Space Launch System

NASA's super heavy-lift expendable launch vehicle

The Space Launch System (SLS) is a NASA rocket.[1][2] It is a super heavy-lift launch vehicle.[1][2] It is the second most powerful rocket ever built, less powerful than Starship.[1] The SLS is a replacement for the retired Space Shuttle.[1] Many parts are modified versions of parts designed for the Space Shuttle. Others are new designs.

An artist's picture of the Space Launch System flying

The first flight with astronauts will be no earlier than 2025's third quarter. The planned flight is Artemis 3.

Left to right: Block 1, Block 1B, Block 2.

The Space Launch System comes in many different types meant to launch different kinds of missions.

Block 1


The least powerful kind of the SLS is the Block 1. The core stage will use the parts of the Space Shuttle External Tank. It will also use four Space Shuttle Main Engines. The rocket boosters are connected to the sides are the 5-segment Space Shuttle Solid Rocket Boosters. The top stage will use is the Interim Cryogenic Propulsion Stage (ICPS).

Block 1B


Block 1B is similar to the Block 1. The top stage will change with Exploration Upper Stage (EUS). A crew version and a cargo version will be made.

Block 2


Block 2 is similar to Block 1B. The 5-segment SRBs will be changed with advanced boosters.



  1. 1.0 1.1 1.2 1.3 "NASA unveils super rocket", BBC Focus Magazine, no. 235, Bristol Magazines, p. 17, November 2011
  2. 2.0 2.1 "NASA unveils mega rocket", How it Works, no. 26, Imagine Publishing, pp. 6–7, 2011-10-06