Students Examine Launch Pad for Flame Trench Model
A team of Louisiana State University students who proposed to build a tabletop-sized flame trench to test flame-resistant materials took a look at the real thing at Launch Complex 39B on Oct. 14.
Dr. Luz Marina Calle, a materials researcher at NASA's Kennedy Space Center in Florida, posted the requirement for a lab-sized model of the flame trench and Christine Woodfield, Jacob Koch and Kevin Schenker, all mechanical engineering students at LSU, took on the assignment with their professor, Dr. Shengmin Guo. Their senior design engineering project is funded through the Exploration Space Grant Project managed for the Agency by the Kennedy Space Center Education Program Office.
"The pictures are pretty accurate, but the size . . . and then seeing the effects the environment has that it's exposed to," Woodfield said.
"You can't understand it until you come and see it," Koch said as the group looked up from the bottom of the 40-foot deep trench.
Upgrading the flame trench is a high priority as the launch complex is modernized following the retirement of the space shuttle, said Jose Perez Morales, project manager for the work at Pad 39B.
"It's one of the most challenging projects we've got," Perez Morales said.
The flame trenches were built when Pads 39A and 39B were constructed in 1966 to handle the Saturn V moon rocket. They were lined with thousands of fireproof bricks, many of which remain in place today. However, the fasteners holding some of the bricks in place occasionally gave way in the face of intense flame and the force of 7 million pounds of thrust during dozens of shuttle launches.
"We have a unique condition here, so there are no commercial materials out there for this," Perez Morales said. "The water deluge and the acid from the solid rocket boosters also have to be considered."
A cement-like compound called Fondue Fyre was used to cover suspect areas, but it required maintenance after each launch, Perez Morales said.
"We have spent a lot of money on the maintenance of the insulating material," Perez Morales said. "After every launch there's a lot that has to be refurbished."
Recognizing that there may not be a commercially available product that can stand the flame trench conditions and require little maintenance, Kennedy's scientists are working to come up with an alternate material to handle the job. Testing it on a small scale is important to the project, Calle said. If it proves handy to another industry, then NASA can get a commercial company to produce it, too.
"If there is a potential material, we're going to need to test it in the lab," Calle said.
The students also will build a system that simulates the flames of a rocket. Since the pad is to be used for the Space Launch System, which currently is planned for four space shuttle main engines and two solid rocket boosters, the thrust will be on par with a Saturn V.
"Trying to make it as close to the real thing as possible is the objective," Koch said. "I think we're going to use a plasma torch or a plasma cutter."
The team expects to begin work on the project soon after returning to school.
"This semester we'll go into putting down a plan and then next semester we'll build it early and go through samples and prepare them with things like saltwater," Woodfield said.
While the trip had a scientific reason for it, the history of the area was not lost on the students.
"This has always seemed out of reach to me, so I never dreamed that I would get to come and tour a launch pad," Woodfield said.
NASA's John F. Kennedy Space Center