NASA's test
launch of a brand new rocket this week will last only minutes, but the space
agency is expecting thousands of spectators to flock to its Florida launching
site to watch the historic show.
The Ares
I-X rocket, a suborbital
prototype for a new booster designed to launch NASA's planned shuttle
replacement craft Orion, is slated to blast off Tuesday morning, weather
permitting. But what exactly will the throngs of onlookers see at liftoff?
"It's going
to look pretty spectacular," said Bob Ess, NASA's Ares I-X project manager.
Standing at
327 feet (100 meters), Ares I-X is a towering rocket — and currently the world's
tallest booster in service. Its $445 million test flight, which should last
about two minutes, is poised to launch Tuesday at 8 a.m. EDT (1200 GMT) from
Launch Pad 39B at NASA's Kennedy Space Center in Florida.
It has been
more than 30 years since NASA launched something other than a space shuttle to test
a manned spaceflight system. NASA will broadcast the launch live on NASA TV,
which will be webcast simultaneously.
For those
spectators in the area of the Kennedy Space Center on central Florida's eastern
coast, the test launch should be viewable for miles around. The Kennedy Space
Center Visitor's Complex is selling tickets but other venues are available,
much like during shuttle launches.
Just don't
expect Ares I-X to blast off like a shuttle. For one thing, it will roar off
the pad a bit faster than a space shuttle, Ess said.
A fast
blast off
When NASA
shuttles liftoff, they actually ignite their three main engines six seconds
early to begin building up thrust before the countdown clock hits zero. After
those six seconds, a shuttle's twin solid rocket boosters ignite, explosive
bolts holding the spacecraft down are severed and the entire stack soars
spaceward.
The gleaming
white Ares I-X, at its core, is a giant solid rocket booster. As a
prototype for the two-stage Ares I rocket, its first stage is a four-segment solid
rocket motor capped with a dummy fifth segment. The second stage, Orion capsule
and launch abort tower atop Ares I-X are all dummy segments, too. There is a
1-in-10,000 chance of a disastrous failure during the test, but NASA is
confident it will go as planned.
So when the
clock hits zero, there will be no six-second build up or giant plumes of steam
from the water sound suppression system like those seen during shuttle
launches. The explosive hold-down bolts will fire and the rocket should simply
zoom off the pad, mission managers said.
"It'll get
up and go a bit faster than the shuttle does," said Ares I-X launch director Ed
Mango.
An odd
white rocket
Unlike
recent shuttle launches to the International Space Station, which head
northeast after liftoff, Ares I-X will head due east out over the Atlantic
Ocean. The rocket is long and slender, and fatter on top because its second
stage is thicker than its solid rocket motor-powered first stage.
That means
it will look weird, Ess said.
"I think,
being long and thin and slender, optically it will look very strange coming
across," Ess said, adding that the first visible thing should be the standard
roll program to orient the rocket. "You'll see the whole vehicle turn around by
itself and then just kind of head due east ... I think it will move pretty
quickly."
There are
700 sensors on the Ares I-X rocket to measure things like vibration, speed,
performance and other data. Mission designers have added little tweaks to the
flight profile to move the rocket's motor nozzle slightly in order to measure
its effect on the booster.
"It
probably won't be visible to you," Ess told reporters.
Clear
skies vital for viewing
NASA needs
good weather to launch Ares I-X because engineers need to see the rocket flight
all the way through first stage separation, which will mark the end of the
test.
That
staging point is expected to come at about the 124-second mark, when the
supersonic Ares I-X rocket is traveling Mach 4.7 — more than four times the
speed of sound, its max speed for the flight. The rocket stages should separate
at an altitude of about 130,000 feet (24.6 miles or 39 km) and continue upwards
until they hit a maximum altitude of 150,000 feet (28 miles or 45 km).
"Once
separation occurs, that's really the end of the launch trajectory," said Doug
Cooke, associate administrator of NASA's exploration program.
Observers at
NASA's Kennedy Space Center and nearby viewing areas around the region, like
the banks of the Banana River, may get a glimpse of stage separation. But only
if the weather is clear. Ares I-X will be a bit farther away than a launching
shuttle, Ess said.
"I think
you may be able to see something happen in the sky, two white dots instead of
one white dot. But I don't think it's going to be very clear," Ess said, adding
that television camera views should be better. "If we have any cloud cover,
it's going to be difficult."
The Ares
I-X dummy second stage is expected to crash into the ocean about 147 miles (236
km) east of the launch pad. The first stage, however, is equipped with
parachutes and designed to splash down in the ocean — much like shuttle rocket boosters
— to be retrieved by a recovery ship.
A report
released last week by an independent panel appointed by the White House to
review NASA's human
spaceflight plans suggested that President Barack Obama and the space
agency consider scrubbing the Ares I and pursue commercial rocket boosters
instead. But Mango said the data gleaned from the test flight and its
preparation will be vital, even though the Ares I rocket's ultimate fate is
uncertain.
"Even
getting to this point, the team has learned about getting a vehicle designed
and ready to be launched," Mango said. "It's really an inspiring point to be
at."
SPACE.com
will provide full coverage of NASA's Ares I-X test flight with Staff Writer
Clara Moskowitz in Cape Canaveral, Fla., and Managing Editor Tariq Malik in New
York. Click here for full mission
coverage.
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