OSP: reliability and survivability

Rand Simberg wrote:


I think that he meant health monitoring the vehicle, so you know ASAP
whether or not to abort.



That would make a lot more sense, although monitoring the crew's health
would probably allow one to know to the second when the **** hit the fan.

Pat

In sci.space.policy Pat Flannery wrote:


Rand Simberg wrote:


I think that he meant health monitoring the vehicle, so you know ASAP
whether or not to abort.



That would make a lot more sense, although monitoring the crew's health
would probably allow one to know to the second when the **** hit the fan.

But that would be too late for teh crew. Given the extremely low tolerance
level for losing crews, you need to know well in advance to anything that
would sigifcantly affect crew health readouts, or you won't have time for
counteraction.


Pat


--
Sander

+++ Out of cheese error +++

Sander Vesik wrote:

But that would be too late for teh crew. Given the extremely low tolerance
level for losing crews, you need to know well in advance to anything that
would sigifcantly affect crew health readouts, or you won't have time for
counteraction.



I should have stuck a "wink" on that one... I wasn't being completely
serious.

Pat

h (Rand Simberg) wrote

I think that he meant health monitoring the vehicle, so you know ASAP
whether or not to abort.

Oh. In that case, one can imagine a vast, multidimensional
and nonlinear set of circumstances that need to be monitored and
interpreted in realish time. Hopeless overall, but maybe you
could pick out the major threats and try to identify predictive
indicators.

On Sun, 14 Sep 2003 21:17:15 CST, in a place far, far away,
(Allen Thomson) made the phosphor on my monitor
glow in such a way as to indicate that:

(Rand Simberg) wrote

I think that he meant health monitoring the vehicle, so you know ASAP
whether or not to abort.

Oh. In that case, one can imagine a vast, multidimensional
and nonlinear set of circumstances that need to be monitored and
interpreted in realish time. Hopeless overall, but maybe you
could pick out the major threats and try to identify predictive
indicators.

Yes, one of the many reasons that the concept of "man rating" is
nonsensical in the twenty-first century.

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

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om...
In deciding whether or not to fund NASA's proposed Orbital Space
Plane
- a "space taxi" dedicated to crew transport, in contrast to the
current "space truck" - Congressional mavens are making a faulty
assumption. That is that because OSP will be launched on unproven
Delta and Atlas-family rockets, it will be fundamentally no more

By the time that OSP actually flys, both the Delta 4 and Atlas V will
have
flown many missions, with both commercial and government payloads.
Both
systems will be far from "unproven" by that time. In order to
actually
FLY
the OSP, there will have to be some modifications made, especially
with
regard to avionics, adapter interface, etc. ALL of these mods will be
made
with the intent of actually making the launchers even MORE safe and
reliable. Will they be 100% safe and reliable? No. No space launch
system
ever has been, nor ever will be 100% safe and reliable. But to say
that
the
Delta 4 or Atlas V will be unproven by that time is not factually
true.

Remember that Ariane V is supposed to be Man-rated ( triple
redundancy ).
Would you take a flight on it at this time?

Why would ANY Ariane be truly and fully man-rated. I can not imagine why
this would be done, since it can be hideously expensive to man-rate a
vehicle. And since Ariane is first and foremost a commercial launch
vehicle, there is no economic incentive (as yet) to man-rate it.


You guys may have forgotten this but in the late '80's the plan was floating
around ESA to launch a manned space Shuttle, which looks remarkably similar
to the OSP designs that NASA is currently studying. The plan was to use the
Ariane 5 to launch the thing (called Hermes) so the Ariane 5 had to be
man-rated at some point, and they probably designed it with manned flights
in mind.

Ultimate Buu wrote:

You guys may have forgotten this but in the late '80's the plan was floating
around ESA to launch a manned space Shuttle, which looks remarkably similar
to the OSP designs that NASA is currently studying. The plan was to use the
Ariane 5 to launch the thing (called Hermes) so the Ariane 5 had to be
man-rated at some point, and they probably designed it with manned flights
in mind.


It got started with the Hermes in mind; but the Hermes suffered such
weight gain during its design phase that it became less and less
practical looking, and the modifications required to the Ariane V to
carry it would have made it less than optimal for its commercial
satellite mission- given the choice between a prestige spaceplane and a
potentially money making booster, they went the commercial route, and
ditched Hermes. I wouldn't be at all surprised if we run into the same
weight problem if we try to make an operational small spaceplane- I
wrote a posting about this a few years ago:

"They are hard to make from a mass-to-mission viewpoint though; I wrote a
post about this around a year ago; here is the basic problem- any manned
aerodynamic vehicle needs certain systems; for on orbit work it needs: Life
support for it's crew, a means to maneuver itself, a means of radiating the
heat created by it's crew and electronics, and sufficient space to carry a
worthwhile mission payload (cargo, passengers, recon gear, death ray, etc.)
Add to this, for landing: landing gear of some sort, heat shielding,
aerodynamic control surfaces, fuel to deaccelerate from orbit, and avionics
capable of both orbital and atmospheric control.
Right from square one, it's obvious that is quite a bit to pack into a small
vehicle- but it gets worse- the avionics for a thirty foot long shuttle will
be about the same weight as a 130 foot long one...same with life support,
control panel, seats, suits, and crew. Propellant storage tanks will be
about the same thickness. Reaction control systems may be smaller, but will
need all of the valves and pumping systems associated with a large system,
and plumbing of equal tubing thickness to a large system. The amount of
insulation to protect it during re-entry stays the same thickness and weight
per square foot- and you have a lot fewer square feet to give you lift, so
the mass of it goes up proportionately to that of the vehicle-the same
applies to the skinning, and structural members of the machine. Then you hit
the next thorny problem- heat dissipation- the material that keeps the heat
out during re-entry tends to keep it in on-orbit; you need big radiators of
some sort to make this work. We (the U.S.) thought this wouldn't be too
difficult when we designed Dyna-Soar, and watched the weight steadily climb
to where a Gemini capable on-orbit vehicle with a single man crew was going
to need a Titan III or Saturn I to make orbit, all for the sake of greater
cross-range on landing, and gliding in horizontally, the way that God, and
the U.S. Air Force intended spacemen to land!
With true Gaulic pride, the French tried the same idea twenty-odd years
later with "Hermes"- and hit the same weight snag, as the vehicle got more
and more complex, to the point where the payload had to be put into a
jettisonable mission module on the back end along with the retrorocket and
other vehicle systems- as it's original payload bay had to be given over to
radiators. The Soviets took a crack at the problem with "Spiral"... and ran
into the same weight-to-mission capability problem.
We tried it again with the HL-20... this time it was going to take a Titan
IV to get it into orbit! And all for some increased cross range on landing-
you will notice that the semi-canceled ISS escape vehicle looks like a
lifting body, re-enters like a lifting body, but floats down to earth under
a parachute- which might make one ask... why not a ballistic capsule? The
argument is "Greater Cross Range For Landing"- but a ballistic capsule could
simply stay in orbit for a turn or two, until a suitable emergency landing
site fell under it's orbital track."

Pat

"Pat Flannery" wrote in message
...


Ultimate Buu wrote:

You guys may have forgotten this but in the late '80's the plan was
floating
around ESA to launch a manned space Shuttle, which looks remarkably
similar
to the OSP designs that NASA is currently studying. The plan was to use
the
Ariane 5 to launch the thing (called Hermes) so the Ariane 5 had to be
man-rated at some point, and they probably designed it with manned
flights
in mind.


It got started with the Hermes in mind; but the Hermes suffered such
weight gain during its design phase that it became less and less
practical looking, and the modifications required to the Ariane V to
carry it would have made it less than optimal for its commercial
satellite mission- given the choice between a prestige spaceplane and a
potentially money making booster, they went the commercial route, and
ditched Hermes. I wouldn't be at all surprised if we run into the same
weight problem if we try to make an operational small spaceplane- I
wrote a posting about this a few years ago:

"They are hard to make from a mass-to-mission viewpoint though; I wrote a
post about this around a year ago; here is the basic problem- any manned
aerodynamic vehicle needs certain systems; for on orbit work it needs:
Life
support for it's crew, a means to maneuver itself, a means of radiating
the
heat created by it's crew and electronics, and sufficient space to carry a
worthwhile mission payload (cargo, passengers, recon gear, death ray,
etc.)
Add to this, for landing: landing gear of some sort, heat shielding,
aerodynamic control surfaces, fuel to deaccelerate from orbit, and
avionics
capable of both orbital and atmospheric control.
Right from square one, it's obvious that is quite a bit to pack into a
small
vehicle- but it gets worse- the avionics for a thirty foot long shuttle
will
be about the same weight as a 130 foot long one...same with life support,
control panel, seats, suits, and crew. Propellant storage tanks will be
about the same thickness. Reaction control systems may be smaller, but
will
need all of the valves and pumping systems associated with a large system,
and plumbing of equal tubing thickness to a large system. The amount of
insulation to protect it during re-entry stays the same thickness and
weight
per square foot- and you have a lot fewer square feet to give you lift, so
the mass of it goes up proportionately to that of the vehicle-the same
applies to the skinning, and structural members of the machine. Then you
hit
the next thorny problem- heat dissipation- the material that keeps the
heat
out during re-entry tends to keep it in on-orbit; you need big radiators
of
some sort to make this work. We (the U.S.) thought this wouldn't be too
difficult when we designed Dyna-Soar, and watched the weight steadily
climb
to where a Gemini capable on-orbit vehicle with a single man crew was
going
to need a Titan III or Saturn I to make orbit, all for the sake of greater
cross-range on landing, and gliding in horizontally, the way that God, and
the U.S. Air Force intended spacemen to land!
With true Gaulic pride, the French tried the same idea twenty-odd years
later with "Hermes"- and hit the same weight snag, as the vehicle got more
and more complex, to the point where the payload had to be put into a
jettisonable mission module on the back end along with the retrorocket and
other vehicle systems- as it's original payload bay had to be given over
to
radiators. The Soviets took a crack at the problem with "Spiral"... and
ran
into the same weight-to-mission capability problem.
We tried it again with the HL-20... this time it was going to take a Titan
IV to get it into orbit! And all for some increased cross range on
landing-
you will notice that the semi-canceled ISS escape vehicle looks like a
lifting body, re-enters like a lifting body, but floats down to earth
under
a parachute- which might make one ask... why not a ballistic capsule? The
argument is "Greater Cross Range For Landing"- but a ballistic capsule
could
simply stay in orbit for a turn or two, until a suitable emergency landing
site fell under it's orbital track."


But most of these problems also apply to a capule as well, right? The short
answer is: there ain't no easy answer. And the public perception is that
going with a capsule would be a step backwards, so it ain't gonna happen.

In sci.space.policy Ultimate Buu wrote:

But most of these problems also apply to a capule as well, right? The short
answer is: there ain't no easy answer. And the public perception is that
going with a capsule would be a step backwards, so it ain't gonna happen.


ESA doesn't presently have a manned module - whetever winged or not - at
all. How can anybody view having one over not having one as a step backwards?
I could see reusability (trashing the entire module after each use sounds
very wasteful) as being a goal, but why start with a bunch of prejudices
as to how the manned orbit/reentry vechice should look like?

--
Sander

+++ Out of cheese error +++

Ultimate Buu wrote:

But most of these problems also apply to a capule as well, right? The short
answer is: there ain't no easy answer. And the public perception is that
going with a capsule would be a step backwards, so it ain't gonna happen.



The capsule is a lot less complex overall, particularly if it uses some
sort of parachute/splashdown or parachute/landing rocket or impact bag
system, as only the bottom surface really needs a heat shield of any
great weight- if you can keep the size of that heat shield fairly small
in diameter, as the Soviets did with Soyuz by using a separate on-orbit
module for most of the crew activities as opposed to Apollo's large
heatshielded CM, you can make some really impressive savings in vehicle
weight; the complete Soyuz Earth orbital spacecraft weighed only 754 kg
more than the Apollo CM, (Apollo CM-5806 kg; Soyuz 7K-OK spacecraft-6560
kg; the 7K-L1 Lunar-loop Soyuz variant reentry module was 10 kg lighter
than the orbital variant's- 2800 kg vs the orbital one's 2810 kg;
although the lunar one needed a better heat shield, the skip-style
reentry profile and removal of the reserve parachute kept its weight
down.) and actually has around 1/3 more internal volume for its crew (9
m3 vs. Apollo's 6.17 m3). The closer to a sphere the reentry module is,
the more internal volume it has in relation to its external area; and
the Soyuz "gumdrop" shaped small reentry module plus spherical orbital
work area was a lot more efficient than the Apollo's conical "all in
one" CM concept in this regard.

Pat