CEV PDQ

On 10 May 2005 12:35:13 GMT, in a place far, far away, Andrew Gray
made the phosphor on my monitor glow in
such a way as to indicate that:

On 2005-05-10, Neil Gerace wrote:
"Rand Simberg" wrote in message
...

Which is one of the several reasons that STS (to the surprise of many)
is not "human rated."

Well, it happens to airliners too. An abort (all engines out, no control
surfaces responding) is often not survivable. But they are still allowed to
fly.

The analogy isn't quite the same, though - this would be equivalent to
saying that there's a dead-zone during takeoff where you can't try to
do an emergency landing of the airliner, surely?

Well, actually there is. If you lose all propulsion shortly after
rotation and takeoff, there's not a lot you can do.

On Tue, 10 May 2005 12:32:19 GMT, in a place far, far away, Reed
Snellenberger made the phosphor on my
monitor glow in such a way as to indicate that:

Rand Simberg wrote:

Last time I had a house built, I don't recall demanding that it be
delivered assembled on a giant truck.

So I'm guessing you didn't buy a modular home?

No, I didn't, and if I had, it would have been much smaller. Also,
I'm not aware that they come with furniture and appliances installed.

Rand Simberg wrote:

Could be, but it's still better than losing an entire mission with a
single loss, and you can pay for a lot of lost pieces with the
development cost savings for the unneeded HLLV.


But in the case of the Shuttle-derived one, we already have most of the
cost covered in the development arena.
Building a new cargo pod would be around as difficult as building a new
third stage for the Saturn V, particularly now that we have the RS-68 to
use.


If you have to build a complete back-up modular Mars ship that will be
expensive; the other concern is the launch window- can you get the
replacement component for the lost one up and docked while the launch
window is still open?



If you put enough slack in the schedule. If not, launch windows to
Mars occur relatively frequently. This discussion presupposes much
more routine capability to get things into orbit (as well as doing
orbital assembly) than we have today. Developing that kind of
capability would have much greater long-term value for our prospects
in space than a heavy lifter.



But it also means an expanded civilian as well as military and
governmental demand to get the high volume of payload into orbit that
would justify a high launch rate capability for medium lift vehicles. So
far that hasn't happened, and if it does happen I wouldn't be surprised
to see a lot of those payloads going up on a Chinese-made rocket that
offers far lower cost than a U.S. one.
The obvious counter-argument is to launch the parts of the U.S. Mars
ship on the Chinese made booster; that presupposes that the Chinese
would launch our Mars ship on their boosters....rather than launch
_their_ Mars ship on their boosters. ;-)

Pat

OM om@our_blessed_lady_mary_of_the_holy_nasa_researc h_facility.org wrote:
On Mon, 09 May 2005 23:59:21 -0500, Pat Flannery
wrote:

Meanwhile, from far-off Hawaii, Jeffrey Bell looks at the CEV plan-
surprisingly, he doesn't like it ;-) :

...Someone needs to explain to Bell his urgent need to simply shut the
**** up. Preferably with a large baseball bat.

He's always flaming and looks like a fool, but it's entertaining to
read, much more than the usual press release language or the
mangled-through-ten-rewrites afp/upi/whatever snippets.

He has some point about needing to settle on some real requirements
before design work. Though, if the specs were more precise, many would
complain "let the contractors decide" instead.

What would be best is a charismatic chief designer who is able to convince
everyone about the general lines - sometimes it's good to just make
_some_ decision.

--
meiza

Rand Simberg wrote:

Not necessarily. It's a lot easier to do a mission to Phobos for an
initial mission than it is to land on the planet, and a lot of good
science could still result.



After the amount of time it would take to get to Mars and back is
considered, getting that close and not landing would be pathetic.

Pat

OM wrote:



If it's going to be flags and footprints, as you imply, then we
shouldn't do it at all.



...Gosh, then I guess scaling Everest shouldn't be done, either. Much
less crossing the street.

Coward.



If it gets done, it'll be about flags and footprints.
Or International Cooperation; and after the "international cooperation"
experience of the ISS, that would be a very stupid approach to use.
So I imagine that will be the approach used. :-D

Pat

On Tue, 10 May 2005 11:24:23 -0500, Pat Flannery
wrote:

OM wrote:

If it's going to be flags and footprints, as you imply, then we
shouldn't do it at all.

...Gosh, then I guess scaling Everest shouldn't be done, either. Much
less crossing the street.

Coward.

If it gets done, it'll be about flags and footprints.

....You and I both know that. It's the reason *anything* on that kind
of scale gets done. It's what basic human motivation beyond survival
is all about. Guys like Rand - whose cowardice extends to pretending
to ignore my points - just can't accept this concept, and do all they
can do denounce efforts towards these accomplishments.

....Anyone got photos of Rand and Jeffrey Bell? I want to see if they
resemble each other enough to work up a quick "separated at abortion?"
image for my blog.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

On Tue, 10 May 2005 06:04:29 -0700, in a place far, far away, Dale
made the phosphor on my monitor glow in such a way as to
indicate that:

Well, it happens to airliners too. An abort (all engines out, no control
surfaces responding) is often not survivable. But they are still allowed to
fly.

Because, unlike a vehicle that has to be essentially rebuilt each
time, and only flies a few times a year (if that), they are reliable.

What does rebuilding/not rebuilding have to do with a possible
designed-in vulnerability to catastrophic failure?

Nothing, but there are other failure modes that aren't a function of
design. Most, in fact.

Rand Simberg wrote:

That's why it's important to build the infrastructure necessary to
make it affordable to privately fund it. Heavy lift definitely
doesn't do that.



Flyin' to Mars ain't like dusting crops, boy! :-)
Bill Gates could probably afford to finance the whole kit and kaboodle
right now if he felt like it... but he hasn't done it yet.
And I'm glad he hasn't...because when Windows crashes it's annoying-
but nowhere near as annoying as having a planet crash sometime. ;-)

On 10 May 2005 13:23:46 GMT, in a place far, far away, "Jorge R.
Frank" made the phosphor on my monitor glow in
such a way as to indicate that:

the DIV has to fly an odd trajectory (due to structural
concerns) that means that there are points in the ascent when abort is
*not* survivable.

Is that bad? Seems to me that it happens to STS as well.

No. That's due to not being able to terminate the SRBs safely, not due to
trajectory as is the case with the D-IV.

Even if they could terminate SRBs, an abort just after liftoff
wouldn't be survivable.