US company readies first space capsule launch

source: dminuszero.com

Never before has a private company attempted the risky feat of sending a spacecraft into orbit and bringing it back to Earth for a splash landing in the Pacific Ocean, and even the owner, SpaceX, admits it is not sure it will succeed.

But NASA gave the green light for the launch of the Dragon capsule late Tuesday, after SpaceX engineers fixed some cracks in the rocket's engine nozzle that were found Monday and forced a brief postponement of the flight.

"It's Go for launch," NASA said in a tweet late Tuesday. "The launch of the SpaceX Falcon 9 is on for Wednesday."

The launch window opens at 9 am (1400 GMT) and closes at 12:22 pm (1722 GMT).

"During a routine inspection this week, SpaceX engineers observed two small cracks in the rocket's second stage engine nozzle. SpaceX completed repairs to the cracked nozzle Tuesday," NASA said in a statement.

The Dragon spacecraft aims to blast off from Cape Canaveral in Florida, hurtle into orbit and then survive a re-entry into Earth's atmosphere for a water landing about four to five hours later, said SpaceX.

The operation hopes to showcase the capsule's ability to launch and separate from the Falcon 9 rocket, orbit Earth, transmit signals and receive commands.

If the Dragon launch is successful, the next step is for a fly-by of the ISS as part of a five-day mission in which the Dragon will approach the orbiting station within six miles (10 kilometers).

Later, an actual cargo and crew mission to the ISS is planned. Both are scheduled to take place in 2011.

But the company was not overly optimistic that all would go according to plan in its demonstration launches.

"History would say that we are going to have a substantial issue in one of the first of the three flights, that is just empirical that has nothing to do with our process or our hopes," said Space X president Gwynne Shotwell.

"If I want to have a cloud over my head I would put success at the same percentage (as prior company estimates), 70 per cent," she told reporters on Monday.

"I'm not a statistician so I don't necessarily want to put a number but it isn't any lower than 70."

As tall as an 18-story building, the Falcon 9 rocket that will carry the Dragon was successfully test launched in June.

The US space agency NASA signed a $1.6-billion contract with SpaceX in December 2008 under the Commercial Orbital Transportation Services (COTS) program to provide 12 spacecraft with cargo capacity of at least 20 tonnes to resupply the International Space Station (ISS) through 2016.

NASA has also signed a contract of $1.9 billion with Orbital Space Corporation for eight launches of its Taurus II rocket starting in 2011.

President Barack Obama hopes the private sector will help fill the gap that will open when the space shuttle fleet is retired next year, and before a new generation of spacecraft is developed.

The three US shuttles -- Discovery, Atlantis and Endeavour -- will become museum pieces after a final shuttle mission to the space station in 2011.

Obama has proposed spending six billion dollars over five years to help the private sector develop reliable and affordable launchers to transport cargo and US astronauts to the International Space Station.

During the transition period, the United States will depend on Russian Soyuz rockets for access to the ISS.