Orbital ATK preparing for next phase of NGL rocket development

by Chris Gebhardt

Orbital ATK is preparing for the next phase of development for their Next Generation Launcher (NGL) – a solid and liquid fueled rocket designed for National Security, NASA science missions, and commercial flights.  Under the current plan, Orbital ATK intends to introduce NGL from LC-39B at the Kennedy Space Center, FL, with certification flights in early 2021, with operational flights set to begin later that year.

NGL aims for debut in three years:

The progeny of NGL can be traced back to 2004, when then U.S. President George W. Bush announced the Constellation program, consisting of the crew launch vehicle known as Ares I – a five-segment Solid Rocket Booster (SRB) rocket, atop which sat a Liquid Oxygen/Liquid Hydrogen (LOX/LH2) upper stage.  

A test flight variant of Ares I, known as Ares I-X, completed a successful test flight on 29 October 2009, shortly after which the Constellation program was cancelled by then U.S. President Barack Obama in favor of developing a more robust rocket that could carry both crew and cargo, the SLS, to locations Beyond Low Earth Orbit and shifting International Space Station crew rotation missions from NASA-made rockets to commercial rockets and capsules – a goal SpaceX and Boeing plan to fulfill.

Despite the Constellation program’s cancellation, Orbital ATK, the predecessor of which would have built the five-segment SRB for Ares I and the company that is now building the five-segment dual SRBs for SLS, continued to see a usefulness for the overall Ares I design.  This initially translated in 2011 to the Liberty rocket, a five-segment SRB first stage with an Ariane V core serving as the upper stage.

By May 2016, this overall design was incorporated into Orbital ATK’s participation and contract award from the U.S. Air Force as part of the Air Force’s Rocket Propulsion Systems Development project to replace the Russian-made RD-180 engine used on United Launch Alliance’s Atlas V rocket and to also streamline the EELV (Evolved Expendable Launch Vehicle) program to reduce the overall cost and increase efficiency of U.S. rockets used for national security and government missions.

Orbital ATK, with NGL, has passed through the first two phases of the Rocket Propulsion System Development project, with Phase 3, now called the Launch Service Agreement, awards scheduled to be announced by the end of July 2018.

Orbital ATK has already been told by the Air Force that NGL is within the competitive range of the program, and the company hopes that the Phase 3 awards – which will continue partial Air Force funding for the development of NGL – will allow the vehicle to maintain its overall development schedule and be certified for national security missions and be available for competitive commercial launches in 2021.

Recently, NASASpaceflight’s Chris Gebhardt talked with Mike Laidley, Vice President of Space Launch Programs for Orbital ATK, about NGL’s development and future.  “The initial launch – which will be the intermediate configuration – will fly in the first quarter of 2021 for a certification flight,” stated Mr. Laidley.  “We have two certification flights planned for 2021, and then we’ll be in regular launching activity late in the year 2021.”

Under this plan, Orbital ATK will have NGL fully certified for government missions by the end of 2021 and hopes to offer the initial two certification flights at reduced cost to commercial companies for LEO (Low Earth Orbit) or GEO (Geostationary Orbit) missions.

Artist’s conception of the Liberty rocket rolling out to the launch pad at the Kennedy Space Center, FL. (Credit: Orbital ATK)

The two certification flights will utilize the intermediate variant of NGL, consisting of a two-segment SRB (the C-600) first stage, a single-segment (C-300) SRB second stage, and a 70,000 lbs propellant load LOX/LH2 upper stage that is being designed in-house by Orbital ATK.

The C-600 first stage will produce a maximum of 2.2 million pounds thrust and the second stage C-300 will produce a maximum of 875,000 pounds thrust during flight.

The SRB segments for NGL will be roughly the same diameter as the SRB segments used during the Space Shuttle program as well as those that will be used for SLS; however, NGL’s SRB segments will be slightly longer and heavier than their Shuttle and SLS counterparts.

The added weight will come from additional propellant inside the segments, as the segments themselves will be made of a new, lighter weight and stronger composite material compared to the steel casings used for Shuttle and SLS.  The creation of the NGL composite SRB segments – as well as their propellant casting – is also switching to a more automated process, a change that will help reduce the cost of production for the SRB segments while capitalizing on new technologies that have emerged since the Shuttle SRBs were first designed in the 1970s.

An NGL rocket launches into the Florida sky, as envisioned by Nathan Koga for NSF/L2

“We’re currently in the process of going through verification efforts on the case design.  Initial testing of a single segment is done and we’re in the process of going through load testing,” noted Mr. Laidley.  “Later this year we’ll pour an inert motor that will verify our ability to put propellant in a case segment.  All that leads up to static fire testing in 2019 for those solid motor products.  So by the time we get to the third quarter of 2019, we will have static fired both the C-300 and C-600 stages,” said Mr. Laidley.

The new design will capitalize on Orbital ATK’s – and their various former companies’ – history of producing SRBs since the 1970s and will include a rigorous test regime to ensure the SRB segment designs are capable of withstanding all of the possible flight environments they will encounter during operation.

“We have in our solid propulsion design and production activities a long history of designing solid motors.  And we have processes setup to qualify for maximum environments and maximum scenarios where we can predict what the thermal environments are, what kind of heating all these components are going to see, and what kind of vibrations and shock environments they’re going to experience,” stated Mr. Laidley.

This will include subjecting the segmented design to significant amounts of pressure and temperature differential tests as well as load testing to verify flight environments and qualification for flight.  “At the component and subsystem levels, we put these motors through some pretty severe paces, and we design in margins of safety so that we are very confident that they are going to perform reliably over all the mission scenarios we’re going to have to fly,” noted Mr. Laidley.

The future and current EELV fleet, with NGL, Vulcan, and New Glenn included. SpaceX’s Falcon 9 and Falcon Heavy shown together. (Credit: Orbital ATK)

This robust test environment will include all of the lessons learned from the 30+ years of SRB operation for the Space Shuttle, including post-Challenger SRB redesign testing undertaken by Morton Thiokol – predecessor to ATK and Orbital ATK – that intentionally introduced defects into SRB segment O-ring field joint seals to see exactly how far hot gas would penetrate into the field joints of two SRB segments under different temperature and pressure environments.

Understanding how the SRB field joints perform under these various conditions is vital to the ground testing and development arena for NGL as the rocket’s segmented SRB stages will not be recovered for evaluation of in-flight performance – something Orbital ATK is already familiar with in SRB design as NASA’s SLS rocket will utilize expendable segmented SRBs instead of recoverable ones.

Once the overall design of the SRBs is certified, NGL will debut in its intermediate configuration in 2021.  The intermediate variant of NGL can also include strap-on GEM-63XL solid rocket motors produced by Orbital ATK to provide additional lift capacity for LEO or GEO missions.

Three years after the initial introduction of NGL, Orbital ATK plans to introduce the NGL heavy variant, consisting of a four-segment SRB first stage, known as the C-1200, a single-segment SRB second stage, the C-300, and a slightly larger LOX/LH2 upper stage – 110,000 lbs of propellant instead of 70,000 lbs.

In the heavy configuration, meant to fly the same types of missions ULA’s retiring Delta IV-Heavy currently flies, the first stage four-segment SRB would produce roughly 3.1 million pounds of thrust during flight.  While both the intermediate and heavy NGL configurations will fly with a 5 meter diameter payload fairing, the heavy configuration payload fairing will be roughly 20 feet (6.09 meters) longer.

Utilizing Kennedy Space Center resources:

To introduce NGL to the government and commercial markets, Orbital ATK will launch the certification flights and initial three years worth of missions from LC-39B at the Kennedy Space Center, sharing the launch pad with NASA’s SLS rocket.

“We have been working closely with the KSC agreements office and the management at KSC to outline a strategy where NGL can co-process along with SLS over the time frames allowed,” said Mr. Laidley.  “And SLS has a fairly low launch rate, so we don’t see a huge concern with deconflicting our activities with SLS.  We are certainly working with NASA KSC and with the FAA (Federal Aviation Administration) to make sure that we lay out processes that are safe for everyone so that we can all use those vital government facilities as efficiently as possible.”

In addition to sharing LC-39B with SLS, Orbital ATK already have agreements in place to take ownership of MLP-3 – Mobile Launch Platform 3, previously used for the Apollo and Shuttle programs – and modify it for use by both the intermediate and heavy NGL variants as well as for use of High Bay 2 of the Vehicle Assembly Building (VAB) for stacking and integration  of NGL before rolling out to Pad-B.

Space Shuttle Atlantis seen in front of VAB High Bay 2 for Shuttle VAB safe haven fit checks ahead of STS-106 rollout to the launch pad. (Credit: NASA)

High Bay 2 was utilized in the Shuttle program for External Tank pre-mate inspections and configuration.  Beginning in the 2000s, High Bay 3 was configured to serve as a storage High Bay for a complete Space Shuttle stack in case a vehicle at the pad needed to return to the VAB for safe haven from an approaching hurricane at a time when both of the stacking High Bays – High Bays 1 and 3 – were occupied.

The only fully assembled Space Shuttle stack to take residence in High Bay 2 was STS-106/Atlantis, which after stacking and integration operations in High Bay 1 was rolled around the VAB into High Bay 2 for fit checks.  No Shuttle stack ever needed to take refuge in High Bay 2 for a hurricane.

MLP-3 and High Bay 2 reconfigurations for NGL are expected to begin in late-2019 and will only begin once NGL has passed through both its Preliminary Design Review in summer 2018 and its Critical Design Review in summer 2019.

However, Orbital ATK is already in contact with contractors in Florida who have current and prior experience building and reconfiguring Mobile Launch Platforms and the VAB High Bays so that once NGL completes its CDR next year, reconfiguration work on MLP-3 and High Bay 2 can begin in earnest.

Artist’s conception of NGL at Pad-B before launch. (Credit: Orbital ATK)

As for deconflicting operations with SLS, one thing that will greatly aid that endeavor is the extremely limited amount of time NGL will spend on the pad between rollout and launch.  “We envision a scenario where we can get down to a very short amount of time on the pad.  I think we’re talking on the order of a day or two on the pad from the time we arrive after rollout to when we’re ready to launch and get off the pad and then bring our MLP back,” noted Mr. Laidley.

Nonetheless, the Kennedy Space Center is not the only location NGL will launch from.  The vehicle is also designed to serve national security, government, and commercial polar orbit needs via launches from Vandenberg Air Force Base, California.

Currently, Orbital ATK states they have no specific plan and no agreement in place for which launch facility they will use at Vandenberg; however, their ideal plan would be to take over SLC-6 from United Launch Alliance once the last Delta IV-Heavy flies from that pad in 2023.

“We’re working with the Air Force to see if there’s an opportunity for us to step in when ULA leaves [SLC-6] and utilize that facility.  That’s one of the options that works for us and our timeline for a first Vandenberg launch in 2024,” said Mr. Laidley.

SLC-6 at Vandenberg – ULA photo

Nonetheless, “a lot of hard work remains in front of us as we flesh out the design and get the details worked out”, and Orbital ATK is confident that NGL will be available to the government and commercial markets at a competitive price to current launch pricing models that are publicly available.

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