Spaceflight Insider

Vulcan’s hammer: United Launch Alliance lofts secretive NROL-55 mission

An Atlas V rocket carrying the NROL-55 mission lifts off from Space Launch Complex 3.

An Atlas V rocket carrying the NROL-55 mission lifts off from Space Launch Complex 3. (Click to enlarge.) Photo Credit: United Launch Alliance

From Space Launch Complex 3E (SLC-3E) located at Vandenberg Air Force Base in California, United Launch Alliance (ULA) sent one of its Atlas V 401 rockets aloft on the classified NROL-55 mission for the National Reconnaissance Office (NRO). Liftoff took place at 5:49 a.m. PDT (12:49 GMT).

“Congratulations on today’s successful launch of NROL-55! ULA is honored to have collaborated with the NRO Office of Space Launch and the Air Force on the integration and launch of the NROL-55 spacecraft to orbit with our Atlas V vehicle,” said Jim Sponnick, ULA vice president, Atlas and Delta Programs. “Launches like this only happen with exceptional teamwork by an extremely talented team and a one-launch-at-a-time focus on mission success.”

NRO L-55 mission logo National Reconnaissance United Launch Alliance image posted on SpaceFlight Insider

NROL-55 mission logo. Image Credit: United Launch Alliance

Although the mission’s primary payload was not announced, ULA did mention that 13 CubeSats shared a ride with the booster’s precious cargo. This was part of the NRO’s Government Rideshare Advanced Concepts Experiment (GRACE) auxiliary payload initiative.

Nine of these tiny spacecraft were sponsored by the NRO and four of them through NASA.

The GRACE portion of the mission will travel in the Atlas V’s Aft Bulkhead Carrier, which is in the rear of the rocket’s Centaur upper stage.

GRACE is the name of the NRO auxiliary payload that saw a total of 13 CubeSats, nine sponsored by the NRO and four sponsored by NASA, to orbit on this morning’s flight. The NRO has conducted similar rideshare efforts in 2012, 2013, and earlier this year.

This morning’s flight marked the 58th time that the Atlas V booster has been sent aloft since the launch vehicle’s first launch in 2002. It marked the 10th launch of 2015 and the 101st launch that ULA has conducted since the company was founded in December of 2006 from components of Boeing and Lockheed Martin.

The Atlas V has an almost perfect track record. Only an issue with the engine in the booster’s Centaur upper stage during a 2007 flight even slightly diminishes that record. During that mission, the two NROL-30 spacecraft were placed into a slightly lower than planned orbit.

The 401 configuration of the Atlas V booster utilizes a four-meter fairing to protect and shield the payload through the atmosphere. This version used none of the Aerojet Rocketdyne AJ-60A solid rocket boosters that are used on some of the other versions of the rocket. ULA recently announced that the AJ-60A will be replaced by Orbital ATK’s GEM 63 solid rocket booster (with the changeout occurring sometime in the 2018-2019 time frame). Lastly, a single Aerojet Rocketdyne RL-10C was used in the booster’s upper, Centaur stage.

The Atlas V currently uses an NPO Energomash RD-180 rocket engine in the launch vehicle’s core stage. Since Russia’s military activities in Ukraine last year (2014) and the subsequent U.S. sanctions that followed, the RD-180 has become a political lightning rod.

ULA, in part due to outside competition from firms such as Hawthorne, California-based SpaceX, has opted to gradually phase out the Atlas V and Delta IV boosters that it currently fields.

The Colorado-based company hopes to begin launching the new Vulcan Next Generation Launch System as early as 2019. When it does so, it will likely employ Blue Origin’s BE-4 rocket engines in its first stage, a Blue Origin BE-3 in its Advanced Cryogenics Evolved Stage (ACES) and, as the mission requires, Orbital ATK GEM 63 XL solid rocket boosters.

Photo Credit: ULA

An Atlas V with the NROL-55 mission lifts off into the sky. (Click to enlarge.) Photo Credit: ULA

As noted, the Atlas V 401 lifted off for the first time on Aug. 21, 2002. Since that time, the booster has been repeatedly used on a wide range missions, from those similar to the one carried out today, to more open scientific endeavors such as the launch of NASA’s Lunar Reconnaissance Orbiter in 2009.

As the 401 has no SRBs, it lifts off at a rather languid pace, slowly strolling across the sky, before building up speed. Given that this was a classified mission, a rough flight profile of this morning’s events are as follows:

• About 17 seconds after lifting off from the launch pad at SLC-3E, the Atlas V carried out a pitch/yaw maneuver to place it on the correct trajectory.

• At one minute and 28 seconds into the flight, the Atlas V and its precious cargo had exceeded Mach 1 and were traveling faster than the speed of sound. Just shy of twelve seconds later, the rocket entered into the most stressful part of the flight.

• At approximately one minute and 30 seconds after the NROL-55 mission had left the pad, it entered the region of the atmosphere where Atlas’ speed, conspires with the atmosphere to place the rocket (and the payload fairing with the spacecraft tucked away inside) under the greatest amount of stress – known as “max-Q”.

• Four minutes and 35 seconds mission elapsed time and the Atlas Booster Engine Cutoff (BECO) took place – which was followed 6 seconds later by the separation of the booster from the Centaur upper stage.

“This launch was [a] great achievement for Team Vandenberg, ULA, NRO and our launch partners,” said Col. J. Christopher Moss, 30th Space Wing commander. “Their outstanding professionalism and teamwork ensured a fantastic launch and I am proud to work with this team of experts in support of national defense.”

The logo (above right) for this mission appears to show the Roman god Vulcan (or, perhaps the Greek god Hephaestus) hammering on a forge from which the Atlas V rocket appears to launch from, the meaning behind this imagery is as mysterious as the actual payload itself. Interestingly, some 13 stars surround the rocket as it ascends in the image.

The imagery could have a simpler explanation – the new rocket ULA is working on is called “Vulcan” after all.

The next launch currently on schedule for ULA is the flight of another Atlas V 401, this time the payload will be the GPS IIF-11 navigation satellite. That mission is set to get underway on Oct. 30 from Cape Canaveral Air Force Station’s Space Launch Complex 41 (SLC-41) in Florida.

Video Courtesy of United Launch Alliance



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

That logo though. Looks like some creepy overblown propaganda poster had a baby with a low-budget game cover.

It’ll always be the Pratt and Whitney RL10 to me.

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