1 min readJ-2X Powerpack on the A-1 Test StandNASAJul 19, 2012 Image Article The J-2X powerpack is installed and ready for testing in the A-1 test stand at the Stennis Space Center. The J-2X powerpack is installed and ready for testing in the A-1 test stand at the Stennis Space Center. Image credit: NASA/SSC