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

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

s used to transport

launch vehicles A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistag ...

from

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

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) in Florida, designed to assemble large pre-manufactured space vehicle components, such as the massive Satu ...

(VAB) along the Crawlerway to

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

. 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 National Aeronautics and Space Administration (NASA) for the Apollo program. It uprated the Saturn I by replacing the S-IV second stage (, 43,3 ...

and

Saturn V 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 multistage rocket, three stages, and was powered by liquid-propel ...

rocket A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...

s during the

Apollo Apollo is one of the Twelve Olympians, Olympian deities in Ancient Greek religion, ancient Greek and Ancient Roman religion, Roman religion and Greek mythology, Greek and Roman mythology. Apollo has been recognized as a god of archery, mu ...

Skylab Skylab was the United States' first space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three trios of astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Skylab was constructe ...

and

Apollo–Soyuz Apollo–Soyuz was the first crewed international Space exploration, 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 an American Apollo comm ...

programs. They were then used to transport

Space Shuttle The Space Shuttle is a retired, partially reusable launch system, 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. ...

s from 1981 to 2011. The crawler-transporters carry vehicles on the mobile launcher platforms (MLPs) 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 majo ...

using some components designed and built by

Rockwell International Rockwell International was a major American manufacturing conglomerate (company), conglomerate. It was involved in aircraft, the space industry, defense and commercial electronics, components in the automotive industry, printing presses, avioni ...

at a cost of ( in 2022) each. Upon its construction, the crawler-transporter became the largest self-powered land vehicle in the world until it was beaten in 2013 with the production of the ultraheavy XGC88000 crawler crane. While other vehicles such as

bucket-wheel excavator A bucket-wheel excavator (BWE) is a large heavy equipment machine used in surface mining. Their primary function is that of a continuous digging machine in large-scale open-pit mining operations, removing thousands of tons of overburden a day. Wh ...

s like Bagger 288,

dragline excavator A dragline excavator is a heavy-duty excavator used in civil engineering and surface mining. It was invented in 1904, and presented an immediate challenge to the steam shovel and its diesel and electric powered descendant, the power shovel. M ...

s like

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

and

power shovel A power shovel, also known as a motor shovel, stripping shovel, front shovel, mining shovel or rope shovel, is a bucket-equipped machine usually powered by steam, diesel fuel, gasoline or electricity and used for digging and loading earth or frag ...

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 level within 10

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

(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). After the 2003 refit, 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 the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

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 launch vehicle, super heavy-lift Expendable launch system, expendable launch vehicle used by NASA. As the primary launch vehicle of the Artemis program, Artemis Moon landing progra ...

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 and LC-39B, 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'' (''SNL'') is an American Late night television in the United States, late-night live television, live sketch comedy variety show created by Lorne Michaels and developed by Michaels and Dick Ebersol that airs on NBC. The ...

'', played by

Dana Carvey Dana Thomas Carvey (born June 2, 1955) is an American stand-up comedian, actor, podcaster, screenwriter and producer. Carvey is best known for his seven seasons on ''Saturday Night Live'', from 1986 to 1993, which earned him five consecutive Pri ...

and

Kevin Nealon Kevin Nealon (; born November 18, 1953) is an American comedian and actor. He has earned a Primetime Emmy Award nomination and two Screen Actors Guild Award nominations. He first gained widespread attention during his tenure as a cast member on ...

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

Miami Miami is a East Coast of the United States, coastal city in the U.S. state of Florida and the county seat of Miami-Dade County, Florida, Miami-Dade County in South Florida. It is the core of the Miami metropolitan area, which, with a populat ...

Seattle Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...

Future use

Crawler-Transporter 2

NASA currently uses crawler-transporter 2 to transport the

with the

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

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 Exploration of the Moon, Moon exploration program led by the United States' National Aeronautics and Space Administration (NASA), formally established in 2017 via Space Policy Directive 1. The program's stated long-ter ...

. NASA performed a rollout of the

Artemis 1 Artemis I, formerly Exploration Mission-1 (EM-1), was an uncrewed Moon-orbiting mission that was launched in November 2022. As the first major spaceflight of NASA's Artemis program, Artemis I marked the agency's return to lunar exploration a ...

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 ...

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 Orbital ATK Inc. was an American aerospace manufacturer and defense industry company. It was formed in February 9, 2015 from the merger of Orbital Sciences Corporation and parts of Alliant Techsystems (ATK). Orbital ATK designed, built, and deli ...

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

OmegA Omega (, ; uppercase Ω, lowercase ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and last letter in the Greek alphabet. In the Greek numerals, Greek numeric system/isopsephy (gematria), it has a value ...

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

National Security Space Launch National Security Space Launch (NSSL) is a program of the United States Space Force (USSF) intended to assure access to space for United States Department of Defense and other Federal government of the United States, United States government paylo ...

contract to

United Launch Alliance United Launch Alliance, LLC (ULA) is an American launch service provider formed in December 2006 as a joint venture between Lockheed Martin Space and Boeing Defense, Space & Security. The company designs, assembles, sells and launches rockets ...

and

SpaceX Space Exploration Technologies Corp., commonly referred to as SpaceX, is an America, American space technology company headquartered at the SpaceX Starbase, Starbase development site in Starbase, Texas. Since its founding in 2002, the compa ...

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 sho ...

'', 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 program, Apollo space program and would have been the third Moon landing. The craft was launched from Kennedy Space Center on April 11, 1970, but the landing was abort ...

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

Apollo 11 Apollo 11 was a spaceflight conducted from July 16 to 24, 1969, by the United States and launched by NASA. It marked the first time that humans Moon landing, landed on the Moon. Commander Neil Armstrong and Lunar Module pilot Buzz Aldrin l ...

''. 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 geological Pacific Ring of Fire. List ...

''. In the 2009 ''

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 plane ...

'', various units are called "crawlers" and feature chassis based on the crawler-transporters. In '' Asphalt 8: Airborne'', three 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 and MLP on top of a crawler File:Crawlertreds.jpg, Detail of crawler treads File:STS-79 rollout.jpg, (STS-79) 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 (

STS-51-L STS-51-L was the disastrous 25th mission of NASA's Space Shuttle program and the final flight of Space Shuttle ''Challenger''. It was planned as the first Teacher in Space Project flight in addition to observing Halley's Comet for six day ...

), January 28, 1986 File:Ares I-X rollout on mobile launch platform.jpg, Crawler carrying the Ares I-X atop an MLP

References

External links

* - Crawler-transporter parking area at Kennedy Space Center {{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