SpaceX Set for Historic Launch of Private Spacecraft on Wednesday

Editor's Note: SpaceX aborted the first launch attempt for the Dragon spacecraft less than three minutes before liftoff. Another launch attempt is possible today around 10:38 EST (1538 GMT). SpaceX Mission Updates.

CAPE CANAVERAL, Fla. ? The private spaceflight company SpaceX is poised to launch its rocket and new commercial space capsule on its inaugural test flight tomorrow (Dec. 8), following a 24-hour delay due to cracks on one of the rocket engine's nozzles, NASA officials confirmed.

The company's Falcon 9 rocket and Dragon space capsule are set to lift off from the Cape Canaveral Air Force Station's Launch Complex 40 here in Florida tomorrow morning. The launch window will open at 9 a.m. EST (1400 GMT) and close at 12:22 p.m. EST (1722 GMT).

The test flight of SpaceX's Dragon spacecraft was originally planned for Dec. 7, but the launch was delayed after two cracks were found in the aft end of the second-stage engine nozzle extension of the Falcon 9 rocket.

SpaceX engineers worked overnight to fix the nozzle, and the decision to launch Wednesday was announced Tuesday evening. [INFOGRAPHIC: Inside Look at SpaceX's Dragon Capsule]

Historic test flight ahead

The Hawthorne, Calif.-based SpaceX, short for Space Exploration Technologies, was founded by millionaire Elon Musk, co-founder of the PayPal online payment system and CEO of the Tesla electric car company.

For tomorrow's demonstration flight, the Falcon 9 rocket will carry the Dragon space capsule into low-Earth orbit. The capsule will then separate from the rocket's second stage and between two and three orbits of the Earth, demonstrating its operational communications, navigation and maneuvering abilities.

The spaceship will then re-enter the Earth's atmosphere and land in the Pacific Ocean to be recovered by a ship. The target splashdown area is about 500 miles (nearly 805 km) west of Mexico, SpaceX officials said. The full duration of the test flight is expected to last approximately 3 1/2 hours, they added.

"When Dragon returns, whether on this mission or a future one, it will herald the dawn of an incredibly exciting new era in space travel," Musk said in a statement. "This will be the first new American human-capable spacecraft to travel to orbit and back since the Space Shuttle took flight three decades ago."

SpaceX has reportedly spent about $600 million to date on its Dragon and Falcon rocket programs since Musk founded the company in 2002.

That investment has netted SpaceX a $1.6 billion contract with NASA to use its Dragon spacecraft for cargo flights to the International Space Station following the retirement of the agency's space shuttle fleet next year. SpaceX plans to fly at least 12 unmanned Dragon missions through 2016 to deliver supplies to the space station.

The Dragon space capsules are named after Puff the Magic Dragon, since many critics considered it to be impossible, SpaceX officials have said. SpaceX's Falcon 9 and smaller Falcon 1 rockets are named after the Millennium Falcon, the fictional "Star Wars" spaceship of choice for the character Han Solo.

SpaceX's Falcon 9 rockets stand about 180 feet (nearly 55 meters) tall and are 12 feet (3.6 meters) wide, according to SpaceX descriptions. The Dragon capsule and its unpressurized trunk are just over 20 feet (6 meters) long and have an interior cabin that is just over 10 feet (3 meters) wide at its widest point.  

Commercial space taking flight

If successful, SpaceX will be the first commercial company to launch and re-enter a spacecraft from low-Earth orbit. The mission is also SpaceX's second launch of its two-stage Falcon rocket. The first Falcon 9 rocket launched on a successful test flight in mid-June.

"This is an extremely exciting milestone for both NASA and SpaceX," said Phil McAlister, acting director of commercial space flight development at NASA Headquarters in Washington, D.C. "We've got an extremely challenging year ahead with the remaining milestones, but getting this far this fast has been a remarkable achievement."

The test flight will also be the first by any company under NASA's Commercial Orbital Transportation Services (COTS) program, which is designed to stimulate the development of private space vehicles capable of carrying cargo and crew to the International Space Station.

"[NASA has] been a fantastic customer for us," said Gwynne Shotwell, president of SpaceX, in a prelaunch news briefing Monday. "The relationship has been extraordinary, and both teams have learned a lot."

SpaceX's $1.6 billion space station cargo contract with NASA is separate from its COTS deal, which offers $278 million for successful demonstration tests of hardware capable of space station deliveries.  

NASA has also awarded another cargo contract to the Virginia-based company Orbital Sciences to provide robotic delivery ships for the space station. That deal promises Orbital Sciences $1.9 billion for eight cargo flights using its new unmanned Cygnus spacecraft and Taurus 2 rockets.

SpaceX also hopes to win a contract to one day ferry astronauts to the station ? though the Dragon capsule is not yet certified to carry human passengers into space.

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• Gallery: Photos of the Dragon Space Capsule, Dragon Video
• INFOGRAPHIC: Inside Look at SpaceX's Dragon Capsule

You can follow SPACE.com Staff Writer Denise Chow on Twitter @denisechow. Visit SPACE.com for complete coverage of SpaceX's debut Dragon spacecraft launch.