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Jacobson, R.

Publications and source records attributed to Jacobson, R..

17 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

NorthernSTAR 1-1/2-Story Demonstration House of Cold Climate Solutions for Affordable Housing

Single family homes in urban areas that are available for renovation by nonprofit developers are often in rough shape (1MM to 2MM nationally). Budgeting has historically focused on improving homes to meet basic housing standards. A rising interest in the long-term impact of homeownership has introduced the need to balance basic needs with home performance. This demonstration project aims to help nonprofit affordable housing developers become familiar with three Building America performance measures, the installation processes, and impacts and benefits of each. A story and a half home in North Minneapolis, MN was presented by Urban Homeworks our local nonprofit partner. The team helped them install three researched upgrade measures: exterior roof insulation or 'overcoat,' exterior foundation insulation, or 'excavationless', and a combined space and water heating HVAC system or 'combi'. To maximize efficiency of application and to address budget issues, the Team worked with Urban Homeworks to identify ways to use volunteers and construction training programs to install the measures. An open invitation to visit the job site was extended to other nonprofit developers and industry partners to encourage dialog about the systems during live installation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

NorthernSTAR 1-½-Story Demonstration House of Cold Climate Solutions for Affordable Housing

This demonstration project is an example of three high-performance measures applied to one house in Minneapolis, Minnesota. The selected vacant home was completely renovated by Urban Homeworks (UHW), which is a nonprofit housing partner, with the intent of selling the home to a low-income family. The renovation included the addition of the three advanced-performance technologies that were applied to the overall scope of the project.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

Innovative Retrofit Insulation Strategies for Concrete Masonry Foundations

This study was designed to test a new approach for foundation insulation retrofits, with the goal of demonstrating improved moisture control, improved occupant comfort, and reduced heat loss. Because conducting experimental research on existing below-grade assemblies is very difficult, most of the results are based on simulations. The retrofit approach consists of filling open concrete block cores with an insulating material and adding R-10 exterior insulation that extends 1 ft below grade. The core fill is designed to improve the R-value of the foundation wall and increase the interior wall surface temperature, but more importantly to block convection currents that could otherwise increase moisture loads on the foundation wall and interior space. The exterior insulation significantly reduces heat loss through the most exposed part of the foundation and further increases the interior wall surface temperature. This improves occupant comfort and decreases the risk of condensation. Such an insulation package avoids the full-depth excavation necessary for exterior insulation retrofits, reduces costs, and eliminates the moisture and indoor air quality risks associated with interior insulation retrofits. Retrofit costs for the proposed approach were estimated at roughly half those of a full-depth exterior insulation retrofit.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

Innovative Retrofit Insulation Strategies for Concrete Masonry Foundations

Basements in climates 6 and 7 can account for a fraction of a home's total heat loss when fully conditioned. Such foundations are a source of moisture, with convection in open block cavities redistributing water from the wall base, usually when heating. Even when block cavities are capped, the cold foundation concrete can act as a moisture source for wood rim joist components that are in contact with it. Because below-grade basements are increasingly used for habitable space, cold foundation walls pose challenges for moisture contribution, energy use, and occupant comfort.

42 ENGINEERING↗
DOE OSTI2012

IRREGULAR SATELLITES OF THE OUTER PLANETS: ORBITAL UNCERTAINTIES AND ASTROMETRIC RECOVERIES IN 2009-2011

More than 100 small satellites have been identified orbiting the giant planets in distant, inclined, eccentric orbits. Detailed study of these objects requires that their orbits be known well enough to permit routine observations both from the Earth and from spacecraft. Unfortunately, many of the satellites have very poorly known orbits due to a scarcity of astrometric measurements. We have developed a reliable method to estimate the future on-sky position uncertainties of the satellites and have verified that those uncertainties provide a correct measure of the true on-sky positional uncertainty. Based on the uncertainties, we identified a set of satellites that are effectively 'lost' and another set that would be lost if additional observations were not obtained in the near future. We attempted recoveries of 26 of the latter group using the Hale 5 m and CFHT 3.6 m telescopes and found 23. This validated our method's predictions and led to significant improvements in our knowledge of the orbits of the recovered moons. There remains a handful of irregular moons which are recoverable and whose orbits will benefit from additional observations during the next decade, while 16 moons of Jupiter and Saturn are essentially lost and will require a re-survey to be located again.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS2011

Does Vesta Have Moons?

Previous searches for moons around Vesta have found nothing to an upper limit of 22.5 magnitude, that corresponds to 44 +/- 4 m diameter assuming the same albedo as Vesta. The Dawn mission's approach phase has dedicated satellite search observations consisting of two mosaic sequences bracketing the first observations of a complete rotation of Vesta scheduled for early July, 2011. In addition, we use the approach optical navigation image sequences for initial satellite searches. We will report any findings from these observations, and upper limits of magnitude and size.

McFadden, L. A.↗
NASA NTRS2006

Use of Very Long Baseline Array Interferometric Data for Spacecraft Navigation

The main VLBI technique that is used at JPL is known as the Delta Differential One-way Ranging ((Delta)DOR). Two DSN antennas simultaneously track a source, and alternate between sources. The signals recorded at the antennas from each source are correlated to obtain the delay in arrival to the two antennas, and the delays are differenced to remove common-source errors. An alternative technique is to use carrier phase differences between antennas. This is routinely done by the Very Large Baseline Array (VLBA) as part of source imaging. The VLBA capabilities are used for scientific research, but also have the potential to be used for navigation. Two main experiments were performed with the VLBA and JPL spacecraft. This paper describes and analyzes these experiments and discusses the possible uses of VLBA tracking for spacecraft navigation.

Very Large Baseline Array (VLBA)↗
NASA NTRS2000

Shape, Mean Radius, Gravity Field and Interior Structure of Callisto

Radio Doppler data generated by the Deep Space Network (DSN) from five encounters of the Galileo spacecraft with Callisto, Jupiter's outermost Galilean satellite, have been used to determine the quadrupole moments of the satellite's external gravitational field.

Galileo Mission gravity radio science Jupiter sate↗
NASA NTRS1978

Solar sailing - The concept made realistic

The practicability of using solar sails as a means of spacecraft propulsion is discussed with reference to a Haley's comet rendezvous mission in 1981. Two types of sails are examined: square and heliogyro. Because of ease of deployment (release into space from a space shuttle, and unfolding of the blades through solar radiation pressure) the latter is preferred. Structural and mission parameters are given for the heliogyro configuration, with attention to operational temperature limits and material coefficients. A cranking orbit is described, where a sail-powered spacecraft flies first toward the sun, and then away from it in order to achieve rendezvous with a comet. Other missions using solar sails, including a back-up mission to Encke's comet in 1983, are also discussed.

Friedman, L.↗