COLD-SAT: A technology satellite for cryogenic experimentation

NASA-Lewis (LeRC) is involved in the development and validation of analytical models which describe the fluid dynamic and thermodynamic processes associated with the storage, acquisition and transfer of subcritical cryogenic fluids in low gravity. Four concurrent studies, including one in-house at LeRC, are underway to determine the feasibility of performing model validation experiments aboard a free-flying spacecraft (S/C) called Cryogenic On-Orbit Liquid Depot-Storage, Acquisition and Transfer (COLD-SAT), using liquid hydrogen as the cryogen. The technology requirements for the experiments are described along with the initial LeRC concepts for the S/C and an experiment subsystem comprising of cryogenic tankage (a supply dewar and three receiver tanks), gas pressurization bottles (both helium and autogenous hydrogen), their associated plumbing, and instrumentation for data collection. Experiments were categorized into enabling/high priority Class 1 technologies and component/system Class 2 demonstrations. As initially envisioned by LeRC, COLD-SAT would have had a 1997 launch aboard a Delta-2 for a 6 month active lifetime in a 925 km orbit with a pseudo-inertial attitude

Phase coherence length and quantum interference patterns at step edges

The accepted approximation used to describe quantum interference patterns at steps is shown to be incorrect. As a result, electron lifetimes determined using it are in error by a factor 2.Comment: 3 pages, 1 figur

Discovering the Profound Wisdom of Pope Paul VI’s Evangelii Nuntiandi

St. Pope Paul VI (1963-1978), canonized forty years after his death on October 14, 2018, will always be remembered as a modern missionary pope. He made missionary journeys to all continents and authored Evangelii Nuntiandi (EN), which became the magna carta for Catholic evangelization in the last quarter of Christianity’s second millennium and without a doubt one of the most important ecclesial documents of the post-Vatican II era. It presents a concise, inspiring, and programmatic challenge for the Church to engage enthusiastically in her God-given mission to preach the Gospel to the contemporary world—to living peoples, with their aspirations and anxieties, their cultures and religions, their hopes and conflicts. EN boldly addresses the topic of evangelization in the modern world.