CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, has been delivered to the Vehicle Assembly Building (VAB) atop a crawler-transporter. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is making its last journey atop a massive crawler-transporter from Launch Pad 39A into the Vehicle Assembly Building (VAB). For more than 40 years, the MLPs have traveled between the VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is making its last journey from Launch Pad 39A back to the Vehicle Assembly Building (VAB) atop a massive crawler-transporter. For more than 40 years, the MLPs have traveled between the VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, has been delivered to the Vehicle Assembly Building (VAB) atop a crawler-transporter. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, has been delivered to the Vehicle Assembly Building (VAB) atop a crawler-transporter. Seen also is the Space Shuttle Program's Launch Control Center (left). For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, has been delivered to the Vehicle Assembly Building (VAB) atop a crawler-transporter. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is making its last journey from Launch Pad 39A into the Vehicle Assembly Building (VAB) atop a massive crawler-transporter. For more than 40 years, the MLPs have traveled between the VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, workers accompany Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, while making its last journey from Launch Pad 39A back to the Vehicle Assembly Building (VAB) atop a massive crawler-transporter. For more than 40 years, the MLPs have traveled between the VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Jim Grossmann

STS-135 Commander Chris Ferguson, right, talks with NASA Administrator Charles Bolden atop of the Mobile Launch Platform (MLP) as the space shuttle Atlantis (STS-135) rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. A water truck leads the way spraying water on the dry crawlerway to reduce dust particles in the air. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers have moved a massive crawler-transporter under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers monitor the process as a massive crawler-transporter positioned under the MLP, the last mobile launcher platform to launch a shuttle, begins its trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers are moving a massive crawler-transporter under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers are moving a massive crawler-transporter under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers have moved a massive crawler-transporter under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. A water truck leads the way spraying water on the dry crawlerway to reduce dust particles in the air. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers are moving a massive crawler-transporter under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers are moving a massive crawler-transporter under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. A water truck leads the way spraying water on the dry crawlerway to reduce dust particles in the air. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers check the position of the massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is being prepared for its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). Here, workers check the position of the massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is taking its last journey from Launch Pad 39A to the Vehicle Assembly Building (VAB). A massive crawler-transporter positioned under the MLP -- the last mobile launcher platform to launch a shuttle, begins the trek back to the VAB. A water truck leads the way spraying water on the dry crawlerway to reduce dust particles in the air. For more than 40 years, the MLPs have traveled between the massive VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Kim Shiflett

NASA Administrator Charles Bolden looks at the space shuttle Atlantis atop of the Mobile Launch Platform (MLP) just prior to rollout of Atlantis (STS-135) from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden looks at the space shuttle Atlantis atop of the Mobile Launch Platform (MLP) just prior to rollout of Atlantis (STS-135) from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop a Mobile Launcher Platform (MLP) just prior to beginning its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop the Mobile Launch Platform (MLP) during its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop the Mobile Launch Platform (MLP) during its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop the Mobile Launch Platform (MLP) as it begins its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop the Mobile Launch Platform (MLP) as it begins its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop the Mobile Launch Platform (MLP) as it begins its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden watches as a truck sprays water on the crawler way to help minimize dust as the space shuttle Atlantis (STS-135), atop of the Mobile Launch Platform (MLP), rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden talks with other NASA management atop of the Mobile Launcher Platform (MLP) just prior to rollout of the Space Shuttle Atlantis (STS-135) from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden looks at the large crowds gathered from atop of the Mobile Launch Platform (MLP) as the space shuttle Atlantis (STS-135) rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop the Mobile Launch Platform (MLP) during its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

A truck sprays water on the crawler way to help minimize dust as the space shuttle Atlantis (STS-135), atop of the Mobile Launch Platform (MLP), rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop a Mobile Launcher Platform (MLP) just prior to beginning its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Atlantis (STS-135) is seen atop a Mobile Launcher Platform (MLP) just prior to beginning its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is making its last journey from Launch Pad 39A back to the Vehicle Assembly Building (VAB) atop a massive crawler-transporter. A water truck leads the way spraying water on the dry crawlerway to reduce dust particles in the air. For more than 40 years, the MLPs have traveled between the VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Mobile Launcher Platform-3 (MLP), which supported space shuttle Atlantis for its final flight to the International Space Station on the STS-135 mission, is making its last journey from Launch Pad 39A into the Vehicle Assembly Building (VAB) atop a massive crawler-transporter. Seen also is the Space Shuttle Program's Launch Control Center (left). For more than 40 years, the MLPs have traveled between the VAB to both launch pads at Launch Complex 39, and then returned to the VAB for future use. MLP-3 was first used to launch Columbia on the STS-32 mission on Jan. 9, 1990. Photo credit: NASA/Jim Grossmann

STS-135 crew members Chris Ferguson, left, Douglas Hurley, second from left, Sandra Magnus, and Rex Walheim, right, pose for a group photograph atop of the Mobile Launch Platform (MLP) as the space shuttle Atlantis (STS-135) rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Crowds of people are seen watching the rollout of the space shuttle Atlantis in this image made atop of the Mobile Launcher Platform (MLP) that is carrying Atlantis from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

United Space Alliance Senior Space Shuttle Technician Mitchell Bromwell, left, and Randy Meyers of United Space Alliance display an American flag that has been flown all over the world by the U.S. military from atop the Mobile Launch Platform (MLP) as the space shuttle Atlantis begins its journey from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)