NASA Encounters Possible Problems With Crew Launch Vehicle Design

I have a prediction, provided the next shuttle flight fixes the foam
reasonably well the shuttles retirement date will be moved to 2015 or
so, because we cant go that long without a manned launcher and ISS
support.

Contiuning the shuttle will be based on the need to keep the workers
around for CEV. All involved just love the pork and shuttle derived
will win out

NASA really DOESNT want to end the shuttle, and thus is screwing around
wasting time to help the cause.

I do see the flight rate dropping to perhaps 3 a year. once the
decision to continue the shuttle is made, nasa will use attrition only
in a slow workforce reduction.

the fix is in, most just dont realize it.............

Hi!

I have a prediction, provided the next shuttle flight fixes the foam
reasonably well the shuttles retirement date will be moved to 2015
or so, because we cant go that long without a manned launcher and
ISS support.

Or they cancel the CLV(stick), put CEV on an EELV and immediately
start on the heavy lifter with the redundant shuttle engineers split
between CEV development and EELV integration and the heavy lifter.

Best regards,
--
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Phone: Sweden (0)13 34 00 676 or (0)705 16 00 46

Henry Spencer wrote:
In article AWCzf.499940$084.50286@attbi_s22,
John Crichton wrote:
...I'm curious as to your opinion as to the scope of work to man
rate the EELV.

It depends greatly, nay overwhelmingly, on whether NASA has decided that
it *wants* to use an EELV.

Back in the pre-Griffin days when that was actually the plan, it was
thought to be no big deal. (And there is no reason why it *should* be,
given that NASA man-rated Titan II for Gemini with no great difficulty.)

But when upper management decided that a shuttle derivative was preferred,
man-rating an EELV quite suddenly became a difficult and costly task -- so
daunting that a mostly-new shuttle-derived launcher seemed preferable.
--

In fairness to NASA, some of the circumstances have changed. The pre
2004 designs assumed ISS visits only. If that was the only requirement,
the current CEV design would shrink from 23 tonnes to sixteen or less.
That's the difference between comfortably fitting on a stock EELV and
wanting a more powerful upper stage.

A capsule optimized for the ISS mission could be even lighter than
that.

Second, only a few years ago the EELVs were expected to fly a lot more
commercial missions between now and 2012. With less flight experience,
there's more pressure to try to achieve confidence in reliability
through testing and paperwork.

Will McLean

On Thu, 19 Jan 2006 03:53:53 +0000, Henry Spencer wrote:

In article uYzzf.499021$084.16084@attbi_s22,
George wrote:
The most devastating lethal accident with a SRB would be a SRB or SRB
segment going off during ground handling... But nobody seems to care.

Really? No one cares, eh? Do you know of even one such incident occurring
regarding SRBs in the U.S. space program? No?

Yes -- there was a spectacular accident at Edwards some years ago when a
Titan SRB segment was accidentally dropped, during stacking operations on
a test stand I think. Fortunately, it fell on the ground rather than on
the stand, and there was nobody nearby.

The consequences of a similar accident inside the VAB don't bear thinking
about.


Did the drop end with a flash or thud? Humm, "spectacular", must have been
a flash.

--
Craig Fink
Courtesy E-Mail Welcome @

In article , John Doe wrote:
man-rating an EELV quite suddenly became a difficult and costly task...

What are the requirements for the launcher that are not already there by
default, even for cargo launches ?

To borrow from an s.s.h posting of mine a few months ago:

Speaking rationally rather than politically, the minimum is a careful
study of the system for ways in which a single failure could kill a crew.
If there are any, you have to fix them somehow. Assuming the spacecraft
has an escape system of some kind, the key issue is generally whether a
plausible failure gives adequate warning time for the crew to activate the
escape system; if not, you must eliminate that class of failure, add
instrumentation to improve warning, or automate escape in that case.

For example, Gemini added redundant guidance hardware and a backup
first-stage hydraulic system to Titan II, because analysis suggested that
a first-stage engine-hard-over-to-one-side failure might happen too
quickly for successful manual escape. The added redundancy improved
reliability in general, but its *purpose* was specifically to make that
one class of failure vanishingly unlikely. The second-stage hydraulic
system was left non-redundant, because hard-over failures there were not
time-critical and the payload penalty for redundancy was excessive.

Man-rating might also involve giving special attention to quality control
in manufacturing for boosters intended to fly manned... although of
course, that raises the question of why you weren't doing it anyway, given
how expensive even an unmanned launch failure is.

What sort of hardware/design does Delta-4 lack ?

Most likely, it would be the same story as Titan II: it would need some
added redundancy in the first stage to prevent sudden loss of control due
to a single failure, and some extra instrumentation to alert the crew to
less abrupt problems.

(assuming all the
navigation/command/control would be in the CEV capsule and which would
be mad rated no matter what the launcher would be).

Not clear that this would be so, actually -- Delta IV has its own control
system, which I believe is redundant already, and you'd probably want to
stick with that. You might possibly want to provide for control by the
spacecraft as a backup option; that was done on Apollo.

Or would man rating Delta 4 really be the space equivalent of ISO-9000,
a process to fully document the process to ensure quality control ?

There would undoubtedly be a lot of that. Historically, the most
prominent effect of man-rating is to greatly increase the paperwork.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

"Will McLean" :

A capsule optimized for the ISS mission could be even lighter than
that.

And the fact that NASA is not designing one to me seems to show what is wrong
with NASA.

Why not design a light and simple (relatively to the present CEV) capsule for
ISS work. Fly it, use the lessons learnt to make an upgraded version for
moon missions. Fly it, use the lessons learnt to make a further upgraded
version for Mars missions?

NASA messes up to diffirent ways.

One, like the space shuttle - trying to design a single craft to do every
single job possible.

Two, if my above suggestion was started up they probably instead of doing
basic upgades would make such radial changes in each generation of design
that infact they would be building totally diffirent space-crafts and the
lessons learnt in each generation will be wasted.

Three, a refusal to use outside contractors without interfering with internal
operations. NASA should pay for results not for how a job is done.

Earl Colby Pottinger

--
Cruising, building a Catamaran, Rebuilding Cabin, New Peroxide Still Design,
Writting SF, Programming FOSS - What happened to the time?

Pat Flannery wrote:
Will McLean wrote:

The sensible way to use it is at the bottom of a Delta-IVH. Using an
EELV as the CLV should be seriously reexamined if these reports are
true and the rapid development of the stick, one of its primary selling
points, turns out to have been oversold.



There's always the RL10 cluster option.

Pat

For the stick? I don't think you could fit more than seven within the
interstage, which would leave the upper stage seriously underpowered.
Six was what the Saturn I used with about the same diameter.

Will McLean

Yes -- there was a spectacular accident at Edwards some years ago when a
Titan SRB segment was accidentally dropped, during stacking operations on
a test stand I think. Fortunately, it fell on the ground rather than on
the stand, and there was nobody nearby.

Hmm. Sounds like the September 7, 1990 incident. Looks like one
worker was killed, but not by the SRB ignition.

A Lampson Transi-Lift 900, a somewhat smaller version of Big Blue,
dropped the Titan rocket motor Sept. 7, 1990, when an arm of the crane
gave way, according to news accounts at the time. The motor segment
that fell included about 270,000 pounds of solid fuel, which ignited
in a flash fire and huge, mushroom-shaped cloud of smoke. A worker who
was responsible for positioning the crane died when he was crushed by
weights used to balance the crane. Nine others sustained minor
injuries.

News accounts from the period also say the crane slipped because it
was operating on a hazardous surface of plywood over pea gravel.
http://www.jsonline.com/news/metro/j...mp22072199.asp

In article .com,
Will McLean wrote:
But when upper management decided that a shuttle derivative was preferred,
man-rating an EELV quite suddenly became a difficult and costly task -- so
daunting that a mostly-new shuttle-derived launcher seemed preferable.

In fairness to NASA, some of the circumstances have changed. The pre
2004 designs assumed ISS visits only. If that was the only requirement,
the current CEV design would shrink from 23 tonnes to sixteen or less.
That's the difference between comfortably fitting on a stock EELV and
wanting a more powerful upper stage.

Not really. Let's assume use of Delta IV, to avoid the political problem
of the Russian engines on Atlas V. That means Delta IV Heavy, because the
single-core Delta IVs are just too small. The Block 2 (lunar) CEV totals
22.6_t. Delta IV Heavy can lift 21.9_t to ISS, a lift shortfall of less
than 1_t. Moreover, that Delta number is payload taken *all the way* to
ISS, while even if Porklauncher IB meets its specs, if I recall correctly,
it can't get CEV into even a low parking orbit without help from CEV's own
propulsion system. The actual shortfall is probably negative; if it is
positive, it's so small that a slightly firmer hand on mass control during
CEV development should eliminate it.

And of course, there's no problem at all with any of the ISS versions of
CEV. And given how long it is before the lunar version is needed, you
just might be able to talk Boeing into improving Delta IV Heavy's lift
performance just a wee bit before then, wouldn't you think?

If we use Atlas V, the five-strapon single-core configuration gets 17.6_t
to ISS. That's plenty for the manned ISS CEV, but requires a bit of
offloading for the cargo versions. (Maybe not very much, because again,
that Atlas number is for delivery all the way.) For the lunar version,
you fund Atlas V Heavy, with a nominal 26.9_t to ISS (!).

Second, only a few years ago the EELVs were expected to fly a lot more
commercial missions between now and 2012. With less flight experience,
there's more pressure to try to achieve confidence in reliability
through testing and paperwork.

How many EELV test flights can you buy for the cost of developing
Porklauncher IB? You could even put payloads on some of them.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

Or they cancel the CLV(stick), put CEV on an EELV and immediately
start on the heavy lifter with the redundant shuttle engineers split
between CEV development and EELV integration and the heavy lifter.

Best regards,


NASa doesnt like this, too many connected people would lose $$. ET
tanks, solids etc. EELV is really the better way to go, but it would
hurt the pork....


nasa wants desperately a excuse to keep the wasteful dangerous shuttle
flying to keep the $$$ flowing!