Doug Gard
Mechanical
Engineer
DANA Corporation
TRA
Sept.
17, 2003
Dave Ketchledge
sent this essay about the OSP design:
With some
32 years in model rocketry, published works in aerodynamics and
flight mechanics for the NAR
and TRA along
with my 1988 Microshuttle work (see the Compuserve, ModelNet
forum). I would like to offer some insights into the Space
Shuttle and the OSP that you may be overlooking in the recent
OSP debate.
Back in 1971, the Air Force wanted a high cross ranging space
shuttle with a 60-65 foot long cargo bay for its spy satellites.
In addition the Air Force wanted to be able to fly a single orbit
back to Vandenberg. Orbital Mechanics and physics moved the earth
some 1200 miles in that 90 minute period. Note the Air Force did
not help fund the Shuttle
At the MSFC, Max Faget was pushing for a straight wing space shuttle
that would come in at a 60 degree angle of attack, literally belly
flopping into the atmosphere at Mach 25, until at 40,000 it would
nose dive into a landing at a reasonable subsonic speed. Any pilot
who has flown a stall knows that doing this is unstable and the
Air Force and Mr. Drapper at the Flight Dynamics Laboratory held
firm to the idea that lifting entry works.
Faget was not for lifting reentry, his ball game was the capsule
of the Mercury, Gemini and Apollo era. Those saying he designed
the shuttle is bunk! He had no technical basis for designing the
Space Shuttle. Far better were the people at Edwards who flew
the X-15 and the lifting body programs like Dale Reed.
Enter the OMB who forced NASA, with no real support by the Nixon
Administration into a fixed budget that would only allow an orbiter
and no fly back booster. Mathematica who did the cost analysis
said a launch rate of 50 flights a year would help NASA breakeven
and NASA ran around painting a pipe dream to Congress.
The Air Force won a delta high cross range orbiter with a large
cargo bay. But at what cost? Certainly Casper Weinberger was one
of the few Space Shuttle supporters after his staff trimmed the
NASA budget 3 times in 18 months leading to the canceling of the
last two Apollo flights. We should not continue paying for these
mistakes.
What is also clear from an engineering stand point is that the
J-2 engine on the Saturn was a very good engine able to run continuously
for some 90 minutes without signs of wear. That's a very long
time in terms of liquid fuel engine operation.
But NASA got greedy wanting a high pressure combustion chamber
in the SSME. (Again it was MSFC pushing the wrong way.) The SSME
by the way needs its bearings replaced every two flights. With
my 20 years in nuclear engineering and maintenance, I understand
reliable design and equipment operation. And NASA missed the ball
entirely. You design for reliability not because you have a new
toy or idea to try out. Would you want me to get creative with
a nuclear reactor core? I think not.
So here we are in 2003 and have to develop a small crew orbiter
and ISS life boat. You have learned that the ceramic reentry tiles
and carbon carbon leading edges are maintenance intensive. Langley
has a inconel alloy metal tile that is low maintenance, easy to
manufacture and will cut then of thousands of hours off the operation
and maintenance expense a "lifting" reentry vehicle. You see some
good did come out of the X-33 effort.
May I remind you the X-20 would have worked using hot structures
and metal skin back in 1968 had Robert McNamara not canceled that
effort.
Those of you saying capsules are our only choice are equally wrong!
You end up splashing down in the ocean, costing a tidy sum for
recovery. The reentry heat shielding is not reusable, and the
gee loads to the crew are high. Considering the ISS crew can have
the cardiovascular health problem space flight entails, you are
risking them in a ballistic reentry.
And finally what comes after the OSP? If we want a low cost two
stage to orbit system eventually, would it be better to have a
small manned vehicle that would serve as a lead on orbiter? The
early Hope X, or HERMES efforts fall into this range. Married
with a metal heat shielding, you could get a very good return
on the investment, and greatly improve crew safety as well. As
the X-38 successfully demonstrated, a para-wing will work at subsonic
speeds.
Dale Reed was absolutely right for the role that a lifting body
can perform, and some designs can achieve lift to drag ratios
of 6:1 ( i.e. the Lockheed Star Clipper ).
Now take that OSP shape and put it on top of an Andrews Aerospace
(LACES ) air liquidfier air breathing booster. And for the size
and weight of a 747 you have a vehicle that can service the ISS
and paint a vivid space program.
What is lacking is an informed and well established course of
action not driven by political or institutional goals. OMB has
no right to dabble in the design of such a craft.
Would I want an economist to tell me not to buy the right parts
for a nuclear safety system. The MBA's be damned, you are not
rocket scientists. And if congress wants to blame someone for
the Challenger and Columbia accidents, part of the blame in in
their own court as well, not only NASA management. But are those
political animals man enough to admit that. That would takes some
ethics wouldn't it?
The smart and informed way to rebuild our space transportation
system is to separate the crew from the cargo as the CAIB stated.
Either flying a lifting body or blended body delta orbiter (HOPE-X)
that later would be part of a two stage to orbit transport system.
Designed
to good hypersonic and supersonic aerodynamics. Please note the
ASSET program of he 1960's proved that the X-24 shape works in
such regions of flight.
Keep the Space Shuttle to fly large and heavy payloads infrequently.
You could build a Dr. Zubrin style Mars ship for a fraction of
the program cost or return to the moon in only a few years with
a new lander. Certainly just orbiting the planet in a can, brings
no public excitement or drive to explore.
Lets build the right program with the right tools in the right
sequence. A nuclear-electric powered VASIMR
engine could carry a crew to Mars in 4 months. That is shorter
than some of my old submarine patrols !!
The focus has to be both strategic and tactical to meet the immediate
goals and long term needs in a cost effective design. Going back
to a capsule has a low development cost and high recurring cost.
That sank the Shuttle and we should not repeat that failure again.
Lets get a design with a metal heat shield, low maintenance and
rapid turnaround. So when the day comes to get to space repeatedly
we can.
Look at the crew compartment separation ability of the B-1 bomber
as a possible example of what can be done for crew escape. A liquid
fueled booster like the Atlas or Delta IV allows you at any time
to separate the orbiter. You can not do that with a vehicle running
large SRM's. Had OMB been less pencil pushers, we would have gotten
liquid fueled boosters
We have the technology to do much more that what we do today in
both the manned and unmanned programs. A real vision is needed
to lift our aerospace and NASA teams to new goals and a brighter
future.
Dave Ketchledge
Fmr. USN Reactor Operator, Nuclear Engineer
Member TRA and NAR
Space
act: just a wish list or a step in the right direction?...
A reader wrote in to point out that the H.
R. 3057 "Space Exploration Act of 2003", Rep. Lampson - Spaceref
- Sept.12.03. mentioned on Sept.
12.03 does not provide any funding for the RLVs and other
projects that it lists. He states that the bill, which was also
introduced in 2002, is not an appropriations bill but just "an
authorization bill. Everyone on the Hill knows that it is worthless
and does nothing except placate constituents by making it appear
that something is doing something."
My response
is that the bill is still a worthwhile effort. The wording of the
act is quite explicit that it is just setting long term goals for
NASA and not giving it money. I also know about the history of this
bill and similar ones (see Space
Legislation in the Activism section for a listing of
various proposed space legislation.)
The fact that
it's getting more attention this year is because after Columbia
there is a much greater focus on deciding exactly what NASA's long
term mission should be. I disagree that because the bill does not
authorize funding, it is not meaningful. NASA requests money for
projects that fulfill its mission. Ever since Apollo ended, manned
missions into deep space (well, some may not consider the Moon "deep"
space but for NASA it is) have not been part of its mission. For
Congress to make it explicit that they should be would, in fact,
signal a huge change from 30 years of not looking beyond LEO with
respect to manned spaceflight.
I come from
a physics background and I know that committees formed to decide
on the long term priorities of a field, such as in high energy physics
or astrophysics, are taken extremely seriously by researchers even
though the committees can only issue recommendations and have absolutely
no power to obtain the money directly. This is because they realize
that DOE (for high energy physics and fusion), NSF, and NASA will
only allocate funding (or go to Congress and request funding) according
to what the people in that field believe are their top priorities.
In the case
of NASA, the setting of priorities can't be done by it alone but
must be done via interaction with Congress and the public. However,
once the goals are set, NASA can then come up with explicit proposals
to fulfill those goals. It's quite true that Congress may then turn
down funding requests for RLV's to L1/L2 or whatever, just as it
may turn down funding for a new accelerator or a scientific satellite
that physicists say they absolutely need. But NASA won't even get
to the request stage for such projects if it doesn't know where
it is supposed to be going.
In Paula Berinstein's
book "Making Space Happen" she interviews the lunar and planetary
scientist Wendell Mendell about space activism and NASA. He said
that when students doing some sort of project like a Moon base design
came to talk with him, it would take him an hour to convince them
that he could not just reach into a drawer and pull out a detailed
plan for such a project. In fact, NASA has no such blueprint for
a lunar base, a Mars base, or any of the other possible exciting
missions that people expect NASA to be working on. And it won't
create such blueprints until it is told by Congress that it should.
So, the bottom
line, is that I believe that passage of such a bill would be quite
significant even though it would only be a first step in reforming
NASA.
March
3, 2003
I just
read the interview
with Mr. Diamandis on Hobbyspace, very good one.
I also have read the recent X-Prize press release by Mr. Diamandis
where he stresses the need for frequent space flights. It
would have been very interesting to hear comments from Mr.
Diamandis on "A
Rocket a Day" concept, proposed in 1993 ...
There
has been a lot of discussion of benefits and shortfalls of
prizes to advance space developments recently. Some people
say that one-time prize will not be sufficient to sustain
continued interest in space access by private sector. Also,
manned flight sets very high reliability requirements for
space vehicles. And as is said "when failure is not an option,
success can get very expensive". Unmanned "a rocket a day"
launcher would be very good stepping stone for private enterpreneurs
to build up experience and reliability of their vehicles incrementally.
Obviously,
the usual launch customers ( satellites, space probes ) will not
trust their multimillion-dollar hardware to launch vehicles with
60% success rate, even if those are indeed very cheap. If there
were market for raw materials, like rocket fuels or bulk construction
materials up there, that cost very little on earth but can be
of high value up in orbit, such vehicles can be very useful.
For instance,
putting an orbital "gas station" up there ( perhaps even on ISS
) would possibly serve as very good kickstart to cheap space access.
Theorethically, there could be many customers ( space tugs, interplanetary
vehicles, manned orbital vehicles with powered reentry as opposed
to thermal). Also, supply could potentially come both from earth,
and from space ( asteroid mining, lunar LOX ).
Essentially
this would create a entire new market and economy on orbit, plus
it would finally establish some real space infrastructure to build
on. This is something that government should initially fund, but
probably wont....
Yes, mass
production of rockets would be one good way to lower the costs
to orbit. I think, though, I would let the RLV companies also
bid for the contract. E.g. the government would promise up to
$500 M to the first company that can launch X amount of payload
per day or week. If an ELV approach wins, fine, but fast turnaround,
even one-day, is not impossible for RLVs and so such a design
might win.
BTW: Kistler
has proposed a somewhat similar concept in the sense of providing
potential small payload users a fixed date launch service. See
"Space Access for Small Satellites on the K-1" at http://www.kistleraerospace.com/publications.html
They would like to sell "Tickets-to-Orbit" that would guarantee
a slot on their multiple payload dispsenser for a launch on a
particular day. Kistler claims the K-1 could fly every 9 days
for $17 million with up to 4000kg to LEO equatorial.
I do think
their would be a strong response to such reliable and low cost
launch opportunities. I attended the Utah Smallsat meeting a few
years ago and came away very impressed with all of the great ideas
for small payloads. I also was very pleased to see many young
people, including a lot of undergrads, involved in satellite projects.
(The undergrads seemed to be in a state of giddy amazement that
they were actually building something that would go into space.)
However, I'm sure that most of the undergrads long graduated before
their birds made it to space. There really is a serious deficiency
in low cost, frequent rides even for nanosats.
With
Mr. Diamandis being the most recognized proponent of frequent
space access, it would have been very interesting to hear his
thoughts on the matter. Could there be a follow-up interview ?
Not so keen
on asking for another interview so soon. Like most of the interviews
I have in progress, it can takes a few weeks to get responses
back from super busy people like Peter. I will send him a suggestion
that he start a regular column at the X PRIZE site where he responds
to feedback from the public.
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