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Volume 46 | Issue 5 | June 2004


photo:Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) spacecraft

Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) spacecraft, an Earth Science satellite set to launch in 2005.
NASA Illustration

NESC presents initial findings

By Keith Henry
Deputy, Langley Research Center Office of Public Affairs

The NASA Engineering and Safety Center (NESC), created in the aftermath of the Space Shuttle Columbia accident to serve as an independent technical resource for NASA managers and employees, reported May 12 on its initial assessments.

Results of the four "Pathfinder" studies were reported to senior NASA leadership from around the country at a meeting at NASA Headquarters. The reporting approach taken - proactive sharing of lessons learned - was modeled after a similar method used by the U.S. Navy Board of Inspection and Survey.

photo: The X-43A hypersonic vehicle.

The X-43A hypersonic vehicle. NASA Photo

Created in November 2003, the NESC was established with the twin goals of improving safety through in-depth independent engineering assessments, testing, analyses and evaluation aimed at uncovering technical vulnerabilities and recommending appropriate preventive and corrective actions for problems, trends or concerns within NASA's programs, projects and institutions. It is based at Langley Research Center, Hampton, Va.

"I feel very good about what we've accomplished in our first six months," said NESC Director Ralph Roe. "We have a talented core of people working within NESC and an outstanding group of people matrixed to NESC that we can call upon when needed. We have positive feedback from the partnerships we've begun with industry and academia. We've completed our first four technical assessments; we're working on several new major activities, and requests for our services keep coming in."

The initial assessments were related to four research projects: the Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) spacecraft, an earth science satellite set to launch in 2005; X-43A, a hypersonic research vehicle that recorded a successful flight in March; the Space Shuttle orbiter rudder/speed brake system, and the Mars Exploration Rovers.

photo: The Space Shuttle orbiter rudder/speed brake system

The Space Shuttle orbiter rudder/speed brake system NASA Photo

While work at the NESC is currently focused on a successful Space Shuttle return to flight and the International Space Station, other activities across NASA also are being evaluated. The NESC, for example, is providing independent expertise for the Cassini Saturn Orbit Insertion critical events readiness review.

The initial study topics were chosen because of their importance, their manageable size and their potential for teaching NESC staff how best to organize and conduct independent analyses of critical technical issues.

In the case of CALIPSO, a joint science mission by NASA and the French space agency Centre National d'Etudes Spatiales (CNES), a concern about possible leaks of the spacecraft's highly reactive fuel - from joints in the fuel lines during ground processing - led to multiple recommendations aimed at minimizing risk to personnel, the mission and the environment.

The record-breaking hypersonic X-43A did not fly until a dissenting opinion by one X-43A team member was properly addressed. The employee contacted the NESC with a concern that the research vehicle's aerodynamic characteristics could potentially lead to a loss of vehicle control, resulting in failure to achieve mission objectives. The NESC worked in conjunction with the X-43A project team to ensure that the employee's concern was properly addressed.

photo: Mars Exploration Rovers

Mars Exploration Rovers. NASA Concept Illustration

During renewal of hardware in a Space Shuttle orbiter rudder/speed brake system, a concern was raised about the effectiveness of grease in the gear set of   replacement hardware that had been retrieved from long-term storage. NESC staff conducted extensive tests and analyses to confirm that the grease was still effective. A lesson learned was that programs should periodically review hardware components to ensure that qualification and certification limits are not exceeded.

Prior to the two Mars Exploration Rover landings in January, the NESC participated in two program reviews. One review dealt with the very human challenge of supporting round-the-clock staffing for a mission to Mars, where the Martian day is 40 minutes longer than an Earth day. The second evaluated entry, descent and landing data from the first rover landing as a guide to fine-tuning those of the second rover. While both landings were highly successful, the review revealed that current spacecraft instrumentation was not designed to adequately record the aerodynamic environment encountered during descent.

Summaries of the four Pathfinder reports, a video clip, publication-quality images and additional information about NESC are available at: