The next Atlas 5 rocket stack starts at Cape Canaveral – Spaceflight Now


The first phase for ULA’s next Atlas 5 rocket mission was lifted on Friday on a mobile launch platform at Cape Canaveral Air Force Station. Credit: United Launch Alliance

United Launch Alliance technicians deployed the first stage for the next Atlas 5 rocket on a mobile launch platform on Friday in Cape Canaveral, an important step in preparation for the October mission that will usher in a new solid-fuel booster design.

This launch marks the 86th flight of the Atlas 5 rocket since 2002, and will carry a classified payload into orbit for the National Reconnaissance Office, for this year’s fifth Atlas 5 launch. The mission is designated NROL-101 in the NRO’s numerical naming scheme.

Atlas 5’s bronze first stage – tail number AV-090 – was moved from the Atlas Spaceflight Operations Center at the Cape Canaveral Air Force Station to the Vertical Integration Facility just south of the pad in the early hours of Friday. Ground crew at the VIF lifted 107 feet (32-m) in the first stage on the Atlas 5’s mobile launch platform placed inside the vertical hangar.

The launch of the rocket’s Russian-built RD-180 main engine will load the first stage with 25,000 gallons of RP-1 kerosene fuel and 49,000 gallons of liquid oxygen on launch day, generating 860,000 pounds of thrust with full throttle .

The start of the first phase inside the VIF marked the launch vehicle on stand milestone for ULA’s launch team.

In the coming days, three Northrop Grumman-built GEM 63 solid rocket motors will be placed in the first stage of the Atlas 5. The ULA would then hoist the rocket’s centaur upper stage on top of Atlas 5, with the bottom of the launch vehicle’s payload fairing.

After the rocket’s initial checkout, technicians will add the rocket’s secret satellite payload to complete the build-up of Atlas 5 for the NROL-101 mission.

Atlas 5 is scheduled for liftoff in October, according to officials at the US Defense Force’s Space and Missile Systems Center, which oversees the launch of national security satellites.

The GEM 63 Solid Rocket Booster will fly for the first time on the NROL-101 mission. They replace the Aerojet Rocketdyne AJ-60A strap-on boosters that were flown on previous Atlas 5 rockets.

ULA technicians receive inspection on the GEM 63 motor in Cape Canaveral. Credit: United Launch Alliance

Each 63-inch-diameter (1.6-m) booster – officially called a graphite epoxy motor – is 66 feet (20 m) long and can produce 373,800 pounds at maximum power. The GEM 63 booster will fire on the launch pad and burn for 94 seconds, consuming 97,500 pounds (44.2 metric tons) of pre-packed solid propellant before falling into the sea.

The GEM 63 booster design is the development of a 60-inch GEM 60 motor manufactured by Northrop Grumman for the Glee Delta 4 rocket family. No more Delta Delta to fly for the GEM 60 Solid Rocket Booster.

Northrop Grumman, through its predecessors ATK and Orbital ATK, supplied small strap-on boosters to the now retired Delta 2 and Delta 3 rocket families.

Boosters give rockets an extra push to rockets carrying heavy payloads, or missions that require satellites to be placed in high altitude orbits.

Like the AJ-60A motor, the GEM 63 will have a nozzle and a curved, or augmented, nose cone fixed, providing the appropriate aerodynamic shape to clean the booster away from the Atlas 5 after the burner. Northrop Grumman’s GEM 63 booster produces almost the same thrust and has roughly the same dimensions as the AJ-60A, allowing ULA to introduce the new booster model as a “direct replacement” for the older Aerojet rocket version.

Aerojet Rocketdyne’s AJ-60A motor has a flawless record since its first use at the third launch of the Atlas 5 in July 2003, with 127 boosters swept to date.

ULA announced in 2015 the selection of Orbital ATK – now part of Northrop Grumman – for future Atlas 5 launches and to provide solid rocket boosters for the next-generation Vulcan Centaur rocket. At the time, ULA stated that the selection of the GEM 63 rocket motor would “significantly reduce the price to the ULA and the US government.”

The Northrop Grumman Booster, built with the help of advanced robotics and automation, has also been made easier to connect to the launch vehicle in the vertical integration facility.

A longer version of the GEM 63, known as the GEM 63XL, will fly on ULA’s new Vulcan Centaur rocket, which is scheduled for opening in the second half of 2021. The Atlas 5 rocket can fly from zero to any number of solid rocket boosters. At five, while the Vulcan Centaur rocket can launch with two Blue Origin BE-4 main engines in a configuration with two, four or six boosters.

Northrop Grumman performed three test-fires of the GEM 63 booster at a test site in Promontory, Utah, before clearing a solid-fueled rocket motor to fly.

AJ-60A motors from Aerojet Rocketdyne have not been done yet.

Ula spokesman Julie Arnold said the company would continue the Aerojet Rocketdyne booster on future Atlas 5 missions until the rocket was completely replaced at Northrop Grumman Motors. The AJ-60As will continue to launch on missions with Boeing’s Starliner commercial crew capsule, and ULA is working with NASA towards future use of GEM 63 at the launch of astronauts.

Arnold said ULA plans for all Atlas 5 launches after 2021 to use the new GEM 63.

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