SBIRS GEO-6 | Atlas V 421

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Featured image credit: ULA
Launch Window
(Subject to change)

August 4, 2022 10:29 – 11:09 UTC | 06:29 – 07:09 EDT

Mission Name

SBIRS GEO-6

Launch Provider
(What rocket company is launching it?)

United Launch Alliance (ULA)

Customer
(Who’s paying for this?)

United States Space Force

Rocket

Atlas V 421

Launch Location

Space Launch Complex-41, Cape Canaveral Space Force Station, Florida, USA

Payload mass

4,500 kg (~10,000)

Where are the satellite(s) going?

Geostationary Transfer Orbit (GTO)

Will they be attempting to recover the first stage?

No, this is not a capability of ULA

Where will the first stage land?

It will crash into the Atlantic Ocean

Will they be attempting to recover the fairings?

No, this is not a capability of ULA

Are these fairings new?

Yes

How’s the weather looking?

TBD

This will be the:

– 5th launch of ULA in 2022 
79th Atlas V launch from Cape Canaveral
– 9th launch of an Atlas V in the 421 configuration
– 152nd ULA mission 
– 93rd orbital launch of 2022

Where to watch

If available, an official livestream will be listed here

What Does All This Mean?

ULA will launch the SBIRS GEO-6 satellite atop an Atlas V rocket in the 421 configuration for the United States Space Force’s Space Systems Command (SSC). The rocket is scheduled to lift off from Space Launch Complex-41 at Cape Canaveral Space Force Station, Florida, USA on August 4, 2022.

What Is The SBIRS GEO-6 Mission?

The Space Based Infrared System (SBIRS) is a network of satellites and hosted payloads in Geosynchronous Earth Orbit (GEO) and Highly Elliptical Orbit (HEO), which utilize scanning and staring infrared sensors to provide early missile warning and defense capabilities to the U.S Space Force’s Space and Missile Systems Center. The main aim of the program is to support missile defense, missile warning, battlespace awareness, and technical intelligence.

SBIRS GEO-6 is the sixth and final satellite in the program, which was designed to replace the Defense Support Program, Northrop Grumman’s system of early warning satellites, which has been in operation since the 1970s. The first of the SBIRS satellites was launched in 2011, with subsequent satellites being launched in 2013, 2017, and 2018.

While this is the 6th SBIRS spacecraft to be built by Lockheed Martin, it is the second to be built on the company’s LM 2100 combat bus, which provides enhanced security features, and improved power, propulsion, and electronics. The SBIRS GEO-5 satellite was the first to be built on the LM 2100M bus.

An Atlas V rocket will be used to take the satellite to Geostationary Transfer Orbit (GTO), after which the satellite will use its own propulsion system to gradually raise its orbit to geosynchronous orbit.

The SBIRS GEO-5 mission warning satellite during acoustic testing. (Credit: Lockheed Martin)

SBIRS GEO-5 Flight Profile

Hrs:Min:Sec
From Lift-OffEvents0:00:00Liftoff0:00:47Maximum Dynamic Pressure (Max Q)0:02:09  SRB Jettison0:04:10Atlas Booster Engine Cutoff 0:04:16Atlas Centaur Separation 0:04:26Centaur Main Engine Start (MES-1)0:04:34Payload Fairing Jettison 0:15:06Centaur Main Engine Cutoff (MECO-1)0:15:37EZ-3 Deployment 0:16:25EZ-4 Deployment 0:31:06Centaur Main Engine Start (MES-2)0:34:27Centaur Main Engine Cutoff (MECO-2)0:42:26SBIRS GEO-5 Separation 

The Atlas V payload fairing which will enclose the SBIRS GEO-5 satellite. (Credit: ULA)

What Is The Atlas V?

The Atlas V is an expendable medium lift launch system and member of the Atlas rocket family. The rocket is one of the most reliable in the world, having more than 76 launches (As of November 2020) with no complete failures.

The rocket has two stages. The first is a Common Core Booster (CCB), which is powered by an RD-180 engine and burns kerosene (RP-1) and liquid oxygen (LOx). This is accompanied by up to five strap-on solid rocket boosters. 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).

In the 421 configuration, the Atlas V is capable of carrying up to 14,067 kg to Low Earth Orbit (LEO), and 6,890 kg to Geostationary Transfer Orbit (GTO).

What Does 421 Mean?

Atlas V rockets have a three number configuration code. The first number represents the fairing diameter size in meters, so in this instance there is a 4 meter fairing. The second number denotes the number of solid rocket boosters (SRBs), which attach to the base of the rocket. The number of SRBs for a 4 meter fairing can range from 0 – 3. In this case there will be 2 SRBs attached to the center core. The third number shows the number of engines on the Centaur Upper Stage, which is 1 in this configuration. So this means that this rocket will have a 4 meter faring, 2 solid rocket boosters, and 1 engine on the Centaur Upper Stage.

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

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