An artistic view of Space Launch System (SLS). Credit: NASA

NASA is working on a new super-heavy-lift launch vehicle called Space Launch System or SLS. The Space Launch System will be used to launch the Artemis I, the mission to go back on moon (Artemis is the twin sister of Apollo). The SLS will produce around 8.8 million pounds of thrust during initial stage at lift-off, becoming the most powerful lanuch vehicle ever built.

SLS components. Credit: NASA

Solid boosters

The SLS will use two solid fueled booster rockets and four RS-25 engines as main engine. The largest human-rated solid rocket boosters ever built for flight, the SLS twin boosters, built by Northrop Grumman, stand 17 stories tall and burn about six tons of propellant every second. The twin rocket boosters burn more than two million pounds of solid propellant to create more than seven million pounds of thrust (each booster generates more thrust than 14 four-engine jumbo commercial airliners). Together, the SLS twin boosters provide more than 75% of the total thrust at launch.

RS-25 mian engines

RS-25 main engines. Credit: NASA

Four RS-25 (built by Aerojet Rocketdyne) engines will produce more than 2 million pounds of thrust (at altitude). Combined with two five-segment solid rocket boosters, the propulsion system will give SLS about 8.8 million pounds of thrust at launch — more lift than any current rocket and 15% more than the Saturn V (which was used in famous Apollo 11 mission that put the first man, Neil Armstrong, on moon). An RS-25 variant is under production for Artemis missions past the first four.

Main engine fuel tank

The liquid hydrogen (LH2) tank (built by Boeing) comprises two-thirds of the core stage, weighs 150,000 pounds (68,000 kilograms) and holds 537,000 gallons (2 million liters) of liquid hydrogen cooled to minus 423 degrees Fahrenheit. Thermal foam keeps the LH2 at the right temperature and pressure. The liquid oxygen (LOX) tank (built by Boeing) holds 196,000 gallons (742,000 liters) of liquid oxygen cooled to minus 297 degrees Fahrenheit. Its thermal foam coating protects it from extreme temperatures — the cold of the propellants and the heat of friction.

Criyogenic upper stage

The Interim Cryogenic Propulsion System or ICPS, (built by United Launch Alliance and Boeing) for SLS Block 1 is the initial configuration that can deliver 27 metric tons of payload to the moon. Based on the proven Delta Cryogenic Second Stage and powered by one Aerojet Rocketdyne RL10 engine, ICPS will propel an uncrewed Orion spacecraft to fly beyond the moon and back on the Artemis I mission.

The Space Launch System or SLS is itself a very complicated system. It will help NASA to conduct more missions into deep space like moon, mars and other interplanetary mission.

_{Data Sources: https://blogs.nasa.gov/artemis/2020/11/20/nasa-prepares-for-next-series-of-rs-25-engine-tests-for-sls-rocket/
https://www.boeing.com/space/space-launch-system/ https://www.nasa.gov/exploration/systems/sls/to-the-moon.html https://www.nasa.gov/press-release/nasa-commits-to-future-artemis-missions-with-more-sls-rocket-engines}