Resource Library: Multimedia/Resource Library: Multimedia.iso/space/faq/dltclppr

Text File | 1993-06-11 | 8.9 KB | 171 lines

    This document was obtained from Allen W. Sherzer ([e-mail]).

          20  question about the Delta Clipper

1>   What is the Delta Clipper?
     A new spaceship that will take off straight up and land the
same way, not gliding but under power, just like the rocketships
in the 1950's science-fiction movies.  Because of its improved
engines, high-tech light-weight materials, and airline-like
service procedures, the Delta Clipper could reduce the cost of
getting to and from space by 90% or greater. Because it will be
certified for flight like an aircraft, it will be able to operate
from spaceports located in any state.

2>   What will it look like?
     The production model Delta Clipper will be conical shaped,
approximatley 130 feet high and 40 feet accross the base. It will
have eight or more rocket engines, providing safe return engine out
capability like any airliner. The Delta Clipper will not have wings
like the Shuttle but will use small moveable flaps to help maneuver.
It will not require strap-on external tanks or boosters.

3>   When will it be flying?
     A 1/3 sized experimental vehicle, the DC-X, is on schedule for
launch in April of 1993. The full sized orbital prototype, the DC-Y,
could be ready to fly as early as the summer of 1997.

4>   Where will it launch from?
     Test flights will be from White Sands Missile Range, New Mexico,
but when the Delta Clipper goes into production any state in the Union
will be able to have its own spaceport.  Unlike the Shuttle, the Delta
Clipper won't need a long runway, huge Vehicle Assembly Building, or
Mission Control but only a 200 foot diameter concrete pad, a maintenance
hangar, and a hydrogen/oxygen fuel facility.  It will use existing global
positioning satellites for navigation.

5>   What will it cost to design and build the 1st Delta Clipper?
     The total cost of developing the first flight certified Delta
Clipper will be comparable to or less than the development of a new
commercial airliner. The cost of building an experimental prototype vehicle
to demonstrate the concept and validate the operating and cost goals would
be substantially less.

6>   What will I have to pay to fly the Delta Clipper?
     The ticket price for early versions of the Delta Clipper, if it
met current cost goals, could be less then the price for a  round-the-world
cruise on the QE2 ($40,000 to $140,000). A second generation vehicle could
further reduce this cost.

7>   How dangerous will it be?
     Once fully operational the Delta Clipper will be safe as flying
on a typical commercial airliner. Delta Clipper will have engine out and
all altitude abort capability. Plans are to have the Delta Clipper
certified by the Department of Transportation, Office of Commercial Space
flight.

8>   What about air pollution, especially near the ozone layer?
     The Delta Clipper will burn only hydrogen and oxygen. Its exaust
consists primarily of pure water vapor.

9>   What about sonic booms and noise when launching or landing?
     When an airplane flies above the ground faster than sound,
it generates a cone-shaped shock wave which we experience as a
sonic boom.  For this reason, the Concorde jet can't fly
supersonically to inland airports in the US.  Since the Delta
Clipper launches straight up, the sonic boom is largely restricted
to the spaceport area. When landing, the Delta Clipper will slow
down to sub-sonic speed at about 70,000 feet altitude, thus minimizing
the sonic boom to a barely audible level.

10>  Who's building it?
     McDonnell Douglas, under a contract from the Strategic
Defense Initiative Organization (SDIO), is building the DC-X for
demonstration of the technological and operational feasibility of single
stage rockets for supporting either suborbital flights. Based on successful
testing of the DC-X, SDIO is interested in developing a fully reusable
suborbital rocket to support their numberous suborbital test missions. The
design, test results, and concepts will be available to other agencies to
develop and demonstrate the orbital vehicle, the DC-Y. We hope to find
another "home" for the DC-Y and Delta Clipper in DoD or NASA.

11>  How much will the Delta Clipper be able to carry?
     Two crew members and 10 tons of cargo and/or passengers to
Low Earth Orbit or 2 crew members and 5 tons of cargo/passengers
to Polar Orbit.

12>  Will it be able to fly to the Moon?
     A Delta clipper derivative vehicle, re-fueled in Low Earth Orbit,
would be able to fly to the Moon, land there, and then return to Earth.
The modifications required, however, would be substantial.

13>  How often will the Delta Clipper be able to fly?
     The anticipated turn-around time for the Delta Clipper is a maximum
of seven days. However, a one day turnaround may be feasible.

14>  Why haven't we built a single-stage rocket before?
     The reason most rockets, including the Shuttle, have parts that
drop off (stages) is this: every additional pound of vehicle that we
lift all the way to orbit requires additional pounds of fuel.  The
additional fuel requires a little larger, and heavier, fuel tank,
which then requires even more fuel to carry, and so on.  There
are three ways to deal with this problem: 1) make the rocket so
huge (and expensive) that it can carry enough fuel to lift itself
all the way to orbit, or 2) toss off empty tanks as you go (the
traditional multi-stage method), or 3) make your engines and vehicle
structure so efficient and light weight that you don't need to carry
huge amounts of fuel or throw away pieces of your ship. This last is
the principle behind the Delta Clipper. It is only recently, under
such programs as NASP, and aircraft developments that we have
sufficently developed and demonstrated light weight materials that
will allow the Delta Clipper to work.

15>  What if something goes wrong during a flight?
     Commercial airplanes don't need all their engines to fly
safely.  The same principle will be used with the Delta Clipper.
If there is an engine malfunction during the assent, the Delta Clipper
will be capable of either continuing on to orbit orreturning to the
spaceport. If the Delta Clipper needs to return from orbit sooner than
expected, it will be able to maneuver over 1200 miles to either side.
Unlike the Shuttle, which requires a three mile long landing strip, the
Delta Clipper will be able to land on nbalmost any reasonably flat spot.

16>  Why should I believe all these claims for the Delta Clipper
     when similar ones were made for the Shuttle twenty years ago?

     The Shuttle's design was "frozen" in the 1970's.  Using the technology
available then would have resulted in a SSTO that was extremely large and
expensive. A Delta Clipper sized SSTO based on 1970's technology would not
have ben able to reach orbit. In the 20 years since then, we have learned
a lot about design, light-weight materials, trajectory optimization, avionics,
computers, and engine design.

     In addition, the Delta Clipper is being designed with supportability
and operability as priority considerations. For example, the engines
on the Delta Clipper won't run at 110% of their design capacity, as the
Shuttle's do, so they won't have to be torn down and repaired before each
flight. If on-board diagnostic instruments indicate a problem with a
Delta Clipper engine or any other component, it is designed so components
(called line replaceable units) can be pulled and replaced quickly after
landing.

17>  Why isn't NASA building the Delta Clipper?
     The task of proving the technology availability for a single stage
rocket vehicle was assigned to SDIO. SDIO with its streamlined management
style is an excellent agency for developing and demonstrating new
technology initiatives. Once the technology demonstration is completed,
the concept will be available for either Department of Defense or NASA to
develop an orbital capable Delta Clipper.

18>  Why isn't industry building the Delta Clipper?
     McDonnell Douglas and its teammates have already made a significant
investment in the basic technologies and the skills and facilities
necessary to develop a SSTO. The government needs to take the next step
of funding an experimental prototype vehicle to prove the Delta Clipper's
basic concepts and technologies. Once demonstrated, the commercial sector
may be interested in investing in an operational system. Such a system
could have an enormous impact on the development of space as an commercial
market as well as the future of the US space program.

19>  What factors could cause the Delta Clipper program to founder?
     Money: Though the Delta Clipper program is cheaper than many
Federal programs, it still is in danger from a budget-conscious
Congress who may not be aware of the benefits of the Delta Clipper or
who feel the program has no real constituency.    We hope to change
their minds about this.

20>  What can I do to help?
     Get on our mailing list, be willing to write letters to Congres
when asked, learn about the Delta Clipper, ask all your friends to
support it too.