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NASA Moving Forward on Test Stand Upgrades for SLS Core Stage Testing

NASA is nearing completion on two major structural restoration construction packages for the B-2 Test Stand at the agency’s Stennis Space Center near Bay St. Louis, Mississippi, marking critical milestones for testing the core stage of the new Space Launch System (SLS).

“The stand is certainly busy these days,” said Rick Rauch, manager of the B-2 Test Stand project. “We’re making significant progress toward 2016 and the arrival of the SLS core stage. It’s a very exciting time.”

NASA is building the SLS to carry humans deeper into space than ever before. Beginning in 2016, the agency will test the core stage of the new launch vehicle at Stennis, which is powered by four RS-25 rocket engines, modified versions of the same engines that powered the space shuttle. After testing is complete, the core stage will be used for the maiden, unmanned flight of the SLS.

Completion of major B-2 Test Stand structural restoration elements under work package No. 1 by Harry Pepper & Associates of Jacksonville, Florida, is scheduled for later this month. Restoration and upgrading of the main derrick crane, which sits atop the stand and will be used to lift the core stage into the test stand, is scheduled for completion in early September. The SLS stage is nearly 50 percent longer than the Saturn stages previously tested on the stand, so the main derrick has to be significantly upgraded.

Completion of B-2 Test Stand work package No. 2 by Sauer Inc. of Jacksonville, Florida, is scheduled for July. The work primarily focuses on replacement of fixed and movable platforms on the engine servicing deck and restoration of the booster support frame.

Work package No. 3 has also been awarded to Harry Pepper & Associates. It completes B-2’s restoration activity, focusing on mechanical/piping and high voltage electrical restoration, and begins the structural buildout of the stand to accommodate the core stage. A new 100-foot superstructure will be constructed for thrust takeout and access to the core stage. Completion is scheduled for spring 2015.

Work package No. 4 will be awarded later this year for completion of mechanical/piping and high voltage electrical buildout activities and replacement of the existing tarmac at the loading dock to accommodate barge offloading of the core stage transporter and insertion into the B-2 Test Stand. It also is scheduled for completion in 2015.

In addition to those packages, NASA will install a new pump alongside existing ones at Stennis’ high-pressure industrial water facility to supply an additional 25,000 gallons of water per minute to the B-2 Stand. The additional water will be used to suppress the sound of tests and lessen the vibro-acoustic impact on the core stage.

Activation of the stand is set to begin in early 2016. The SLS core stage is slated for delivery in early fall 2016. Once installed, NASA engineers will conduct three types of tests:

  • Modal tests to assess the structural vibration modes.
  • Tanking tests to verify pre-launch sequences for pressurizing stage systems and for filling and draining propellants. This will mark the first time cryogenic propellants are introduced into the core stage. Engineers will monitor and collect data on various items regarding how the stage reacts to the very low propellant temperatures.
  • Hotfire tests that will involve the simultaneous firing of four RS-25 engines, just as will occur during an actual mission. NASA plans only one or two full tests since the stage is designed for a limited number of chilldowns, including those related to pre-launch and launch activities.

The core stage will be removed from the B-2 Test Stand in early 2017 in preparation for SLS’s first mission.

A key aspect of the ongoing B-2 Test Stand restoration/modification project is the coordination of work on various fronts, including exactly how the stand needs to be configured to enable testing of an SLS vehicle still in design.

“It’s a much more complex process than most people realize,” Rauch said. “It requires a lot of communication with multiple stakeholders to make sure tests are conducted properly to supply the needed data to verify flight readiness. This has traditionally been Stennis’ special area of expertise.”

The SLS Program is managed at NASA’s Marshall Space Flight Center in Huntsville, Ala.
For information about NASA’s SLS Program, visit:

For information about Stennis Space Center, visit:

Watch a video that shows a time-lapse view of some of the B-2 Test Stand main derrick crane removal at Stennis:

Late afternoon clouds on a winter afternoon provide a dramatic highlight to the new Facilities Support Center at NASA’s Dryden Flight Research Center. Desert landscaping around the 38,000-square-foot structure is intended to minimize water usage with drought-tolerant shrubbery. The structure was designed to meet the Leadership in Energy and Environmental Design (LEED) new construction platinum certification for environment and energy efficiency. NASA facilities engineers forecast that energy consumption will be reduced about 36 percent over conventional construction.
Jan. 21, 2014
NASA / Tom Tschida

Rebecca Strecker
Stennis Space Center, Miss.