 |
| NASA's Orion spacecraft at Space Launch Complex 37-B. Photo credit: NASA/Kim Shiflett |
CAPE CANAVERAL, Florida -- NASA's Orion spacecraft is still on schedule to make its first flight test atop of a United Launch Alliance Delta IV Heavy Configuration rocket from Space Launch Complex 37-B at Cape Canaveral Air Force Station on December 4, 2014 at 7:04 a.m. EST.
Technicians and engineers are conducting a series of electrical and battery checks
between the connections between the crew module, service module and
Delta IV Heavy second stage. Orion's processing schedule also leaves room
for more testing on Orion and its system if needed without impacting the
launch schedule.
Here are the top five things that NASA scientists and engineers will be paying attention to during the two-orbit, four-hour Orion Flight Test:
1. Launch Abort System Separation – The launch abort
system (LAS) is a key reason that Orion is intended to become the
safest spacecraft ever built. In an emergency it could activate to pull
the crew module and the astronauts it will carry away from the launch
pad and the rocket in milliseconds.
During launch, the 904-pound LAS jettison
motor has to perform flawlessly. If it doesn’t get rid of the LAS 6
minutes and 20 seconds into the mission, there will be no landing – the
LAS protects the crew module during ascent, but to do so, it blocks the
parachutes that allow Orion to safely splashdown.
The Launch Abort System separation is just the first of 17
separations or jettisons that have to happen exactly as planned for the
mission to be successful.
 |
A test version of NASA’s Orion spacecraft
touches down in the Arizona desert
Image Credit: NASA
|
2. Parachute Deployment – For EFT-1, Orion will
travel 3,600 miles above the Earth so that when it performs its deorbit
burn, it will descend back into the Earth’s atmosphere at almost
20,000 miles per hour. Before it splashes down in the Pacific Ocean, it
needs to slow down to 1/1000th of its entry speed – a relatively gentle
20 miles per hour.
Earth’s atmosphere does its part to put on the brakes, but to make
landing survivable, Orion relies on its parachute system – primarily two
drogue parachutes and three massive mains that together would cover
almost an entire football field. They’ve been tested on Earth; test
versions of Orion have been dropped from airplanes with a multitude of
failure scenarios programmed into the parachute deployment sequence in
an effort to make sure that every possibly problem is accounted for.
But the sheer number of possible problems to be tested indicates how
complicated the system is – each parachute must deploy at the exact
right time, open to the exact right percentages in the exact right
stages, and be cut away exactly as planned. And no test on Earth can
exactly simulate what the spacecraft will really experience on its
return from space.
 |
This computer-generated art depicts
Orion's heat shield protecting the crew
module as it enters the Earth's atmosphere.
Image Credit: NASA
|
3. Heat Shield Protection – Before the parachutes
even get a chance to deploy, Orion has to make it safely through Earth’s
atmosphere. The reason that Orion is traveling so far and coming back
in so fast is to give the heat shield a good workout – the idea is to
get as close as possible to the temperatures Orion would experience
during a return from Mars. At the speed it will be traveling, the
temperature should reach almost 4,000 degrees Fahrenheit. At that same
temperature, a nuclear reactor would melt down.
Standing between the crew module and all that heat is no more than
1.6 inches of Avcoat, a material that’s designed to burn away rather
than transfer the temperatures back to Orion. Some 20 percent of the
Avcoat will erode during the spacecraft’s journey back to Earth, and
although it’s not the first time the materials has been used for this
purpose, at 16.5 feet wide, Orion’s heat shield is the largest ever
built. Technicians filled with Avcoat each of the 320,000 honeycomb
cells that make up the shield’s structure by hand, then machined them to
the precise fractions of inches called for by the design. Getting it
exactly right is all that will get Orion through one of the most dynamic
periods of its mission.
4. Radiation Levels – Traveling 15 times farther
into space than the International Space Station will take Orion beyond
the radiation protection offered by Earth’s atmosphere and magnetic
field. In fact, the majority of EFT-1 will take place inside the Van
Allen Belts, clouds of heavy radiation that surround Earth. No
spacecraft built for humans has passed through the Van Allen Belts since
the Apollo missions, and even those only passed through the belts –
they didn’t linger.
Future crews don’t plan to spend more time than necessary inside the
Van Allen Belts, either, but long missions to deep space will expose
them to more radiation than astronauts have ever dealt with before.
EFT-1’s extended stay in the Van Allen Belts offers a unique opportunity
to see how Orion’s shielding will hold up to it. Sensors will record
the peak radiation seen during the flight, as well as radiation levels
throughout the flight, which can be mapped back to geographic hot spots.
5. Computer Function – Orion’s computer is the first
of its kind to be flown in space. It can process 480 million
instructions per second. That’s 25 times faster than the International
Space Station’s computers, 400 times faster than the space shuttle’s
computers and 4,000 times faster than Apollo’s.
But to operate in space, it has to be able to handle extreme heat and
cold, heavy radiation and the intense vibrations of launches, aborts
and landings. And it has to operate through all of that without a single
mistake. Just restarting the computer would take 15 seconds; and while
that might sound lightning fast compared to your PC, you can cover a lot
of ground in 15 seconds when you’re strapped to a rocket.
Where Is The Best Place That You Can Watch NASA's Orion Rocket Launch?
A. There are several locations available for guests to view the
launch from the Kennedy Space Center
Visitor Complex. General admission tickets required. Visit the Kennedy Space Center Visitor Complex website for directions and more information.
Free areas to watch the Orion Rocket Launch (in order of best viewing):
1. Titusville, Florida southward
along
the Indian River on the east side of US Highway 1.
2. Between Merritt Island and Cape Canaveral along the north side of State
Road 528.
3. Port Canaveral, with best viewing and paid parking available at Jetty Park.
4. Along the beaches of Cape Canaveral and Cocoa Beach, Florida (there
is metered parking in Cocoa Beach that only accepts quarters, so bring
some change).
 |
| Map of Launch Complex 37-B at Cape Canaveral Air Force Station in Florida. Credit: Google. Rocket launch viewing locations added by Brevard Times. |
