The crawler-transporters, formally known as the Missile Crawler Transporter Facilities, are a pair of tracked

vehicle A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), wa ...

s used to transport

spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...

from

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

Vehicle Assembly Building The Vehicle Assembly Building (originally the Vertical Assembly Building), or VAB, is a large building at NASA's Kennedy Space Center (KSC), designed to assemble large pre-manufactured space vehicle components, such as the massive Saturn V and th ...

(VAB) along the

Crawlerway The Crawlerway is a double pathway at the Kennedy Space Center in Florida. It runs between the Vehicle Assembly Building and the two launch pads at Launch Complex 39. It has a length of to Pad 39A and Pad 39B, respectively. A bed of stones l ...

Launch Complex 39 Launch Complex 39 (LC-39) is a rocket launch site at the John F. Kennedy Space Center on Merritt Island in Florida, United States. The site and its collection of facilities were originally built as the Apollo program's "Moonport" and later m ...

. They were originally used to transport the

Saturn IB The Saturn IB (also known as the uprated Saturn I) was an American launch vehicle commissioned by the NASA, National Aeronautics and Space Administration (NASA) for the Apollo program. It uprated the Saturn I by replacing the S-IV second stage (, ...

and

Saturn V 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, with multistage rocket, three stages, and powered with liquid-propellant r ...

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...

s during the

Apollo Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label= ...

Skylab Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations in ...

and

Apollo–Soyuz Apollo–Soyuz was the first crewed international space mission, carried out jointly by the United States and the Soviet Union in July 1975. Millions of people around the world watched on television as a United States Apollo spacecraft docked ...

programs. They were then used to transport

Space Shuttle 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 na ...

s from 1981 to 2011. The crawler-transporters carry vehicles on the

mobile launcher platform 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 (e.g. the Vehicle Assembly Building) and t ...

s used by NASA, and after each launch return to the pad to take the platform back to the VAB. The two crawler-transporters were designed and built by

Marion Power Shovel Company Marion Power Shovel Company was an American firm that designed, manufactured and sold steam shovels, power shovels, blast hole drills, excavators, and dragline excavators for use in the construction and mining industries. The company was a ma ...

using some components designed and built by

Rockwell International Rockwell International was a major American manufacturing conglomerate involved in aircraft, the space industry, defense and commercial electronics, components in the automotive industry, printing presses, avionics and industrial products. R ...

at a cost of ( in 2022) each. Upon its construction, the crawler-transporter became the largest self-powered land vehicle in the world. While other vehicles such as

bucket-wheel excavator A bucket-wheel excavator (BWE) is a large heavy equipment machine used in surface mining. The primary function of BWEs is ...

s like

Bagger 288 Bagger 288 (Excavator 288), built by the German company Krupp for the energy and mining firm Rheinbraun, is a bucket-wheel excavator or mobile strip mining machine. When its construction was completed in 1978, Bagger 288 superseded Big Muskie a ...

dragline excavator A dragline excavator is a piece of heavy equipment used in civil engineering and surface mining. Draglines fall into two broad categories: those that are based on standard, lifting cranes, and the heavy units which have to be built on-site. Mo ...

s like

Big Muskie Big Muskie was a coal mining Bucyrus-Erie dragline excavator owned by the Central Ohio Coal Company (formerly a division of American Electric Power), weighing and standing nearly 22 stories tall. It operated in the U.S. state of Ohio from 19 ...

and

power shovel A power shovel (also stripping shovel or front shovel or electric mining shovel or electric rope shovel) is a bucket-equipped machine, usually electrically powered, used for digging and loading earth or fragmented rock and for mineral extraction ...

s like The Captain are significantly larger, they are powered by external sources. The two crawler-transporters were added to the National Register of Historic Places on January 21, 2000.

Specifications

The crawler-transporter has a mass of and has eight tracks, two on each corner. Each track has 57 shoes, and each shoe weighs . The vehicle measures . The height from ground level to the platform is adjustable from , and each side can be raised and lowered independently of the other. The crawler uses a laser guidance system and a leveling system to keep the

Mobile Launcher Platform 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 (e.g. the Vehicle Assembly Building) and t ...

level within 10

minutes of arc A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...

(0.16 degrees; about at the top of the Saturn V), while moving up the 5 percent grade to the launch site. A separate laser docking system provides pinpoint accuracy when the crawler-transporter and Mobile Launch Platform are positioned in the VAB or at the launch pad. A team of nearly 30 engineers, technicians and drivers operate the vehicle, centered on an internal control room, and the crawler is driven from two control cabs located at either end. Before the launch the crawler-transporter is removed. The crawlers were overhauled in 2003 with upgrades to the Motor Control Center, which houses the switchgear and electrical controls of all of major systems on board; a new engine and pump ventilation system; new diesel engine radiators; and replacement of the two driver cabs on each vehicle (one on each end). As of 2003, each crawler had 16 traction motors, powered by four generators, in turn driven by two V16 ALCO 251C

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

s. Two generators, driven by two engines, were used for jacking, steering, lighting, and ventilating. Two generators were also available to power the Mobile Launcher Platform. The crawler's tanks held of diesel fuel, and it burned . Due to their age and the need to support the heavier

Space Launch System The Space Launch System (SLS) is an American super heavy-lift expendable launch vehicle developed by NASA. As of 2022, SLS has the highest payload capacity of any rocket in operational service, as well as the greatest liftoff thrust of any r ...

and its launch tower, in 2012–2014 the crawlers were undergoing an upgrade involving "new engines, new exhausts, new brakes, new hydraulics, new computers"; CT-2 was further upgraded in 2014–2016 to increase its lifting capacity from . The crawlers traveled along the Crawlerways, to

LC-39A Launch Complex 39A (LC-39A) is the first of Launch Complex 39's three launch pads, located at NASA's Kennedy Space Center in Merritt Island, Florida. The pad, along with Launch Complex 39B, were first designed for the Saturn V launch vehicle. Ty ...

and

LC-39B Launch Complex 39B (LC-39B) is the second of Launch Complex 39's three launch pads, located at NASA's Kennedy Space Center in Merritt Island, Florida. The pad, along with Launch Complex 39A, was first designed for the Saturn V launch vehicle, ...

, respectively, at a maximum speed of loaded, or unloaded. The average trip time from the VAB along the Crawlerway to Launch Complex 39 is about five hours. Each Crawlerway is deep and covered with Alabama and Tennessee river rock for its low friction properties to reduce the possibility of sparks. In 2000, NASA unearthed and restored an Apollo-era segment of the Crawlerway to provide access to High Bay 2 in the VAB in order to provide protection from a hurricane for up to three Shuttles at the same time. Kennedy Space Center has been using the same two crawlers since their initial delivery in 1965. They are now nicknamed " Hans and Franz", after the parodic Austrian body-builder characters on ''

Saturday Night Live ''Saturday Night Live'' (often abbreviated to ''SNL'') is an American late-night live television sketch comedy and variety show created by Lorne Michaels and developed by Dick Ebersol that airs on NBC and Peacock. Michaels currently serves a ...

'', played by

Dana Carvey Dana Thomas Carvey (born June 2, 1955) is an American stand-up comedian, actor, impressionist, screenwriter, and producer. He is best known for his seven seasons as a cast member on ''Saturday Night Live'' from 1986 to 1993, which earned him fiv ...

and

Kevin Nealon Kevin Nealon (; born November 18, 1953) is an American comedian and actor. He was a cast member on ''Saturday Night Live'' from 1986 to 1995, acted in several of the Happy Madison films, played Doug Wilson on the Showtime series '' Weeds'', and pr ...

. In their lifetime, they have traveled more than , about the same driving distance as from

Miami Miami ( ), officially the City of Miami, known as "the 305", "The Magic City", and "Gateway to the Americas", is a East Coast of the United States, coastal metropolis and the County seat, county seat of Miami-Dade County, Florida, Miami-Dade C ...

Seattle Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest regio ...

Future use

Crawler-Transporter 2

NASA currently plans to use crawler-transporter 2 to transport the

with the

Orion spacecraft Orion (officially Orion Multi-Purpose Crew Vehicle or Orion MPCV) is a Reusable spacecraft, partially reusable crewed spacecraft used in NASA's Artemis program. The spacecraft consists of a Crew Module (CM) space capsule designed by Lockheed ...

atop it from the

to Launch Pad 39B for the Artemis missions. Early in 2016, NASA finished upgrading crawler-transporter 2 (CT-2) to a "Super Crawler" for use in the

Artemis program The Artemis program is a robotic and human Moon exploration program led by the United States' National Aeronautics and Space Administration (NASA) along with three partner agencies: European Space Agency (ESA), Japan Aerospace Exploration ...

. NASA performed a rollout of the

Artemis 1 Artemis 1, officially Artemis I and formerly Exploration Mission-1 (EM-1), was an uncrewed Moon-orbiting mission. As the first major spaceflight of NASA's Artemis program, Artemis 1 marked the return of the agency to lunar exploration original ...

Space Launch System and Orion on March 17, 2022 for the first Wet Dress Rehearsal, and the rollout for launch, which launched in November 2022. The rollout for the WDR, marked the first time one of the crawler transporters rolled a launch vehicle to the launch pad since

STS-135 STS-135 ( ISS assembly flight ULF7) was the 135th and final mission of the American Space Shuttle program. It used the orbiter ''Atlantis'' and hardware originally processed for the STS-335 contingency mission, which was not flown. STS-135 la ...

Crawler-Transporter 1

NASA had originally planned for crawler-transporter 1 to be used by commercial launch vehicles. In April 2016, then Orbital ATK, now

Northrop Grumman Innovation Systems Northrop Grumman Innovation Systems (NGIS) was a sector (business segment) of Northrop Grumman from 2018 through 2019. It was formed from Orbital ATK Inc. a company which resulted from the merger of Orbital Sciences Corporation and parts of Alli ...

, and NASA entered negotiations for the lease of CT-1 and one of the four Vehicle Assembly Building bays. Northrop Grumman has originally planned to use CT-1 to transport their

OmegA Omega (; capital: Ω, lowercase: ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and final letter in the Greek alphabet. In the Greek numeric system/isopsephy (gematria), it has a value of 800. The wo ...

from the Vehicle Assembly Building to Launch Pad 39B. OmegA however was cancelled in September of 2020 after Northrop Grumman lost the National Security Space Launch contract to

United Launch Alliance United Launch Alliance (ULA), legally United Launch Alliance, LLC, is an American spacecraft launch service provider that manufactures and operates a number of rocket vehicles that are capable of launching spacecraft into orbits around Earth, a ...

and

SpaceX Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of ...

Appearances in popular culture

The crawler-transporters have featured in television and movies. In a 2007 season three episode of ''

Dirty Jobs ''Dirty Jobs'' is an American television series that originally aired on the Discovery Channel in which host Mike Rowe is shown performing difficult, strange, disgusting, or messy occupational duties alongside the job's current employees. The sh ...

'', host

Mike Rowe Michael Gregory Rowe (born March 18, 1962) is an American television host and narrator. He is known for his work on the Discovery Channel series '' Dirty Jobs'' and the series '' Somebody's Gotta Do It'' originally developed for CNN. He hosted ...

helps workers maintain a crawler-transporter and takes the vehicle for a short drive. The crawler was also seen in the 1995 film ''

Apollo 13 Apollo 13 (April 1117, 1970) was the seventh crewed mission in the Apollo space program and the third meant to land on the Moon. The craft was launched from Kennedy Space Center on April 11, 1970, but the lunar landing was aborted aft ...

'', the 2011 film '' Transformers: Dark of the Moon'' and the 2019 film ''

Apollo 11 Apollo 11 (July 16–24, 1969) was the American spaceflight that first landed humans on the Moon. Commander Neil Armstrong and lunar module pilot Buzz Aldrin landed the Apollo Lunar Module ''Eagle'' on July 20, 1969, at 20:17 UTC, an ...

''. Similar vehicles also appeared in the 2013 film ''

Pacific Rim The Pacific Rim comprises the lands around the rim of the Pacific Ocean. The ''Pacific Basin'' includes the Pacific Rim and the islands in the Pacific Ocean. The Pacific Rim roughly overlaps with the geologic Pacific Ring of Fire. List of co ...

''. In the ''

Fallout 3 ''Fallout 3'' is a 2008 action role-playing game developed by Bethesda Game Studios and published by Bethesda Softworks. The third major installment in the ''Fallout'' series, it is the first game to be developed by Bethesda after acquiring ...

'' video game add-on pack " Broken Steel", the US government survivors, The Enclave, have a mobile base built on and into a heavily modified crawler. In ''

Sid Meier's Alpha Centauri ''Sid Meier's Alpha Centauri'' is a 4X video game, considered a spiritual sequel to the ''Civilization'' series. Set in a science fiction depiction of the 22nd century, the game begins as seven competing ideological factions land on the planet ...

'', various units are called "crawlers" and feature chassis based on the crawler-transporters. In '' Asphalt 8: Airborne'', 3 crawler-transporters drive over the space center French Guiana track.

Gallery

File:LC-39 Observation gantry pano.jpg, Crawlerway junction at the LC-39 observation gantry. The right track leads to pad LC-39A (pictured with ), while the left track leads to pad LC-39B. File:Ap11-KSC-69PC-241HR.jpg, Saturn V,

service structure A service structure is a steel framework or tower that is built on a rocket launch pad to facilitate assembly and servicing. An umbilical tower also usually includes an elevator which allows maintenance and crew access. Immediately before igniti ...

and MLP on top of a crawler File:Crawlertreds.jpg, Detail of crawler treads File:STS-79 rollout.jpg, atop an MLP (and crawler beneath) File:STS-114 rollout.jpg, A crawler-transporter carrying (STS-114) travels the ramp to Launch Pad 39B. The vehicle's back end can be raised, keeping the Shuttle and the MLP level. File:STS-51-L - Space Shuttle Challenger on the Crawler-Transporter.jpg, atop an MLP atop a crawler, in transit to its launch pad prior to its final flight, January 28, 1986 File:Ares I-X rollout on mobile launch platform.jpg, Crawler carrying the

Ares I-X 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, 200 ...

atop an MLP

References

External links

* - Crawler-transporter parking area at Kennedy Space Center
Virtual tour of Crawler-Transporter 2 upgrades
at Nasatech.net {{DEFAULTSORT:Crawler-Transporter Apollo program hardware Kennedy Space Center Marion Power Shovel Company NASA vehicles National Register of Historic Places in Brevard County, Florida Space Shuttle program Tracked vehicles Vehicles introduced in 1965