Engineering topics

Schubert, Kathy

Publications and source records attributed to Schubert, Kathy.

3 records

NASA NTRS2012

Building Transatlantic Partnerships in Space Exploration The MPCV-SM Study

Following the approval of the ESA ISS Exploitation Declaration for the ISS lifetime at the ESA Council Meeting in March 2011, ESA decided to partially offset the European obligations deriving from the extension of the ISS Programme until end 2020 with different means than ATVs, following the ATV-5 mission foreseen in mid 2014. The envisioned approach is based on a barter element(s) that would generate cost avoidance on the NASA side. NASA and ESA considered a number of Barter options, and concluded that the provision by ESA of the Service Module for the NASA Multi-Purpose Crew Vehicle (MPCV) was the barter with the most interest. A joint ESA - NASA working group was established to assess the feasibility of Europe developing this Module based on ATV heritage. The working group was supported by European and US industry namely Astrium, TAS-I and Lockheed-Martin. This paper gives an overview of the results of the on-going study as well as its perspective utilisation for the global space exploration endeavour.

Wilde Detlef↗

NASA NTRS2004

Single-Walled Carbon Nanotubes, Carbon Nanofibers and Laser-Induced Incandescence

Laser induced incandescence applied to a heterogeneous, multi-element reacting flows is characterized by a) temporally resolved emission spectra, time-resolved emission at selected detection wavelengths and fluence dependence. Laser fluences above 0.6 Joules per square centimeter at 1064 nm initiate laser-induced vaporization, yielding a lower incandescence intensity, as found through fluence dependence measurements. Spectrally derived temperatures show that values of excitation laser fluence beyond this value lead to a super-heated plasma, well above the vaporization of temperature of carbon. The temporal evolution of the emission signal at these fluences is consistent with plasma dissipation processes, not incandescence from solid-like structures.

Schubert, Kathy↗

NASA NTRS2003

Laser Synthesis of Supported Catalysts for Carbon Nanotubes

Four methods of laser assisted catalyst generation for carbon nanotube (CNT) synthesis have been tested. These include pulsed laser transfer (PLT), photolytic deposition (PLD), photothermal deposition (PTD) and laser ablation deposition (LABD). Results from each method are compared based on CNT yield, morphology and structure. Under the conditions tested, the PLT was the easiest method to implement, required the least time and also yielded the best pattemation. The photolytic and photothermal methods required organometallics, extended processing time and partial vacuums. The latter two requirements also held for the ablation deposition approach. In addition to control of the substrate position, controlled deposition duration was necessary to achieve an active catalyst layer. Although all methods were tested on both metal and quartz substrates, only the quartz substrates proved to be inactive towards the deposited catalyst particles.

VanderWal, Randall L.↗