Headlines

A Closer Look at Mars

(Photo courtesy of JPL/NASA)

Intriguing data from several recent missions to Mars suggest the planet may have once held surface water. But if so, where did it go? The successful launch of NASA's Mars Reconnaissance Orbiter may help bring an answer to that question. Launched from Cape Canaveral atop an Atlas V rocket in August, the probe will take about seven months to reach the red planet. Once there, it will survey the surface from low orbit with unprecedented detail, charting the topography, monitoring the climate, measuring gravity gradients, and presenting new clues about the planet's geologic history. Most important, the orbiter will scout out sites for future surface landers, identifying locales with the greatest potential for answering questions about the presence of water and the prospects for harboring life.

For example, images from the high-spatial-resolution camera—the most powerful ever sent to another planet—will be used to select a landing site for a future mobile science lab that would maximize the chance of drilling into sedimentary rocks that still preserve information about how they were originally formed. Hyperspectral image data will provide detailed maps of aqueous mineral traces, including deposits that are too small to be resolved through other means. Ground-penetrating radar will see roughly half a kilometer below Mars's surface, searching for underground layers of ice, rock, and maybe even melted water.

The Mars Reconnaissance Orbiter will also serve as a communications relay satellite for later surface landers.

Aerospace, in conjunction with NASA's Jet Propulsion Laboratory, contributed expertise during mission planning and launch. Trade-off studies at Aerospace revealed how variable data rates at selected orbital heights could yield greater data throughput when the orbiter begins functioning as a communications relay. Aerospace assisted in developing project-level risk-management strategies, similar to work performed for the successful Mars Rover missions. Aerospace also performed cost and technical evaluations for the numerous instrument proposals.

The launch of the orbiter was the first U.S. government mission and the first interplanetary mission aboard the Atlas V vehicle. Aerospace provided technical insight into the development and qualification of the Atlas V family in support of the Air Force EELV program, contributing to the early string of launch successes, including the success of the Mars Reconnaissance Orbiter. To maintain awareness of the Atlas V fleet health, Aerospace supported all technical reviews and events leading up to launch and participated as an integral part of the launch team at Cape Canaveral and at the mission support center at Aerospace headquarters in El Segundo, California. This included review and disposition of the gyro and software issues that delayed the launch two days. The successful launch was preceded by a smooth, nominal count with no major issues.

STS-114 Return to Flight

(Photo courtesy of JPL/NASA)

The crew of the space shuttle Discovery returned safely to Earth in August after two weeks in space. The mission, which marked the shuttle's return to flight after the Columbia disaster, was not without tension and drama. First, a large piece of insulating foam broke off from the external tank during liftoff. Later, astronauts performed the first-ever in-flight shuttle repair, removing protruding gap fillers from Discovery's heat shield.

Prior to this mission, Aerospace assisted NASA in identifying risk from space shuttle debris sources by developing an alternative probabilistic (Monte Carlo) approach for those cases where it was not possible to identify risk using a deterministic worst-on-worst analysis. NASA had asked Aerospace to analyze several external tank foam cases for the Discovery launch as a result of the April 2005 Debris Verification Reviews. Specifically, Aerospace analyzed the liquid-oxygen protuberance air load ramp, which consists of thick manually sprayed layers of foam, the liquid-oxygen tank-to-intertank flange, the liquid-hydrogen tank-to-intertank flange, and the liquid-oxygen and intertank ice/frost ramps. The intertank is the structural connection that joins the liquid-hydrogen and liquid-oxygen tanks, which are affixed to flanges at the top and bottom. After the two tanks are joined to the intertank, the flange is insulated with foam.

Aerospace conducted additional non-Monte Carlo analyses on the bipod region and the liquid-hydrogen tank-to-intertank flange cryo divots. After a series of internal and external technical reviews throughout May 2005, Aerospace presented the analyses in June 2005 at the final Debris Verification Review. The space shuttle program accepted the results.

Aerospace also provided support to the program during the mission. Aerospace was tasked to perform sensitivity studies on the large debris and also trajectory and impact analysis on the extruding protective blanket. The analysis results were used to assist in determining the need for an additional space walk.

A Positive Impact

(Photo courtesy of JPL/NASA)

On July 4, 2005, NASA's Deep Impact mission slammed a tiny spacecraft into comet Tempel 1, kicking up a spectacular cloud of dust and debris that was recorded by a second mission spacecraft. Scientists will pore over the resulting gigabytes of data to learn more about the solar system's formative years.

Aerospace played key developmental roles in this remarkable mission, lending personnel to the flight project engineering team for launch vehicle mission design. Aerospace also provided analyses on launch probability that helped determine the length of the launch window. These analyses led to the decision to accommodate two launch opportunities for each day of the launch window. Aerospace verified trajectory information supplied by the launch service provider and wrote both the final target specification document and the day-of-launch documentation used by the launch director.

During development of the Deep Impact spacecraft, two serious technical questions emerged. The first concerned the integrity of the mounting welds on the spacecraft inertial reference unit, and the second involved timing and back-plane contention issues with the spacecraft control unit. To address the weld problem, Aerospace evaluated material samples and performed nondestructive testing and analyses, ultimately confirming that the weld strength was within acceptable limits. To address the timing and back-plane contention issues, Aerospace analyzed the problem and recommended a number of flight software changes that mitigated the risk during flight.

Last of the Titans

(Photo from Lockheed Martin)

The last Titan IVB heavy-lift vehicle to launch from Cape Canaveral successfully lifted off on April 29, 2005, carrying a National Reconnaissance Office (NRO) payload. The historic launch closed the penultimate chapter in the Titan family saga, which began half a century ago with the Titan ICBM.

Throughout these years, Aerospace provided integral support to the program. In all, 27 Titan IVs have been launched from Cape Canaveral and 11 from Vandenberg. The vast majority of these carried essential national security payloads for the Department of Defense and the NRO. The final Titan IVB is scheduled to launch from Vandenberg in late October, once again carrying an NRO payload.

Airborne Laser

The airborne laser (ABL) recently completed an important phase of testing. In May, the laser's conformal window was unstowed for the first time during flight, a maneuver necessary for the weapon system to complete its mission of shooting down a ballistic missile in flight.

Aerospace personnel in Albuquerque have been a part of the team that supports the ABL's Beam Control/Fire Control (BCFC) segment. This portion of the ABL is responsible for target tracking, aiming of the lasers, and compensating for atmospheric conditions. In everything from BCFC systems engineering, integration and testing, and performance evaluation, Aerospace has provided on-site support for the ABL team.

By the final month of last year, the ABL program accomplished both of its planned 2004 milestones: the first light of the high-energy laser system and the first flight of the integrated BCFC segment.

To Fall 2005 Table of Contents