RS-68

Last updated

RS-68
RS-68 rocket engine test.jpg
An RS-68 engine undergoing hot-fire testing at NASA's Stennis Space Center during its developmental phase.
Country of originUnited States
First flight20 November 2002 (2002-11-20)
Last flight9 April 2024 (2024-04-09)
Designer Rocketdyne
Manufacturer
ApplicationFirst stage engine
Associated LV Delta IV  · Delta IV Heavy
StatusRetired
Liquid-fuel engine
Propellant LOX / LH2
Cycle Gas-generator
Configuration
Nozzle ratio21.5:1
Performance
Thrust, sea-levelRS-68: 2,950 kN (660,000 lbf)
RS-68A: 3,137 kN (705,000 lbf) [1]
Thrust-to-weight ratio RS-68: 45.3:1
RS-68A: 47.4:1
Chamber pressure 1,488 psi (10.26 MPa)
Specific impulse, vacuumRS-68: 410 s (4.0 km/s)
RS-68A: 411.9 s (4.039 km/s) [2]
Dimensions
Length5.20 m (17.1 ft)
Diameter2.43 m (8 ft 0 in)
Dry massRS-68: 6,600 kg (14,560 lb)
RS-68A: 6,740 kg (14,870 lb) [1]

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. [3]

Contents

Designed and manufactured in the United States by Rocketdyne (later Pratt & Whitney Rocketdyne and Aerojet Rocketdyne). Development started in the 1990s with the goal of producing a simpler, less costly, heavy-lift engine for the Delta IV launch system. Two versions of the engine have been produced: the original RS-68 and the improved RS-68A. A third version, the RS-68B, was planned for the National Aeronautics and Space Administration's (NASA) Ares V rocket before the cancellation of the rocket and the Constellation Program in 2010.

Design and development

One of the main goals of the RS-68 program was to produce a simple engine that would be cost-effective when used for a single launch. To achieve this, the RS-68 has 80% fewer parts than the multi-launch RS-25 Space Shuttle Main Engine (SSME). [4] The adverse consequences of this simplicity were a significantly lower thrust-to-weight ratio and a 10% lower specific impulse compared to the SSME. The benefit of this simplicity is the RS-68's reduced construction cost. [4]

The RS-68 was developed at Rocketdyne Propulsion and Power, located in Canoga Park, Los Angeles, California, where the SSME was manufactured. It was designed to power the Delta IV Evolved Expendable Launch Vehicle (EELV). The initial development engines were assembled at the nearby Santa Susana Field Laboratory where the Saturn V's Rocketdyne F-1 engines were developed and tested for the Apollo missions to the Moon. The initial testing of the RS-68 occurred at the Air Force Research Laboratory (AFRL), Edwards Air Force Base, California, and later at NASA's Stennis Space Center. [5] [6] The RS-68 was certified in December 2001 for use on Delta IV rockets. [7]

An RS-68 was part of each Delta IV Common Booster Core. The largest of the launch vehicles, the Delta IV Heavy, used three CBCs mounted together. [8]

The engine produced 758,000 pounds-force (3,370  kN ) in a vacuum and 663,000 pounds-force (2,950 kN) at sea level. The engine's mass was 14,560 pounds (6,600 kg). With this thrust, the engine had a thrust-to-weight ratio of 51.2 and a specific impulse of 410 seconds (4.0 km/s) in a vacuum and 365 seconds (3.58 km/s) at sea level. [9] The RS-68 was gimbaled hydraulically and was capable of throttling between 58% and 102% thrust. [10]

The RS-68A is an updated version of the RS-68, with increased specific impulse and thrust (to over 700,000 pounds-force (3,100 kN) at sea level). [11] The first launch on 29 June 2012, from the Cape Canaveral Air Force Station used three RS-68A engines mounted in a Delta IV Heavy rocket. [12]

The RS-68 was retired as of the last Delta IV Heavy flight in April 2024.

Proposed uses

In 2006, NASA announced an intention to use five RS-68 engines instead of SSMEs on the planned Ares V. NASA chose the RS-68 because of its lower cost, about $20 million per engine including the cost of NASA's upgrades. The upgrades included a different ablative nozzle to accommodate a longer burn, a shorter start sequence, hardware changes to limit free hydrogen at ignition, and a reduction in the amount of helium used during countdown and flight. Thrust and specific impulse increases would occur under a separate upgrade program for the Delta IV rocket. [13] Later, the Ares V was changed to use six RS-68 engines, designated the RS-68B. [14] Ares V was dropped as part of the cancellation of the Constellation program in 2010. [15] NASA's current successor heavy-lift vehicle, the Space Launch System, uses four RS-25 engines instead. [16]

Human-rating

In 2008, it was reported that the RS-68 needed over 200 changes to receive a human-rating certification. [17] NASA has stated that those changes include health monitoring, removal of the fuel-rich environment at liftoff, and improving the robustness of its subsystems. [18] [19]

Variants

See also

Related Research Articles

<span class="mw-page-title-main">Rocketdyne</span> American rocket engine design and production company

Rocketdyne is an American rocket engine design and production company headquartered in Canoga Park, in the western San Fernando Valley of suburban Los Angeles, in southern California.

<span class="mw-page-title-main">Delta (rocket family)</span> Rocket family

The Delta rocket family was a versatile range of American rocket-powered expendable launch systems that provided space launch capability in the United States from 1960 to 2024. Japan also launched license-built derivatives from 1975 to 1992. More than 300 Delta rockets were launched with a 95% success rate. The series was phased out in favor of the Vulcan Centaur, with the Delta IV Heavy rocket's last launch occurring on April 9, 2024.

<span class="mw-page-title-main">Space Shuttle Solid Rocket Booster</span> Solid propellant rocket used to launch the Space Shuttle orbiter

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.

<span class="mw-page-title-main">Delta IV</span> Retired expendable launch system in the Delta rocket family

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.

<span class="mw-page-title-main">RS-25</span> Space Shuttle and SLS main engine

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).

<span class="mw-page-title-main">RL10</span> Liquid fuel cryogenic rocket engine, typically used on rocket upper stages

The RL10 is a liquid-fuel cryogenic rocket engine built in the United States by Aerojet Rocketdyne that burns cryogenic liquid hydrogen and liquid oxygen propellants. Modern versions produce up to 110 kN (24,729 lbf) of thrust per engine in vacuum. Three RL10 versions are in production for the Centaur upper stage of the Atlas V and the DCSS of the Delta IV. Three more versions are in development for the Exploration Upper Stage of the Space Launch System and the Centaur V of the Vulcan rocket.

<span class="mw-page-title-main">Aerojet Rocketdyne</span> American aerospace propulsion manufacturer

Aerojet Rocketdyne is a subsidiary of American defense company L3Harris that manufactures rocket, hypersonic, and electric propulsive systems for space, defense, civil and commercial applications. Aerojet traces its origins to the General Tire and Rubber Company established in 1915, while Rocketdyne was created as a division of North American Aviation in 1955. Aerojet Rocketdyne was formed in 2013 when Aerojet and Pratt & Whitney Rocketdyne were merged, following the latter's acquisition by GenCorp from Pratt & Whitney. Aerojet Rocketdyne was acquired by L3Harris in July 2023 for $4.7 billion.

<span class="mw-page-title-main">Shuttle-derived vehicle</span> Launch vehicle built from Space Shuttle components

Shuttle-derived vehicles (SDV) are space launch vehicles and spacecraft that use components, technology, and infrastructure originally developed for the Space Shuttle program.

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.

<span class="mw-page-title-main">Ares V</span> Canceled NASA rocket key to Project Constellation

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.

<span class="mw-page-title-main">Ares I</span> Canceled NASA rocket key to the Constellation program

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).

The RS-83 was a rocket engine design for a reusable liquid hydrogen/liquid oxygen rocket larger and more powerful than any other. The RS-83 was designed to last 100 missions, and was intended for use on the first stage of a two-stage-to-orbit reusable launch vehicle.

<span class="mw-page-title-main">J-2X</span> Liquid-fueled rocket engine

The J-2X is a liquid-fueled cryogenic rocket engine that was planned for use on the Ares rockets of NASA's Constellation program, and later the Space Launch System. Built in the United States by Aerojet Rocketdyne (formerly, Pratt & Whitney Rocketdyne), the J-2X burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,307 kN (294,000 lbf) of thrust in vacuum at a specific impulse (Isp) of 448 seconds (4.39 km/s). The engine's mass is approximately 2,470 kg (5,450 Lb), significantly heavier than its predecessors.

<span class="mw-page-title-main">Space Launch Initiative</span> US NASA & DOD program 2000-2002

The Space Launch Initiative (SLI) was a NASA and U.S. Department of Defense joint research and technology project to determine the requirements to meet all the nation's hypersonics, space launch and space technology needs. It was also known as the second generation Reusable Launch Vehicle program, after the failure of the first. The program began with the award of RLV study contracts in 2000.

<span class="mw-page-title-main">National Launch System</span> Proposed family of US super heavy-lift launch vehicles

The National 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. Shortly thereafter, NASA asked Lockheed Missiles and Space, McDonnell Douglas, and TRW to perform a ten-month study.

<span class="mw-page-title-main">Shuttle-Derived Heavy Lift Launch Vehicle</span> Space launch vehicle concept

The Shuttle-Derived Heavy Lift Launch Vehicle ("HLV") was an alternate super heavy-lift launch vehicle proposal for the NASA Constellation program. It was first presented to the Augustine Commission on 17 June 2009.

<span class="mw-page-title-main">DIRECT & Jupiter Rocket Family</span> Proposed family of US super heavy-lift launch vehicles

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.

<span class="mw-page-title-main">Delta Cryogenic Second Stage</span> Japanese-American rocket stage

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 MARC-60, also known as MB-60, MB-XX, and RS-73, is a liquid-fuel cryogenic rocket engine designed as a collaborative effort by Japan's Mitsubishi Heavy Industries and US' Aerojet Rocketdyne. The engine burns cryogenic liquid oxygen and liquid hydrogen in an open expander cycle, driving the turbopumps with waste heat from the main combustion process.

<span class="mw-page-title-main">S-IC-T</span> American super heavy-lift expendable rocket first stage of Saturn V, test unit

S-IC-T is a Saturn V first stage, S-IC rocket, of the three stage rocket system. S-IC-T was built by Boeing Company, under contract from National Aeronautics and Space Administration, to be a static test rocket. The main role of the S-IC-T was the testing of the five liquid fuel rocket engines to be used in the Apollo program. S-IC-T static test fired the rockets at NASA Mississippi Test Facility, now known as Stennis Space Center. S-IC-T was assembled at the Marshall Space Flight Center in Huntsville, Alabama. S-IC-T was given the nickname T-Bird. The first burn test was on April 10, 1965. The Saturn V's S-IC-T rocket is a first stage of the super heavy-lift launch vehicle. S-IC-T is now on display at Kennedy Space Center in Florida.

References

  1. 1 2 "DELTA IV". United Launch Alliance. Archived from the original on 20 July 2014. Retrieved 13 July 2014.
  2. ↑ "Delta IV User's Guide" (PDF). United Launch Alliance. June 2013. Archived (PDF) from the original on 10 July 2014. Retrieved 13 July 2014.
  3. ↑ "ATK Propulsion and Composite Technologies Help Launch National Reconnaissance Office Satellite" (Press release). Alliant Techsystems. 19 January 2009. Archived from the original on 22 February 2014.
  4. 1 2 "AIAA 2002-4324, Propulsion for the 21st Century—RS-68" Archived 19 March 2009 at the Wayback Machine . AIAA, 8–10 July 2002.
  5. ↑ "Boeing Tests RS-68 Rocket Engine (Apr. 24)". Defense Aerospace. 23 April 2001. Retrieved 26 June 2023.
  6. ↑ "Boeing Delta IV CBC/RS-68 Engine Successfully Completes Test Program" (Press release). Boeing. 9 May 2001. Retrieved 26 June 2023.
  7. ↑ "Rocketdyne RS-68 Engine Certified for Boeing Delta IV" (Press release). Boeing. 19 December 2001. Archived from the original on 10 October 2012.
  8. ↑ "Atlas V and Delta IV Technical Summary" (PDF).
  9. ↑ "United Launch Alliance Delta IV Heavy".
  10. ↑ Boeing white paper on RS-68 development Archived 15 April 2007 at the Wayback Machine
  11. ↑ "United Launch Alliance First RS-68A Hot-Fire Engine Test a Success" (Press release). United Launch Alliance. 25 September 2008. Retrieved 10 April 2023. Currently, the RS-68 engine can deliver more than 660,000 pounds of sea level thrust and the upgraded RS-68A will increase this to more than 700,000 pounds. The RS-68A also improves on the specific impulse, or fuel efficiency, of the RS-68.
  12. ↑ "United Launch Alliance Upgraded Delta IV Heavy rocket successfully Launches Second Payload in Nine Days for the National Reconnaissance Office" (Press release). United Launch Alliance. 29 June 2012. Archived from the original on 20 August 2016.
  13. ↑ "NASA's Exploration Systems Progress Report" (Press release). National Aeronautics and Space Administration. 18 May 2006. Archived from the original on 5 April 2012. Retrieved 30 May 2006.
  14. 1 2 "Overview: Ares V Cargo Launch Vehicle". National Aeronautics and Space Administration. Archived from the original on 26 September 2008. Retrieved 30 September 2008.
  15. ↑ Amos, Jonathan (11 October 2010). "Obama signs Nasa up to new future". BBC news. Retrieved 7 June 2019.
  16. ↑ "Space Launch System Factsheet" (PDF). National Aeronautics and Space Administration. Archived from the original (PDF) on 13 May 2019. Retrieved 7 June 2019.
  17. ↑ "United Launch Alliance First RS-68A Hot-Fire Engine Test a Success". NASAspaceflight.com. 27 September 2008. Archived from the original on 28 March 2018.
  18. ↑ "Frequently Asked Questions, question 3". National Aeronautics and Space Administration ESMD. Archived from the original on 12 January 2010.
  19. ↑ Bearden, David A.; Skratt, John P.; Hart, Matthew J. (1 June 2009). "Human Rated Delta IV Heavy Study Constellation Impacts" (PDF). National Aeronautics and Space Administration. p. 8. Archived (PDF) from the original on 28 February 2017.
  20. ↑ "RS-68 Propulsion System" (PDF). Pratt & Whitney Rocketdyne. October 2005. Archived from the original (PDF) on 14 July 2018. Retrieved 7 April 2019.
  21. ↑ "P&W Successfully Completes Hot-Fire Test on 2nd RS-68A Certi". asdnews.com. Archived from the original on 25 July 2011. Retrieved 25 April 2018.
  22. ↑ "Delta IV User's Guide" (PDF). United Launch Alliance. June 2013. Archived (PDF) from the original on 10 July 2014. Retrieved 13 July 2014.
  23. ↑ "RS-68A | L3Harris® Fast. Forward". www.l3harris.com. Retrieved 6 February 2024.
  24. ↑ "The engines that refused to retire – RS-25s prepare for SLS testing". nasaspaceflight.com. June 2013. Archived from the original on 30 August 2017.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.