Space Launch System
The Space Launch System, or SLS, is a Space Shuttle-derived
Shuttle-Derived Launch Vehicle
Shuttle-Derived Launch Vehicle, or simply Shuttle-Derived Vehicle , is a term describing one of a wide array of concepts that have been developed for creating space launch vehicles from the components, technology and/or infrastructure of the Space Shuttle program. SDVs have also been part of...

 heavy launch vehicle
Launch vehicle
In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad and other infrastructure....

 being designed by NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

, following the cancellation of the Constellation Program, to replace the retired Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

. The NASA Authorization Act of 2010
NASA Authorization Act of 2010
The NASA Authorization Act of 2010 is a U.S. law which authorizes NASA appropriations for fiscal years 2011–2013 with the same top-line budget values as requested by President of the United States Barack Obama...

 envisions the transformation of the Ares I
Ares I
Ares I was the crew launch vehicle that was being developed by NASA as part of the Constellation Program. The name "Ares" refers to the Greek deity Ares, who is identified with the Roman god Mars...

 and Ares V
Ares V
The Ares V was the planned cargo launch component of the Constellation program, which was to have replaced the Space Shuttle after its retirement in 2011. Ares V was also planned to carry supplies for a human presence on Mars...

 vehicle designs into a single launch vehicle usable for both crew and cargo. It is to be upgraded over time with more powerful versions.

Design and development

The Space Launch System is to be a Shuttle-Derived heavy launch vehicle. The initial capability of the core elements, without an upper stage, should be for between 70 metric tons (for the 3-engine, partially fuelled core) and 100 metric tons (for the preferred 4-engine, fully fuelled core) into low-Earth orbit (LEO) in preparation for transit for missions beyond low-Earth orbit. With the addition of integrated upper Earth Departure Stage
Earth Departure Stage
The Ares V Earth Departure Stage was a rocket stage which NASA planned to design at its Marshall Space Flight Center in Huntsville, Alabama as part of Project Constellation...

 and 5th SSME derived core engine, the total lift capability of the Space Launch System should be 130 metric tons or more.

Preliminary designs indicate that the current Space Shuttle Main Engine
Space Shuttle main engine
The RS-25, otherwise known as the Space Shuttle Main Engine , is a reusable liquid-fuel rocket engine built by Pratt & Whitney Rocketdyne for the Space Shuttle, running on liquid hydrogen and oxygen. Each Space Shuttle was propelled by three SSMEs mated to one powerhead...

s (RS-25D) and Space Shuttle Solid Rocket Booster
Space Shuttle Solid Rocket Booster
The Space Shuttle Solid Rocket Boosters were the pair of large solid rockets used by the United States' NASA Space Shuttle during the first two minutes of powered flight. Together they provided about 83% of liftoff thrust for the Space Shuttle. They were located on either side of the rusty or...

s would be utilized, and much of the External Tank design would remain the same. This design would require dramatically less development time than the Ares V
Ares V
The Ares V was the planned cargo launch component of the Constellation program, which was to have replaced the Space Shuttle after its retirement in 2011. Ares V was also planned to carry supplies for a human presence on Mars...

 heavy lift launch vehicle. On May 24, 2011, NASA announced that development of the Orion
Orion (spacecraft)
Orion is a spacecraft designed by Lockheed Martin for NASA, the space agency of the United States. Orion development began in 2005 as part of the Constellation program, where Orion would fulfill the function of a Crew Exploration Vehicle....

 from the Constellation program will continue under the name Orion Multi-Purpose Crew Vehicle (MPCV).

On June 17, 2011, Aerojet
Aerojet is an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California with divisions in Redmond, Washington, Orange, Gainesville and Camden, Arkansas. Aerojet is owned by GenCorp. They are the only US propulsion company that provides both solid rocket...

 announced a strategic partnership with Teledyne Brown
Teledyne Technologies Incorporated is an industrial conglomerate primarily based in the United States but with global operations. It was founded in 1960, as Teledyne, Inc., by Henry Singleton and George Kozmetsky....

 to develop and produce a domestic version of the NK-33
The NK-33 and NK-43 are rocket engines designed and built in the late 1960s and early 1970s by the Kuznetsov Design Bureau. They were intended for the ill-fated Soviet N-1 rocket moon shot. The NK-33 engine achieves the highest thrust-to-weight ratio of any Earth-launchable rocket engine, whilst...

 engine, with its thrust increased to 500000 pound-forces (2.2 MN) at sea level. This booster is to compete against Shuttle-derived solid rocket boosters for the SLS launch vehicle.

On September 14, 2011, NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 announced that it had selected the design of the new Space Launch System. NASA declared that it would take the agency's astronauts farther into space than ever before and provide the cornerstone for future human space exploration efforts by the U.S. For early flights SLS has an 8.4-meter diameter core with three RS-25D/E engines, 8.4-meter upper stage with a J-2X engine, and two 5-segment solid rocket boosters. Later versions will use five RS-25D/E engines and the boosters will be upgraded as well. Selection of the upgraded boosters will be by competitive bid. The proposed SLS is visually similar to the legacy Saturn V
Saturn V
The Saturn V was an American human-rated expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. A multistage liquid-fueled launch vehicle, NASA launched 13 Saturn Vs from the Kennedy Space Center, Florida with no loss of crew or payload...

 booster and in particular the proposed, two-stage, Saturn INT-20
Saturn INT-20
The Saturn INT-20 was a proposed intermediate payload follow-on from the Apollo Saturn V launch vehicle. An interstage would be fitted on top of the S-IC stage to support the S-IVB stage, so it could be considered either a retrofitted Saturn IB with a more powerful first stage, or a stubby,...

. The initial two stage variant will have a similar lift capability to the Saturn INT-20's 60,000 kg. The proposed final variant will have similar lift capacity and height compared to the original Saturn V.

As of November 2011 NASA has selected five rocket configurations for wind tunnel
Wind tunnel
A wind tunnel is a research tool used in aerodynamic research to study the effects of air moving past solid objects.-Theory of operation:Wind tunnels were first proposed as a means of studying vehicles in free flight...

 testing. Said configurations are described in three Low Earth Orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

 classes; 70 mt, 95 mt, and 140 mt.

Program costs

During the joint Senate-NASA presentation in September 2011, it was stated that the SLS program has a projected development cost of $18 billion through 2017, with $10B for the SLS rocket, $6B for the Orion Multi-Purpose Crew Vehicle and $2B for upgrades to the launch pad and other facilities at Kennedy Space Center. An unofficial NASA document estimates the cost of the program through 2025 will total at least $41B for four 70 metric ton launches (1 unmanned in 2017, 3 manned starting in 2021). The 130 metric ton version should not be ready earlier than 2030.


In August and September 2011, U.S. Representative Dana Rohrabacher
Dana Rohrabacher
Dana Tyron Rohrabacher is the U.S. Representative for , and previously the 45th and 42nd, serving since 1989. He is a member of the Republican Party...

 said the SLS budget should be used to accelerate the Commercial Crew Development
Commercial Crew Development
Commercial Crew Development is a multiphase space technology development program, funded by the U.S. government, and administered by NASA. The program is intended to stimulate development of privately operated crew vehicles to low Earth orbit. It is run by the Commercial Crew and Cargo Program...

 (CCDev) program and for the construction of an orbital Propellant depot
Propellant depot
An orbital propellant depot is a cache of propellant that is placed on an orbit about the Earth or another body to allow spacecraft to be fuelled in space. Launching a spacecraft separately from some of its propellant enables missions with more massive payloads...

 that a NASA unofficial study demonstrate as a cheaper, faster and more flexible alternative architecture for a manned mission to the moon or an asteroid (in 2024 for $64B vs $143B in 2029). In October 2011 Rohrabacher added "There's nothing new or innovative in this approach, especially its astronomical price tag, and that's the real tragedy. Unfortunately, after a number of years, perhaps during development or just after a few flights like Saturn, budget pressures will bring this program to an end".

The Space Access Society
Space Access Society
The Space Access Society is an organization dedicated to increasing the viability and reducing the cost of commercial access to space travel...

, Space Frontier Foundation
Space Frontier Foundation
The Space Frontier Foundation is a space advocacy nonprofit corporation organized to promote the interests of increased involvement of the private sector, in collaboration with government, in the exploration and development of space...

 and The Planetary Society called for cancellation arguing that it will consume the funds for other projects and will not reduce the per pound launch costs. Others suggest it will cost less to use an existing (Falcon 9
Falcon 9
Falcon 9 is a rocket-powered spaceflight launch system designed and manufactured by SpaceX. Both stages of its two-stage-to-orbit vehicle use liquid oxygen and rocket-grade kerosene propellants...

, Atlas V
Atlas V
Atlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance...

, Delta IV), or proposed derivative (Falcon Heavy
Falcon Heavy
Falcon Heavy, previously known as the Falcon 9 Heavy, is a spaceflight launch system that uses rocket engines currently being designed and manufactured by SpaceX. Both stages of the two-stage-to-orbit vehicles use liquid oxygen and rocket-grade kerosene propellants...

) American commercial rocket with on-orbit assembly/fueling as needed, than to develop a new launch vehicle for space exploration without competitive bid for the whole design.

The Competitive Space Task Force points out that spending billions to try to create a new Government launcher to replicate/replace existing/proven private American boosters directly violates NASA’s charter, the Space Act, and the 1998 Commercial Space Act requirements for NASA to pursue the "fullest possible engagement of commercial providers" and to "seek and encourage, to the maximum extent possible, the fullest commercial use of space". "It is a sad day for our space program. The amazing possibilities offered by engaging commercial space to lower costs and develop a sustainable long term infrastructure to support NASA space exploration, settlement and a new space industry have been trumped by the greed, parochialism
Parochialism means being provincial, being narrow in scope, or considering only small sections of an issue. It may, particularly when used pejoratively, be contrasted to universalism....

, and lack of vision of a few congressional pork barrelers
Pork barrel
Pork barrel is a derogatory term referring to appropriation of government spending for localized projects secured solely or primarily to bring money to a representative's district...

 intent once again on building a government super rocket," said Space Frontier Foundation co-founder Rick Tumlinson
Rick Tumlinson
Rick Tumlinson is the co-founder of the Space Frontier Foundation and a space activist. He has testified on space-related topics before the U.S. Congress six times since 1995...

. "We’ve been to this party before, it was a bust then, and it will be this time as well."

The Space Review also criticized that the SLS plan will be too costly and will drain resources from NASA's other projects. Rep. Dana Rohrabacher added, "… this plan will suffer the same fate as Constellation: overpromised, under-delivered, and cancelled. Where will we be then?", Congressman Tom McClinton and other groups argue that the Congressional mandates forcing NASA to use Space Shuttle components for SLS amounts to a de-facto non-competitive, single source requirement assuring contracts to existing shuttle suppliers, and calling the Government Accountability Office
Government Accountability Office
The Government Accountability Office is the audit, evaluation, and investigative arm of the United States Congress. It is located in the legislative branch of the United States government.-History:...

 (GAO) to investigate possible violations of the Competition in Contracting Act (CICA).


A very preliminary and unofficial schedule based on a worst case budget has outlined some early SLS flights as:
Mission Targeted date Notes
SLS-1 December 2017 Send Orion/MPCV on unmanned trip around the Moon.
SLS-2 August 2019 Send Orion/MPCV on a manned trip around the Moon.
SLS-3 August 2022
SLS-4 August 2023
SLS-5 August 2024 First launch of SLS Cargo configuration
SLS-6 August 2025 Manned "Exploration" Mission
SLS-7 August 2026 Cargo launch
SLS-8 August 2027 Manned launch
SLS-9 August 2028 Cargo launch
SLS-10 August 2029 Manned launch
SLS-11 August 2030 New configuration, Cargo launch
SLS-12 August 2031 Manned mission
SLS-13 August 2032 New configuration, Cargo launch

See also

  • Comparison of orbital launch systems
    Comparison of orbital launch systems
    This page exposes the full list of orbital launch systems. For the short simple list of launchers families, see Comparison of orbital launchers families....

  • Jupiter (rocket family)
    Jupiter (rocket family)
    The Jupiter family of Heavy Lift Launch Vehicles is part of the proposed DIRECT Shuttle-Derived Launch Vehicle architecture. It is intended to be an alternative to the Ares I and Ares V rockets which were under development for the United States National Aeronautics and Space Administration's ...

    DIRECT is a proposed alternative heavy lift launch vehicle architecture supporting NASA's Vision for Space Exploration, which would replace the space agency's planned Ares I and Ares V rockets...

  • Shuttle-Derived Launch Vehicle
    Shuttle-Derived Launch Vehicle
    Shuttle-Derived Launch Vehicle, or simply Shuttle-Derived Vehicle , is a term describing one of a wide array of concepts that have been developed for creating space launch vehicles from the components, technology and/or infrastructure of the Space Shuttle program. SDVs have also been part of...

External links

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