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 An
experiment designed to study the dynamics of tethered spacecraft
formation, will help maturing space tether technology that promises
supporting formations of many pico-satellites forming large
synthetic aperture radar systems for high resolution earth observation.
These same tethers can also establish 'space elevators', lifting
payloads from low-earth-orbits to higher orbits as well as de-orbiting
expired spacecraft to minimize 'space junk'.
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| The promise
of tethers in space revolves around their potential to provide
lower cost alternatives for propulsion and power. Momentum-Exchange
tethers can be used to provide space propulsion without consuming
propellant by slinging a payload from low earth orbit to a higher
orbit. Conductive space tethers can generate electrical power
or produce thrust forces through interactions with the Earth's
magnetic field to change orbits, or de-orbiting a spacecraft
after its mission to minimize space junk. Tether systems can
also enable groups of satellites to fly in formation for applications
like long- baseline interferometry for detection of planets
around other suns, or the creation of large synthetic aperture
radar systems in space for Earth observation. In addition, high-voltage
electrostatic tethers may enable remediation of the Earth's
radiation belts. The data to be collected by the picosatellite
crawling up and down the TUI tether will result in key survivability
projections for these future tether projects.
The "Multi-Application Survivable Tether" (MAST)
is scheduled to be launched into Low-Earth-Orbit (LEO) April
17th, 2007 launched on a Russian launcher from Kazakhstan. The
experiment consists of three GPS receiver-equipped picosatellites
stacked for launch into a volume about the size of a loaf of
bread. Once in orbit, two of the satellites will separate and
deploy a 1,000 meter long version of the Tethers Unlimited Inc's
patented Hoytether structure. A third picosatellite, dubbed
"Gadget," will then crawl slowly along the tether's
length, recording and transmitting images of the tether to enable
detection of any damage to the tether. The MAST picosatellites
were developed by TUI in collaboration with Stanford University.
TUI hopes to prove the survivability of their newest generation
of multi- strand tether technology in orbit where it will be
exposed to impacts by micrometeoroids, orbital debris, and erosion
by atomic oxygen and UV light. Previous tether experiments have
had inconsistent lifetimes in the space environment, with the
Naval Research Laboratory's TiPS tether lasting ten years while
NASA's SEDS-2 tether lasted just five days. Over a period of
several months, data from the MAST experiment will prove whether
TUI's Hoytether design can enable tethers to operate reliably
for long durations in space.
TUI hopes to prove the survivability of their newest generation
of multi- strand tether technology in orbit where it will be
exposed to impacts by micrometeoroids, orbital debris, and erosion
by atomic oxygen and UV light. Previous tether experiments have
had inconsistent lifetimes in the space environment, with the
Naval Research Laboratory's TiPS tether lasting ten years while
NASA's SEDS-2 tether lasted just five days. Over a period of
several months, data from the MAST experiment will prove whether
TUI's Hoytether design can enable tethers to operate reliably
for long durations in space.
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