Engineers and government officials said the critical stage of the liftoff of the Korea Space Launch Vehicle-1 (KSLV-1), set for Tuesday, will be during the initial ascent from the Naro Space Center, located 485km south of Seoul.

"Initially, the rocket will be moving relatively slowly, making it hard to maintain stability as the main engine tries to push up the 140t launch vehicle and satellite payload," said Min Kyung-ju, director of the space center.

"If there is a sudden gust of strong wind or any other slight problem in the stabilization mechanism, the rocket can tip over and be lost," he said.

The aerospace engineers said the KSLV-1, also called the Naro-1, will become more stable as it gains speed, and that after overcoming the stress of exceeding the speed of sound 55 seconds after blastoff, there is less chance of it crashing to Earth.

At the time, the Naro-1 will be 7.4km from the ground and heading in a southerly direction, with the Russian-made first stage rocket providing 170t of thrust.

Lee pointed out that many rockets have been lost during the critical initial ascent stage, saying that the U.S.-made Vanguard and Atlas G, Europe's Ariane 5 and several other launch vehicles from countries such as China and Russia were all lost within a minute of liftoff.

South Korea, with no experience of its own in building powerful rockets, teamed up with Russia to design and build the rocket.

In addition to the need to pick up speed, the Naro-1 is programed to make a "kick-turn" maneuver 10 seconds after takeoff, roughly 900m above the launch pad.

The maneuver is designed to steer the rocket south to place the scientific satellite into orbit while not passing over populated areas during the rest of its flight.

The director said if the Naro-1 fails to make the turn and takes an unauthorized trajectory, ground controllers will destroy it by remote control.

"The turn must be precise and carried out at a time when the rocket is not moving very fast, making it very tricky," he said.

Others, like Deputy Science and Technology Minister Lee Sang-mok, said the success of the satellite mission will depend on the proper release of the fairings housing the payload, the separation of the first and second stage rockets, and the ignition of the second stage solid fuel rocket.

The official said if the fairings are not ejected 245km from the launch pad at an altitude of 177km, the satellite cannot deploy in orbit and the mission will not be a complete success.

The fairing assembly was made in South Korea and has never been tested in flight.

Another critical moment is expected to come when the first stage main booster is turned off and separates from the second stage rocket at an altitude of 196km, with the first stage rocket made in Russia falling to the ocean.

Failure to separate 232 seconds into the flight can result in the rocket failing to reach proper altitude, which is 300km or more from the Earth's surface.

The last challenge is expected when the locally made second stage rocket's kick motor has to be ignited over a 1,000km from the Naro center and 395 seconds after liftoff.

"If the kick-motor functions properly, there is a good chance of the scientific satellite reaching orbit," Lee said.

Engineers said that if this phase is reached, the mission can be considered 90 percent successful.

Once the satellite is deployed, South Korean controllers will determine its exact altitude and trajectory. They will try to make contact 13 hours after liftoff.

The Korea Advanced Institute of Science and Technology, which made the satellite, said not making contact on the first attempt would not signify failure, as long as the satellite deploys its solar panels and generates power.

"As long as the satellite is generating power, contact can be made at a later date if its exact location is known," a research said.

The small 100kg scientific satellite does not have the ability to correct its course, so it is important for it to have reached its proper trajectory to conduct experiments properly.

If contact is made, South Korea will become the world's 10th country to successfully send a locally developed scientific satellite into orbit from its own soil.

South Korea spent 502.5 billion won (US$402.3 million) on the Naro-1, which stands 33m tall and has a diameter of 2.9m. It spent 13.6 billion won on the satellite.

A source in the Ministry of Education, Science and Technology in change of the country's space exploration project, meanwhile, said if the launch is postponed once again due to technical issues, there is a chance Naro-1's liftoff will have to be pushed back several weeks.

"Seoul will have to notify both the International Civil Aviation Organization and the International Maritime Organization to get new launch dates, which can take up to eight days," said an official, who declined to be identified.

The two organizations need to be notified so boats and commercial aircraft operating in the trajectory of the rocket can be warned in advance.

He added that if the launch is delayed again due to a technical problem, local experts may have to conduct an overall assessment of the launch and related mechanical systems with their Russian counterparts.

"Public opinion may call for a more detailed assessment of the program, making it necessary to take a more measured approach," he said.

Share This Article With Planet Earth

del.icio.us	Digg	Reddit
YahooMyWeb	Google	Facebook

Related Links
Korea Aerospace Research Institute
Launch Pad at Space-Travel.com

Memory Foam Mattress Review

SPACE MEDIA NETWORK PROMOTIONS Solar Energy Solutions Tempur-Pedic Mattress Comparison ... Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News