In-Space Propulsion Assessment Processes and Criteria for Affordable Systems

In a world of high launch costs to Low Earth Orbit (LEO), and of costs nearly twice as high to Geosynchronous Earth Orbit (GEO), it is clear that processes and criteria are required which will surface the path to greater affordability. Further, with propulsion systems making up a major part of the systems placed into multiple orbits, or beyond, it is clear that addressing propulsion systems for in-space propulsion (ISP) is a key part to breaking the barriers to affordable systems. While multitudes of Earth to Orbit transportation system efforts focus on reduced costs, the often neglected costs and related interactions of the in-space system equally require improvements that will enable broad end-to end customer affordability

Launch Vehicle Propulsion Life Cycle Cost Lessons Learned

This paper will review lessons learned for space transportation systems from the viewpoint of the NASA, Industry and academia Space Propulsion Synergy Team (SPST). The paper provides the basic idea and history of "lessons learned". Recommendations that are extremely relevant to NASA's future investments in research, program development and operations are"'provided. Lastly, a novel and useful approach to documenting lessons learned is recommended, so as to most effectively guide future NASA investments. Applying lessons learned can significantly improve access to space for cargo or people by focusing limited funds on the right areas and needs for improvement. Many NASA human space flight initiatives have faltered, been re-directed or been outright canceled since the birth of the Space Shuttle program. The reasons given at the time have been seemingly unique. It will be shown that there are common threads as lessons learned in many a past initiative

Miniature Neutron‐Alpha Activation Spectrometer

We are developing a miniature neutron‐alpha activation spectrometer for in‐situ analysis of chem‐bio samples, including rocks, fines, ices, and drill cores, suitable for a lander or Rover platform for Mars or outer‐planet missions. In the neutron‐activation mode, penetrating analysis will be performed of the whole sample using a γ spectrometer and in the α‐activation mode, the sample surface will be analyzed using Rutherford‐backscatter and x‐ray spectrometers. Novel in our approach is the development of a switchable radioactive neutron source and a small high‐resolution γ detector. The detectors and electronics will benefit from remote unattended operation capabilities resulting from our NEAR XGRS heritage and recent development of a Ge γ detector for MESSENGER. Much of the technology used in this instrument can be adapted to portable or unattended terrestrial applications for detection of explosives, chemical toxins, nuclear weapons, and contraband. © 2002 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87580/2/101_1.pd

Shuttle Shortfalls and Lessons Learned for the Sustainment of Human Space Exploration

Much debate and national soul searching has taken place over the value of the Space Shuttle which first flew in 1981 and which is currently scheduled to be retired in 2010. Originally developed post-Saturn Apollo to emphasize affordability and safety, the reusable Space Shuttle instead came to be perceived as economically unsustainable and lacking the technology maturity to assure safe, routine access to low earth orbit (LEO). After the loss of two crews, aboard Challenger and Columbia, followed by the decision to retire the system in 2010, it is critical that this three decades worth of human space flight experience be well understood. Understanding of the past is imperative to further those goals for which the Space Shuttle was a stepping-stone in the advancement of knowledge. There was significant reduction in life cycle costs between the Saturn Apollo and the Space Shuttle. However, the advancement in life cycle cost reduction from Saturn Apollo to the Space Shuttle fell far short of its goal. This paper will explore the reasons for this shortfall. Shortfalls and lessons learned can be categorized as related to design factors, at the architecture, element and sub-system levels, as well as to programmatic factors, in terms of goals, requirements, management and organization. Additionally, no review of the Space Shuttle program and attempt to take away key lessons would be complete without a strategic review. That is, how do national space goals drive future space transportation development strategies? The lessons of the Space Shuttle are invaluable in all respects - technical, as in design, program-wise, as in organizational approach and goal setting, and strategically, within the context of the generational march toward an expanded human presence in space. Beyond lessons though (and the innumerable papers, anecdotes and opinions published on this topic) this paper traces tangible, achievable steps, derived from the Space Shuttle program experience, that must be a part of any 2l century initiatives furthering a growing human presence beyond earth

Concepts for Life Cycle Cost Control Required to Achieve Space Transportation Affordability and Sustainability

Cost control must be implemented through the establishment of requirements and controlled continually by managing to these requirements. Cost control of the non-recurring side of life cycle cost has traditionally been implemented in both commercial and government programs. The government uses the budget process to implement this control. The commercial approach is to use a similar process of allocating the non-recurring cost to major elements of the program. This type of control generally manages through a work breakdown structure (WBS) by defining the major elements of the program. If the cost control is to be applied across the entire program life cycle cost (LCC), the approach must be addressed very differently. A functional breakdown structure (FBS) is defined and recommended. Use of a FBS provides the visibifity to allow the choice of an integrated solution reducing the cost of providing many different elements of like function. The different functional solutions that drive the hardware logistics, quantity of documentation, operational labor, reliability and maintainability balance, and total integration of the entire system from DDT&E through the life of the program must be fully defined, compared, and final decisions made among these competing solutions. The major drivers of recurring cost have been identified and are presented and discussed. The LCC requirements must be established and flowed down to provide control of LCC. This LCC control will require a structured rigid process similar to the one traditionally used to control weight/performance for space transportation systems throughout the entire program. It has been demonstrated over the last 30 years that without a firm requirement and methodically structured cost control, it is unlikely that affordable and sustainable space transportation system LCC will be achieved

The Ursinus Weekly, November 6, 1908

The Halloween fete • Union meeting • An apology from the press • Brotherhood of St. Paul • Football • In the sporting world • Hill School game • Societies • Seminary notes • Game with Rutgers • Personals • The Literary Supplement: Thanksgiving season; Anarchism; America\u27s call to duty; The European count and the American countess; Wendell Phillips; The endowment to future generationshttps://digitalcommons.ursinus.edu/weekly/2847/thumbnail.jp

Engineering higher order Van Hove singularities in two dimensions: the example of the surface layer of Sr2_2RuO4_4

The properties of correlated electron materials are often intricately linked to Van Hove singularities (VHs) in the vicinity of the Fermi energy. The class of these VHs is of great importance, with higher order ones -- with power-law divergence in the density of states -- leaving frequently distinct signatures in physical properties. We use a new theoretical method to detect and analyse higher order Van Hove singularities (HOVHs) in two-dimensional materials and apply it to the electronic structure of the surface layer of Sr$_2$RuO$_4$. We then constrain a low energy model of the VHs of the surface layer of Sr$_2$RuO$_4$ against angle-resolved photoemission spectroscopy and quasiparticle interference data to analyse the VHs near the Fermi level. We show how these VHs can be engineered into HOVHs.Comment: 8 pages including Supplemental Material, 5 figure

1908 Ruby Yearbook

A digitized copy of the 1908 Ruby, the Ursinus College yearbook.https://digitalcommons.ursinus.edu/ruby/1011/thumbnail.jp

Aluminum Abundance on the Surface of Mercury: Application of a New Background-Reduction Technique for the Analysis of Gamma-Ray Spectroscopy Data

A new technique has been developed for characterizing gamma-ray emission from a planetary surface in the presence of large background signals generated in a spacecraft. This technique is applied to the analysis of Al gamma rays measured by the MESSENGER Gamma-Ray Spectrometer to determine the abundance of Al on the surface of Mercury. The result (Al/Si = 0.29-0.13+0.05) is consistent with Al/Si ratios derived from the MESSENGER X-Ray Spectrometer and confirms the finding of low Al abundances. The measured abundance rules out a global, lunar-like feldspar-rich crust and is consistent with previously suggested analogs for surface material on Mercury, including terrestrial komatiites, low-iron basalts, partial melts of CB chondrites, and partial melts of enstatite chondrites. Additional applications of this technique include the measurement of other elements on Mercury's surface as well as the analysis of data from other planetary gamma-ray spectrometer experiments

Developments in radiation hodoscope technology for arms control treaty verification

New hodoscope radiation detection technology developments offer a wide range of unique capabilities for arms control treaty verification (ACTV). Originally developed for civilian nuclear power research by Argonne National Laboratory, this concept uses a radiation detector array to detect objects inside opaque containments. To avoid unnecessary intrusiveness in treaty verification, spatial resolution must be limited and confirmed. Material density data and identification by radiation means may be either required or prohibited. ACTV instruments also should be inherently resistant to false indications--either accidental, or from attempt at deception. Hodoscope technology can meet these needs. ACTV hodoscopes do not require the heavy collimators of reactor hodoscopes, and relatively weak sources are sufficient. Gamma-ray transmission hodoscopes can be used to inspect canisters, railcars, etc. or to monitor objects such as rocket motors. This technique is deception-resistant: absorbers hidden to mask objects will be detected; and sources hidden to mask absorption will be substracted out as background. Nuclear warheads are detectable by strong gamma-ray absorption. In some cases, intrinsic gamma-ray radiation from warheads also could be used in a passive mode. Neutron hodoscopes can utilize neutron transmission, intrinsic neutron emission, or neutron reactions (either prompt or delayed) stimulated by a neutron source. Warheads can be counted by tomography, or by simple analysis of count rate curve patterns, depending on application. Hodoscope technology is a powerful tool for potential treaty verification uses; This paper considers that technology. 21 refs., 8 figs., 1 tab