NASA&#x27;s SLS, which is having its first test flight in 2018, will launch with a Block I config with 2 SRB of 3,600,000 lbf each,  4 RS-25D&#x2F;E shuttle engines at 512,300 lbf each for stage one and RL10B-2 for stage two at 24,800 lbf OR a stage two Block 1B config of 4 RL10&#x27;s at 99,000 lbf.  So about 9m lbf in its heaviest configuration. The Saturn V produced 7m lbf for comparison.<p>Boeing also has the Delta IV which uses the home grown RS-68 series engines. The Heavy configuration of this rocket has 2m lbf.<p>Only the Atlas series uses the Russian RD-180. ULA just ordered 20 more RD-180s at the cost of a great deal of political capital. Its assumed this is the last batch until the replacement BE-4 engine is ready.