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“Weightless Wonder V” retires

After a lifetime of 34,700 ups and downs, NASA’s last KC-135A aircraft, the "Weightless Wonder V," made its final flight on 29 October 2004.

KC-135A aircrafts, four-engine turbojets, were used by the military for cargo and refueling. However, two KC-135As were modified for their special role in NASA’s Reduced Gravity Program and they were called "Weightless Wonders".

The Reduced Gravity Program was started in 1957 at Wright Patterson Air Force Base to investigate human and hardware reactions to operating in a weightless environment. The operations moved to NASA and Houston in 1973.

The Reduced Gravity Program employed Weightless Wonder V nine years ago. It flies parabolic arcs to produce weightless periods of 20 to 25 seconds. It can also provide short periods of lunar (1/6) and Martian (1/3) gravity. "Weightless Wonder V" was more commonly used by researchers to conduct experiments in a zero-gravity environment. During nine years at Ellington, it has accumulated almost 2,000 hours of flight time, creating almost 200 hours of weightlessness, 20 seconds at a time.

Weightless Wonder V cargo bay test area is approximately 60 feet long, 10 feet wide, and 7 feet high. The aircraft is equipped with electrical power, an overboard vent system, and photographic lights. Air and nitrogen sources are also available. Ground facilities include a test equipment build-up area, briefing room, fax, and telephones.

A typical mission is 2 to 3 hours long and consists of 30 to 40 parabolas. These parabolas can be flown in succession or with short breaks between maneuvers to reconfigure test equipment. The Reduced Gravity Office provides scheduling, test coordination, and in-flight direction for the test programs.

Many different types of experiments have been performed on the Weightless Wonder. Some of them show how equipment will function in microgravity. For example, researchers took showers while flying in the it. This helped them develop better ways to shower in space. Experiments have also been done to see how flames behave in microgravity.

More than 2,000 college students have flown aboard the aircraft through the Reduced Gravity Student Flight Opportunities Program. They are provided an opportunity to design and conduct their own experiments in weightlessness. In addition to its primary use as the "Weightless Wonder," KC-135A also has helped move the Space Shuttle fleet across the country, flying as an advance scout ahead of the Shuttle Carrier Aircraft 747 jet. It also has been used to transport many critical space hardware items, and has been on standby as a personnel transport in the event of Shuttle abort landings. KC-135A played a key role as a transport during the Columbia accident recovery.

The first KC-135A, retired in 2000, has even been a movie star. The aircraft played a major role in the hit movie, "Apollo 13." While most films that involve weightless characters use special effects, the actors in "Apollo 13" were really floating. The aircraft was used to film scenes involving weightlessness to make the characters look like they were really in space. The crew of the movie rented time and space on the aircraft over the course of half a year to complete the weightless scenes.

"Weightless Wonder V" will be replaced by the "Weightless Wonder VI," a C-9 aircraft acquired by NASA from the Navy to begin reduced gravity flights next year.

posted by: kyawoo at 10:58 | link | comments |
space science

Magnetized-beam plasma propulsion

A new means of propelling spacecraft, known as magnetized-beam plasma propulsion, or mag-beam, could cut the time required for long journeys around the solar system from years to weeks. Currently, using conventional technology, it would take astronauts about 2.5 years to travel to Mars, conduct their scientific mission and return. With mag-beam scientists hope to get to Mars and back in 90 days.

How can it do this?

Under the mag-beam concept, a space-based station would generate a stream of magnetized ions that would interact with a magnetic sail on a spacecraft and propel it through the Solar System at high speeds that increase with the size of the plasma beam.

The mag-beam propulsion system is being developed at the University of Washington; earth and space sciences professor Robert Winglee is leading the project.

But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft.

Winglee envisions units being placed around the Solar System by missions already planned by NASA. One could be used as an integral part of a research mission to Jupiter, for instance, and then left in orbit there when the mission is completed. Units placed farther out in the Solar System would use nuclear power to create the ionised plasma; those closer to the Sun would be able to use electricity generated by solar panels.

Mag-beam propulsion offers significant advantages over conventional rockets:

· One power source could be used to power multiple craft (serially, not at the same time).

· The power source could use solar energy, resulting in additional cost savings.

· Plasma propellants are accelerated to speeds an order of magnitude greater than those achieved by chemical rocket propellants, resulting in higher spacecraft velocities - at least 26,000 miles per hour.

Winglee acknowledges that it would take an initial investment of billions of dollars to place stations around the solar system. But once they are in place, their power sources should allow them to generate plasma indefinitely. The system ultimately would reduce spacecraft costs, since individual craft would no longer have to carry their own propulsion systems. They would get up to speed quickly with a strong push from a plasma station, then coast at high speed until they reach their destination, where they would be slowed by another plasma station.

posted by: kyawoo at 07:40 | link | comments |
space science