Subj : As Centaur turns 60 years old, ULA prepares to evolve Centaur V To : All From : NasaSpaceFlight Date : Mon May 09 2022 15:00:04 As Centaur turns 60 years old, ULA prepares to evolve Centaur V Date: Mon, 09 May 2022 13:53:31 +0000 Description: 60 years ago, on May 8, 1962, Atlas-LV3C Centaur-A designated Atlas Centaur-1 (AC-1) The post As Centaur turns 60 years old, ULA prepares to evolve Centaur V appeared first on NASASpaceFlight.com . FULL STORY ====================================================================== 60 years ago, on May 8, 1962, Atlas-LV3C Centaur-A designated Atlas Centaur-1 (AC-1) lifted off from the newly-constructed Launch Complex-36A (LC-36A). AC-1 was the first flight test of the hydrogen-powered Centaur upper stage. Since the maiden flight of Centaur, the stage has flown on several different rocket families across six decades. Centaur has launched military, commercial, and science missions allowing access to every planetary body in the solar system and even beyond. As of early May 2022, 263 flight-capable Centaur upper stages have flown and continue to operate on the Atlas V rocket. Soon new variants of the Centaur upper stage will be introduced on United Launch Alliance (ULA)s future Vulcan-Centaur rocket. Early days of Centaur In the 1950s, the USSR and the US were both creating orbital rocket systems to become the first to reach orbit. In 1956, the US Air Force began a study with General Dynamics/Convair to develop a new high-energy rocket stage to launch heavy payloads in the shortest possible time. This program would lead to the Centaur upper stage. Centaur is a Liquid Hydrogen/Liquid Oxygen upper stage utilizing one or two RL10 engines. The stage is 3.05-meters in diameter and was designed to be used on the Atlas and Titan rockets. Like Atlas, Centaur uses pressure-stabilized stainless steel balloon-style tanks to keep the weight as low as possible. A Centaur upper stage in assembly at a General Dynamics factory. (Credit: NASA) On October 4, 1957, the USSR successfully launched Sputnik I into Earth orbit using an R7 Sputnik 8K71PS rocket. This caused the US to accelerate its space program to advance its technology in space exploration. Less than a year later in August 1958, the Advanced Research Products Agency (ARPA) accepted the Air Forces proposal for Centaur with General Dynamics/Convair producing the stage. In 1958, Pratt & Whitney Aircraft was selected to develop the RL10 engine. A year later, the first test of the RL10 was completed. RL10 initially produced 67 kN of thrust with a specific impulse of 425 seconds. It would become the first operational rocket engine to use Liquid Hydrogen. In the same year, the nearly created NASA took over the Centaur program. NASA would use Centaur to expand its ability to conduct Earth science, lunar exploration, and interplanetary studies. The military would still use Centaur for their missions. From the beginning, Centaur was designed to be used on the operational Atlas and Titan rockets, and NASA also assigned Centaur to be used on the Saturn 1 rocket. On October 27, 1961, the first Saturn 1 rocket took flight as the first mission of the Apollo program. Designated Saturn Apollo-1 (SA-1), it was the first test flight of the S-I first stage. SA-1 to SA-4 would all be tests of the S-I first stage with the second and third stages being inactive. Centaur was used as the third stage of Saturn 1, with the designation of S-V. While still the first flight of Centaur, S-V was never active nor fueled with propellant on any Saturn 1 mission. On SA-2 and SA-3, the second stage S-IV and S-V were filled with water as a test for Project Highwater. After being carried to space by the S-I, the water in the two stages was released to study the effects of liquids being released into the atmosphere in case of a rocket failure. Following SA-4, an S-V was never used on a Saturn 1, and Centaur never flew on Saturn again. After its extensive test and development program, Centaur was ready for its proper test flight on an Atlas-LV3C booster. For the program, each Centaur would have a designation with a letter to show its version. Centaur-A was used on AC-1 and Centaur-B on AC-2. The twin LC-36 pads were constructed to support the Atlas-Centaur rockets. On May 8, 1962, AC-1 took flight from LC-36A. AC-1 performed normally for the first ~50 seconds into flight. At T+54 seconds into the flight, the Centaur disintegrated taking the Atlas Booster with it. While not successful, the launch was the first time the US launched a hydrogen propellent stage. Following the flight, it was discovered a structural failure caused by a loose insulation panel led to Centaurs failure. As investigations and fixes were underway, many critics of Centaur were calling for its cancellation and scrapping of the program. Many thought the program would not be successful due to the still-experimental liquid hydrogen and balloon-style tanks. However, NASA continued with the program and a second launch was planned for 1963. On November 17, 1963, AC-2 launched from LC-36A on the second test flight for Centaur. Centaur successfully reached orbit. On a single burn, it reached an orbit of 469 km x 1554 km at an inclination of 30.3 degrees. With the success of AC-2, it marked the first time a liquid hydrogen upper stage was fired in space and reached orbit. AC-2 was designed as a simplified orbital flight test. The payload fairings and insulation panels would normally be jettisoned in-flight to shed weight. To avoid the same failure on AC-2, the panels were permanently bolted to the structure and the fairings were not separated in flight. The next flight, AC-3, was to test every part of the Atlas-Centaur system. On its third and final test flight, AC-3 launched from LC-36A on June 30, 1964. The flight continued as normal until Centaur ignition when one of the RL10 engines hydraulic pumps failed. This caused the Centaur to roll and the engines to shut down. The loss of both engines caused the failure of the flight. When Centaur began to roll, the propellant began to slosh around in the tanks and could no longer feed propellant into the engines. Centaur-C was first used on AC-3 but continued to be used on two more missions. As the first operational Centaur mission, AC-4 launched on December 11, 1964. It carried Surveyor-Model 1, which was a mockup of the Surveyor lunar lander. AC-4 was intended to have its engines reignite. Centaur successfully placed itself in a 165 km x 178 km orbit and began its coast period to begin its second burn. The second burn was supposed to take place 25 minutes after reaching orbit, however, the engines never reignited. It was supposed to reach a 160 km x 8,000 km orbit. To lower the weight, AC-4 used redesigned ullage motors to settle down the propellant. These new motors were not enough to settle the propellant and Centaur failed to ignite. While the reignition of Centaur was one of the objectives, it still completed a test of its new guidance system for the first time. At the lowest point of Centaurs program, yet another failure took place during AC-5. On March 2, 1965, AC-5 took place from LC-36A with Surveyor-SD 1. Just a second after liftoff, the Atlas booster engine shut down, and the vehicle fell back on the pad. The large explosion caused by AC-5 severely damaged LC-36A. By this point, the unfinished LC-36B was mothballed due to budgetary issues and the Atlas-Centaur program only had one successful flight. Centaur-C was quickly replaced by Centaur-D, and LC-36B was completed while LC-36A was repaired. The issue on the Atlas, which was found to be a pre-valve that suddenly closed after liftoff, was fixed. AC-6 launched from LC-36B on August 11, 1965, with the Surveyor SD-2. The Centaur successfully placed the Surveyor SD-2 into a 166 km x 815085 km orbit. This began a string of successful Centaur launches with the only issues on the Surveyor Model-3 launch due to fuel depletion on the ullage motors. On AC-10, the first Surveyor lunar lander was launched from LC-36A becoming the first successful US spacecraft to land on the Moon. Two years later, AC-15 successfully launched Surveyor 7, completing the Surveyor program with all seven missions launched. AC-17 on August 10, 1968, Centaur launched its first non-Surveyor-related payload on the Applications Technology Satellite-4 mission. However, it ended in a partial failure due to the Centaur failing to reignite. The next mission, AC-16, successfully carried NASAs first space telescope to orbit. In 1969, AC-20 and AC-19 respectively launched the Mariner 6 and 7 missions. These missions were the first time a Centaur launched an interplanetary mission and a mission to Mars. Both missions were successful. Ten days before the scheduled launch of Mariner 6, a faulty switch caused the valves on the Atlas booster to open. Due to the balloon tanks, the Atlas could no longer hold its own weight and began to collapse. Two ground personnel started repressurizing the tanks saving the Atlas from further collapse. Mariner 6 was moved to another Atlas-Centaur and launched successfully. On the ATS-5 mission using AC-18, it was the first mission for a Centaur to reach geostationary transfer orbit (GTO). AC-25 launched the Intelsat-IV 2 as the first commercial mission on an Atlas-Centaur rocket. Mariner 9 was launched on AC-23 on May 30, 1971, and would later become the first spacecraft to orbit Mars. AC-27 was used to launch the Pioneer 10 mission. Pioneer 10 was the first Centaur to launch with a Star motor kick stage. The spacecraft later became the first mission to reach the outer solar system and the first to visit Jupiter. Today, Pioneer 10 has likely reached the distance to pass the heliosphere. On Pioneer 11, both the Atlas and Centaur saw upgrades that introduced Centaur-D1A. Designated AC-30, and with another kick stage, it carried Pioneer 11 to Jupiter and Saturn. Pioneer 11 became the first to reach Saturn. In November 1973, AC-34 launched the Mariner 10 mission, it became the first to fly by Mercury and Venus. Atlas-Centaur launches Pioneer 11. (Credit: NASA) To further expand Centaurs capability, it was combined with the Air Forces Titan III rocket to launch even larger spacecraft. A new Centaur variant was developed to launch on the Titan III. Named Centaur D-1T, it had more thermal insulation and a longer orbital lifespan. The Titan III used to launch Centaur was named Titan-IIIE. The first flight of Titan IIIE took place on February 11, 1974. This flight failed due to a failure of the turbopump of the RL10. Titan IIIEs second flight took place in December 1974 and successfully carried the Helio-A mission. Helio-A became the spacecraft to orbit the Sun at a distance closer than Mercury. Another Atlas-Centaur upgrade took place on the Intelsat-IVA 1 took place with the new Centaur-D1AR variant. Both Atlas-Centaur and Titan-Centaur would launch alongside for multiple periods. In 1975 and 1976, Titan IIIE launched three missions to both Mars and the Sun. Viking 1 and 2 were launched in 1975, becoming the first NASA missions to successfully land on the surface of Mars. A year later, Helios-B was launched and held the record for the fastest object relative to the Sun. August and September 1977, two Titan IIIEs with Star 37E kick stages successfully launched the Voyager 1 and 2 missions. Voyager 2 launched first in August. It would later become the first spacecraft to visit Jupiter, Saturn, Uranus, and Neptune all on a single mission. To date, it is still the only spacecraft to visit all outer planets. Voyager 1 launched in September, it would later fly by Jupiter and Saturn to become the first spacecraft to exit the heliosphere. During the launch of Voyager 1, the Titan had hardware issues that caused the second-stage engine to shut down early. Centaur then compensated for the issues from the Titan rocket and completed a successful mission. Voyager 1 was the final mission of the Titan IIIE rocket. Atlas once again became the sole launcher for the Centaur upper stage. On April 12, 1981, Space Shuttle Columbia launched for the first time which was thought to mark the end of expendable rockets. As a reusable system, the Space Shuttle was designed to make access to space cheaper and more frequent. The Space Shuttle became the USs primary launch vehicle. Atlas still had consistent launches, with military and commercial launches. In 1984, another upgrade was made to the Atlas booster which became the Atlas-G Centaur-D1AR. Launches for Atlas slowed down a bit from 1984 to 1989. Work began to use Centaur on the Space Shuttle. For the Space Shuttle, the Centaur had its tanks widened and was called Centaur-G with an extended variant called Centaur-G Prime. Centaurs first flight on the Space Shuttle was set on Challenger in May 1986 with Ulysses on STS-61-F. It was also set to launch on STS-61-G, with Atlantis launching Galileo. Preparations for the two missions were already underway when tragedy struck on January 28, 1986. The loss of the Space Shuttle Challenger and the STS-51-L crew caused NASA to reevaluate the Space Shuttle program. Plans to use Centaur on the Space Shuttle were canceled due to the possible risks added from using the stage. NASA used the Inertial Upper Stage (IUS) in place of Centaur. Launch of NASAs Cassini on a Titan IVB with Centaur. (Credit: NASA) In the mid-1980s, work had previously begun on a backup launch vehicle to the Space Shuttle by the US Air Force. The vehicle would later become Titan IV and would use Centaur and IUS. Following the Shuttle-Centaur cancellation, Titan IV would use hardware from the Centaur G variants. 16 Titan-Centaur (Centaur-T) were made for Titan IV. In 1990 and 1991, both Atlas and Centaur saw more major changes. In these years, the Atlas I and Atlas II rockets took their maiden flights. Atlas I and Atlas-G were similar vehicles that saw changes made to the Centaur. An opportunity was made with the vehicles to change their names to number designations. Atlas I flew 11 times with three failures. Two of the missions were caused by issues with the Centaur due to LH2 mixing with nitrogen and getting stuck in the turbopump. The third failure was caused by an issue with the Atlas booster but would be the last time an Atlas had a complete mission failure. Atlas II was the primary Atlas vehicle once it took its maiden flight. The Atlas saw upgrades to its tanks and engines with Centaur-II being introduced. Other Atlas II variants would later have an updated Centaur-IIA and new solid rocket motors to the Atlas. Titan IV took its first flight with a Centaur in 1994. The Atlas II and Titan IV rockets would co-exist, with Atlas launching mostly commercial and NASA missions with Titan launching large military satellites. In 1996, an Atlas I became the 100th Atlas-Centaur to launch. The final Centaur to cause a mission failure took place in 1999 on a Titan IV. Due to a software issue, the Centaur completed incorrect burns placing the satellite into the wrong orbit. Following this mission, Centaur would never cause a mission failure. In December 1999, AC-141 on an Atlas IIAS launched from Vandenberg Space Launch Complex-3 East (SLC-3E) as the first Centaur to launch from Vandenburg. Atlas III saw its first launch in May 2000, it saw a change for both Atlas and Centaur. The first stage used a single Russian-built RD-180 engine and the first Centaur variant to a single RL10 engine. Centaur on Atlas III would be called Centaur III also known as Common Centaur. Common Centaur used either a single or dual engine configuration. Present and future of Centaur The final Titan IV launch with a Centaur took place in 2003. A year later, Atlas II was retired with Atlas III following shortly after in 2006. To replace the three rockets, Lockheed Martin developed the Atlas V rocket. Atlas V uses the same RD-180 and Common Centaur used on Atlas III. The first stage would use a non-balloon tank, solid rocket boosters, and either a 4.2 or 5.4-meter diameter payload fairing. As Atlas Vs first stage is different from other Atlas vehicles, it marked the end of the original Atlas vehicle. Atlas III was the last Atlas-Centaur vehicle to fly. Atlas V took its first flight in August 2002 from SLC-41. The Atlas V rocket has since been a workhorse for both NASA and the US Military. For most Atlas V flights, only a single RL10 engine has been used on the Centaur. Since its maiden flight, Atlas V has flown 92 times with a near-flawless record. The Atlas V launched its first NASA mission in 2005. It carried the Mars Reconnaissance Orbiter (MRO) also on its first mission to Mars. In 2006, an Atlas V launched NASAs New Horizons mission. It became the first spacecraft to conduct a flyby of Pluto and a second object in the Kuiper belt. On Atlas Vs ninth mission, it carried the Space Test Program (STP)-1 mission on its first mission for the military. During Atlas Vs 10th mission, Centaur shut down its engine a few seconds short of its intended orbit. The satellites, owned by the National Reconnaissance Office (NRO), compensated for the lower than intended orbit. The NRO called the mission a success. On the NROL-30 mission, it was the Atlas V mission for the NRO. Atlas Vs 28th mission saw the launch of the Mars Science Laboratory to land NASAs Curiosity rover on Mars. It was the first Mars rover to be launched on Centaur and one of the heaviest objects to land on Mars. On the 62nd flight of the Atlas V, the first shut down six seconds early causing Centaur to burn nearly a minute longer than the planned orbital insertion burn. Centaur was able to compensate for the successful mission to deploy the Cygnus OA-6 mission. Following the primary mission, Centaur was able to complete its deorbit burn but it didnt reach its intended location. Throughout the Atlas Vs flight history, Centaur saw several minor upgrades with two new RL10 variants introduced. In October 2018, during the AEHF-4 mission, it used the 250th Centaur ever made. On December 20, 2019, Atlas V successfully carried the Boeing Starliner spacecraft on its first test flight. While Starliner had several issues in orbit, Atlas and Centaur completed their mission perfectly. It was the first time a dual-engine Centaur was used on an Atlas V rocket. Starliner is one of the heaviest spacecraft ever lifted by Centaur. The Atlas V launched NASAs Mars 2020 mission carrying the Perseverance Rover and Ingunity Helicopter as its last mission to Mars. During the SBIRS GEO-5 mission in 2021, Atlas V introduced the RL10C-1-1 variant. In October 2021, the Atlas V completed NASAs Lucy on its final interplanetary mission. In December 2021, Atlas V completed its longest mission yet on STP-3. Centaur successfully took multiple payloads to a direct Geostationary orbit and saw even more upgrades to increase its orbital lifespan. Its most recent launch took place on March 1, 2022, on the GOES-T mission for NOAA and NASA. Its next launch is set for the OFT-2 for Boeings Starliner on May 19, 2022. The JPSS-2 mission currently NET September 30, 2022, will be the last mission to use the 4.2-meter fairing which was used on many previous Atlas vehicles. Currently set for Q4 2022, an Atlas V N22 will launch the Starliner Crew Flight Test (CFT). This will be the first time a Centaur upper stage will carry a crew into space. With 24 launches remaining, the Atlas V rocket will be retired marking the end of the Atlas family. This, however, does not mark the end of the Centaur upper stage. The largest upgrade to Centaur will take place for the ULAs Vulcan-Centaur rocket. Early Centaur upper stages were different compared to the one used today. For Centaur-C, it used two RL10A-3C with a max thrust of 133.45 kN with a specific impulse of 425 seconds. Centaur-C was 9.14-meters in height with most Centaur upper stages keeping the 3.05-meter diameter. The early Centaur stages would use separating insulation panels to help with thermo-protection before launch. Common Centaur uses the aforementioned one or two RL10 engines. The RL10A4-2, RL10C-1, or RL10C-1-1 are used on single-engine Centaur providing up to 108 kN of thrust with a specific impulse of 453 seconds. This Centaur keeps the diameter the same but has a height of 12.7-meters. Insulation panels were ditched on earlier versions of Centaur. Vulcan will use a new variant of Centaur. Named Centaur V, it is built specifically for the new rocket. Centaur V will return to the normal dual-engine configuration with the RL10C-1-1. The two RL10 engines will provide a total thrust of 212 kN with a specific impulse of 453 seconds. This will also see Centaurs largest size increase to 5.4-meters in diameter with a height of 12.6-meters. Infographic of Centaur III and Centaur V capabilities. (Credit: United Launch Alliance) The structure of Centaur V will still use the same pressure-stabilized balloon-style stainless steel tanks. Currently, on the Atlas V 500 series of rockets, it uses a Centaur Forward Load Reactor (CFLR) to help lower the stresses Centaur sees during flight. The CFLR takes the load of the Centaur and moves it to the fairings. It is used on heavier payloads and is required for the four and five SRB variants. On Centaur V, it will no longer need the CFLR as it can support the weight and stresses during the more powerful Vulcan launches. An aft-equipment shelf will be used to provide mountings for the electronics. Spray-on foam insulation (SOFI) will also be used to manage temperatures for their cryogenic propellant during flight. Other changes allow for an on-orbit lifespan of 12-hours and increase its overall orbital capabilities. Later flights will introduce the new RL10C-X variant. RL10C-X will use 3D Printing to help with manufacturing and lower the cost of the engine. The engine will be equipped with fixed nozzle extensions to increase its efficiency. This engine will have a thrust of 107 kN and an increased specific impulse of 460 seconds. Vulcan with Centaur V will become one of the most efficient rockets. With its later upgrades, Vulcan will be able to lift 27.2 tons to low-Earth orbit (LEO) and up to 15.3 tons to GTO. On top of Centaur will have a 5.4-meter diameter payload fairing with standard and long variants. The long variants will have the ability to have multi-manifest capabilities. Centaur V will also have an LEO-optimized version. Known as CVL, this version of Centaur V will be used for LEO and Amazons Kuiper missions. CVL was announced shortly after ULAs record 38-launch contract with Amazon to launch its Kuiper satellites. At the same time, ULA also announced the purchase of 116 RL10C-X engines to engine manufacturer Aerojet Rocketdyne. The launch contract with Amazon will allow ULA to expand its operations for Vulcan. ULA will see a third mobile launch platform, a second vertical integration facility, a new barge, and a second Centaur V manufacturing line. I spy a Centaur V out for a cruise on the Tennessee. On its way from the Rocket Factory in Decatur to @NASA_Marshall for cryogenic testing. #CountdownToVulcan pic.twitter.com/6n2Bp82dJh Tory Bruno (@torybruno) January 19, 2022 As Vulcan flies, more upgrades will be introduced to Centaur V to increase its on-orbit capabilities. Possible upgrades will allow for multiple days of operation while in orbit and eventually allow capabilities to be refueled in flight. The first Centaur V was completed in late-2021 at their manufacturing facility in Decatur, Alabama. In January 2022, a ground testing Centaur V was moved to the Marshall Space Flight Center to be cryogenically tested. Currently, the first-flight-ready Centaur V is in fabrication. This Centaur V will then pair with the second pathfinder Vulcan first stage to conduct testing. Then with the first stage, it will take its maiden flight with the Peregrine lunar lander in NET Q4 2022. (Lead image: Render of a Centaur V carrying two co-manifested payloads. Credit: Mack Crawford for NSF/L2) The post As Centaur turns 60 years old, ULA prepares to evolve Centaur V appeared first on NASASpaceFlight.com . ====================================================================== Link to news story: https://www.nasaspaceflight.com/2022/05/centaur-turns-60/ --- Mystic BBS v1.12 A47 (Linux/64) * Origin: tqwNet Science News (1337:1/100) .