X-Prize Article
Michael Walsh
Flight Mechanicsa of Manned Sub-Orbital Reusable Launch Vehicles
with Recommendations for Launch and Recovery
by Marti Sarigul-Klijn and Nesrin Sarigul-Klijn of the
Mechanical and Aeronautical Engineering Department,
University of California, Davis, CA 95616-5294
http://mae.ucdavis.edu/faculty/sarigul/AIAA_2003_0909.pdf
You can download the document with the full address, but
trying to get to the faculty site gets you a "not allowed"
message. I was unsuccessful trying to download using
Netscape but got the file with Internet Explorer. I might have
done something wrong with Netscape.
The 18 page document spends quite a bit of time with basic
rocket design and equations. I suspect the two faculty members
might use their report as a teaching tool for their students.
They like either vertical rocket launch or air launch and
wings and decelerators (parachute types) for recovery and
have quite a few more recommendations.
There is a short article in Craig Covault's "IN ORBIT" section of
the May 19, 2003 issue of Aviation Week.
The article also carried Burt Rutan's criticism that the assessment
made too much of historical comparisons and not enough of
first-principals analysis.
I also note that the former chief engineer of Rotary Rocket called
the Roton difficult to fly.
Mike Walsh
Jim Davis
> http://mae.ucdavis.edu/faculty/sarigul/AIAA_2003_0909.pdf
Thanks for posting this, Mike!
Jim Davis
Len
> OK, it is actually AIAA 2003-0909 titled:
>
> Flight Mechanicsa of Manned Sub-Orbital Reusable Launch Vehicles
> with Recommendations for Launch and Recovery
>
> by Marti Sarigul-Klijn and Nesrin Sarigul-Klijn of the
> Mechanical and Aeronautical Engineering Department,
> University of California, Davis, CA 95616-5294
>
> http://mae.ucdavis.edu/faculty/sarigul/AIAA_2003_0909.pdf
> > Mike Walsh
As Jim Davis says, thanks for posting this interesting article,
Mike.
However, as Burt Rutan notes, the paper is heavy on historical
approaches--and a little light on novel system design approaches
that could work, even though they are not on the list of
"approaches that could win the prize."
Best regards,
Len (Cormier)
PanAero, Inc. and Third Millennium Aerospace, Inc.
l...@tour2space.com ( http://www.tour2space.com )
Ultimate Buu
"Michael Walsh" <mp1w...@Adelphia.net> wrote in message
news:3EC96771...@Adelphia.net...
>
> Flight Mechanicsa of Manned Sub-Orbital Reusable Launch Vehicles
> with Recommendations for Launch and Recovery
>
> by Marti Sarigul-Klijn and Nesrin Sarigul-Klijn of the
> Mechanical and Aeronautical Engineering Department,
> University of California, Davis, CA 95616-5294
>
> http://mae.ucdavis.edu/faculty/sarigul/AIAA_2003_0909.pdf
>
> You can download the document with the full address, but
> trying to get to the faculty site gets you a "not allowed"
> message. I was unsuccessful trying to download using
> Netscape but got the file with Internet Explorer. I might have
> done something wrong with Netscape.
>
> The 18 page document spends quite a bit of time with basic
> rocket design and equations. I suspect the two faculty members
> might use their report as a teaching tool for their students.
>
> They like either vertical rocket launch or air launch and
> wings and decelerators (parachute types) for recovery and
> have quite a few more recommendations.
>
Nice article, but their design for a suborbital vehicle based on the X-34
isn't ambitious enough. I would like to see a TSTO (two-stage to orbit)
hybrid shuttle design at the very least.
andy2001
but suffered too much from the 'our idea is best, so lets rubbish all
others' mindset. One thing I found very anoying is the way it states
the highest altitudes reached by rocket planes in the fifties, and so
therefore that is the highest altitude rocketplanes can reach. I
remember another AiAA report by these guys where they rubbished all
the RLV concepts of the time (pathfinder, astroliner, etc) to promote
their swiftlaunch concept. In one part they said that the hightest
mass fraction obtained by a rocket plane was .63 (X-15, IIRC), so
therefore that is the maximum possible; they did not even consider
what might be possible with modern materials. I do like their idea of
using X-34 as the basis of a tourist craft, I wounder it it would be
possible to get them off, and how hard it would be to convert them...
Andy
John Carmack
> Nice article, but their design for a suborbital vehicle based on the X-34
> isn't ambitious enough. I would like to see a TSTO (two-stage to orbit)
> hybrid shuttle design at the very least.
We have seen altogether too many people with ambitious designs. We
need more pragmatic designs that may actually make the transition to
reality.
John Carmack
www.armadilloaerospace.com
Michael Walsh
Len wrote:
I believe their statement that horizontal launch approaches are not viable
is questionable. They certainly have their difficulties but it is a bit hard for
me to see why a suitably sized aircraft taking off on turbojets with a
rocket engine couldn't be successful, not only for the X-Prize but as
a baseline for either a first stage booster or a suborbital tourist vehicle.
Len, wasn't that one of your concepts?
Mike Walsh
Michael Walsh
andy2001 wrote:
Yes, I should have mentioned that they have their own favored concept
and are not exactly unbiased bystanders.
The article was interesting and Burt Rutan's comment was quite on target,
they depended a lot on historical data. Sort of the attitude that if we
haven't done it yet we aren't likely to do it.
I do note that it is hard to find too many articles like this that take a
broad
look at many different concepts. I doubt that you will ever find one
where the
author does not have some kind of a personal bias.
Mike Walsh
Jonathan Goff
> We have seen altogether too many people with ambitious designs. We
> need more pragmatic designs that may actually make the transition to
> reality.
No joke.
I kinda like XCOR's statement about their design philosophy.
Something like "we make it reliable and cheap first, then
we increase the performance".
Home runs aren't needed, just getting a few base hits would be a very
good start in the right direction.
~Jon
Len
> Len wrote:
>
...snip...
> > However, as Burt Rutan notes, the paper is heavy on historical
> > approaches--and a little light on novel system design approaches
> > that could work, even though they are not on the list of
> > "approaches that could win the prize."
> >
> I believe their statement that horizontal launch approaches are not viable
> is questionable. They certainly have their difficulties but it is a bit
> hard for
> me to see why a suitably sized aircraft taking off on turbojets with a
> rocket engine couldn't be successful, not only for the X-Prize but as
> a baseline for either a first stage booster or a suborbital tourist vehicle.
>
> Len, wasn't that one of your concepts?
>
> Mike Walsh
Yes. Our current concept--as noted at Space Access--
would convert a Learjet 23. Our previous concept
envisaged a converted Sabre-40. The Learjet 23 is
smaller, which I feel is more appropriate. However,
I was initially concerned about the T-tail and
recovery from our planned high angle-of-attack reentry
in which we use the wing as a drag device, rather than
a lift device, a la Max Faget. But I like Burt's idea
for passive stability rather than active reaction controls
or a drogue chute system. Acccordingly, stealing a bit
from Burt, I now feel that we can replace the T-tail
with a flying tail that would pop up and move from
60 deg nose up to 30 degree nose down. The NF-104 had
a T-tail, but was limited to a 10 degree angle of attack
for pullup. From 100 km, rather than 37 km, this would
result in much higher heating--as well as somewhat higher
g's with a significant "eyeballs out" component.
Both the Learjet 23 and the Sabre-40 are strong airplanes.
The Learjet 23 can pull 4.4 g'a at full gross mass of
5,670 kg. The cabin is good for a differential pressure
of 57,225 Pa; I personally would rather rely on this cabin
pressure capability (with an oxygen mask) than a pressure
suit.
The J-85s allow us to takeoff from the ground and meet
the low delta-v requirments of the X PRIZE--while
providing a powered landing. Single-stage to 100 km
requires a decently performing rocket system, however.
With money, we could still be dangerous.
For higher delta-v requirements--i.e. orbit--I remain a
big fan of air launch and an unpowered orbiter horizontal
landing at low wing loading and reasonable lift/drag ratio.
Ultimate Buu
"John Carmack" <jo...@idsoftware.com> wrote in message
news:c0e0a1dd.03052...@posting.google.com...
There are many people out there making rocket engines these days (mostly
solids and hybrids, and a few doing liquid fueled gigs). None of these are
very large (i.e. they need to be scaled up), but they're perfectly capable
of putting a vehicle into orbit. As long as they're stooled on sound
mathematical theory (like in the aforementioned document), they should do
all right.
And a hybrid powered TSTO (either vertically or horizontally launched) is
certainly feasible. I figure 15 minute suborbital hops won't be enough to
satisfy most customers. They want to get into orbit!!
Andrew Case
>I figure 15 minute suborbital hops won't be enough to
>satisfy most customers. They want to get into orbit!!
There are already customers for ballistic arcs in MiGs and on Vomit Comet
type aircraft. Why do you believe that increasing the altitude and the
time at zero g will not be worth a few more bucks to some of those
people? There are market studies showing real interest, and people willing
to ink contracts right now, before the vehicles are even built.
Don't let the cool things available in orbit blind you to the many cool
things that are possible without going to orbit, any more than you would
allow the cool things available on the moon to blind you to the
possibilities of LEO.
......Andrew
--
--
Andrew Case |
ac...@plasma.umd.edu |
James Steven York
fractions of various systems. It's interesting to note that the
weight and mass fraction for Mercury Redstone and Pegasus is almost
identical (at least on the scale of the chart, which can be
deceiving). It's also interesting to see that the mass fraction of a
Concorde is almost as high as an X-15, which of course highlights the
difference between a rocket (which can burn off the available
propellent in seconds or minutes at most) and a turbojet (which
relatively sips the fuel for hours). Of course, it also shows how
mass fraction numbers can be deceptive when it comes to actual
performance.