Spaceflight Insider

ULA launches MUOS-3 satellite to orbit atop Atlas V 551 booster

Atlas V launch viewing guide as seen on Spaceflight Insider

MMS is set to launch atop an Atlas V rocket at 10:44 p.m. on March 12. Photo Credit: Michael Seeley / Spaceflight Insider

CAPE CANAVERAL, Fla — Colorado-based United Launch Alliance (ULA ) successfully launched the third Mobile User Objective System (MUOS-3) satellite to orbit atop the most powerful iteration of the company’s Atlas V booster on Jan. 20,2015. The flight lifted off from Cape Canaveral Air Force Station’s Space Launch Complex 41 (SLC-41) in Florida at 8:04 p.m. EST (0104 GMT) after several delays due to range issues and upper level winds. The launch of MUOS-3, marked the first flight of the year that ULA has carried out under its 2015 launch manifest, which if the company can complete its full docket – should see more than one launch per month.

The launch of MUOS-3 began under mostly clear, crisp skies with the Atlas V booster’s RD-180 engine and five Aerojet Rocketdyne AJ-60A solid rocket boosters producing a staccato roar – and a blazing flame, as bright as a blowtorch. The launch saw the count pushed back a few times due to range issues and upper wind delays. The booster lifted off with time to spare with 22 minutes remaining in the launch window (ULA had a window lasting some 44 minutes, which opened at 7:43 p.m.).

United Launch Alliance Atlas V 551 MUOS-3 satellite photo credit Michael Seeley Spacecraft

United Launch Alliance rolled the Atlas V 551 rocket out to Space Launch Complex 41 at Cape Canaveral at 10:01 a.m. EST. Photo Credit: Michael Seeley / SpaceFlight Insider

Predictions for weather conditions – were accurate. With an 80 percent of favorable conditions for launch – the launch team, operating out of the Atlas Space Operations Center (ASOC), encountered minor technical issues on the way to launch. Working quickly, the team was able to resolve the command interference issue.

Unleashing some 2.5 million pounds of thrust at liftoff, the Atlas V 551 had little problem lifting the roughly 15,000 lb MUOS-3 spacecraft off of the launch pad and on its way to orbit. The 551 configuration of the Atlas V stands some 206 feet (63 meters) tall and has a diameter of approximately 12.5 feet (3.81 meters). This evening’s events started about three seconds prior to launch.

At about 2.8 seconds prior to the rocket and its precious cargo leaving
the launch pad, the RD-180 rocket engine, produced by Russian aerospace firm RPO Energomash, funneled its fury through two nozzles took the first step on the path to orbit About one second later, the five AJ-60As came to life and causing the stack to leap off of the launch pad at SLC-41.

Almost a minute and 45 seconds into the flight and just 15 seconds after the booster had passed through the portion of the flight which is known as maximum dynamic pressure or “max-Q,” the five SRMs, having spent their fuel around the time that the mission had crossed the max-Q threshold – were jettisoned. All five SRMs were not jettisoned at the same time. Two fell away at first with the remaining three dropping away about one-and-a-half seconds later.

“We’ve flown all combinations, anywhere from one-to-five solid rocket motors on any of the 61 prior missions that the AJ-60A has been used on,” said Aerojet Rocketdyne’s Peter Cova. “MUOS happened to be a five motor configuration, which was driven by the weight of the payload, However, there are a lot of other factors that mission analysts need to take into consideration as they configure the vehicle to handle the payload for its particular mission.”

United Launch Alliance ULA Atlas V 551 MUOS-3 Cape Canaveral Air Force Station Space Launch Complex 41 SLC-41 Photo Credit Jared Haworth SpaceFlight Insider

After a handful of brief delays, the ULA Atlas V 551 leaves the pad at Space Launch Complex 41 on its way to orbit. Photo Credit: Jared Haworth / SpaceFlight Insider

The rocket and spacecraft duo were rolled out from the adjacent Vertical Integration Facility or “VIF” to SLC-41 at 10:01 a.m. EST (1401 GMT).

About three minutes and seventeen seconds into the mission, having completed its pivotal portion of the mission, the Payload Fairing or “PLF” separated into its two halves – and was also jettisoned.

ULA United Launch Alliance Atlas V 551 Cape Canaveral Air Force Station Space Launch Complex 41 SLC-41 photo credit Jared Haworth  SpaceFlight Insider a

Photo Credit: Jared Haworth / SpaceFlight Insider

Four minutes and 20 seconds into the flight, main engine cutoff (MECO) occurred once the RD-180 expended its supply of RP-1 and liquid oxygen (LOX). This prepared the mission for staging – which took place just shy of 4.5 minutes into the flight.

Shortly afterward, the Centaur upper stage was readied for its part of the flight – which began about 10 seconds after staging had taken place. Centaur’s RL-10 engine, produced by Aerojet Rocketdyne, has three burns planned to place MUOS-3 in the proper orbital alignment.

The first burn lasted for about 7 minutes and 45 seconds and placed the Centaur/MUOS-3 into its initial parking orbit. The second firing took place at about 8:24 p.m., it lasted approximately six minutes. The final burn for the flight is scheduled to begin two hours and 49 minutes into the flight and end four minutes later – when it does, it will close out the roughly three hour flight with the MUOS-3 satellite safely placed into a geostationary transfer orbit (GTO).

SpaceFlight Insider reached out to Lockheed Martin regarding the MUOS-3 mission and Iris Bombelyn, Vice President of Narrowband Communications for Lockheed Martin provided us with the following insight into the mission:

SFI: Can you provide us with a little background information about what this particular MUOS spacecraft will provide the fleet?  Is there anything different with the MUOS-3 satellite as opposed to the MUOS-1 and MUOS-2 spacecraft?

Bombelyn: “MUOS-3 will further expand the reach of the Mobile User Objective System, allowing this smart phone-like communications network in space to now provide coverage over more than three-quarters of the globe. So from a warfighter’s perspective, for those with MUOS terminals under this expanded territory, they will start having access to MUOS’s new capabilities. This IP-based, 3G system will allow them to text, exchange data, and talk (even in group) directly with any other warfighter around the world under the system’s coverage. Prioritization for access on the network, specific groupings, and access to the government information grid are new features that provide enhanced capabilities. For the warfighter, it means they can call a secure phone on a desk in the Pentagon or log into their secure e-mail as conveniently as when at their desks. Warfighters using the legacy UHF system today just have “voice” and are limited to talking with other warfighters in the area covered by the same UHF communications satellite.  MUOS also has a requirement to provide clear, recognizable voice, which is a tremendous sound quality improvement over current UHF conversations in the field.

United Launch Alliance Atlas V 551 MUOS-3 photo credit Mike Howard SpaceFlight Insider

This evening’s launch took place at the very opening of a 44 minute launch window and marked the third MUOS spacecraft to be placed on orbit by the most powerful variant of the Atlas family of boosters. Photo Credit: Mike Howard / SpaceFlight Insider

MUOS-3 is nearly an exact technical clone of the two predecessor MUOS satellites — as MUOS-4 and MUOS-5 also will be in the future under Lockheed Martin’s fixed price contract with the Navy. Making “the same” satellite three times has actually provided Lockheed Martin the opportunity to significantly improve our efficiency and the time it takes to process each satellite.”

I think it also is important to note that although the Navy is our direct customer, MUOS will benefit more than the Navy fleet. Warfighters in the air, on the ground and at sea will eventually be using its capabilities.  The initial capability is intended to be deployed to the Army, in the form of the HMS Manpack  PRC-155. Other radio terminal providers are developing their own offerings for the government.The Army is already in testing with it and the other services – the Marines, Air Force and Coast Guard – who are dependent on UHF communications, will also be using MUOS in the future. We take it very seriously that we are providing “game changing” communications capabilities to so many service men and women who protect our nation.”

SFI: MUOS is believed to have made the most northerly call from a geosynch satellite, how will MUOS-3 help to strengthen these capabilities – or will it?

United Launch Alliance ULA Atlas V 551 MUOS-3 Cape Canaveral Air Force Station Space Launch Complex 41 SLC-41 Photo Credit Dawn Haworth SpaceFlight Insider

With tonight’s launch, two more MUOS spacecraft are left to be deployed. Photo Credit: Dawn Haworth / SpaceFlight Insider

Bombelyn: “It is true.  The MUOS program has a requirement to operate up to 65-degrees latitude, both North and South.  However, we determined – based on the design of the satellite itself and adding nothing extra – that MUOS should be able to reach pole to pole. In order to demonstrate this, our advanced programs group chartered a plane and brought three radio terminal manufacturers to the pole. Though two were not yet certified to go “over the air” with MUOS, the one which was did maintain clear voice communication and exchanged data all the way to 89.5 degrees North.  So as we place more MUOS satellites into orbit, expanding coverage around the world, this also provides MUOS greater coverage of these polar regions, which we know are communications-challenged areas of increasing interest for many nations.  As this capability is inherent in the satellite’s design, for the U.S. Navy and our warfighters, polar coverage is just an extra benefit they pick up from MUOS, at no extra cost.”

SFI: Can you tell our readers what you consider to be the most unique aspect of this particular mission?

Bombelyn: “I hate to say “routine” vs. “unique,” but perhaps that is what makes this particular launch mission more “unique.”  From the very beginning, the MUOS program was designed to be very stable, with five satellites all produced nearly identical under a fixed price contract. So this is the launch of number three (MUOS-3) and it’s a little like we’ve stepped up to the plate here at Cape Canaveral two times before with essentially the same satellite. Of course, with this repetition, we have had more opportunities to tweak our processes for efficiencies. It has also allowed us to build close relationships with our Navy and industry partners, and I think we all have a greater understanding of what we need to do.

In the end, MUOS-3 brings the Navy’s Mobile User Objective System to the brink of being able to provide global coverage. Once the constellation is completed, our warfighters all over the world be able to clearly communicate with each other, no matter where they are, as well as take advantage of MUOS’ other smart-phone like capabilities.”

The timeline of these events was produced using sources at United Launch Alliance and SpaceFlight Now.

United Launch Alliance Atlas V 551 rocket Cape Canaveral Air Force Station Space Launch Complex 41 SLC-41 MUOS-3 photo credit Mike Deep SpaceFlight Insider

Photo Credit: Mike Deep / SpaceFlight Insider


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Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

I am continually amazed at how fast this vehicle accelerates off the pad. Must be the benefit of the SRB’s. Does anyone know of an instance when the SRB’s did NOT separate as scheduled, and what would the ramifications be? I’d also be curious to know if SpaceX is considering SRB’s to add to it’s lifting capacity? Time will tell.

That was an amazing launch! The camera views were great too, and they even showed the satellite release.

Ron- I have not heard of any launches where a SRB did not disengage. It doesn’t mean that hasn’t happened, I’ve never read/heard about it anywhere.
SpaceX has stated, several times, that they want to stay away from solid fuel in all forms. Apparently it does not fit within the ‘rapidly reusable’ mission.

Cool, thanks for the info.

Does the MUOS 3 stack configuration for the BULA Atlas V with Agena also include a PAM for payload insertion into geosynchronous orbit?

Hi Christopher,
We’ve tried to get an answer for your question, but, given that Agena hasn’t been used since (I believe) 1966 – we’re not sure what you’re asking. Also, MUOS-3 – launched in Dec. 2014. Please clarify.
Sincerely, Jason Rhian – Editor, SpaceFlight Insider

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