Should NASA again send a rocket to the moon, local engineering firm Southern Earth Sciences Inc. will know that it played a small but critical role in the early part of the process. The test launch of the Ares V cargo rocket is not scheduled until 2018, but the groundwork is already being laid, literally, for the milestone.
Last month, Southern Earth Sciences wrapped up a weeklong series of load-bearing tests on a pathway at John F. Kennedy Space Center on Florida’s eastern coast. The 100-foot-wide, 4-mile double pathway known as the Crawlerway was built to support the weight of a Saturn V rocket plus its massive transporter (imagine a flat, wide military tank on steroids) during the Apollo program. Linking the vehicle assembly building with a pair of launch pads, the pathway consists of a 7-foot-deep bed of stone beneath a gravel layer. Using a high-tech method known as cone penetration, Southern Earth Sciences tested the ground beneath the pathway to make sure that it can support the weight of the Ares rocket and its transporter. The cargo rocket is capable of carrying nearly 188 metric tons to low-Earth orbit and 71 metric tons to the moon, according to NASA. The Ares V and its carrier are expected to be more than 30 percent heavier than any previous load. NASA is evaluating the data collected by Southern Earth Sciences, said Bill Brenner, company president, a process that he expects to take several months. Ensuring the soil along the pathway can support such a heavy load, he said, is important because “a failure would be catastrophic.”
Southern Earth Sciences was called into the project in December by NASA’s prime engineering contractor, Florida’s Jones Edmunds & Associates. Through a mutual associate at the University of Florida, Jones Edmunds knew that the Mobile company had the expertise and the equipment to do the job. The job required the largest and most capable of the four mobile cone penetrometers owned and operated by Southern Earth. The 10-foot-by-15-foot piece of equipment used for the project weighs about 20 tons. It’s essentially a small, mobile building outfitted with a steel cone about 1½ inches in diameter and 18 inches long. The cone, which has sensors that record real-time information about soil characteristics and strength, is inserted via remote control at specific intervals by two employees within the unit. For the NASA project, it went to depths of 50 feet about 160 times, according to Brenner.
The results were relayed to a computer in the unit, then back to the home office, and then on to the customer. Southern Earth purchased the penetrometer used in the NASA project about 15 years ago for about $300,000, and Brenner said it has been used on projects including the ThyssenKrupp steel mill in north Mobile County, the University of South Alabama’s Cancer Center and the RSA parking garage projects, among others. The investment has easily paid for itself, he said. Since Katrina, it’s been busy testing levee strength in New Orleans, and this month is scheduled for a similar job in Dallas. The cone penetration niche accounts for about 10 percent of Southern Earth Sciences’ $15 million in annual revenue, Brenner said. “It’s actually generating a lot more dollars than just those tests, because it gets us in on a lot of other projects where other fees are involved,” Brenner said.
Southern Earth has about 200 employees throughout the Southeast. It’s not the only company in town that’s pursuing cone penetration work. Mobile’s Thompson Engineering bought a penetrometer two years ago and sold it last week in order to upgrade to one that’s capable of bigger projects and faster data transmission, said John Baker, that company’s president. Thompson has done such work on the Pinto Island ThyssenKrupp terminal, the new RSA tower in Montgomery, Austal shipyard expansions, and a “major industrial client” on the Mississippi coast, Baker said. He said the testing accounts for less than 5 percent of the firm’s annual revenue, which he declined to reveal. He would like to see that grow, however, with a more capable machine. Baker described cone penetration — a test whose roots date to 1930s Holland — as “another tool in the arsenal of geotechnical investigation.” It provides a much faster method of receiving subsurface data than rotary wash drilling techniques that are the norm, he said. In most cases, he said, it cuts the testing time in half.