Albuquerque, NM--With the landing of the Atlantis last week, the final space shuttle mission, STS-135, ended. The mission also marked the last use of a Sandia National Laboratories-developed instrument, a laser dynamic range imager (LDRI) attached to the orbiter's boom. During a mission, the LDRI Orbiter Inspection System (LOIS) scans the space shuttle's heat shield twice--once 18 hours after liftoff, and again the day before re-entry--to ensure that no part of the heat shield has been damaged during launch or orbit.
Three hours of video per scan
The sensor generates images of 720 by 480 pixels at a 30 Hz rate. The light-detection and-ranging (LADAR)-based instrument produces 2D scans that are converted to 3D videos; about three hours of video are acquired each time the shuttle is scanned.
The LDRI was developed after Columbia's debris-damaged heat shield failed in 2003 on re-entry, causing the tragic accident that took the lives of all seven astronauts on board. For the past 22 missions (every one since NASA's 2005 return to space), the LDRI has flown, monitored by Sandia Labs engineers. On the final shuttle mission, nine Sandia engineers monitored the LDRI's operation from Mission Control at Johnson Space Center (Houston, TX).
The effort needed to execute the scan is extensive. In the early days, beginning with the launch of Discovery on July 26, 2005, Sandia took a 24-person team to Texas to oversee all aspects of LOIS; some of that work was eventually turned over to NASA, so for the last 17 missions, usually only nine or 10 Sandians went to Houston for the hands-on work.
"It's been an excellent relationship between Sandia and NASA and a true team effort," said Bob Habbit, manager of Sandia's Remote Sensing and Communications System group. "The people we work with here are, in effect, co-workers. We've had a very tight relationship, so it's tough to see that relationship come to a close for this project, but again, we are very proud of what we've been able to do and the support we've provided for NASA."
"We led the inspection activity and operations in the payloads operations center for the data collections. We validated that the data was correct and that the sensor was operating properly, and then we reviewed the work of the NASA team to make sure that the data had been processed correctly," Habbit said. "That was our principal role, but in the event that there was some defect found, we provided technical expertise and support to the mission management team."
