Engineering topics
Lee, W.
Publications and source records attributed to Lee, W..
Covariance Fitting of Highly-correlated Data in Lattice QCD
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Proton Radiography Peers into Metal Solidification
Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. In this study, we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm 3 ) during melting and solidification. We also show complementary x-ray results from a small volume (<1mm 3 ), bridging four orders of magnitude. In conclusion, real-time imaging will enable efficient process development and the control of the structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models.
The Mars Exploration Rovers entry descent and landing and the use of aerodynamic decelerators
The Mars Exploration Rovers (MER) project, the next United States mission to the surface of Mars, uses extensive aerodynamic deceleration in during its entry, descent and landing (EDL) phase.
Preliminary Engineering Constraints and Potential Landing Sites for the Mars Exploration Rovers
Preliminary engineering constraints on Mars Exploration Rover landing sites are derived, mapped into remote sensing criteria, and used to identify potential landing sites. High-priority sites via an open request to the science community and future plans are described. Additional information is contained in the original extended abstract.
Mars Sample Return Spacecraft Systems Architecture
The Mars Sample Return mission plans to collect sets of samples from two different sites on Mars and return them to Earth in 2008.
Mars Orbit Rendezvous Strategy for the Mars 2003/2005 Sample Return Mission
The baseline scenario for the Mars 2003/2005 Sample Return Mission utilizes Mars orbit rendezvous to retrieve two orbiting sample canisters containing Martian surface material.
Mars Orbit Rendezvous Strategy for the Mars 2003/2005 Sample Return Mission
The primary objective of the Mars 2003/2005 Sample Return Project is to return Martian surface materials to Earth from two different sites by the year 2008.
Mars Sample Return Spacecraft Systems Architecture
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Mission Design Overview for Mars Sample Return
In May 2003, a new and exciting chapter in Mars exploration will begin with a launch that will ultimately lead to the delivery of samples from the Red Planet to Earth.
A Few Good Rocks: The 2005 Mars Sample Return Mission Architecture
A Mars sample return is the culmination of many years of exciting missions of the Mars Surveyor Program.
A Few Good Rocks: The Mars Sample Return Mission Architecture
A Mars sample return is the culmination of many years of exciting missions of the Mars Surveyor Program.