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Ross, S.

Publications and source records attributed to Ross, S..

The 2015-2016 SEPMAP Program at NASA JSC: Science, Engineering, and Program Management Training

The Systems Engineering Project Management Advancement Program (SEPMAP) at NASA Johnson Space Center (JSC) is an employee development program designed to provide graduate level training in project management and systems engineering. The program includes an applied learning project with engineering and integrated science goals requirements. The teams were presented with a task: Collect a representative sample set from a field site using a hexacopter platform, as if performing a scientific reconnaissance to assess whether the site is of sufficient scientific interest to justify exploration by astronauts. Four teams worked through the eighteen-month course to design customized sampling payloads integrated with the hexacopter, and then operate the aircraft to meet sampling requirements of number (≥ 5) and mass (≥ 5g each). The "Mars Yard" at JSC was utilized for this purpose. This project activity closely parallels NASA plans for the future exploration of Mars, where remote sites will be reconnoitered ahead of crewed exploration.

Graham, L.

Chaotic Celestial Pachinko

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Chaotic orbits Space missions La Grange Points

Shoot the Moon

In 1991, the Japanese Hiten mission used a low energy transfer with a ballistic capture at the Moon which required less delta V than a standard Hohmann transfer to the Moon.

Ballistic

Halo Orbit Mission Correction Maneuvers Using Optimal Control

This paper addresses the computation of the required trajectory correction maneuvers (TCM) for a halo orbit space mission to compensate for the launch velocity errors introduced by inaccuracies of the launch vehicle.

Halo Orbit trajectory error correction optimal con

The Genesis Trajectory and Heteroclinic Cycles

The Genesis Mission will be NASA's first robotic sample return mission. The purpose of this mission is to collect solar wind samples for two years in L1 halo orbit and return it to the Utah Test and Training Range (UTTR) for mid-air retrieval by helicopters.

Genesis Halo Orbit Sample Return periodic orbits a

Investigations on transparent liquid-miscibility gap systems

Sedimentation and phase separation is a well known occurrence in monotectic or miscibility gap alloys. Previous investigations indicate that it may be possible to prepare such alloys in a low-gravity space environment but recent experiments indicate that there may be nongravity dependent phase separation processes which can hinder the formation of such alloys. Such phase separation processes are studied using transparent liquid systems and holography. By reconstructing holograms into a commercial-particle-analysis system, real time computer analysis can be performed on emulsions with diameters in the range of 5 micrometers or greater. Thus dynamic effects associated with particle migration and coalescence can be studied. Characterization studies on two selected immiscible systems including an accurate determination of phase diagrams, surface and interfacial tension measurements, surface excess and wetting behavior near critical solution temperatures completed.

Lacy, L. L.

Interactions of technology and society: Impacts of improved airtransport. A study of airports at the grass roots

The feasibility of applying a particular conception of technology and social change to specific examples of technological development was investigated. The social and economic effects of improved airport capabilities on rural communities were examined. Factors which led to the successful implementation of a plan to construct sixty small airports in Ohio are explored and implications derived for forming public policies, evaluating air transportation development, and assessing technology.

Laporte, T.

VLBI determination of synchronous equatorial satellite orbits.

A first-order theory of satellite orbit determination using time-difference data is developed for the case of a synchronous, equatorial spacecraft. Also, a first order error analysis is presented that permits one to estimate how errors in assumed or measured quantities affect the values of the derived orbital parameters. The theory is applied to observational data obtained during a series of VLBI (Very-Long-Baseline Interferometry) experiments conducted between stations at Rosman, North Carolina, and Mojave, California, using the ATS-3 satellite as a radio source. Orbit parameters derived from the VLBI data show good agreement with those determined by the ATS project office using more conventional tracking techniques.

Ross, S.

Tracking of the ATS-3 synchronous satellite by the Very Long Baseline Interferometer (VLBI) technique

During 1971, a series of very long baseline interferometer observations were made of the C-band (6 cm) radio signals from the ATS-3 communications satellite which is in a synchronous, near-equatorial orbit. The first series of observations were conducted during May-June 1971 from Rosman, North Carolina (NASA/ATS Station 85' dish) and Mojave, California (NASA/ATS Station, 40' dish). The second series of observations were conducted during August-September, 1971 from Rosman, North Carolina (NASA/ATS Station, 85' dish), Owens Valley, California (Cal Tech, 130' dish) and Agassiz, Massachusetts (SAO Agassiz Radio Observatory, 84' dish). The ATS-3 Spacecraft position was determined with a precision of 70-100 meters and its velocity with a precision of less than a mm/sec. The ATS-3 orbital elements were computed using the GEODYN program and the derived values are consistent with those derived from conventional tracking data.

Ramasastry, J.