Proportional Limit
The stress at the limit of proportionality between stress and strain.
Super-Pressure Balloon (SPB)
Made with a non-extensible material and is a closed system to prevent gas release. By
the time float altitude is achieved, the free-lift gas has converted into super pressure.
Variations in the radiation environment produce changes in the super pressure, but not
in the balloon volume, therefore the balloon continues to float at the same density
altitude. As long as the balloon is super-pressured, it will continue to float at a constant
density altitude. This type of balloon will play an important role in providing inexpensive access to the near-space environment for science and technology. It will offer
ultra-long duration missions on the order of 100 days or more at mid-latitudes. SPB
will also offer greater stability at float altitude with minimal altitude excursion during
the day/night cycles when compared to that experienced on Zero-Pressure Balloons
(ZPB). This added stability and extended durations at mid-latitudes will enable new
science missions that currently are not feasible with ZPB. Therefore, balloon-borne
telescopes, operating in the regions of the spectrum; namely X-rays and rays that can’t
be studied as effectively at the poles because of the strong background of charged
cosmic rays funneled in by Earth’s magnetic field, will be enabled to venture into new
science and discovery missions on-board a super pressure balloons.
Rossby Waves
Also known as planetary waves, are a type of inertial wave naturally occurring in
rotating fluids. They were first identified by Carl-Gustaf Arvid Rossby (1898- 1957).
They are observed in the atmospheres and oceans of planets owing to the rotation of
the planet. Atmospheric Rossby waves on Earth are giant meanders in high altitude
winds that have a major influence on weather. These waves are associated with pressure systems and the jet stream. Oceanic Rossby waves move along the thermocline:
the boundary between the warm upper layer and the cold deeper part of the ocean.
Shear Strength
The maximum force per unit area for a material loaded in pure shear The forces
must be pure couples, and the restraining area of the material is parallel to the
direction of the couple.
Standard Deviation
A statistical term related to the uniformity of the data collected from a set of specimens. For a sample of significant size, the standard deviation may be a measure of
property variation or test method variation.
Glossary and Terminology 341
The stress at the limit of proportionality between stress and strain.
Super-Pressure Balloon (SPB)
Made with a non-extensible material and is a closed system to prevent gas release. By
the time float altitude is achieved, the free-lift gas has converted into super pressure.
Variations in the radiation environment produce changes in the super pressure, but not
in the balloon volume, therefore the balloon continues to float at the same density
altitude. As long as the balloon is super-pressured, it will continue to float at a constant
density altitude. This type of balloon will play an important role in providing inexpensive access to the near-space environment for science and technology. It will offer
ultra-long duration missions on the order of 100 days or more at mid-latitudes. SPB
will also offer greater stability at float altitude with minimal altitude excursion during
the day/night cycles when compared to that experienced on Zero-Pressure Balloons
(ZPB). This added stability and extended durations at mid-latitudes will enable new
science missions that currently are not feasible with ZPB. Therefore, balloon-borne
telescopes, operating in the regions of the spectrum; namely X-rays and rays that can’t
be studied as effectively at the poles because of the strong background of charged
cosmic rays funneled in by Earth’s magnetic field, will be enabled to venture into new
science and discovery missions on-board a super pressure balloons.
Rossby Waves
Also known as planetary waves, are a type of inertial wave naturally occurring in
rotating fluids. They were first identified by Carl-Gustaf Arvid Rossby (1898- 1957).
They are observed in the atmospheres and oceans of planets owing to the rotation of
the planet. Atmospheric Rossby waves on Earth are giant meanders in high altitude
winds that have a major influence on weather. These waves are associated with pressure systems and the jet stream. Oceanic Rossby waves move along the thermocline:
the boundary between the warm upper layer and the cold deeper part of the ocean.
Shear Strength
The maximum force per unit area for a material loaded in pure shear The forces
must be pure couples, and the restraining area of the material is parallel to the
direction of the couple.
Standard Deviation
A statistical term related to the uniformity of the data collected from a set of specimens. For a sample of significant size, the standard deviation may be a measure of
property variation or test method variation.
Glossary and Terminology 341