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发帖数: 29846 | 1 The first private spacecraft aiming to dock with the international space
station blasted off from Florida and reached orbit early Tuesday with split-
second precision, but the biggest tests for the mission are still days ahead.
The predawn skies around Cape Canaveral filled with the bright glow and deep
rumble of Space Exploration Technologies Corp.'s Falcon 9 rocket lifting
off the pad, carrying an unmanned Dragon spacecraft on a highly anticipated
test flight scheduled to last about two weeks. Within three minutes, the
Falcon 9 reached a velocity of 10 times the speed of sound, with the first
stage dropping off and the second stage continuing to speed toward orbit.
The unmanned capsule reached orbit at around 17,000 miles per hour, roughly
10 minutes after launch. Preliminary data indicated that all major
propulsion, navigation and communications systems worked properly.
The launch came after a faulty engine valve on Saturday forced a last-second
abort of the mission. SpaceX, as the company is known, worked over the
weekend to replace the defective part and test the rocket's systems.
In order to place the Dragon capsule in the correct orbit to be able to link
up with the speeding space station orbiting more than 200 miles above the
earth, SpaceX launched precisely at a predetermined moment.
If sensors and computer-controlled propulsion systems aboard Dragon pass
various in-orbit tests, the capsule is intended to link up with the space
station in about 3½ days.
The launch capped a picture-perfect countdown, with commands to ignite the
rocket's nine first-stage engines issued at 3:44 a.m. Florida time. At that
point, the Falcon 9 was mechanically held down on the launch pad for nearly
a second, until computers determined that all propulsion and other systems
were operating normally.
Tuesday's mission was the second test launch of the bell-shaped unmanned
capsule, which the National Aeronautics and Space Administration intends to
use in the future to transport cargo to the space station.
Marking the historic moment, NASA's mission commentator George Diller ticked
off the final seconds of the countdown, noting that the launch of the
commercially built rocket reflects NASA's shift to "the private sector to
resupply the international space station."
The rocket's cluster of nine engines apparently performed without a major
hitch, putting out roughly one million pounds of thrust and placing the
capsule into position to reach orbit. Roughly 10 minutes after launch, Elon
Musk, the company's founder and chief executive, tweeted: "Falcon flew
perfectly." Mr. Musk, who also is the closely held Southern California
company's chief technical officer, said: "Dragon in orbit, (communications)
locked and solar arrays active!! Feels like a giant weight just came off my
back."
Establishing communications with Dragon and successfully deploying its solar
panels, intended to provide electric power, were among the technical issues
company engineers worried about most before liftoff.
Plans for the test flight include a flyby and docking with the station, but
SpaceX officials and industry experts have stressed the difficult challenges
of meeting all those goals. Even if the mission manages to accomplish only
half its aims, "it's still one for the books," Jeff Greason, chief executive
of space-transportation start-up XCOR Aerospace, told reporters last week.
NASA Administrator Charles Bolden told reporters the successful launch puts
the U.S. "back on the brink of a new future" in space exploration. Saying
that it validates the Obama administration's push to outsource some core
NASA functions to private industry, Mr. Bolden reiterated that the agency
intends to pursue more-ambitious manned exploration efforts such as reaching
an asteroid, which "private industry cannot do or should not do."
After years of bickering with congressional critics about commercial-space
initiatives, NASA officials reveled in the afterglow of the launch. Mr.
Bolden, who has weathered his share of controversies leading the agency,
told a press briefing that the launch represented a "great day for the world
," because there were "people who thought (the U.S.) had gone away" as the
leader in pushing the frontiers of space.
The agency has said private industry can develop unmanned cargo vehicles—
followed by space taxis to take astronauts into orbit—faster and at less
cost than traditional NASA programs.
Minutes after the capsule reached orbit and SpaceX officials said it seemed
to be in good shape, the White House put out a statement congratulating the
company and what it called "the potential of a new era in American
spaceflight."
John Holdren, President Barack Obama's chief science adviser, said the
mission represents an "expanded role for the private sector" in servicing
the space station. The long-term goal, he said, is to "free up more of NASA'
s resources to do what NASA does best— tackle the most demanding
technological challenges in space, including those of human space flight
beyond low-earth orbit."
Congratulatory messages reverberated throughout NASA, and SpaceX officials
cheered loudly as they watched videos of the liftoff at the company's
mission-control facility in Hawthorne, Calif. But government and industry
experts stressed that the rest of the mission would entail tougher
challenges for SpaceX's design and resilience.
William Gerstenmaier, NASA's top manned-space official, told reporters it
was an "absolutely amazing countdown and launch," adding "there is none
better than this team" at managing such complex liftoffs. But he cautioned "
there is still a lot to go" to reach the mission's additional goals.
Mr. Musk, appearing on a videoconference, told reporters that Tuesday's
launch should dispel the doubts of critics about the long-term prospects of
commercial-space ventures. Calling Tuesday's developments akin to winning a
Super Bowl, Mr. Musk said the test flight could be classified as a success,
he said, "no matter what happens with the rest of the mission."
Everything "is looking really good" for the rest of the flight, according to
Mr. Musk, noting that the launch provided "an extremely intense moment"
particularly "when you have given every ounce that you have" to achieve
success.
Mr. Musk's team and the Dragon capsule made history in late 2010, when
SpaceX became the first company to put an unmanned spacecraft into orbit and
then recover it safely. This time, Dragon is carrying about 1,000 pounds of
space station provisions. The mission's goal is to dock with the $100-
billion orbiting laboratory; deliver food and other supplies; and bring back
science experiments. |
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