Chrysler SERV
Encyclopedia
Chrysler
Chrysler Group LLC is a multinational automaker headquartered in Auburn Hills, Michigan, USA. Chrysler was first organized as the Chrysler Corporation in 1925....
's Space Division for the 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...
project. SERV was a single-stage to orbit spacecraft that took off from the existing 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...
complexes and landed vertically at Kennedy for re-use. SERV looked like a greatly expanded Apollo capsule, with an empty central core used to carry up 125000 lb (56,699 kg) of cargo. A separate spaceplane
Spaceplane
A spaceplane is a vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that...
, MURP, could be carried on top of the vehicle. SERV was, however, so radically different than the two-stage spaceplanes that almost every other competitor entered into the Shuttle development process that it was never seriously considered for the shuttle program.
Note that the name "SERV" was also used by an entirely unrelated NASA
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...
project, the "Space Emergency Re-entry Vehicle".
Background
In 1966 the US Air Force started a study effort that explored a variety of manned spacecraft and associated launchers. As the proposals were studied, they broke them down into one of three classes, based on the level of reusability. On the simpler end of the development scale were the "Class I" vehicles that placed a spaceplaneSpaceplane
A spaceplane is a vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that...
on top of an existing or modified ICBM-based launcher. "Class II" vehicles added partial reusability for some of the launcher components, while the "Class III" vehicles were fully reusable. The USAF had already started work on a Class I design in their X-20 Dyna Soar program, which had been cancelled in December 1963, but were interested in the Lockheed Star Clipper
Lockheed Star Clipper
Lockheed's Star Clipper was a proposed Earth-to-orbit shuttle based around a large lifting body spacecraft and a wrap-around drop tank. Originally proposed during a USAF program in 1966, the basic Star Clipper concept lived on during the early years of the NASA Space Shuttle program, and as that...
Class II design as a possible future development. Nothing ever came of the study effort, as the USAF wound down their interest in manned space programs.
At the time, NASA was in the midst of winding down the Project Apollo
Project Apollo
The Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...
build-out, as the vehicles progressed to flight. Looking into the future, a number of NASA offices started programs to explore manned missions in the 1970s and beyond. Among the many proposals, a permanently manned space station
Space station
A space station is a spacecraft capable of supporting a crew which is designed to remain in space for an extended period of time, and to which other spacecraft can dock. A space station is distinguished from other spacecraft used for human spaceflight by its lack of major propulsion or landing...
was a favorite. These plans generally assumed the use of the existing Saturn rockets to launch the stations, and even the crews, but the Saturn systems were not set up for the sort of constant supply and crew turnaround being envisioned. The idea of a simple and inexpensive manned launcher, a "ferry and logistics vehicle", developed out of the space station studies almost as an afterthought, the first mention of it being in the fiscal year 1967 budgets.
Design of a low cost, reusable Space Transportation System
Space Transportation System
The Space Transportation System is another name for the NASA Space Shuttle and Space Shuttle program. However, the name originates from, and can describe a more elaborate set of spacefaring hardware in the 1970s, although this meaning is obscure...
(STS) started in earnest in December 1967, when George Mueller
George Mueller
George Mueller is the name of:*George Mueller , former NASA deputy administrator*George Müller , Christian evangelist and coordinator of orphanages in England...
organized a one-day brainstorming session on the topic. He jump-started the discussion by inviting the USAF to attend, even keeping the original USAF acronym for the project, "ILRV". Like the original USAF studies, a small vehicle was envisioned, carrying replacement crews and basic supplies, with an emphasis on low cost of operations and fast turnarounds. Unlike the USAF, however, NASA's Space Task Force quickly decided to move directly to the Class III designs.
Phase A
NASA envisioned a four-phase program of development for the STS. "Phase A" was a series of initial studies to select an overall technology path, and development contracts for proposals were released in 1968 with the proposals expected back in the fall of 1969. A number of designs were presented from a variety of industry partners. Almost universally, the designs were small, fully reusable, and based around delta wingDelta wing
The delta wing is a wing planform in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta .-Delta-shaped stabilizers:...
or lifting body
Lifting body
A lifting body is a fixed-wing aircraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage with little or no conventional wing...
spaceplanes.
Chrysler Aerospace won contract NAS8-26341 for their entry into the Phase A series, forming a team under Charles Tharratt. Their 1969 report, NASA-CR-148948, outlined the SERV design, preliminary performance measures, and basic mission profiles. Tharratt was convinced that SERV offered better flexibility than any of the winged platforms, allowing it to launch both manned and unmanned missions, and being much smaller overall.
With most of the NASA centers backing one of the winged vehicles, and being dramatically different than any of them, SERV found no supporters within the bureaucracy and was never seriously considered for STS. Additionally, the astronaut corps was adamant that any future NASA spacecraft would have to be manned, so the potentially unmanned SERV won no converts there either. An extension contract was offered anyway, producing the final NASA-CR-150241 report on the SERV design that was turned in on 1 July 1971.
Vehicle design
SERV consisted of a large conical body with a rounded base that Chrysler referred to as a "modified Apollo design". The resemblance is due to the fact that both vehicles used blunt body re-entry profiles, which lessen heating load during re-entry by creating a very large shock waveShock wave
A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...
in front of a rounded surface. Tilting the vehicle in relation to the direction of motion changes the pattern of the shock waves, producing lift that can be used to maneuver the spacecraft - in the case of SERV, up to about 100 NM
Nautical mile
The nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...
on either side of its ballistic path. To aid lift generation, SERV was "stepped", with the lower portion of the cone angled in at about 30 degrees, and the upper portion closer to 45 degrees. SERV was 96 feet (29.3 m) across at the widest point, and 83 feet (25.3 m) tall. Gross lift off weight was just over 6000000 lb (2,721,554.2 kg).
The majority of the SERV airframe consisted of aluminum composite honeycomb. The base was covered with screw-on ablative heat shield panels, which allowed for easy replacement between missions. The upper portions of the airframe, which received dramatically lower heating loads, were covered with metal "shingles" covering a quartz insulation below. Four landing legs extended from the bottom, their "foot" forming their portion of heat shield surface when retracted.
A twelve module LH2/LOX aerospike engine
Aerospike engine
The aerospike engine is a type of rocket engine that maintains its aerodynamic efficiency across a wide range of altitudes through the use of an aerospike nozzle. It is a member of the class of altitude compensating nozzle engines. A vehicle with an aerospike engine uses 25–30% less fuel at low...
was arranged around the rim of the base, covered by movable metal shields. During the ascent the shields would move out from the body to adjust for decreasing air pressure, forming a large altitude compensating nozzle
Altitude compensating nozzle
An altitude compensating nozzle is a class of rocket engine nozzles that are designed to operate efficiently across a wide range of altitudes.- Conventional designs :...
. The module were fed from a set of four cross-linked turbopump
Turbopump
A turbopump is a gas turbine that comprises basically two main components: a rotodynamic pump and a driving turbine, usually both mounted on the same shaft, or sometimes geared together...
s that were designed to run at up to 120% of their nominal power, allowing orbital insertion even if one pump failed immediately after takeoff. The engine as a whole would provide 7,454,000 lbf (25.8 MN) of thrust, about the same as the S-IC
S-IC
The S-IC was the first stage of the Saturn V rocket. The S-IC first stage was built by The Boeing Company. Like the first stages of most rockets, most of its mass of over two thousand metric tonnes at launch was propellant, in this case RP-1 rocket fuel and liquid oxygen oxidizer...
, the first stage of the 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...
.
Also arranged around the base were forty 20000 lbf (89 kN) jet engines, which were fired just prior to touchdown in order to slow the decent. Movable doors above the engines opened for feed air. Two RL-10
RL-10
The RL10 was USA's first liquid hydrogen fueled rocket engine. An updated version is used in several current launch vehicles. Six RL10 engines were used in the S-IV second stage of the Saturn I rocket. One or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets...
's provided de-orbit thrust, so the main engine did not have to be re-started in space. Even on-orbit maneuvering, which was not extensive for the SERV (see below), was provided by small LOX/LH2 engines instead of thrusters using different fuels.
A series of conical tanks around the outside rim of the craft, just above the engines, stored the LOX
Lox
Lox is salmon fillet that has been cured. In its most popular form, it is thinly sliced—less than in thickness—and, typically, served on a bagel, often with cream cheese, onion, tomato, cucumber and capers...
. LH2 was stored in much larger tanks closer to the center of the craft. Much smaller spherical tanks, located in the gaps below the rounded end of the LOX tanks, held the JP-4
JP-4
JP-4, or JP4 was a jet fuel, specified in 1951 by the U.S. government . It was a 50-50 kerosene-gasoline blend. It has lower flash point than JP-1, but was preferred because of its greater availability. It was the primary U.S. Air Force jet fuel between 1951 and 1995. Its NATO code is F-40...
used to feed the jet engines. Orbital maneuvering and de-orbit engines were clustered around the top of the spacecraft, fed by their own tanks interspersed between the LH2. This arrangement of tanks left a large open space in the middle of the craft, 15 by 60 feet (18.3 m), which served as the cargo hold.
Operational modes
Two basic spacecraft configurations and mission profiles were envisioned. "Mode A" missions flew SERV to a high-altitude parking orbit at 260 nmi (481.5 km) inclined at 55 degrees, just below the space station's orbit at 270 nmi (500 km). "Mode B" missions flew to a 110 nmi (203.7 km) low-earth orbit (LEO) inclined at 28.5 degrees, a due-east launch from the Kennedy Space CenterKennedy Space Center
The John F. Kennedy Space Center is the NASA installation that has been the launch site for every United States human space flight since 1968. Although such flights are currently on hiatus, KSC continues to manage and operate unmanned rocket launch facilities for America's civilian space program...
. In either case the SERV was paired with a long cargo container in its bay, and optionally combined with a manned spacecraft on top.
The original proposals used a lifting body spaceplane known as MURP to support manned missions. The MURP was based on the HL-10 design already under study by North American Rockwell as part of their STS efforts. MURP was fitted on top of a cargo container and fairing, which was 114 feet (34.7 m) long overall. In the second version of the study, Chrysler also added an option that replaced MURP with a "personnel module", based on the Apollo CSM, which was 74 feet (22.6 m) long when combined with the same cargo container. The original, "SERV-MURP", was 137 ft (41.8 m) when combined with SERV, while the new configuration, "SERV-PM", was 101 ft (30.8 m) tall. Both systems included an all-aspect abort of the manned portion throughout the entire ascent.
After considering all four combinations of mode and module, two basic mission profiles were selected as the most efficient. With SERV-PM the high-earth orbit would be used and the PM would maneuver only a short distance to reach the station. With SERV-MURP, the low-earth orbit would be used and the MURP would maneuver the rest of the way on its own. In either case, the SERV could return to Earth immediately and let the PM or MURP land on their own, or more commonly, wait in the parking orbit for a cargo module from an earlier mission to rendezvous with it for return to Earth. Weight and balance considerations limited the return payload.
Both configurations delivered 25000 lb (11,339.8 kg) of cargo to the space station, although in the PM configuration the overall thrown weights were much lower. If the PM configuration was used with a fairing instead of the capsule, SERV could deliver 112000 lb (50,802.3 kg) to LEO, or as much as 125000 lb (56,699 kg) with an "Extended Nosecone". The Extended Nosecone was a long spike with a high fineness ratio
Fineness ratio
Fineness ratio is a term used in naval architecture and aerospace engineering to describe the overall shape of a streamlined body. Specifically, it is the ratio of the length of a body to its maximum width; shapes that are "short and fat" have a low fineness ratio, those that are "long and skinny"...
that lowered atmospheric drag by creating shock waves that cleared the vehicle body during ascent.
Chrysler also outlined ways to support 33 ft (10.1 m) wide loads on the front of SERV. This was the diameter of the S-IC
S-IC
The S-IC was the first stage of the Saturn V rocket. The S-IC first stage was built by The Boeing Company. Like the first stages of most rockets, most of its mass of over two thousand metric tonnes at launch was propellant, in this case RP-1 rocket fuel and liquid oxygen oxidizer...
and S-II
S-II
The S-II was the second stage of the Saturn V rocket. It was built by North American Aviation. Using liquid hydrogen and liquid oxygen it had five J-2 engines in a cross pattern...
, the lower stages of the Saturn V. NASA had proposed a wide variety of payloads for the Apollo Applications Program
Apollo Applications program
The Apollo Applications Program was established by NASA headquarters in 1968 to develop science-based manned space missions using surplus material from the Apollo program...
that were based on this diameter that were intended to be launched on the Saturn INT-21
Saturn INT-21
The Saturn INT-21 was a study for an American orbital launch vehicle of the 1970s. It was derived from the Saturn V rocket used for the Apollo program, using its first and second stages, but lacking the third stage. The guidance unit would be moved from the top of the third stage to the top of the...
. Chrysler demonstrated that they could also be launched on SERV, if weight considerations taken into account. However, these plans were based on the earlier SERV designs with the larger 23 ft (7 m) cargo bay. When NASA's loads were adapted to fit to the smaller 15 ft (4.6 m) bay common to all the STS proposals, this option was dropped.
SERV was not expected to remain on orbit for extended periods of time, with the longest missions outlined in the report at just under 48 hours. Typically it would return after a small number of orbits brought its ground track close enough to Kennedy, and abort-once-around missions were contemplated. The vehicle was designed to return to a location within four miles (6 km) of the touchdown point using re-entry maneuvering, the rest would be made up during the jet-powered decent.
Construction and operations
NASA had partnered with Chrysler to build the NASA-designed Saturn IBSaturn IB
The Saturn IB was an American launch vehicle commissioned by the National Aeronautics and Space Administration for use in the Apollo program...
, at the Michoud Assembly Facility
Michoud Assembly Facility
The Michoud Assembly Facility is an 832-acre site owned by NASA and located in New Orleans East, a large district within the city of New Orleans, Louisiana, United States. Organizationally, it is part of NASA's Marshall Space Flight Center...
outside of New Orleans. Chrysler proposed building SERVs at Michoud as well, delivering them to KSC on the Bay-class ships used to deliver Boeing's S-IC from the same factory. Since the SERV was wider than the ships, it had to be carried slightly tilted in order to reduce its overall width. Pontoons were then added to the side of the ships to protect the spacecraft from spray.
SERVs would be fitted out in the Vehicle Assembly Building
Vehicle Assembly Building
The Vehicle Assembly Building, or VAB, at NASA's Kennedy Space Center was used to assemble and house American manned launch vehicles from 1968-2011. It is the fourth largest building in the world by volume...
(VAB) High Bay, mated with the PM or MURP which were prepared in the Low Bay, and then transported to the LC39
Kennedy Space Center Launch Complex 39
Launch Complex 39 is a rocket launch site at the John F. Kennedy Space Center on Merritt Island in Florida, USA. The site and its collection of facilities were originally built for the Apollo program, and later modified to support Space Shuttle operations. NASA began modifying LC-39 in 2007 to...
pads on the existing crawler-transporter
Crawler-Transporter
The crawler-transporters are a pair of tracked vehicles used to transport spacecraft from NASA's Vehicle Assembly Building along the Crawlerway to Launch Complex 39. They were originally used to transport the Saturn IB and Saturn V rockets during the Apollo, Skylab and Apollo–Soyuz programs....
s. The LC39 pads required only minor modifications for SERV use, similar to those needed to launch the Saturn IB
Saturn IB
The Saturn IB was an American launch vehicle commissioned by the National Aeronautics and Space Administration for use in the Apollo program...
. Chrysler proposed building several SERV landing pads between LC39 and the VAB, and a landing strip for the MURP near the existing Space Shuttle landing strip. The SERVs would be returned to the VAB on an enormous flatbed truck. The only other new infrastructure was a set of test stands at the Mississippi Test Operations
John C. Stennis Space Center
The John C. Stennis Space Center , located in Hancock County, Mississippi, at the Mississippi-Louisiana border, is NASA's largest rocket engine test facility.- History :...
engine testing complex, near Michoud.
Re-using much of the existing infrastructure lowered overall program costs; total costs were estimated as $3.565 billion, with each SERV costing $350 million in FY1971 dollars, and being rated for 100 flights over a 10 year service life. This was far less expensive than the two-stage flyback proposals entered by most companies, which had peak development costs on the order of $10 billion.
Similar designs
SERV was similar to the later McDonnell Douglas DC-XMcDonnell Douglas DC-X
The DC-X, short for Delta Clipper or Delta Clipper Experimental, was an unmanned prototype of a reusable single stage to orbit launch vehicle built by McDonnell Douglas in conjunction with the United States Department of Defense's Strategic Defense Initiative Organization from 1991 to 1993...
design. The primary difference between the two was that the DC-X was built to a military mission and required much greater re-entry maneuvering capability. Because of this, the airframe was long and skinny, and the spacecraft re-entered nose-first. Tilting this shape relative to the path of motion generates considerably more lift than the blunt base of SERV, but also subjects the airframe to much higher heating loads.
More recently, the original SERV layout was used in the Blue Origin New Shepard
Blue Origin New Shepard
The Blue Origin New Shepard reusable launch vehicle is a vertical-takeoff, vertical-landing , suborbital manned rocket that is being developed by Blue Origin, a company owned by Amazon.com founder and businessman Jeff Bezos, as a commercial system for suborbital space tourism.The New Shepard makes...
spacecraft. Like the SERV, New Shepard does not need the extended crossrange capabilities of a military launcher, and returned to the simpler blunt-base re-entry profile. The similar Kankoh-maru
Kankoh-maru
The is the name of a proposed vertical takeoff and landing, single-stage to orbit, reusable launch vehicle family of rockets, and the spacecraft tour vehicle designed to be boosted by said rocket.-Details:...
design study also used the same blunt-body VTOL profile.
See also
- Douglas SASSTODouglas SASSTODouglas Aircraft's SASSTO, short for "Saturn Application Single Stage to Orbit", was a single-stage-to-orbit reusable launch system designed by Philip Bono's team in 1967. SASSTO was a study in minimalist designs, a launcher with the specific intent of repeatedly placing a Gemini capsule in orbit...
- List of space launch system designs