Teknologi Kapal Luar Angkasa II

Lightning Protection for the Next Generation Spacecraft

Added and Edited By:

Arip Nurahman Department of Physics, Faculty of sciences and Mathematics
Indonesia University of Education

&

Follower Open Course Ware at MIT-Harvard University, U.S.A.

This artist's concept depicts the completed lightning protection system at Kennedy Space Center's Launch Pad 39B. Credit: NASA






At Launch Pad 39B, pilings are being pounded into the ground to help construct lightning towers for the Constellation Program and Ares/Orion launches. Pad B will be the site of the first Ares vehicle launch, including Ares I-X which is scheduled for April 2009. Credit: NASA/George Shelton

Thunder rumbles in the distance as darkening clouds gather above NASA Kennedy Space Center's Launch Pad 39B, where a sleek Ares I launch vehicle stands awaiting an upcoming flight. A blinding lightning flash suddenly streaks down from the sky, striking one of the pad's tall steel masts. The surge of electrical current quickly is diverted away from the rocket and carried safely into the ground.

This scenario hasn't happened yet; the Ares I rocket is still in development, and NASA is just beginning to transition Launch Pad 39B from a space shuttle facility into the launch site for the Constellation Program's Ares I crew launcher. But lightning is a well-known danger in central Florida, and a team of NASA and contractor personnel already is working to design and build a new lightning protection system that's larger than any the spaceport has ever seen. The new system features large cables strung between three 594-foot-tall steel and fiberglass towers. Called a catenary wire system, it will dominate the launch area's skyline.

The new system will provide better protection from lightning strikes and help avoid delays to the launch schedule by collecting more information on the strike for analysis by launch managers.

Launch Pads 40 and 41, located south of Launch Complex 39, each have lightning protection systems similar to the new version. Each tower is topped with a fiberglass mast and a series of catenary wires and down conductors designed to divert lightning away from the rocket and service structure. This configuration helps keep the vehicle isolated from dangerous currents.

Lightning protection systems have steadily evolved as the space program has progressed. The Apollo system, for example, was a bonded system. "A bonded structure is part of the launch structure," says Constellation Senior Pad Project Manager Jose Perez Morales. "Obviously, if you get a lightning strike, it doesn't matter how well you place your wires -- you're going to get current going through the structure."

For the space shuttle, the lightning protection system consists of a lightning mast on the top of each pad's service structure and two catenary wires. This system provides shielding to the space shuttle and diverts strike currents down to the ground, making it an isolated system and an improvement over the Apollo arrangement. The system under development for the Constellation Program’s next-generation vehicles would significantly increase the shielding level and further separate the electrical current from vital launch hardware.

Additionally, technology has advanced considerably since the early days of space exploration. Lightning detection has become simpler and faster as computer modeling has become more sophisticated.

"In the years of Apollo, most of these things were done by hand," Perez notes. "Because of the new computers and the ability to do a lot of probability models, the whole thing has evolved. That's how they can now design more effective lightning protection systems."

Now there are decades' worth of local lightning data recorded, so computer models are not only faster, but more accurate than ever.

There's another benefit to the new system: An array of sensors, both on the ground and the mobile launcher, will help determine the vehicle's condition after a nearby lightning strike. This can prevent days of delays. Currently, "If there's been a strike and you're not sure whether the vehicle was hit, then at the very least you could have an impact on your schedule because you'll have to stop and test," says NASA Project Manager Lori Jones.

Ivey's Construction Inc., the contractor in charge of building the lightning protection system, received NASA's go-ahead to proceed in September. Construction began in November with the arrival of large cranes and concrete pilings. The system's foundation will include 216 of these pilings extending up to 55 feet below ground. The massive steel towers will be partially assembled horizontally on the ground, then lifted into the vertical position by a 60-story-tall crane. Construction is expected to be complete in 2010.

According to NASA Construction Manager Jason Ritter, along with the standard challenges associated with this construction effort, nature will provide a few of its own.

"Most of the work isn't technically difficult, but it's big and time-consuming," Ritter says. "When you're working on a launch pad that has lightning and high winds and sea breezes, and it's an operational pad, those are the things we consider difficult to work through."

Sumber:

http://www.space-travel.com/reports/Lightning_Protection_For_The_Next_Generation_Spacecraft_999.html


Arip Nurahman

Semoga Bermanfaat

Teknologi Kapal Luar Angkasa I

Added & Edited By:
Arip Nurahman Department of Physics, Faculty of Sciences and Mathematics
Indonesia University of Education

&

Follower Open Course Ware at MIT-Harvard University, U.S.A.

Spaceship Mockup

Image above: A mockup Orion crew module built by NASA Dryden Flight Research Center's Fabrication Branch gets a lift to its new home in the center's former Shuttle hangar. NASA photo by Tom Tschida

NASA's Orion spacecraft now in development is America's first new manned spacecraft since development of the space shuttle 30 years ago.

It's the centerpiece of NASA's Constellation program, which aims to take the next generation of human explorers to the moon and beyond.

Orion's launch abort system, a "rocket on top of the rocket," is designed to ensure the safety of its astronaut crew by pulling the crew module away from it's booster rocket in the event of a booster malfunction, either while on the launch pad or during ascent to orbit.

NASA's Dryden Flight Research Center in Southern California is leading the Orion launch abort system flight testing.

As part of this effort, NASA Dryden's Fabrication Branch constructed a mockup of the Orion crew module. More simplified than the actual spacecraft, the Orion mockup is the actual size of the real thing, inside and out.




Dryden is using the mockup to develop and verify integration and installation procedures for things like avionics, instrumentation, and wire harness routing in advance of the arrival of the first abort flight test article, called "Boilerplate 1."

Image above: NASA Dryden's mockup Orion crew module is located in Dryden's former Shuttle hangar. NASA photo by Tom Tschida.

Boilerplates, in this sense of the term, are flying simulators used in early tests designed to mimic the flight characteristics of the actual vehicle. They have the exact dimensions, aerodynamic and mass properties of the operational vehicle they will simulate in flight, in this case the Orion crew module.

The mockup has no attached forward bay on it's top, but Dryden technicians are building one that will remain separate for parachute integration procedure development.

Two pad abort and four ascent abort flight tests of the launch abort system are planned, all unmanned, with the first scheduled for 2008 and continuing through 2011.

Dryden Educator Resource Center

NASA has established the Educator Resource Center Network (ERCN) across the country to provide educators information about NASA and the educational resources and services it provides. The NASA Dryden ERC serves Southern California and Arizona. If you live outside of these areas, you can find the ERC that serves your region at: http://www.nasa.gov/education/ercn

ERC personnel work with educators to provide curriculum support materials, in-service and pre-service training using NASA educational material, demonstrate and facilitate the use of educational technologies, and partner with local, state, and regional educational organizations to become part of the systemic initiatives in the state.

The NASA Dryden Educator Resource Center materials reflect NASA research and technology development in such curriculum areas as:

Life Science Physical Science Astronomy Energy Earth Resources

Environment Mathematics Geography And careers in aerospace

The NASA Dryden Educator Resource Center is open for visitors on an appointment only basis, to make an appointment please contact 661-276-3992.

Educators can requests materials please send a written request, email, or phone message to NASA Dryden Educator Resource Center.

To Visit the NASA Dryden Educator Resource Center and the Regional ERC’s:

NASA Dryden Educator Resource Center
(Southern California and Arizona)
AERO Institute
38256 Sierra Highway
Palmdale, CA 93550
email: DrydenERC@nasa.gov
phone: 661-276-3992
fax: 661-265-9548

Embry-Riddle/NASA Educator Resource Center (Arizona)
3700 Willow Creek Road
Prescott, AZ 86301
Contact: Stacy Deveau
email: stacy.deveau@erau.edu
phone: 928-777-6281

California Science Center Educator Resource Center
(Los Angeles, California)
700 State Drive
Los Angeles, CA 90037
Contact: Marie Jennings
phone: 213-744-7675

Directions

Click here for MapQuest directions to Aero Institute

Archives

Four Easy Ways Educators Can Receive NASA Materials

NASA's unique research and missions have allowed NASA Education to produce educational materials that engage student interest in science, technology, engineering, and mathematics and support classroom curricula. NASA is working hard to make the materials easily accessible to the educational community through multiple dissemination channels – web, mail, and site visits.

There are Four Ways to Receive Materials

• Download educational resources from the NASA Portal
• Order print resources from Office Max Print-on-Demand Service at an educator discount and pick them up at Office Max store near you or
• Purchase multimedia resources for minimal cost from NASA’s Central Operation of Resources for Educators (CORE)
• Visit or contact the NASA Dryden Educator Resource Center

Portal

The NASA Portal serves as the gateway for information regarding content, programs, and services offered by NASA for the general public and, specifically, for the educational community. Providing educators access to curriculum support materials, that may be downloaded and printed from the following Web sites:
http://www.nasa.gov/education/materials

Educator Guides, Lithographs, Posters, Brochures, Bookmarks
http://www.nasa.gov/audience/foreducators/topnav/materials/about/index.html

Themed Collections of Online Resources (Grades-All Ages)
http://www.nasa.gov/audience/foreducators/topnav/schedule/extrathemes/index.html

Subject Matter Topics (Grades-All Ages)
http://www.nasa.gov/audience/foreducators/topnav/subjects/about/index.html

NASA Education Express Mailing List (Grades-All Ages)
Sign up for announcements about NASA activities and products
http://www.nasa.gov/education/express

OfficeMax

NASA and Office Max have partnered to provide educators an additional venue to acquire NASA curriculum support materials. Using the Internet, educators can search an on-line database of NASA materials, preview these materials to determine if they are appropriate, and order copies through their nearest OfficeMax for pick-up, for a nominal charge. If the educator is not within 50 miles of an OfficeMax, they can have the materials shipped to them, paying only the additional cost of postage. More information can be found at: http://www.nasa.gov/education/officemax

CORE

The Central Operation of Resources for Educators (CORE) serves as the worldwide distribution center for NASA-produced multimedia materials. For a minimal charge, CORE will provide curriculum support materials to educators who are not able to visit one of the Educator Resource Centers, or who are looking for large quantities of materials. Through its on-line catalog, educators can use the mail-order service to purchase NASA education materials, such as subject area classroom modules, DVDs, CD-ROMs and NASA Memorabilia.

Write, call, or email for further information and to request or download CORE catalog. CORE staff can also answer any questions on any of the above resources for obtaining NASA educational materials.

NASA CORE
Lorain County Joint Vocational School
15181 Route 58 South
Oberlin, OH 44074
Phone: 440-775-1400
Fax: 440-775-1460
http://www.nasa.gov/education/core

Sumber:

Gray Creech
NASA Dryden Flight Research Center

Semoga Bermanfaat

Arip Nurahman

Dasar Teknologi Penerbangan Luar Angkasa III

Added and Edited By:
Arip Nurahman Department of Physics, Faculty of sciences and Mathematics
Indonesia University of Education
&
Follower Open Course Ware at MIT-Harvard University U.S.A.

SECTION III

FLIGHT OPERATIONS

14 Launch
15 Cruise
16 Encounter
17 Extended Operations
18 Deep Space Network