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L‘Garde Programs - INFLATABLE ANTENNA EXPERIMENT
Note: This site was originally hosted at:
http://spartans.gsfc.nasa.gov/missions/flown/207/207.html
This abridged version of the site will be posted here until GSFC reposts.
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Special Payloads Division
Code 740
Spartan 207 Mission |
Mission Manager, Mr. Mark Steiner (x5769).
Spartan 207 Preliminary Mission Report.
Spartan 207/IAE Mission Status See what developments were recorded during the mission.
Check out these photos and animation clips:
370K QuickTime movie
and
600K QuickTime movie).
See what CNN had to say:
Objective
The SP207/IAE mission intended to validate and characterize the mechanical function and performance of a 14-meter-diameter inflatable deployable antenna reflector
structure in an operational orbit.
The IAE experiment laid the groundwork for future technology development in inflatable space structures that can be launched in a compact form and then inflated once
207/IAE validated the deployment (inflation) and performance of a large inflatable antenna during a ninety-minute mission before the antenna structure was jettisoned.
The Spartan spacecraft was recovered at mission end and returned to Earth carrying the data and video footage.
The inflation process was also captured by the nearby Shuttle crew by a variety of still cameras, motion picture, and video cameras. The on-orbit performance
(measured by surface accuracy) of the antenna was determined by illuminating the antenna surface with lights mounted on the Spartan and capturing the resulting
image on the Spartan’s video recorders. These patterns were analyzed after the Space Shuttle returned the Spartan carrier to Earth.
Experiment Description
The payload consisted of two main pieces of hardware: the SP207/IAE (Spartan free flyer and experiment) and the Spartan Flight Support Structure (SFSS), which held the
Spartan spacecraft in the Space Shuttle Cargo Bay.
The Spartan spacecraft was rectangular in shape before the antenna inflation. The IAE occupied about half the volume and the support systems occupying the rest.
The IAE is an inflatable antenna 50 feet (14 meters) in diameter mounted on three 92-foot (28 meter) struts. The antenna was developed by L'Garde Inc., of
Tustin, CA, a small aerospace business, and NASA's Jet Propulsion Laboratory (JPL) of Pasadena, CA, under NASA's In-Space Technology Experiments Program, or IN-STEP.
The struts are attached to the Spartan spacecraft, and the entire assembly was deployed and then recovered by the Space Shuttle. Once in low-Earth orbit, the Spartan
became a platform for the antenna that, when inflated in space, was roughly the size of a tennis court. After inflation, an optical system surveyed the antenna and
measured the accuracy of the surface at a variety of internal pressures and thermal conditions.
The SFSS had three assemblies: the main, across-the-bay support structure known as the Mission Peculiar Equipment Support Structure (MPESS), the Release Engage
Mechanism (REM), and the interface hardware between the MPESS and REM known as the Mission Peculiar Equipment (MPE). The SFSS attached to the payload bay through
keel and sill trunnion fittings. The REM interface allowed the SP207/IAE to be attached to and detached from the SFSS.
For still photos from the mission showing the deployment of the SP207/IAE spacecraft.
Mission
On flight day two the crew deployed the Spartan spacecraft and, after the Shuttle separated from the Spartan carrier by approximately 400 feet (112 meters),
a command was issued to begin the IAE inflation sequence. When inflated for 10 minutes, IAE was almost as large as the Shuttle. The experiment inflation and
surface measurements were conducted over a single Shuttle orbit around the earth, which takes approximately 90 minutes.
At the conclusion of the experiment, the IAE was jettisoned from the Spartan carrier. The Spartan then oriented itself for retrieval. On the next day, flight day three,
the Shuttle rendezvoused with the Spartan 207 and replaced it in the payload bay for landing.
The Spartan configuration for this mission was unique in that the experiment, IAE, was in a separate unit that was ejected after the experiment has completed.
Only the Spartan carrier with the experiment recorders were returned to the cargo bay. This was the second flight for this particular Spartan carrier, the fifth for
the cross-bay support structure, and the third for the REM. This carrier flew successfully on STS-63. Overall, this mission was be the eighth Spartan mission to fly
on the Space Shuttle.
Background
In order to gather more definite information on other galaxies and on Earth's environment, there is a need for larger and more reliable space antennas.
At present, however, technology is not available that can produce an antenna that is both affordable and highly reliable.
This experiment will attempt to change improve our technology by validating that inflatable structures can be used in such diverse applications as measuring soil
moisture and ocean salinity or communications and power generation for satellites exploring the far reaches of our solar system. Because of the low operating pressure
in the reflector, any loss of pressure due to collisions with space debris can be compensated by on-board makeup gas. An antenna structure of this type should have an
operational life of 5 to 10 years.
System Advantages
14-meter diameter IAE reflector assembly in ground test.
Because the mass and stowed (uninflated) volume of inflatable components is many times less than an equivalent solid structure, inflatable structures can
significantly reduce the cost of future missions using these components (10 to 100 times less expensive). This inflatable antenna weighed only about 60 kilograms
(132 pounds) and the operational version should be developed for less than $10 million, a substantial savings over current mechanically deployable hard structures
that may cost as much as $200 million to develop and deliver to space. Inflatable structures also have the potential to deploy much more reliably than the
conventional mechanical systems used for deploying rigid structures. In addition, the small packaged size of the inflatable components allows very large structures
to be deployed in space with a single small launch vehicle. For example, large space antennas many times the size of today's mechanical orbiting antennas could
be used for a variety of space applications, including satellite antennas for space and mobile communications, Earth observations, astronomical observations,
and space-based radar.
The IAE is a prime example of a low-cost technology validation experiment. These no-frills, highly focused experiments are designed to inexpensively test the
fundamental performance of a technology in the weightless, vacuum environment of space when it is impossible to do so on the ground. Inflatable systems cannot
be evaluated on Earth due to the effects of gravity and atmospheric pressure on the balloon structure. Inflatable strucutres must be tested on-orbit and
the results compared with analytical predictions to achieve the confidence necessary to allow their use in operational systems.
The inflatable antenna has a range of 10 to 50 meters in size will have the following advantage over current technology (advantages increase with size).
- Lower cost by 1 to 2 orders of magnitude.
- Lower stored volume 1 to 2 orders of magnitude.
- Lower mass by factors of 2 to 8.
Additionally, the Spartan carrier itself implemented new technologies. It tested a Solid State Recorder using flash EEPROM memory, developed under a
Small Business Innovative Research (SBIR) contract between the Goddard Space Flight Center and SEAKR Engineering, Inc. of Englewood, Colorado.
Some of the electronics boxes on the Spartan carrier implemented a Parylene coating process that allowed commercial plastic integrated circuits on-orbit.
Mission Integration Photos
Click Here for cool integration pictures of Spartan 207 from L'Garde and at the Goddard Space Flight Center preparing to ship to
the Kennedy Space Flight Center.
Photos of the Integration Team and the STS-77 crew at KSC. Includes final photos of Spartan 207/IAE during PAD closeouts,
just prior to closing of the Orbiter Payload Bay Doors.
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The Goddard Space Flight Center's Spartan 207/Inflatable Antenna Experiment (IAE) was successfully deployed on May 20, 1996 with a successful inflation of the IAE. Spartan 207/IAE was successfully retrieved by the STS-77 crew on the morning of Tuesday May 21, 1996. |
Mission Management
The Spartan project is managed by the Goddard Space Flight Center for the Office of Space Science, Washington, D.C. The Spartan Project manager is Don Carson ,
and the Spartan 207 mission manager is Mark Steiner , both of Goddard's Special Payloads Division. Mr. Gordon Veal is the IAE Principal Investigator at L'Garde, Inc.,
and Bob Freeland is the IAE Project Manager at the Jet Propulsion Laboratory. IAE is sponsored by NASA's Office of Space Access and Technology, Washington, D.C.
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