NASA’s Space Launch System: Capabilities for Ultra-High C3 Missions

Abstract

1. Executive Summary Designed to meet NASA's requirements for human exploration of the Moon, Mars and beyond, the Space Launch System (SLS) vehicle offers enhancing and enabling capabilities for a variety of missions. Using commercially available propulsion systems as third and/or fourth stages, SLS offers C3 performance double the highest-C3 missions ever flown. This capability can be game-changing for missions into the interstellar medium or for high-energy solar observation missions. Today, SLS is making progress toward its initial launch capability and toward both future launches and future capabilities. In addition, NASA has issued contracts with prime contractors for SLS hardware for delivery well into the 2030s. 2. Overview The initial configuration of SLS, the Block 1 crew vehicle, is powered at launch by four RS-25 engines and two solid rocket boosters, with an almost 67 meter (m) tall core stage. In-space propulsion is provided by an interim cryogenic propulsion stage (ICPS). The Block 1 vehicle can be flown in a cargo configuration utilizing a commercially available 5 m fairing. The next configuration of SLS, Block 1B, upgrades the upper stage to an exploration upper stage (EUS) equipped with four RL10s. Block 1B can be flown in a cargo configuration with an 8.4 m fairing up to 27.4 m in length. The ultimate configuration of the vehicle, Block 2, upgrades the solid rocket boosters to more powerful evolved solid boosters. The Block 2 vehicle offers the potential to fly larger 10 m fairings. In these baseline configurations, SLS offers significant performance for a wide range of missions. The Block 1 vehicle is capable of launching 27 metric tons (t) to trans-lunar injection (TLI), approximately 20 t to Mars, and 6 t direct to Jupiter. The Block 2 vehicle offers the ability to deliver greater than 46 t to TLI, greater than 35 t to Mars, and approximately 8 t direct to Jupiter. More information about SLS performance and environments may be found in the Space Launch System Mission Planner's Guide. [1] 3. SLS for Ultra-High C3 Missions The SLS Program has partnered with the Advanced Concepts Office (ACO) at NASA's Marshall Space Flight Center (MSFC), to perform studies to predict C3 performance of the Block 2 vehicle with the addition of commercially available third and fourth stages encapsulated with the spacecraft/payload in the 8.4 m 19.1 m long fairing. During this study, the approach to predicting the mass delivered targeted a balanced approach that assumed mean vehicle mass, nominal liquid engine performance, and a low-performance booster, allowing for a conservative approach that is below the nominal performance prediction. The stages selected for the study include LH2/LOX