For more information, contact Joel W. Sills, Langley Research Center, joel.w.sills@nasa.gov. Download PDF here Chip resistors are widely used in NASA projects, yet cases of alumina substrate cracking during environmental testing are rare. Two instances of thick-film chip resistor cracking…

For more information, contact Joel W. Sills, Langley Research Center, joel.w.sills@nasa.gov. Download the PDF version An instrumented hammer test does not require an idealized single half-sine waveform. When the complete force and response are measured accurately, crest ripples and separated…

For more information, contact Joel W. Sills, Langley Research Center, joel.w.sills@nasa.gov Download the PDF version Complex mode shapes can emerge in a linear structure even when overall damping is low. This behavior can occur when two structural modes are closely…

For more information, contact Donald S. Parker, Kennedy Space Center, donald.s.parker@nasa.gov Download the PDF version Improper casting and forging processes in the manufacture of aluminum alloy 2219 can lead to microstructural defects that result in a sub-optimal response to anodic…

For more information, contact Jonathan E. Jones, Langley Research Center, jonathan.e.jones@nasa.gov Download the PDF version The purpose of this Technical Bulletin is to communicate the risks associated with freeze–thaw cycles in hydrazine monopropellant systems and to provide general recommendations for…

For more information, contact Mark K. Leader, Glenn Research Center, mark.leader@nasa.gov Download the PDF version NASA’s Chemical Equilibrium with Applications (CEA) code is a foundational tool for propulsion system analysis. It provides equilibrium chemistry, rocket performance, shock, and detonation calculations…

For more information, contact Kamili M. Shaw, Langley Research Center, kamili.j.shaw@nasa.gov Download the PDF version Flammability test results for commercial-off-the-shelf webbings that meet NASA flammability requirements are reported for use in elevated oxygen environments anticipated for future lunar and Martian…

By Donald S. Parkerdonald.s.parker@nasa.gov  Download PDF: A Combination of Techniques Leads to Improved Friction Stir Welding The NESC developed several innovative tools and techniques during an assessment to find the root cause of poor tensile strength and low topography anomalies…

By Patrick E. Leserpatrick.e.leser@nasa.gov  Download PDF: NESC Develops Method for Estimating Risk When Reducing NDE  Performing nondestructive evaluation (NDE) can have both cost and schedule impacts, leading some to question whether descoping (i.e., reducing or eliminating) NDE inspections on certain spaceflight…

This article is from the 2025 Technical Update. The exact date when the crew of Space Shuttle Columbia was lost is readily recalled by Patrick Forrester, as it likely would be for any NASA employee in service that Saturday morning…