Ares I was the crew launch vehicle that was being developed by NASA as part of the Constellation program.[2] The name "Ares" refers to the Greek deity Ares,who is identified with the Roman god Mars.[3] Ares I was originally known as the "Crew Launch Vehicle" (CLV).[4]
NASA planned to use Ares I to launch Orion,the spacecraft intended for NASA human spaceflight missions after the Space Shuttle was retired in 2011. Ares I was to complement the larger,uncrewed Ares V,which was the cargo launch vehicle for Constellation. NASA selected the Ares designs for their anticipated overall safety,reliability and cost-effectiveness.[5] However,the Constellation program,including Ares I,was cancelled by U.S. president Barack Obama in October 2010 with the passage of his 2010 NASA authorization bill. In September 2011,NASA detailed the Space Launch System as its new vehicle for human exploration beyond Earth's orbit.[6]
Development
Advanced Transportation System Studies
In 1995 Lockheed Martin produced an Advanced Transportation System Studies (ATSS) report for the Marshall Space Flight Center. A section of the ATSS report describes several possible vehicles much like the Ares I design,with liquid rocket second stages stacked above segmented solid rocket booster (SRB) first stages.[7] The variants that were considered included both the J-2S engines and Space Shuttle Main Engines (SSMEs) for the second stage. The variants also assumed use of the Advanced Solid Rocket Motor (ASRM) as a first stage,but the ASRM was cancelled in 1993 due to significant cost overruns.
determine the "top-level requirements and configurations for crew and cargo launch systems to support the lunar and Mars exploration programs"
assess the "CEV requirements and plans to enable the CEV to provide crew transport to the ISS"
"develop a reference lunar exploration architecture concept to support sustained human and robotic lunar exploration operations"
"identify key technologies required to enable and significantly enhance these reference exploration systems"
Concept image of the evolution of the Ares I design from pre-ESAS to latest developments.
A Shuttle-derived launch architecture was selected by NASA for the Ares I. Originally,the crewed vehicle would have used a four-segment solid rocket booster (SRB) for the first stage,and a simplified Space Shuttle Main Engine (SSME) for the second stage. An uncrewed version was to use a five-segment booster with the same second stage.[9] Shortly after the initial design was approved,additional tests revealed that the Orion spacecraft would be too heavy for the four-segment booster to lift,[10] and in January 2006 NASA announced they would slightly reduce the size of the Orion spacecraft,add a fifth segment to the solid-rocket first stage,and replace the single SSME with the Apollo-derived J-2X motor.[11] While the change from a four-segment first stage to a five-segment version would allow NASA to construct virtually identical motors,the main reason for the change to the five-segment booster was the move to the J-2X.[12]
The Exploration Systems Architecture Study concluded that the cost and safety of the Ares was superior to that of either of the Evolved Expendable Launch Vehicle (EELVs).[8] The cost estimates in the study were based on the assumption that new launch pads would be needed for human-rated EELVs.[8] The facilities for the current EELVs (LC-37 for Delta IV,LC-41 for Atlas V) are in place and could be modified,but this may not have been the most cost effective solution as LC-37 is a contractor owned and operated (COGO) facility and modifications for the Delta IV H were determined to be similar to those required for Ares I.[13] The ESAS launch safety estimates for the Ares were based on the Space Shuttle,despite the differences,and included only launches after the post-Challenger Space Shuttle redesign.[14] The estimate counted each Shuttle launch as two safe launches of the Ares booster. The safety of the Atlas V and Delta IV was estimated from the failure rates of all Delta II,Atlas-Centaur,and Titan launches since 1992,although they are not similar designs.[citation needed]
Role in Constellation program
An early concept image of the Ares I (right) and Ares V (left) rockets
Ares I was the crew launch component of the Constellation program. Originally named the "Crew Launch Vehicle" or CLV,the Ares name was chosen from the Greek deity Ares.[4] Unlike the Space Shuttle,where both crew and cargo were launched simultaneously on the same rocket,the plans for Project Constellation outlined having two separate launch vehicles,the Ares I and the Ares V,for crew and cargo,respectively. Having two separate launch vehicles allows for more specialized designs for the crew and heavy cargo launch rockets.[15]
The Ares I rocket was specifically being designed to launch the Orion Multi-Purpose Crew Vehicle. Orion was intended as a crew capsule,similar in design to the Apollo program capsule,to transport astronauts to the International Space Station,the Moon,and eventually Mars. Ares I might have also delivered some (limited) resources to orbit,including supplies for the International Space Station or subsequent delivery to the planned lunar base.[5]
Contractor selection
NASA selected Alliant Techsystems,the builder of the Space Shuttle Solid Rocket Boosters,as the prime contractor for the Ares I first stage.[16][17] NASA announced that Rocketdyne would be the main subcontractor for the J-2X rocket engine on July 16,2007.[18] NASA selected Boeing to provide and install the avionics for the Ares I rocket on December 12,2007.[19]
On August 28,2007,NASA awarded the Ares I Upper Stage manufacturing contract to Boeing. The upper stage of Ares I was to have been built at Michoud Aerospace Factory,which was used for the Space Shuttle's External Tank and the Saturn V's S-IC first stage.[20][21]
At approximately US$20–25 million per engine,the Rocketdyne-designed and produced J-2X would have cost less than half as much as the more complex RS-25 engine (around $55 million).[22] Unlike the Space Shuttle Main Engine,which was designed to start on the ground,the J-2X was designed from inception to be started in both mid-air and in near-vacuum. This air-start capability was critical,especially in the original J-2 engine used on the Saturn V's S-IVB stage,to propel the Apollo spacecraft to the Moon. The Space Shuttle Main Engine,on the other hand,would have required extensive modifications to add an air-start capability[23][12]
On January 4,2007,NASA announced that the Ares I had completed its system requirements review,the first such review completed for any crewed spacecraft design since the Space Shuttle.[24] This review was the first major milestone in the design process,and was intended to ensure that the Ares I launch system met all the requirements necessary for the Constellation Program. In addition to the release of the review,NASA also announced that a redesign in the tank hardware was made. Instead of separate LH2 and LO2 tanks,separated by an "intertank" like that of the Space Shuttle External Tank,the new LH2 and LOX tanks would have been separated by a common bulkhead like that employed on the Saturn V S-II and S-IVB stages. This would have provided a significant mass saving and eliminated the need to design a second stage interstage unit that would have had to carry the weight of the Orion spacecraft with it.[17]
Analysis and testing
In January 2008,NASA Watch revealed that the first stage solid rocket of the Ares I could have created high vibrations during the first few minutes of ascent. The vibrations would have been caused by thrust oscillations inside the first stage.[25] NASA officials had identified the potential problem at the Ares I system design review in late October 2007,stating in a press release that it wanted to solve it by March 2008.[26] NASA admitted that this problem was very severe,rating it four out of five on a risk scale,but the agency was very confident in solving it.[25] The mitigation approach developed by the Ares engineering team included active and passive vibration damping,adding an active tuned-mass absorber and a passive "compliance structure" –essentially a spring-loaded ring that would have detuned the Ares I stack.[27] NASA also pointed out that,since this would have been a new launch system,like the Apollo or Space Shuttle systems,it was normal for such problems to arise during the development stage.[28] According to NASA,analysis of the data and telemetry from the Ares I-X flight showed that vibrations from thrust oscillation were within the normal range for a Space Shuttle flight.[29]
A study released in July 2009 by the 45th Space Wing of the US Air Force concluded that an abort 30–60 seconds after launch would have a ≈100% chance of killing all crew,due to the capsule being engulfed until ground impact by a cloud of 4,000°F (2,200°C) solid propellant fragments,which would melt the capsule's nylon parachute material. NASA's study showed the crew capsule would have flown beyond the more severe danger.[30][31]
The Ares I igniter was an advanced version of the flight-proven igniter used on the Space Shuttle's solid rocket boosters. It was approximately 18 inches (46cm) in diameter and 36 inches (91cm) long,and took advantage of upgraded insulation materials that had improved thermal properties to protect the igniter's case from the burning solid propellant.[32] NASA successfully completed test firing of the igniter for the Ares I engines on March 10,2009,at ATK Launch Systems test facilities near Promontory,Utah. The igniter test generated a flame 200 feet (61 meters) in length,and preliminary data showed the igniter performed as planned.[32]
Development of the Ares I propulsion elements continued to make strong progress. On September 10,2009,the first Ares I development motor (DM-1) was successfully tested in a full-scale,full-duration test firing.[33] This test was followed by two more development motor tests,DM-2 on August 31,2010,and DM-3 on September 8,2011. For DM-2 the motor was cooled to a core temperature of 40 degrees Fahrenheit (4 degrees Celsius),and for DM-3 it was heated to above 90 degrees Fahrenheit (32 degrees Celsius). In addition to other objectives,these two tests validated Ares motor performance at extreme temperatures.[34][35] NASA conducted a successful 500-second test firing of the J-2X rocket engine at John C. Stennis Space Center in November 2011.[36]
The Ares I prototype,Ares I-X,successfully completed a test launch on October 28,2009.[37][38][39] Launch Pad 39B was damaged more than with a Space Shuttle launch. During descent,one of the three parachutes of the Ares I-X's first stage failed to open,and another opened only partially,causing the booster to splash down harder and suffer structural damage.[40] The launch accomplished all primary test objectives.[40][41]
Schedule and cost
NASA completed the Ares I system requirements review in January 2007.[24] Project design was to have continued through the end of 2009,with development and qualification testing running concurrently through 2012. As of July2009[update],flight articles were to have begun production towards the end of 2009 for a first launch in June 2011.[42] Since 2006 the first launch of a human was planned for no later than 2014,[43] which is four years after the planned retirement of the Space Shuttle.
Delays in the Ares I development schedule due to budgetary pressures and unforeseen engineering and technical difficulties would have increased the gap between the end of the Space Shuttle program and the first operational flight of Ares I.[44] Because the Constellation program was never allocated the funding originally projected,[45] the total estimated cost to develop the Ares I through 2015 rose from $28 billion in 2006 to more than $40 billion in 2009.[46] The Ares I-X project cost was $445 million.[47]
Mobile Launcher-1 for Ares I at east park site
Originally scheduled for first test flights in 2011,the independent analysis by the Augustine Commission found in late 2009 that due to technical and financial problems Ares I was not likely to have had its first crewed launch until 2017–2019 under the current budget,or late 2016 with an unconstrained budget.[48] The Augustine Commission also stated that Ares I and Orion would have an estimated recurring cost of almost $1 billion per flight.[49] However,later financial analysis in March 2010 showed that the Ares I would have cost $1 billion or more to operate per flight had the Ares I flown just once a year. If the Ares I system were flown multiple times a year the marginal costs could have fallen to as low as $138 million per launch.[1] In March 2010,NASA administrator Charlie Bolden testified to congress that the Ares I would cost $4–4.5 billion a year,and $1.6 billion per flight.[50] The Ares I marginal cost was predicted to have been a fraction of the Shuttle's marginal costs even had it flown multiple times per year. By comparison,the cost of launching three astronauts on a crewed Russian Soyuz is $153 million.[51] Representative Robert Aderholt stated in March 2010 that he had received a letter from NASA which claimed that it would have cost $1.1 billion to fly the Ares I rocket three times a year.[52]
On February 8,2011,it was reported that Alliant Techsystems and Astrium proposed to use Ares I's first stage with the second stage from the Ariane 5 to form a new rocket named Liberty.[53]
Cancellation
On February 1,2010,President Barack Obama announced a proposal to cancel the Constellation program effective with the U.S. 2011 fiscal year budget,[54] but later announced changes to the proposal in a major space policy speech at Kennedy Space Center on April 15,2010. In October 2010,the NASA authorization bill for 2010 was signed into law which canceled Constellation.[55] Previous legislation kept Constellation contracts in force until passage of a new funding bill for 2011.[56][57]
Ares I had a payload capability in the 25-tonne (28-short-ton;25-long-ton) class and was comparable to vehicles such as the Delta IV and the Atlas V.[5] The NASA study group that selected what would become the Ares I rated the vehicle as almost twice as safe as an Atlas or Delta IV-derived design.[58]
Exploded view of the Ares I
First stage
The first stage was to have been a more powerful and reusable solid fuel rocket derived from the Space Shuttle Solid Rocket Booster (SRB). Compared with the Solid Rocket Booster,which had four segments,the most notable difference was the addition of a fifth segment. This fifth segment would have enabled the Ares I to produce more thrust.[5][59] Other changes made to the Solid Rocket Booster were to have been the removal of the Space Shuttle External Tank (ET) attachment points and the replacement of the Solid Rocket Booster nosecone with a new forward adapter that would have interfaced with the liquid-fueled second stage. The adapter was to have been equipped with solid-fueled separation motors to facilitate the disconnection of the stages during ascent.[5] The grain design was also changed,and so were the insulation and liner. By the Ares I first stage ground test,the case,grain design,number of segments,insulation,liner,throat diameter,thermal protection systems and nozzle had all changed.[60]
Upper stage
The upper stage,derived from the Shuttle's External Tank (ET) and based on the S-IVB stage of the Saturn V,was to be propelled by a single J-2X rocket engine fueled by liquid hydrogen (LH2) and liquid oxygen (LOX).[61] The J-2X was derived from the original J-2 engine used during the Apollo program,but with more thrust (≈294,000lbf or 1.31MN) and fewer parts than the original engine. On July 16,2007,NASA awarded Rocketdyne a sole-source contract for the J-2X engines to be used for ground and flight tests.[62] Rocketdyne was the prime contractor for the original J-2 engines used in the Apollo program.
Although its J-2X engine was derived from an established design,the upper stage itself would have been wholly new. Originally to have been based on both the internal and external structure of the ET,the original design called for separate fuel and oxidizer tanks,joined by an "intertank" structure,and covered with the spray-on foam insulation to keep venting to a minimum. The only new hardware on the original ET-derived second stage would have been the thrust assembly for the J-2X engine,new fill/drain/vent disconnects for the fuel and oxidizer,and mounting interfaces for the solid-fueled first stage and the Orion spacecraft.
Using a concept going back to the Apollo program,the "intertank" structure was dropped to decrease mass,and in its place,a common bulkhead,similar to that used on both the S-II and S-IVB stages of the Saturn V,would have been used between the tanks. The savings from these changes were used to increase propellant capacity,which was 297,900 pounds (135,100kg).[63]
See also
Ares IV,a proposed heavy-lift variant of Ares I and V combined.
DIRECT,shuttle-derived launcher proposed as alternative to Ares I and Ares V.
Liberty (rocket),a proposed medium-lift rocket like the Ares I,a SDLV using an SRB-derivative first stage
Omega,ATK's proposed new rocket based on SDLV SRB-derived first and second stages and Aerojet Rocketdyne RL10 third stage
The Space Shuttle is a retired,partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was Space Transportation System (STS),taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development.
The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA),which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its official name,Space Transportation System (STS),was taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development. It flew 135 missions and carried 355 astronauts from 16 countries,many on multiple trips.
The Constellation program was a crewed spaceflight program developed by NASA,the space agency of the United States,from 2005 to 2009. The major goals of the program were "completion of the International Space Station" and a "return to the Moon no later than 2020" with a crewed flight to the planet Mars as the ultimate goal. The program's logo reflected the three stages of the program:the Earth (ISS),the Moon,and finally Mars—while the Mars goal also found expression in the name given to the program's booster rockets:Ares. The technological aims of the program included the regaining of significant astronaut experience beyond low Earth orbit and the development of technologies necessary to enable sustained human presence on other planetary bodies.
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.
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 Aerojet Rocketdyne RS-68 was a liquid-fuel rocket engine that used liquid hydrogen (LH2) and liquid oxygen (LOX) as propellants in a gas-generator power 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.
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-X was the first-stage prototype and design concept demonstrator of Ares I,a launch system for human spaceflight developed by the National Aeronautics and Space Administration (NASA). Ares I-X was successfully launched on October 28,2009. The project cost was $445 million. It was the final launch from LC-39B until Artemis 1 13 years later.
The Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated,had three stages,and was powered by liquid fuel. Flown from 1967 to 1973,it was used for nine crewed flights to the Moon,and to launch Skylab,the first American space station.
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.
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 retirement of NASA's Space Shuttle fleet took place from March to July 2011. Discovery was the first of the three active Space Shuttles to be retired,completing its final mission on March 9,2011;Endeavour did so on June 1. The final shuttle mission was completed with the landing of Atlantis on July 21,2011,closing the 30-year Space Shuttle program.
Liberty was a 2011 launch vehicle concept proposed by Northrop Grumman Space Systems and Airbus Defence and Space for phase 2 of the NASA Commercial Crew Development (CCDev) program intended to stimulate development of privately operated crew vehicles to low Earth orbit.
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.
OmegA was a medium-lift to heavy-lift launch vehicle concept that spent several years in development by Northrop Grumman during 2016–2020,with that development substantially funded by the U.S. government. OmegA was intended for launching U.S. national security satellites,as part of the U.S. Department of the Air Force National Security Space Launch (NSSL) replacement program.
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.
↑ Karlgaard, Christopher D.; Beck, Roger E.; Derry, Stephen D.; Brandon, Jay M.; Starr, Brett R.; Tartabini, Paul V.; Olds, Aaron D. (n.d.). "Ares I-X Best Estimated Trajectory and Comparison with Pre-Flight Predictions"(PDF). American Institute of Aeronautics and Astronautics. NASA Langley Research Center. Retrieved September 15, 2011.
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