eccentricity
Calculating...
Argument of Perigee
317.70°
Period
1446.17 min
Mean Motion
1.00 rev/day
Latitude
Calculating...
Longitude
Calculating...
Altitude
Calculating...
Velocity
Calculating...
Polar Plot
3D Visualization
Basic Satellite Info
Name
SPACENET 4 (ASC 2)
Alternative Name
ASC 2
Type
Payload
Status
Non-operational
Owner
CONTG
Country
United States
Constellation
N/A
Related Satellites
Major Events
N/A
Latest TLEs
1 21227U 91028A 26184.82746992 -.00000196 00000-0 00000-0 0 9999
2 21227 13.7688 13.7266 0006197 317.7037 55.2747 0.99573476126543
Source: Celestrak
Summary
SPACENET 4 (ASC 2), also known as ASC 2, is a communication satellite launched by the US on April 13, 1991, from Cape Canaveral Air Force Station’s Launch Complex 17B using a Delta 7925 launch vehicle. The satellite measures 2 meters in length and has a diameter of 1.3 meters with a span of 14 meters. It features a box shape with two panels and carries 18 C-band and 6 Ku-band transponders for communication purposes. SPACENET 4 was manufactured by GEEW (General Electric Aerospace) and weighed 705 kilograms at launch, with a dry mass of 550 kilograms. Its power supply consists of two deployable solar arrays and batteries. The satellite’s mission is to provide communication services and it has an expected lifetime of 10 years.
Physical Characteristics
Length
2
Diameter
1.3
Span
14
Dry Mass
550
Launch Mass
705
Shape
Box + 2 Pan
Radar Cross Section
6.3095
Visual Magnitude
Unknown
Color
Unknown
Material Composition
Unknown
Technical Details
Payload
ASC 2
Purpose
Communication
Mission
Communication
Manufacturer
GEEW
Life Expectancy
10 years
Bus
AS3000
Configuration
AS-3000
Motor
TE-M-700-18
Equipment
18 C-band, 6 Ku-band transponders
Power System
2 deployable solar arrays, 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.
X Report 14 Feb 2025
Starship testing progresses at the Cape; Lynk Global secures funding amidst rising satellite competition.
Space Brief 9 Oct 2025
Today's briefing covers key developments in defense budgets reshaping the space sector, significant Space Force contracts, and the latest news from the Chinese space station.
Space Brief 18 Jul 2025
Today's highlights include Space Force prioritizing military missions, testing new GPS satellite software, and international defense collaborations impacting space assets.
Space Brief 2 Sep 2025
Today's brief covers key topics such as SpaceX's latest Starlink launch, the European Space Agency's new initiatives, and Space Force's integration of AI into its operations.
Graveyard Orbit
The final resting place for retired satellites, a disposal orbit where defunct spacecraft are sent to stay out of the way
Vulcan Booster Anomaly Under Scrutiny After USSF-87 Launch | KeepTrack Space Brief
ULA Vulcan faces scrutiny after solid booster anomaly on USSF-87 mission. ThinKom wins portable satellite ground station contract. Space Force starts Project Hecate for GPS past 2040.
Space Brief 12 Jan 2025
Today's briefing covers significant events including launch delays for SpaceX's Starship and Blue Origin's New Glenn, BepiColombo's landmark Mercury flyby, and the impact of Los Angeles fires on the space community.