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New derrick crane atop the B-1/B-2 Test Stand at Stennis Space Center
The new derrick crane atop the B-1/B-2 Test Stand at Stennis Space Center has been load tested and commissioned for operational use.

The new derrick crane atop the B-1/B-2 Test Stand at Stennis Space Center has been load tested and commissioned for operational use. Tests of the crane were conducted in the closing days of 2014; the commissioning is a major milestone in preparing the stand for testing the core stage of NASA’s new Space Launch System (SLS). NASA is building the SLS to carry humans deeper into space than ever before. Beginning in late 2016 /early 2017 at Stennis, the agency will test the core stage of the new launch vehicle, 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, uncrewed flight of the SLS in 2018. Similar testing was conducted on Saturn stages for Apollo flights, including those that traveled to the moon. However, major modifications were needed to prepare the B-2 stand to test the new SLS stage. These included upgrading the derrick crane to lift the SLS core stage, which is almost 50 percent taller than the Saturn stages tested during the Apollo era, into place on the stand. In addition to strengthening the crane, the boom was extended 50 feet. With modifications in place late last year, crews began checkout and calibration work on the crane. This included a series of lifts, culminating with lifts of a water-filled tank weighing 429,000 pounds (10 percent above rated capacity). Successful commissioning of the crane marked the final large task of the first of four stand modification work packages; the full package is scheduled for completion by the end of the month. The first work package focused on structural restoration elements and was awarded to Harry Pepper & Associates of Jacksonville, Fla. The second work package primarily focuses on replacement of fixed and movable platforms on the engine servicing deck and restoration of the booster support frame. That work is being performed by Sauer Inc. of Jacksonville, Fla., and is scheduled for completion in February. Work package No. 3 also was awarded to Harry Pepper & Associates, focusing on mechanical/piping and high voltage electrical restoration and beginning the structural buildout of the stand to accommodate the core stage. Its work items include construction of a new 100-foot superstructure for thrust takeout and access to the core stage. Completion is scheduled at the end of March. Work package No. 4, which was awarded in October 2014, will complete the mechanical/piping and high voltage electrical buildout activities. The construction contract for replacing the existing tarmac south of the test stand at the loading dock to accommodate barge offloading of the core stage transporter and insertion into the B-2 Test Stand will be awarded in late March. Modifications at Stennis’ high-pressure industrial water plant to add a 25,000-gallons/minute pump to facilitate vibro-acoustic suppression during core stage testing is on track for completion in December. Activation of the stand is set to begin in early 2016. Once installed, NASA engineers will conduct three types of tests: modal tests to assess the structural vibration modes, tanking tests to verify prelaunch sequences for pressurizing stage systems and for filling and draining propellants, and 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 prelaunch and launch activities.