Transmittance
The ratio of transmitted light intensity to the incident light intensity for a material.
This property is usually dependent upon the wavelength of the incident light.
Ultra-long Duration Balloon (ULDB)
A SPB made of advanced materials and uses a new pumpkin-shaped balloon
designed to achieve durations of up to 100 days. This relatively new balloon design
significantly increases the amount of data that can be collected in one balloon
mission.
WASP
A NASA designed support system called the Wallops Arc Second Pointer which
can accurately point a telescope.
Yield Strength
The tensile stress which is considered to cause a material to yield or to deform an
undesirable degree. The yield strength is usually defined in terms of a point
on the stress-strain curve and may serve as a basis for an allowable design.
Young’s modulus
Young’s modulus is a mechanical property that measures the stiffness of a solid
material. It defines the relationship between stress and strain in a material in the
linear elasticity regime of a uniaxial deformation.
Zylon
IUPAC name: poly(p-phenylene-2,6-benzobisoxazole) is a trademarked name for
a range of thermoset liquid-crystalline polyoxazole. This synthetic polymer material was invented and developed by SRI International in the 1980’s and is manufactured by the Toyobo Corporation. In generic usage, the fiber is referred to as
PBO. Zylon has 5.8 giga Pascal (GPa) of tensile strength, which is 1.6 times that
of Kevlar. Additionally Zylon has a high Young’s modulus of 270 GPa, meaning
that it is very stiff. Like Kevlar, Zylon is used in a number of applications that
require very high strength with excellent thermal stability. Tennis racquets, tabletennis blades, snowboards, various medical applications, and some of the Martian
rovers are some of the better-known instances. It is used in balloon tendons.
Glossary and Terminology 343
The ratio of transmitted light intensity to the incident light intensity for a material.
This property is usually dependent upon the wavelength of the incident light.
Ultra-long Duration Balloon (ULDB)
A SPB made of advanced materials and uses a new pumpkin-shaped balloon
designed to achieve durations of up to 100 days. This relatively new balloon design
significantly increases the amount of data that can be collected in one balloon
mission.
WASP
A NASA designed support system called the Wallops Arc Second Pointer which
can accurately point a telescope.
Yield Strength
The tensile stress which is considered to cause a material to yield or to deform an
undesirable degree. The yield strength is usually defined in terms of a point
on the stress-strain curve and may serve as a basis for an allowable design.
Young’s modulus
Young’s modulus is a mechanical property that measures the stiffness of a solid
material. It defines the relationship between stress and strain in a material in the
linear elasticity regime of a uniaxial deformation.
Zylon
IUPAC name: poly(p-phenylene-2,6-benzobisoxazole) is a trademarked name for
a range of thermoset liquid-crystalline polyoxazole. This synthetic polymer material was invented and developed by SRI International in the 1980’s and is manufactured by the Toyobo Corporation. In generic usage, the fiber is referred to as
PBO. Zylon has 5.8 giga Pascal (GPa) of tensile strength, which is 1.6 times that
of Kevlar. Additionally Zylon has a high Young’s modulus of 270 GPa, meaning
that it is very stiff. Like Kevlar, Zylon is used in a number of applications that
require very high strength with excellent thermal stability. Tennis racquets, tabletennis blades, snowboards, various medical applications, and some of the Martian
rovers are some of the better-known instances. It is used in balloon tendons.
Glossary and Terminology 343