The SLS Block 1B vehicle that is finally nearing its critical design review will utilize quartets of new RS-25 engines in its Core Stage and RL10 engines in the program’s Exploration Upper Stage.

which will see SLS move from the Block 1 vehicle to the Block 1B rocket in the mid-2020s. Just this month NASA confirmed that plan by publishing a solicitation for ML2. “NASA’s purpose for ML2 ...

Boeing and NASA have come in for scathing criticism from federal investigators, who examined the next generation of Space Launch System rockets ... work began on Block 1B in 2014, when it ...