USSF-8 | Atlas V 511

Lift Off Time/Launch Window
(Subject to change)
January 21, 2022 – 14:00 EST | 19:00 UTC
Mission Name
USSF-8, two Geosynchronous Space Situational Awareness Program (GSSAP) satellites
Launch Provider
(What rocket company is launching it?)
United Launch Alliance (ULA)
(Who’s paying for this?)
U.S. Space Force
Atlas V 511 
Launch Location
SLC-41, Cape Canaveral SFS, Florida, United States
Payload mass
~1,300-1,400 kg
Where are the satellites going?
Near-geosynchronous orbit (GEO) ~22,300 miles (36,000 km) above the equator
Will they be attempting to recover the first stage?
No, Atlas V is not capable of recovery
Where will the first stage land?
It will crash into the Atlantic Ocean
Will they be attempting to recover the fairings?
No, Atlas V is not capable of recovery
Are these fairings new?
How’s the weather looking?
The weather is currently 90% GO for launch (as of January 21, 2022 – 18:00 UTC)
This will be the:
– 1st flight of the Atlas V 511 configuration
– 3rd GSSAP mission
– 75th Atlas V launch from Cape Canaveral
148th ULA’s mission
– 6th orbital launch attempt of 2022
Where to watch
Official livestream

What Does All This Mean?

United Launch Alliance (ULA) is preparing to launch another mission for the U.S. Space Force’s Space Systems Command (SSC). On this mission, their Atlas V 511 rocket will carry two identical Geosynchronous Space Situational Awareness Program (GSSAP) satellites — GSSAP-5 and GSSAP-6 — that will be inserted directly into a near-geosynchronous (GEO) orbit. This mission will mark the first launch for the company in 2022 and the first and only planned flight of the Atlas V 511 configuration. The rocket will lift off from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida.

Atlas V, USSF-8, mission artwork
USSF-8 mission artwork (Credit: ULA)

USSF-8 Mission


The USSF-8 mission will launch two GSSAP satellites that will operate in a near-geosynchronous orbit approximately 36,000 km (22,300 miles) above the equator. In conjunction with ground-based radars and telescopes, these satellites will support surveillance operations as a dedicated Space Surveillance network (SSN) sensor for the U.S. Space Force’s SSC.

The GSSAP satellites work in pairs: one of them operates below the GEO belt, while the second one operates above it. The main objective of the GSSAP-5 and GSSAP-6 is to track objects in the heavily-trafficked geosynchronous belt that a lot of companies use for placing their communication satellites. This will help not only to manage traffic and avoid collisions, but also to detect potential threats from space objects. Moreover, the GSSAP-5 and GSSAP-6 satellites will be able to adjust their orbits to approach and image other satellites.

GSSAP satellites, deployed, artist rendition, USSF-8
Deployed GSSAP satellites (Credit: U.S. Air Force)

The GSSAP satellites are developed by the Air Force and Orbital Sciences Corp. (now Northrop Grumman Corp). The first two GSSAP satellites were launched on July 28, 2014, atop a Delta IV M+(4,2) rocket. The second pair of these satellites was deployed on August 19, 2016, again using a Delta IV M+(4,2) rocket.

Even though the GSSAP was declassified in 2014, some of the characteristics of the satellites are still unknown. As can be seen in the render above, two deployable solar arrays generate power for the satellite. It is also reported that, most likely, they use Orbital’s GEOStar-1 bus as a satellite bus and mono-propellant propulsion system to adjust their orbit.


-0:00:02.7RD-180 engine ignition
+0:00:06.9Begin pitch/yaw maneuver
+0:00:57.8Mach 1
+0:01:07.4Maximum dynamic pressure
+0:02:00.5Solid rocket booster jettison
+0:03:30.0Payload fairing jettison
+0:04:21.2Atlas booster engine cutoff (BECO)
+0:04:27.2Atlas Centaur separation
+0:04:37.1Centaur first main engine start (MES-1)
+0:13:07.8Centaur first main engine cutoff (MECO-1)
+1:09:30.4Centaur second main engine start (MES-2)
+1:13:37.0Centaur second main engine cutoff (MECO-2)
+6:31:12.0Centaur third main engine start (MES-3)
+6:32:59.3Centaur third main engine cutoff (MECO-3)
+6:35:48.3GSSAP-5 separation
+6:45:20.3GSSAP-6 separation
+7:11:40.3Start blowdown
+7:46:40.3End of mission

What Is The Atlas V?

The Atlas V is an expendable medium-lift launch system and member of the Atlas rocket family. The rocket has two stages. The first is a Common Core Booster (CCB), which is powered by a single RD-180 engine that burns kerosene (RP-1) and liquid oxygen (LOx). This is accompanied by up to five strap-on solid rocket boosters (SRB). The second stage is the Centaur upper stage, which is powered by one or two RL10 engines and burns liquid hydrogen (LH2) and liquid oxygen (LOx).

Atlas V 511, USSF-8 mission
Atlas V 511 is preparing for its USSF-8 mission (Credit: ULA)

The CCB is 3.8 m (12.5 ft) in diameter and 32.5 m (106.5 ft) in length. This stage is capable of producing 3.83 MN (860,200 lb) of thrust at sea level. Each SRB can provide additional 1.6 MN (371,550 lb) of thrust. The Centaur second stage, in turn, is 3 m (10 ft) in diameter and 12.6 m (41.5 ft) in length and is capable of producing 101.8 kN (22,900 lb) of thrust.

What Does 511 mean?

Atlas V rockets have a three number configuration code. The first number represents the fairing diameter size in meters. The second number denotes the number of solid rocket motors (SRMs), which attach to the base of the rocket. The number of SRMs for a 4 meter fairing can range from 0 – 3. However, the 5-meter fairing Atlas V can support up to 5 SRMs, due to the different aerodynamic properties of the fairing. For the USSF-8 mission, there will be one SRM attached to the center core. The third number denotes the number of engines on the Centaur Upper Stage.

Atlas V, family
A diagram of the entire Atlas V family with the SRM placement for each number shown. (Credit: NASA)

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