Real-Life Communication
Being an aerospace engineer is pretty exciting. You might help design
a rocket to send people and machines into space. Or you might find ways to
make airplanes fly faster.
Aerospace engineers may be experts in various
disciplines: aerodynamics, propulsion, thermodynamics, structures, celestial
mechanics, acoustics or guidance and control systems. Since aerospace projects
are so complex, engineers will often work together on teams. This way, each
person can bring their own expertise to the challenges at hand.
"Aerospace
engineering is very interdisciplinary and... you're communicating with a lot
of different people in different fields and everyone needs to be able to get
their message across and clearly communicate how their system works," says
aerospace engineer Shane Jacobs.
It's important for someone in this
field to be skilled in both engineering and communication. That's because
aerospace engineers deal with various types of technical and professional
documents. These include graphs, drawings, statistics, tables and technical
reports. These documents provide the engineers with vital information.
"The
engineers that are successful are the ones that can also write about what
they're working on and speak about what they're working on," says Jacobs.
You're an aerospace engineer working in NASA's hypersonic flight-test
program. You've been given a document that will be used as part of a press
release.
But the document contains many errors. You have been
asked to edit it for technical and grammatical correctness.
Here's
the document you must edit:
Hyper-X
Hypersonic
Experimental Research Vehicle
For the first time since
the 1994 cancellation of the National Aerospace Plane (NASP) program the National
Aeronautic and Space Administraton (NASA) has re-embarked upon research into
hypersonic aircraft.
Hypersonic speed is defined as being above Mach
5 (five times the speed of light), or the equivalent of one 1.6 kilometers
per second (57,000 kilometers per hour) at sea level. The fastest aircraft
currently in service any where in the world is the Lockhead SR-71 which can
cruise at slightly above Mach 3, and the fastest passenger aircraft is still
the Anglo-French Concorde which cruises at just over Mach 2. Previous research
by NASA conducted during the 50's and 60's culminated with the X-15 project
which, with rocket propulsion, reached a speed of Mach 6.7, the highest speed
ever reached by a man carrying vehicle (in the Earth's atmosphere).
MicroCraft,
Inc. of Tullahoma, Tenn was chosen by NASA to build the Hyper-X vehicles,
and Orbital Sciences Corporations Launch Vehicles Division in Chandler, Ariz
will prepare the launch vehicles. The aircraft will be five meters long with
a wing span of two meters (12 feet and five feet respectively).
One
of NASA's primary goals are to develop the technologies for air breathing
hypersonic flight (the X-15 being jet powered), and the Hyper-X program will
flight validate key propulsion and related technologies toward this aim. Heading
the list for concept demonstration is the ramjet/scramjet engine. Ramjets
are commonly used as power plants for guided missiles. They function only
when there is sufficient forward speed to allow compression of incoming air
within the engine inlet. To get a missile off the ground and up to a sped
at which the ramjet can function. Booster rockets are used. Air entering the
ramjet engine is slowed to subsonic speed and compressed by shockwaves set
up by the geometry of the engine inlet duct. Combustion of fuel then takes
place in a subsonic airstream. This can be a very efficient process at moderate
supersonic speeds. At hypersonic speeds, however, the air passes right through
the engine at speeds greater than Mach 1, and so combustion of fuel in a supersonic
airstream is required. Hence, the Scramjet -- Supersonic Combustion ramjet
-- was developed.
Whereas rocket powered craft such as the X-15 require
a source of oxygen to be carried on-board, the ramjet/scramjet takes it oxygen
from the atmosphere, like a gas turbine. The ramjet/scramjet craft should,
therefore be able to carry more payload because of not having to carry oxygen.