Spaceflight Now Home





Mission Reports




For 11 years, Spaceflight Now has been providing unrivaled coverage of U.S. space launches. Comprehensive reports and voluminous amounts of video are available in our archives.
Space Shuttle
Atlas | Delta | Pegasus
Minotaur | Taurus | Falcon
Titan



NewsAlert



Sign up for our NewsAlert service and have the latest space news e-mailed direct to your desktop.

Enter your e-mail address:

Privacy note: your e-mail address will not be used for any other purpose.



Advertisement






Space Books






Mobile launch tower rolled back to construction site
BY STEPHEN CLARK
SPACEFLIGHT NOW

Posted: November 28, 2011


Bookmark and Share

The towering mobile platform for NASA's heavy-lift rocket moved off the launch pad Wednesday and returned to a construction site at the Kennedy Space Center for substantial modifications to support a hefty 5.5-million-pound vehicle that could take astronauts to new frontiers in space.


Aerial photo of the mobile launcher at pad 39B. Credit: NASA/Kim Shiflett
 
The metallic structure left launch pad 39B at 10:27 a.m. EST (1527 GMT) heading for a park site north of the Vehicle Assembly Building. The four-mile journey was completed after 7 p.m. EST.

"This mobile launcher will not be coming back to pad 39B until around December of 2016," said Larry Schultz, NASA's mobile launcher project manager.

Since moving to the launch pad Nov. 16, the mobile launch tower was connected to the pad's electrical and water systems as engineers verified the platform was compatible with pad 39B, which is undergoing a facelift for the Space Launch System.

"One of the reasons we brought the mobile launcher out was to make sure the fittings of the different systems we were supposed to connect to the mobile launcher were OK before we started the refurbishment," said Jose Perez-Morales, NASA's pad 39B project manager.

"Everything connected exactly like we were expecting," Morales said.

The rollout of the mobile launcher on top of the crawler also confirmed engineering predictions of the stability of the tower while in motion. The top of the structure only sways about one inch, officials said.

Instruments, accelerometers and cameras tracked the rollout and measured loads on the tower.

The SLS is the space agency's planned heavy-lift launch vehicle, a gargantuan rocket designed to initially haul 154,000 pounds into low Earth orbit. Later versions of the rocket will have a payload capacity of 286,000 pounds to orbit.

It's first unmanned test launch is scheduled for December 2017. A manned flight around the moon could follow by 2021.


Accelerometers like this one covered the mobile launcher to measure loads and movements during the two-week test. Credit: Stephen Clark/Spaceflight Now
 
The 390-foot-tall mobile launcher will be the platform from which the Space Launch System will fly, but the structure needs up to $100 million in modifications to adapt to the massive rocket.

The tower was built for the Constellation program, the now-canceled initiative to restart human exploration of the moon. The Ares 1 rocket was the Constellation program's launch vehicle.

NASA says they spent $238 million on the mobile launcher's construction. The final piece of the tower was added in January 2010, days before the Obama administration announced plans to terminate the behind-schedule Constellation program.

Instead of a single solid rocket motor first stage like the Ares 1 concept, the SLS will be powered off the launch pad by two five-segment solid rocket boosters and three hydrogen-fueled main engines generating 8.4 million pounds of thrust. Upgrades with additional main engines will raise the rocket's liftoff thrust to 9.2 million pounds, according to NASA.

"We will be accommodating a rocket that's about two-and-a-half times the weight of the rocket this structure was originally designed for," Schultz said.

NASA will soon sign a contract for the redesign of the launch platform. Construction should begin by early 2013 and take about one year.

Workers will reconfigure the base of the mobile launcher, removing thousands of tons of steel and expanding the platform's exhaust hole. The skinny first stage of the Ares 1 rocket required only a 22-foot square opening, but the Space Launch System needs a rectangular hole 60 feet long and 30 feet wide.


The mobile launcher stands 390 feet tall from the ground, or 355 feet tall from the platform's base. Credit: Stephen Clark/Spaceflight Now
 
Once the changes are completed, NASA will outfit the tower with propellant systems, umbilical arms, access platforms and other equipment for launch operations.

Engineers at pad 39B will finish modernization of the complex at the same time, refurbishing propellant storage tanks, the sound suppression water tower and adding a new flame deflector to handle the Space Launch System.

Side flame deflectors from pad 39A, which supported the final space shuttle missions, will be adapted for the SLS and placed at pad 39B as well, according to Morales.

NASA has already removed 1.3 million feet of Apollo- and shuttle-era cable from launch pad 39B and replaced it with fiber-optic material. Three 600-foot-tall lightning protection masts built in 2008 and 2009 will protect rockets from Florida thunderstorms.

Morales said all the upgrades to pad 39B, the northernmost of KSC's launch facilities, will cost between $300 million and $350 million when complete.

One of NASA's crawlers is also set to receive modifications to carry the heavy load of the mobile launcher and the Space Launch System loaded with solid propellant.