Spaceflight Now STS-110


Station's mobile transporter to take test-drive today
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: April 15, 2002

The Atlantis astronauts will operate the first space railroad today, running a $190 million flatcar about 32 feet along tracks that currently lead nowhere. In fact, there's a 240-mile drop off on either end.

But as NASA adds sections to the international space station's solar power truss, the flatcar eventually will creep the length of a football field, carrying the station's $600 million Canadarm2 space crane to work sites as required to continue the lab's assembly.

"The mobile transporter is nothing more than simply a railroad car," said Atlantis skipper Michael Bloomfield. "There's actually a set of railroad tracks that will span the length of this truss once it's up there. And you have the robotic arm that's up on the international space station, and we want to be able to use this robotic arm, all the way out to both ends of the truss.

"And so what the robotic arm can do is, it can actually grab on to a grapple that's on top of this mobile transporter and it can move from one end of the truss to the other. And so we can use it to transport, in the assembly phase, other truss sections to the end of the truss that's already built. Kind of like you're building a railroad, you run the locomotive out to the end of the track and then you lay more track and you keep going. That's exactly how we're going to build the international space station."

The first section of the station's solar power truss was bolted to the top of the Destiny laboratory module during spacewalks Thursday and Saturday. The mobile transporter and the tracks it will creep along are mounted on the forward face of the $600 million S0 truss. During a spacewalk Sunday, astronauts Steven Smith and Rex Walheim removed launch locks that held the transporter in place during the shuttle's climb to space, clearing the way for "first motion" today.

The 44-foot-long S0 truss is the central element in a nine-section beam that eventually will stretch 356 feet. Huge solar arrays will be mounted on each end and radiators will be deployed halfway out each side to keep the station's electronics cool.

The truss was designed to be built using the station's robot arm, riding atop a mobile transporter that will run the length of the beam as it's being assembled. The completed truss will have 10 work sites where the arm can lock itself down and plug into power sockets and video distribution leads.

The S0 truss, the 27,000-pound central element mounted atop the Destiny module, has two such work sites. During tests today, the astronauts will send commands from a laptop computer to move the transporter from its launch position to work site 4 on the starboard side of S0. From there it will move the other way to work site 5 on the port side and then back to work site 4.

"A lot of the work is going to be behind the scenes," pilot Stephen Frick said in a pre-flight NASA interview. "While we're sleeping, the station flight controllers are going to be going through some very long checkout procedures of the mobile transporter to make sure everything's up and operating and ready when we're ready to move it. So they're going to have worked for hours before we even get ready to go.

"And then Carl (Walz) and I are going to get on the PCS, the control software on the station, and we're going to command the mobile transporter to move from its launch site to two work sites. We have one called work site 4 and one called work site 5 on the S0 truss.

"It's going to be exciting for us because it'll be the first time we'll get it to see it move," Frick said. "But I've got to say it moves at an inch a second, so I don't want people to get their hopes up too much about a NASCAR race up there on the truss."

As it turns out, an inch per second is the design specification of the transporter when it is unloaded. Ben Sellari, the launch package manager for the S0 truss, said the speed will be even slower for the tests planned today. The transporter measures 102 inches by 107 inches and weighs 1,923 pounds.

The transporter moves using a linear drive unit that "is basically like the motor, transmission and brakes in your car," Sellari said. "This is what makes the mobile transporter go. It has two drive devices on it that engage the rail and through friction, allow the mobile transporter to go up and down the rails."

The friction is provided by five spring-loaded wheels. Power and telemetry is provided through two redundant ribbon cables that play out from reels on either side of the transporter.

For the tests today, "our most important role up there is as a safety observer," Frick said. "The commands we're going to send could be sent from the station (but) we're actually going to send them from the shuttle on the station laptop. The reason we're going to be over there is because we can look directly out the overhead window and watch the mobile transporter as it moves.

"The software has been checked out on the ground and it's worked very well. But it's never been done in space and if anything should happen that's unexpected, we want to be there, ready to just stop it and give us a chance to look at what happened. So really we're safety observers. We're going to command it to leave (the) launch site, translate across, stop at the next one, plug itself back in, and then we're just going to be watching it very closely to make sure it does exactly what we expect it to do."

If all goes well, Canadarm2 will mount itself on the mobile transporter this summer, after delivery of a required mounting assembly in early June.

Along with testing the mobile transporter, the astronauts plan to hold a traditional in-flight news conference today at 12:44 p.m. After that, the combined crews will enjoy a bit of off-duty time.

Recent updates

FRIDAY
01:30 PM
Quick-look Data

07:30 AM
Entry Timeline


THURSDAY
12:00 AM
Master Flight Plan

Daily Flight Plan (FD-11/12)


WEDNESDAY
12:50 AM
Undocking timeline


TUESDAY
11:50 PM
NASA TV Sked (rev. I)

05:40 PM
Spacewalk Stats



Soviet Space
For the first time ever available in the West. Rocket & Space Corporation Energia: a complete pictorial history of the Soviet/Russian Space Program from 1946 to the present day all in full color. Available from our store.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Viking patch
This embroidered mission patch celebrates NASA's Viking Project which reached the Red Planet in 1976.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo 7 DVD
For 11 days the crew of Apollo 7 fought colds while they put the Apollo spacecraft through a workout, establishing confidence in the machine what would lead directly to the bold decision to send Apollo 8 to the moon just 2 months later.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Gemini 12
Gemini 12: The NASA Mission Reports covers the voyage of James Lovell and Buzz Aldrin that capped the Gemini program's efforts to prove the technologies and techniques that would be needed for the Apollo Moon landings. Includes CD-ROM.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

An insider's view of how Apollo flight controllers operated and just what they faced when events were crucial.
 Choose your store:
U.S.

STS-134 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Endeavour is symbolized in the official embroidered crew patch for STS-134. Available in our store!
 U.S. STORE
 WORLDWIDE STORE

Final Shuttle Mission Patch

Free shipping to U.S. addresses!

The crew emblem for the final space shuttle mission is now available in our store. Get this piece of history!
 U.S. STORE
 WORLDWIDE STORE

Apollo Collage
This beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.
 U.S. STORE

STS-133 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Discovery is symbolized in the official embroidered crew patch for STS-133. Available in our store!
 U.S. STORE
 WORLDWIDE STORE

Anniversary Shuttle Patch

Free shipping to U.S. addresses!

This embroidered patch commemorates the 30th anniversary of the Space Shuttle Program. The design features the space shuttle Columbia's historic maiden flight of April 12, 1981.
 U.S. STORE
 WORLDWIDE STORE

Mercury anniversary

Free shipping to U.S. addresses!


Celebrate the 50th anniversary of Alan Shephard's historic Mercury mission with this collectors' item, the official commemorative embroidered patch.
 U.S. STORE
 WORLDWIDE STORE

Liberty Bell 7
Lost Spacecraft - the Search for Liberty Bell 7 describes the exploration of two unique and dangerous environments - space and underwater - in the recovery of Gus Grissom's Mercury capsule.
 U.S. STORE
 WORLDWIDE STORE

Get e-mail updates
Sign up for our NewsAlert service and have the latest news in astronomy and space e-mailed direct to your desktop (privacy note: your e-mail address will not be used for any other purpose).
Enter your e-mail address:

Apollo 12 tribute DVD set

New! Featuring the jovial crew of Pete Conrad, Dick Gordon and Alan Bean, the Apollo 12 mission was struck by lightning shortly after liftoff but proceeded on the second successful exploration voyage to the lunar surface. This three-disc DVD brings the mission to life with extraordinary detail.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Fallen Heroes special patch
This special 12-inch embroidered patch commemorates the U.S. astronauts who made the ultimate sacrifice, honoring the crews of Apollo 1, Challenger and Columbia.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Women in Space
Women of Space: Cool Careers on the Final Frontier is for girls, young women, and anyone else interested in learning about exciting careers in space exploration. Includes CD-ROM.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Mars rover poster
This new poster features some of the best pictures from NASA's amazing Mars Exploration Rovers Spirit and Opportunity.
 Choose your store:
U.S.


INDEX | PLUS | NEWS ARCHIVE | LAUNCH SCHEDULE
ASTRONOMY NOW | STORE

ADVERTISE

© 2014 Spaceflight Now Inc.