Space Launch System


NASA Space Launch System (SLS) is a multi-purpose heavy-lift launch vehicle system designed to carry astronauts to an asteroid, moon, mars and beyond. The launch date of the first flight is 17 December, 2017.

SLS First Launch Picture

Space Launch Program

The Space Launch System (SLS) Program is developing a heavy-lift launch vehicle system. These launch vehicles will be capable of lifting:

– Orion Multi-Purpose Crew Vehicle to International Space Station.
– Cargo, equipment and science experiments to Earth’s orbit.
– Orion MPCV and cargo to near-Earth asteroids, to cis-lunar space, the moon, Lagrange points, to Mars and its moons and to other destinations in the solar system and beyond.
– Backup launch system for supplying and supporting the International Space Station cargo and crew requirements not met by other available launch vehicles.
– launching spacecraft to return samples from planets, asteroids, moons.


Core Stage Height: 61 m (200 ft)
Core Diameter 8.4m (27.5 ft)
Payload to LEO: 70,000 to 130,000 kg (150,000 to 290,000 lb)
Stages: 2

The Space Launch Vehicle architecture was chosen because:

(1). NASA can use existing capabilities and lower development costs by using liquid hydrogen and liquid oxygen (lox) for both the core and upper stages.

(2). By using modular common elements, the launch vehicle can be configured for specific missions.

(3). By using a modular approach NASA can develop the high-cost development elements first and then build the rockets in higher numbers to achieve savings.

Space Launch System Picture

Space Shuttle Program and Constellation Program Connection

The SLS rocket incorporates technological investments from the Space Shuttle Program and the Constellation Program. It takes advantage of proven hardware and tooling and manufacturing technology that will significantly reduce development and operations costs. It uses a liquid hydrogen and liquid oxygen propulsion system, which includes the RS-25D/E rocket engines from the Space Shuttle Program for the core stage and the J-2X engine for the upper stage. SLS uses solid rocket boosters (Ares Project solids) for the initial development flights, while follow-on boosters will be competed based on performance requirements and affordability considerations.

The Space Launch System will be evolvable, ultimately carrying 130 metric tons of crew and cargo to low Earth orbit.

Space Launch System (SLS) vehicle configurations picture

Core Stage

The SLS core stage will store liquid hydrogen (LH) and liquid oxygen (LOX) to feed the rocket’s four RS-25 engines. The RS-25 engines are former space shuttle main engines for the first few flights. The SLS Program has an inventory of 16 RS-25 flight engines that were used during the Space Shuttle Program. SLS like the Space Shuttle will be powered initially by two solid rocket boosters on the sides of the launch vehicle.

Boeing is the prime contractor for the SLS core stage, including its avionics.

The SLS will have an initial lift capacity of 70 metric tons (154,000 pounds), roughly the weight of 40 sport utility vehicles. The lift capacity will be evolvable to 130 metric tons – more than 143 tons (286,000 pounds) enough to lift 75 SUVs. The first test flight of NASA’s Space Launch System is scheduled for launch in 17 December 2017. It will feature a configuration for a 77 ton lift capacity.

Upper Stage

The SLS will use various configurations for the upper stages:

Block 0 – No upper stage.

Block I – A Delta Cryogenic Second Stage (DCSS), referred to as the Interim Cryogenic Propulsion Stage (iCPS). This 70-metric ton configuration currently will only fly two missions: Exploration Mission 1 (EM-1) and Exploration Mission 2 (EM-2).

Block IA – A large Cryogenic Propulsion Stage, specifically developed for SLS and powered by liquid hydrogen fuel and liquid oxygen oxidizer. This 105-metric ton rocket will first launch as SLS-3.

Block IB – CPS consisting of four RL10A-4-2 engines with a 8.4 m fairing and 105 mt to LEO.

Block II – A fully-fledged Earth Departure Stage to be powered by three J-2X engines for 130-metric ton rocket.


Possible launch dates:



Launch Date


SLS-1/EM-1Block I17 December 2017Send Orion/MPCV on unmanned trip around the Moon.
SLS-2/EM-2Block I2021Send Orion MPCV with four members into lunar orbit.
SLS-3Block IA2022
SLS-4Block IB2023 ? Europa Orbiter
SLS-5Block II2024First launch of SLS Cargo configuration, first flight with RS-25E engines.
SLS-6Block II2025Manned Exploration Mission to Nearest Earth Asteroid ???
SLS-7Block II2026Cargo launch to Lunar Orbiting Space Station ???
SLS-8Block II2027First launch of Manned Flyby Mission to Venus Orbit???


The Space Launch System is NASA’s first exploration-class vehicle since the Saturn V took American astronauts to the moon in the late 1960s and early 1970s.

SLS rocket and USA flag picture

NASA’s Space Launch System (SLS) was authorized by USA’s Congress after the cancellation of the Ares rockets of the Constellation program.  The rocket will be larger than the famous Saturn V moon rocket in the Block 2 configuration.

NASA announced on 24 May 2011 that development of the Orion spacecraft from the Constellation program will continue as the Multi-Purpose Crew Vehicle (MPCV).

The Delta IV DCSS (Delta Cryogenic Second Stage) was selected in May 2012.

Did you know?

* Previous NASA heavy rocket designs include Apollo program’s Saturn V rocket and Ares V.

* Anchored atop the departure stage is a composite shroud protecting the lunar surface access module, which includes the descent stage that will carry explorers to the moon’s surface and the ascent stage that will return them to lunar orbit to rendezvous with the Orion Spacecraft (Crew Exploration Vehicle) for their return home.


Space Launch System (SLS) Book

Project Constellation Book

Space Launch System (SLS): America’s Next Manned Rocket for NASA Deep Space Exploration to the Moon, Asteroids, Mars – Rocket Plans, Ground Facilities, Tests, Saturn V Comparisons, Configurations by World Spaceflight News & NASA. [Kindle Edition] (April 2012) Buy from:,

The Mighty Saturns – Saturn V (DVD)
Buy from:

This 3-DVD set features incredible footage of the story of the Saturn V. Amazing rare footage of overcoming technological challenges in materials and techniques to stunning digital transfers of original 35mm pad camera footage.

Project Constellation Pocket by Frank Sietzen
Buy from: 

This magnificent guide takes an in-depth look at Project Constellation, the bold new initiative designed to bring America’s space exploration program into the 21st century.

Space Launch System Links and References:

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