ALBERT

Description: NASA's strategic Goals: a) Develop a balanced overall program of science, exploration, and aeronautics consistent with the redirection of human spaceflight program to focus on exploration. b) Study Earth from space to advance scientific understanding and meet societal needs. NASA's partnership efforts in global modeling and data assimilation over the next decade will shorten the distance from observations to answers for important, leading-edge science questions. NASA's Applied Sciences program will continue the Agency's efforts in benchmarking the assimilation of NASA research results into policy and management decision-support tools that are vital for the Nation's environment, economy, safety, and security. NASA also is working with NOAH and inter-agency forums to transition mature research capabilities to operational systems, primarily the polar and geostationary operational environmental satellites, and to utilize fully those assets for research purposes.

Description: The LISA space mission, designed to monitor low frequency gravitational waves, is also sensitive to passages of asteroids nearby one of its three spacecrafts. We report the expected rate of detections of asteroid passages, using the known catalog of asteroids and a modeled population. The method adopted consists of determining for each known asteroid the critical encounter distance capable of producing a detectable event, and then computing the rate of encounters within this distance. Results are then scaled to the modeled population using its differential distribution in absolute magnitude, correcting for selection effects. We find that an average of 2.0 +/- 0.1 events per year at a signal-to-noise ratio of 1 will be detected by LISA, including all the asteroids in the modeled population with absolute magnitude H 〈 22, roughly equivalent to all asteroids with a diameter larger than 100 m.

Description: The effects of space weather on modern technological systems are well documented in both the technical literature and popular accounts. Most often cited perhaps is the collapse within 90 seconds of northeastern Canada's Hydro-Quebec power grid during the great geomagnetic storm of March 1989, which left millions of people without electricity for up to 9 hours. This event exemplifies the dramatic impact that severe space weather can have on a technology upon which modern society critically depends. Nearly two decades have passed since the March 1989 event. During that time, awareness of the risks of severe space weather has increased among the affected industries, mitigation strategies have been developed, new sources of data have become available, new models of the space environment have been created, and a national space weather infrastructure has evolved to provide data, alerts, and forecasts to an increasing number of users. Now, 20 years later and approaching a new interval of increased solar activity, how well equipped are we to manage the effects of space weather? Have recent technological developments made our critical technologies more or less vulnerable? How well do we understand the broader societal and economic impacts of severe space weather events? Are our institutions prepared to cope with the effects of a 'space weather Katrina,' a rare, but according to the historical record, not inconceivable eventuality? On May 22 and 23, 2008, a one-and-a-half-day workshop held in Washington, D.C., under the auspices of the National Research Council's (NRC's) Space Studies Board brought together representatives of industry, the federal government, and the social science community to explore these and related questions. The key themes, ideas, and insights that emerged during the presentations and discussions are summarized in 'Severe Space Weather Events--Understanding Societal and Economic Impacts: A Workshop Report' (The National Academies Press, Washington, D.C., 2008), which was prepared by the Committee on the Societal and Economic Impacts of Severe Space Weather Events: A Workshop. The present document is an expanded summary of that report.

Description: Results are presented for 607 speckle interferometric observations of double stars, as well as 222 measures of single stars or unresolved pairs. All data were obtained in 2006 and 2007 at the Mount Wilson Observatory, using the 2.5 m Hooker telescope. Separations range from 0.06 to 6.31, with a median of 0.34. These three observing runs concentrated on binaries in need of confirmation (mainly Hipparcos and Tycho pairs), as well as systems in need of improved orbital elements. New orbital solutions have been determined for 35 systems as a result.

Description: The U.S. Space Exploration policy outlines an exciting new direction in space for human and robotic exploration and development beyond low Earth orbit. Pressed by this new visionary guidance, human civilization will be able to methodically build capabilities to move off Earth and into the solar system in a step-by-step manner, gradually increasing the capability for humans to stay longer in space and move further away from Earth. The new plans call for an implementation that would create an affordable and sustainable program in order to span over generations of explorers, each new generation pushing back the boundaries and building on the foundations laid by the earlier. To create a sustainable program it is important to enable and encourage the development of a selfsupporting commercial space industry leveraging both traditional and non-traditional segments of the industrial base. Governments will not be able to open the space frontier on their own because their goals change over relatively short timescales and because the large costs associated with human spaceflight cannot be sustained. A strong space development industrial sector is needed that can one day support the needs of commercial space enterprises as well as provide capabilities that the National Aeronautics and Space Administration (NASA) and other national space agencies can buy to achieve their exploration goals. This new industrial space sector will someday provide fundamental capabilities like communications, power, logistics, and even cargo and human space transportation, just as commercial companies are able to provide these services on Earth today. To help develop and bolster this new space industrial sector, NASA and other national space agencies can enable and facilitate it in many ways, including reducing risk by developing important technologies necessary for commercialization of space, and as a paying customer, partner, or anchor tenant. This transition from all or mostly government developed and operated facilities and services to commercial supplied facilities and services should be considered from the very earliest stages of planning. This paper will first discuss the importance of space commercialization to fulfilling national goals and the associated policy and strategic objectives that will enable space exploration and development. Then the paper will offer insights into how government can provide leadership to promote the nascent commercial space industry. In addition, the paper describes programs and policies already in place at NASA and offers five important principles government can use to strengthen space industry.

Description: The FLUKA nuclear transport and reaction code can be developed into a practical tool for calculation of spacecraft and planetary surface asset SEE and TID environments. Nuclear reactions and secondary particle shower effects can be estimated with acceptable accuracy both in-flight and in test. More detailed electronic device and/or spacecraft geometries than are reported here are possible using standard FLUKA geometry utilities. Spacecraft structure and shielding mass. Effects of high Z elements in microelectronic structure as reported previously. Median shielding mass in a generic slab or concentric sphere target geometry are at least approximately applicable to more complex spacecraft shapes. Need the spacecraft shielding mass distribution function applicable to the microelectronic system of interest. SEE environment effects can be calculated for a wide range of spacecraft and microelectronic materials with complete nuclear physics. Evaluate benefits of low Z shielding mass can be evaluated relative to aluminum. Evaluate effects of high Z elements as constituents of microelectronic devices. The principal limitation on the accuracy of the FLUKA based method reported here are found in the limited accuracy and incomplete character of affordable heavy ion test data. To support accurate rate estimates with any calculation method, the aspect ratio of the sensitive volume(s) and the dependence must be better characterized.

Description: The NASA Orbital Debris Program Office (ODPO) developed a high fidelity debris evolutionary model, LEGEND (a LEO-to-GEO Environment Debris model), in 2004 to enhance its capability to better model the near-Earth environment. LEGEND can mimic the growth of the historical debris population and project it into the future based on user-defined scenarios. The first major LEGEND study concluded that even without any future launches, the LEO population would continue to increase due to mutual collisions among existing objects. In reality, the increase will be worse than this prediction because of ongoing satellite launches and unexpected major breakups. Even with a full implementation of the commonly-adopted mitigation measures, the LEO population growth is inevitable. To preserve the near-Earth environment for future generations, active debris removal (ADR) must be considered. A follow-up LEGEND ADR study was completed recently. The main results indicate that (1) the mass and collision probability of each object can be used to establish an effective removal selection criterion and (2) a removal rate of ~5 objects per year is sufficient to stabilize the LEO environment. Due to the limitation of removal techniques, however, different target selection criteria (in size, altitude, inclination, etc.) may be more practical. A careful evaluation of the effectiveness of different proposed techniques must be carried out to maximize the long-term benefit to the environment.

Description: Most LEO debris lies in a limited number of inclination "bands" associated with specific useful orbits. Objects in such narrow inclination bands have all possible Right Ascensions of Ascending Node (RAANs), creating a different orbit plane for nearly every piece of debris. However, a low-orbiting satellite will always phase in RAAN faster than debris objects in higher orbits at the same inclination, potentially solving the problem. Such a low-orbiting base can serve as a "mother ship" that can tend and then send small, disposable common individual catcher/deboost devices--one for each debris object--as the facility drifts into the same RAAN as each higher object. The dV necessary to catch highly-eccentric orbit debris in the center of the band alternatively allows the capture of less-eccentric debris in a wider inclination range around the center. It is demonstrated that most LEO hazardous debris can be removed from orbit in three years, using a single LEO launch of one mother ship--with its onboard magazine of freeflying low-tech catchers--into each of ten identified bands, with second or potentially third launches into only the three highest-inclination bands. The nearly 1000 objects near the geostationary orbit present special challenges in mass, maneuverability, and ultimate disposal options, leading to a dramatically different architecture and technology suite than the LEO solution. It is shown that the entire population of near-GEO derelict objects can be gathered and tethered together within a 3 year period for future scrap-yard operations using achievable technologies and only two earth launches.

Description: Crewmembers on Mars missions will face new and unique challenges compared to those in close communications proximity to Mission Control centers. Crews on Mars will likely become more autonomous and responsible for their day-to-day planning. These explorers will need to make frequent real time decisions without the assistance of large ground support teams. Ground-centric control will no longer be an option due to the communications delays. As a result of the new decision making model, crew dynamics and leadership styles of future astronauts may become significantly different from the demands of today. As a volunteer for the Mars Society on two Mars analog missions, this presenter will discuss observations made during isolated, surface exploration simulations. The need for careful crew selections, not just based on individual skill sets, but on overall team interactions becomes apparent very quickly when the crew is planning their own days and deciding their own priorities. Even more important is the selection of a Mission Commander who can lead a team of highly skilled individuals with strong and varied opinions in a way that promotes crew consensus, maintains fairness, and prevents unnecessary crew fatigue.

Description: The performance of ISS spacecraft materials and systems on prolonged exposure to the low- Earth orbit (LEO) space flight are reported in this paper. In-flight data, flight crew observations, and the results of ground-based test and analysis directly supporting programmatic and operational decision-making are described. The space flight environments definitions (both natural and induced) used for ISS design, material selection, and verification testing are shown, in most cases, to be more severe than the actual flight environment accounting, in part, for the outstanding performance of ISS as a long mission duration spacecraft. No significant ISS material or system failures have been attributed to spacecraft-environments interactions. Nonetheless, ISS materials and systems performance data is contributing to our understanding of spacecraft material interactions with the spaceflight environment so as to reduce cost and risk for future spaceflight projects and programs. Orbital inclination (51.6 deg) and altitude (nominally near 360 km) determine the set of natural environment factors affecting the functional life of materials and systems on ISS. ISS operates in an electrically conducting environment (the F2 region of Earth s ionosphere) with well-defined fluxes of atomic oxygen, other charged and neutral ionospheric plasma species, solar UV, VUV, and x-ray radiation as well as galactic cosmic rays, trapped radiation, and solar cosmic rays. The LEO micrometeoroid and orbital debris environment is an especially important determinant of spacecraft design and operations. The magnitude of several environmental factors varies dramatically with latitude and longitude as ISS orbits the Earth. The high latitude orbital environment also exposes ISS to higher fluences of trapped energetic electrons, auroral electrons, solar cosmic rays, and galactic cosmic rays than would be the case in lower inclination orbits, largely as a result of the overall shape and magnitude of the geomagnetic field. As a result, ISS exposure to many environmental factors can vary dramatically along a particular orbital ground track, and from one ground track to the next, during any 24-hour period. The induced environment results from ISS interactions with the natural environment as well as environmental factors produced by ISS itself and visiting vehicles fleet. Examples include ram-wake effects, hypergolic thruster plume impingement, materials out-gassing, venting and dumping of fluids, and specific photovoltaic (PV) power system interactions with the ionospheric plasma (7-11). Vehicle size (L) and velocity (V), combined with the magnitude and direction of the geomagnetic field (B) produce operationally significant magnetic induction voltages (VxB.L) in ISS conducting structure during flight through high latitudes (〉 +45deg) during each orbit. Finally, an induced ionizing radiation environment is produced by cosmic ray interaction with the relatively thick ISS structure and shielding materials. The intent of this review article is, therefore, to provide a summary of selected aspects and elements of the ISS vehicle with regard to LEO space environment effects, associated with the much larger and more complicated vehicle that ISS has become since 1998, but also with an eye towards performance life extension to the year 2016 and beyond.