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Smith, I. S.

Publications and source records attributed to Smith, I. S..

Exploration of Mars Using Aerial Platforms

The exploration of the atmosphere of Mars can be conducted using aerial platforms such as balloons and airships. Current research and development efforts at NASA include a lobed pressurized balloon system for the Ultra Long Duration Balloon Program. The capabilities of this system, in regards to pressure, load carrying capability, and duration, are far greater than anything previously flown. This technology can be adapted for use in the atmosphere of Mars.

Fairbrother, D. A.↗

Mars Aerobot Missions

Mars aerobots constitute a class of mission nearly a factor of 10 smaller than earlier concepts for Mars balloons. A key goal is to achieve high payload mass fraction in a small total systems mass and to maximize the scientific potential of that payload. The "low and slow" attributes of aerobot flight paths afford advantages for many observations and measurements of Mars. Scientific objectives include surveys of remnant magnetism, studies of the surface with high resolution stereo imaging, and investigations of the structure and dynamics of the atmosphere with an in situ meteorology payload.

Greeley, R.↗

Mars 2001 Aerobot/Balloon System Overview

The purpose of the study was to determine technical feasibiltiy of a long duration 2001 aerobot mission in the Martian atmosphere, to formulate a baseline concept, to identify pre-project technology requirements and to develop a preliminary cost, schedule and plan.

Mars↗

A stress index model for balloon design

A NASA stress index model, SINDEX, is discussed which establishes the relative stress magnitudes along a balloon gore as a function of altitude. Application of the model to a data base of over 550 ballon flights demonstrates the effectiveness of the method. The results show a strong correlation between stress levels, failure rates, and the point of maximum stress coinciding with the observed failure locations. It is suggested that the model may be used during the balloon design process to lower the levels of stress in the balloon.

Smith, I. S.↗

A stress index model for ascending balloons

Attention is given to the development on the part of NASA of a simplified stress 'index' model to establish the relative stress magnitudes along a balloon's gore position as a function of altitude. Application of this model to several hundred balloon flights showed a good correlation between balloon failure rate and stress 'index' level. This model can be used during the balloon design process to lower the levels of stress in the balloon. By increasing the wall thickness of the balloon, adding caps, lengthening caps, or using external caps, lower stress can be accomplished. As a result, in January 1985, the NASA Balloon Program established a stress index specification to limit the design and flight stresses for NASA balloons.

Smith, I. S.↗

Recent materials problems relating to catastrophic balloon failures

Balloons fabricated of thin polyethylene materials have provided relatively inexpensive and reliable scientific research platforms for approximately three decades. Reliability of the modern day balloon, as launched by the U.S.A. National Scientific Balloon Facility (NSBF), has been approximately 85 percent. Recent balloon failures, coupled with an increased ocurrence of catastrophic failures, created grave concern over the integrity of the present balloon inventory of the U.S.A. National Aeronautics and Space Administration (NASA). An investigative team was established by NASA to review the circumstances surrounding the catastrophic balloon failures, determine the cause and to make recommendations to correct the problem and to prevent its reoccurrence. The most probable cause of failure as determined by the investigation was the polyethylene balloon film, although the film had passsed the established standard quality control measures of the film manufacturer. The approach, findings, and conclusions of the investigation are presented along with planned procedures to assure future quality balloon film for NASA balloons.

Smith, I. S.↗