Aerospace Team Online
ATO#130 Becoming an Engineer, April 27, 2001
Part 1: Upcoming Chats
Part 2: New Contest
Part 3: Show Me the Money 2
I apologize to everyone for the extra versions of the last
two newsletters. Once we fixed the problem of why it wasn't being sent
out; our previous tries which were still in queue went flying out too.
I regret any inconvenience this caused you.
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UPCOMING CHATS
Enter these chats from the Common Events page http://quest.nasa.gov/common/events/
Aerospace Team Online Chat with Mary Reveley
April 30, 2001, 10 AM Pacific - 1 PM Eastern
Chat with Mary Reveley. Mary adds and subtracts the
costs and benefits of implementing new propulsion and aviation technologies.
Read her bio at: http://quest.nasa.gov/aero/team/reveley.html
- - - - - - -
Planetary Flight Webcast - Designs for a Mars Airplane
May 22, 2001 10 AM
Join Andrew Hahn to discuss Mars Airplane Designs.
Read his bio at http://quest.nasa.gov/aero/team/hahn.html
Try designing your Mars airplane at http://quest.nasa.gov/aero/planetary/
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NEW
CONTEST ANNOUNCED
Planetary Flight Gameboard: April 27 - May
18, 2001
Contest Description: This contest invites students
to design a game board about Planetary Flight. Design and create a game
using information that you have learned from the Planetary Flight Web
Site.
The game should include a game board and directions
for how to play the game. Use your imagination and be creative!
For more information visit: http://quest.nasa.gov/aero/planetary/contest.html
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[Editor's Note: Mary Reveley is an Aerospace
engineer at NASA Glenn research Center where she predicts the costs and
benefits of implementing new propulsion and aviation technologies. Read
her bio at http://quest.nasa.gov/aero/team/reveley.html
SHOW
ME THE MONEY!
by Mary Reveley
Journal entry for June 2, 1999
Money always gets people's attention. My job is to
determine how much money is needed for new and unconventional aeropropulsion
technology concepts on engine/aircraft systems. The results of which are
used to influence the NASA technology investment and decision making processes.
Today I was given a new assignment: determine/find/development
a new cost estimating method for estimating the costs associated with
a reusable rocket based combined cycle launch vehicle.
An active area of hypersonic propulsion research at
Glenn is the application of air-breathing propulsion to launch vehicles
in order to reduce the cost of space access. . Air-breathing propulsion:
the piston engine, turbojet, ramjet- all depend on the combustion of fuel
with air, where the air is obtained directly from the atmosphere. In contrast,
the rocket engine carries both its fuel and oxidizer and is completely
independent of the atmosphere for its combustion. Thus, the rocket can
operate in the vacuum of space, where obviously the air-breathing engines
cannot.
Space access is costly for a number of economic and
technical reasons. A rocket is an expendable launch vehicle used for only
one flight. The Space Shuttle has a number of expendable components such
as the external tank. Others, such as the main engines must be refurbished
after every flight. The various components must then be reassembled prior
to the next flight. This makes the shuttle one of the most expensive means
of putting payload into orbit. From a qualitative technical standpoint,
a case can be made for launch vehicles that would be reused many time's
without refurbishment or re-assembly. This implies a highly reusable,
single-stage-to-orbit launch vehicle.
It currently costs on the order of ten to twenty thousand
dollars per pound to launch payload into orbit. The future of the space
program is hindered by this high cost and associated low reliability.
The rocket-based combined cycle engine combines the
high thrust of a rocket, which is needed for lift-off, with the ram jet
engine, which can be exploited after an initial acceleration to sufficient
velocity. Upon reaching an appropriate maximum ramjet Mach number, the
rocket is re-ignited for the final acceleration to orbit.
Getting back to my problem for the day (and the rest
of the month!) is how do I estimate the costs of developing, manufacturing
and using this rocket-based combined cycle engine? Welcome to NASA where
the unusual is usual! I will spend time researching any work already done
by fellow workers, search for information at our library, and contact
the Air Force since they have done cost estimating work on advanced concepts.
I will also have to learn a cost estimating program used widely by government
and industry called Price- which is a hardware cost estimating computer
model.
Today I have been reviewing how the following engines
work: the rocket-based combined cycle, the scram jet and the ram jet.
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