The National Launch System (or New Launch System) was a study authorized in 1991 by President George H. W. Bush to outline alternatives to the Space Shuttle for access to Earth orbit. [1] Shortly thereafter, NASA asked Lockheed Missiles and Space, McDonnell Douglas, and TRW to perform a ten-month study. [2]
A series of launch vehicles was proposed, based around the proposed Space Transportation Main Engine (STME) liquid-fuel rocket engine. The STME was to be a simplified, expendable version of the Space Shuttle main engine (SSME). [3] [4] The NLS-1 was the largest of three proposed vehicles and would have used a modified Space Shuttle external tank for its core stage. The tank would have fed liquid oxygen and liquid hydrogen to four STMEs attached to the bottom of the tank. A payload or second stage would have fit atop the core stage, and two detachable Space Shuttle Solid Rocket Boosters would have been mounted on the sides of the core stage as on the Shuttle. [3] Period illustrations suggest that much larger rockets than NLS-1 were contemplated, using multiples of the NLS-1 core stage. [5] [6]
The NLS program did not venture beyond the planning stages and did not survive the Presidency of Bill Clinton, which started in January 1993. In 1992, Daniel Goldin was selected to replace Vice Admiral Richard H. Truly as NASA administrator. Goldin championed the motto, "faster, better, cheaper," [7] which may not have fit the ambitious NLS vision. A NASA history from 1998 says that reusable single-stage-to-orbit (SSTO) rockets and space planes such as the McDonnell Douglas DC-X and the Lockheed Martin X-33 seemed attainable and represented smaller, simpler alternatives to the sprawling Shuttle program. [8] The NLS, by contrast, was more of a continuation of the Shuttle legacy. By the beginning of the Clinton administration, the expensive Space Shuttle and planned Space Station Freedom programs had enough momentum to continue, and the SSTO projects showed enough promise to fund. There was no money left for another big program such as the NLS.[ citation needed ]
In 1994, the United States Air Force Evolved Expendable Launch Vehicle (EELV) program led to the development of the Delta IV. Rocketdyne realized that they would need a powerful, simple engine for the proposed liquid-fueled Common Booster Core (CBC). NLS research on the STME, a simpler SSME, served as a starting point for the greatly simplified RS-68 that powered the Delta IV EELV rocket. [9] The Delta IV Heavy rocket is composed of three CBCs. [10]
NASA later developed a very similar launch vehicle to NLS-1 called the Space Launch System, as part of its Artemis program to return astronauts to the Moon in the mid-2020s. The similarities include a lengthened Shuttle external tank-like core stage, four engines meant as expendable versions of the SSME, and large solid rocket boosters (with five segments instead of four). [11] [12] [13] [14] [15]
The Space Shuttle Solid Rocket Booster (SRB) was the first solid-propellant rocket to be used for primary propulsion on a vehicle used for human spaceflight. A pair of these provided 85% of the Space Shuttle's thrust at liftoff and for the first two minutes of ascent. After burnout, they were jettisoned and parachuted into the Atlantic Ocean where they were recovered, examined, refurbished, and reused.
Delta IV was a group of five expendable launch systems in the Delta rocket family. It flew 45 missions from 2002 to 2024. Originally designed by Boeing's Defense, Space and Security division for the Evolved Expendable Launch Vehicle (EELV) program, the Delta IV became a United Launch Alliance (ULA) product in 2006. The Delta IV was primarily a launch vehicle for United States Air Force (USAF) military payloads, but was also used to launch a number of United States government non-military payloads and a single commercial satellite.
The Space Shuttle external tank (ET) was the component of the Space Shuttle launch vehicle that contained the liquid hydrogen fuel and liquid oxygen oxidizer. During lift-off and ascent it supplied the fuel and oxidizer under pressure to the three RS-25 main engines in the orbiter. The ET was jettisoned just over 10 seconds after main engine cut-off (MECO) and it re-entered the Earth's atmosphere. Unlike the Solid Rocket Boosters, external tanks were not re-used. They broke up before impact in the Indian Ocean, away from shipping lanes and were not recovered.
The RS-25, also known as the Space Shuttle Main Engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA's Space Shuttle and is used on the Space Launch System (SLS).
National Security Space Launch (NSSL) is a program of the United States Space Force (USSF) intended to assure access to space for United States Department of Defense and other United States government payloads. The program is managed by the Assured Access to Space Directorate (SSC/AA) of the Space Force's Space Systems Command (SSC), in partnership with the National Reconnaissance Office.
The RS-68 (Rocket System-68) was a liquid-fuel rocket engine that used liquid hydrogen (LH2) and liquid oxygen (LOX) as propellants in a gas-generator cycle. It was the largest hydrogen-fueled rocket engine ever flown.
Shuttle-derived vehicles (SDV) are space launch vehicles and spacecraft that use components, technology, and infrastructure originally developed for the Space Shuttle program.
A mobile launcher platform (MLP), also known as mobile launch platform, is a structure used to support a large multistage space vehicle which is assembled (stacked) vertically in an integration facility and then transported by a crawler-transporter (CT) to a launch pad. This becomes the support structure for launch.
The Exploration Systems Architecture Study (ESAS) is the official title of a large-scale, system level study released by the National Aeronautics and Space Administration (NASA) in November 2005 of his goal of returning astronauts to the Moon and eventually Mars—known as the Vision for Space Exploration. The Constellation Program was cancelled in 2010 by the Obama Administration and replaced with the Space Launch System, later renamed as the Artemis Program in 2017 under the Trump Administration.
The Earth Departure Stage (EDS) is the name given to the proposed second stage of the Block 2 Space Launch System. The EDS is intended to boost the rocket's payload into a parking orbit around the Earth and from there send the payload out of low Earth orbit to its destination in a manner similar to that of the S-IVB rocket stage used on the Saturn V rockets that propelled the Apollo spacecraft to the Moon. Its development has been put on hold until stages capable of transferring heavy payloads to Mars are required.
A modular rocket is a kind of multistage rocket which has components that can interchanged for different missions. Several such rockets use similar concepts such as unified modules to minimize expenses on manufacturing, transportation and for optimization of support infrastructure for flight preparations.
The Ares V was the planned cargo launch component of the cancelled NASA 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. Ares V and the smaller Ares I were named after Ares, the Greek god of war.
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. Ares I was originally known as the "Crew Launch Vehicle" (CLV).
DIRECT was a late-2000s proposed alternative super heavy lift launch vehicle architecture supporting NASA's Vision for Space Exploration that would replace the space agency's planned Ares I and Ares V rockets with a family of Shuttle-Derived Launch Vehicles named "Jupiter". It was intended to be the alternative to the Ares I and Ares V rockets which were under development for the Constellation program, intended to develop the Orion spacecraft for use in Earth orbit, the Moon, and Mars.
The Delta Cryogenic Second Stage (DCSS) is a family of cryogenic-fuelled rocket stages used on the Delta III, Delta IV, and on the Space Launch System Block 1 launch vehicles. The DCSS employs a unique two-tank architecture where the cylindrical liquid hydrogen (LH2) tank carries payload launch loads and forms the upper section. An oblate spheroid tank filled with liquid oxygen (LOX) and the engine are suspended from the LH2 tank and covered by the interstage during initial launch.
The Space Launch System (SLS) is an American super heavy-lift expendable launch vehicle used by NASA. As the primary launch vehicle of the Artemis Moon landing program, SLS is designed to launch the crewed Orion spacecraft on a trans-lunar trajectory. The first SLS launch was the uncrewed Artemis 1, which took place on 16 November 2022.
The Exploration Upper Stage (EUS) is a rocket stage under development that will be used for future flights of NASA's Space Launch System (SLS). Used on SLS Block 1B and Block 2, it will replace the SLS Block 1's Interim Cryogenic Propulsion Stage. The stage will be powered by four RL10C-3 engines burning liquid oxygen and liquid hydrogen to produce a total thrust of 433.1 kN (97,360 lbf). The EUS is expected to first fly on Artemis 4 in 2028.
During the lifetime of the Space Shuttle, Rockwell International and many other organizations studied various Space Shuttle designs. These involved different ways of increasing cargo and crew capacity, as well as investigating further reusability. A large focus of these designs were related to developing new shuttle boosters and improvements to the central tank, but also looked to expand NASA's ability to launch deep space missions and build modular space stations. Many of these concepts and studies would shape the concepts and programs of the 2000s such as the Constellation, Orbital Space Plane Program, and Artemis program.
The Space Launch System core stage, or simply core stage, is the main stage of the American Space Launch System (SLS) rocket, built by The Boeing Company in the NASA Michoud Assembly Facility. At 65 m (212 ft) tall and 8.4 m (27.6 ft) in diameter, the core stage contains approximately 987 t (2,177,000 lb) of its liquid hydrogen and liquid oxygen cryogenic propellants. Propelled by 4 RS-25 engines, the stage generates approximately 7.44 MN (1,670,000 lbf) of thrust, about 25% of the Space Launch System's thrust at liftoff, for approximately 500 seconds, propelling the stage alone for the last 375 seconds of flight. The stage lifts the rocket to an altitude of approximately 162 km (531,380 ft) before separating, reentering the atmosphere over the Pacific Ocean.