Tuesday, August 10, 2010
As America celebrates the fortieth anniversary of humankind's voyages to the moon this year, Atlanta can reflect on the area's own piece of space history with one of the spacecraft which paved the way for deep space travel.
Located at the Fernbank Science Center in East Atlanta, NASA's Apollo 6 spacecraft is a true gift on display following it's earth orbiting test flight in April 1968.
Designed as a test flight article and flew unmanned, Apollo 6 tested not just the craft itself but flew on the second flight of the largest rocket America ever launched -- Saturn 5.
The launch of the Saturn 5 with Apollo 6 a top lifted-off on April 4 at 7:00 a.m. EST, from Cape Canaveral, Florida's launch pad 39-A.
Launch complex 39-A will be used this year to launch the final three space shuttle missions.
On a historical note, the launch occurred the same day and just hours before the assassination of Atlanta's son, the Rev. Martin Luther King, Jr. in Memphis.
Once launched, flight controllers began to notice the rocket was shaking a bit as it ascended through the atmosphere.
Engineers call it a POGO effect, an up and down vibration in the rocket's first stage which reached a force of seven tenths of gravity. It was enough of a shake to have impaired a crew's vision had they been on board.
The Saturn 5's erratic first stage then separated on time and the controllers noticed the second stage began to shake as well as the rocket flew faster and faster.
Two of the second stage's five J-2 engines then shut down by an abort system due to a liquid hydrogen fuel line which broke due to the continuation of the POGO effect.
On the next Saturn 5 flight that December, engineers added more helium to the oxygen fuel lines to stabilize the engine's vibrations. It worked and the rocket sped all the way to lunar orbit as Americans reached the moon for the first time.
One other issue was discovered in post flight data analysis.
The support beam for the center engine of the second stage shifted nearly 18 inches, according to flight director Chris Kraft, "and came perilously close to structural failure".
Kraft states in his 2001 book Flight that "if a beam broke, the the entire second stage would fail catastrophically. It would explode."
Apollo 6's flight saved a future manned space flight from being lost.
This unmanned flight of Apollo 6 saved the moon program for America by working through the several problems discovered during launch.
Apollo 6 flew up to 228 miles above earth and sailed upon the ocean of space much like a boat being checked out before she carries a crew.
After nearly seven full orbits of our planet, the craft reentered the atmosphere and splashed down at 5:23 p.m. It was later recovered by the U.S.S. Okinawa five hours later.
Once you view the exciting exhibits at Fernbank, you discover the spacecraft resting near the center's planetarium.
As you view the module, be sure to examine the underneath region of the space craft known as the heat shield.
It is this region which withstood around 2,500 degrees of heat caused by friction as it hit earth's atmosphere on the way home.
Peer inside the craft through it's single window; and scan the thrusters located around it's base.
Also of interest is the Georgia state flag which flew to the moon aboard the final human landing on the lunar surface, Apollo 17.
Fernbank Science Center is located in Decatur and is open Monday thru Wednesday from noon to 5:00 p.m., and Thursday and Friday noon to 9:00 p.m.
The exhibit center's Saturday hours are from 10:00 a.m. until 5:00 p.m., and closed on Sunday.
Please visit Fernbank's Planetarium's site for the latest times and show information.