CEV PDQ

On Wed, 18 May 2005 00:24:19 -0500, Derek Lyons wrote
(in article ):

You seem incapable of grasping that the topic under discussion IS NOT
doing today's things with today's limitations. The topic has changed
to exploring what might be possible tomorrow after those limitations
have been removed.

The topic has most certainly NOT moved on when I'm being called on the
carpet piecemeal for comments made in the context of present-day design
efforts. To state or imply that it has is dissembling.

--
Herb Schaltegger, GPG Key ID: BBF6FC1C
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." - Benjamin Franklin, 1759
http://www.individual-i.com/

Dale wrote:
Herb Schaltegger wrote:

And with that, I'm outta here. I'll report back on this
when the first post-shuttle vehicle flies in it's crewed
configuration.

Sorry to see you go, Herb.

All he meant is that he's done arguing with Rand. For now.

Geez....

Jeff Findley ) wrote:

[...]

: If we get to Mars and can't do surface EVA's, why in the hell would we be
: spending billions on *manned* missions to Mars in the first place? If we
: can't do Martian surface EVA's, just send big robotic sample return missions
: instead.

That is exactly what we should do prior to a manned mission.

Eric

: Jeff
: --
: Remove icky phrase from email address to get a valid address.

Herb Schaltegger wrote:
George William Herbert wrote:
EVA is really hard, granted.

Orbital assembly for deep space spacecraft is not proven,
but is not necessarily, as a complete problem, as hard as EVA is.

All the more reason NOT to use, or use it absolutely minimally, for a
present-day CEV architecture.

Unless the estimated cost to develop and prove it is less
than the cost of developing heavy lift alternatives.

Which is a usefully arguable argument, with "traditional vendor"
answers on both sides being in the billions of dollars.

My opinion on this matter is that orbital assembly can
be simplified and looked at as a special case of the orbital
docking or berthing problem. Not all docking/berthing mechanisms
under consideration are suitable for high accelleration flight,
but many are, and the problem is simplified if you don't have to
run a pressurized hatch connection between the vehicles.
You need to connect a control run of some sort, but merely
plugging in one cable bundle manually in a minimal EVA
after the docking is not a high risk EVA activity, and there
are credible unmanned ways of doing it as well (short arm with
a plug on the end...).

Orbital assembly at that level is not nearly as mass efficient
as more labor intensive options, but does get you around having
to build and buy a HLV. It's adequate for Moon/Mars missions.


-george william herbert
/

"Rand Simberg" wrote in message
...
The point remains that not all
people think that EVA is something for the distant, unthinkable
future.

But the *funding* appears to be. You're still welcome to provide some
verifiable examples of *current* funding.

"George William Herbert" wrote in message
...
Michael P. Walsh wrote:
Rand committed:
Armadillo was nowhere near flying any kind of manned vehicle by
the time Scaled Composites won the X-Prize and had just suffered
a failure that resulted in much lost time.

Partly because they'd backed off on their rush to do so, because they
knew that they wouldn't be able to get a site license for their
vehicle.

This is not backed up by anything I read on the Armadillo
web site. Do you have a source for your claim, perhaps
something I missed on the Armadillo test site?

John has said stuff at Space Access conference presentations,
private conversations, and in email lists and such which has
more info on some topics than is on the website.

I'm not sure how much of what details are ok for general public
consumption, but Rand's summary is completely in line with all
of what I recall having heard directly from John Carmack.
The licensing issues with White Sands were the proximate cause
of them giving up on the prize chase.


Then I have to presume that he gave up much earlier than he
conceded (either in an email or in one of his posts to a newsgroup).

Several months before the X-Prize was won I posted a remark
that I did not believe, based on his project progress to that date,
that he had a chance of winning the X-Prize. He conceded in a
reply to that post of mine that he was unlikely to win the X-Prize
but would continue and eventually fly his vehicle even if it didn't
happen until after the X-Prize deadline.

I based my remark on my evaluation of the progress reported on
his website. Carmack has been unusually open in his reports to
the world so, in my opinion, it didn't take more than some basic
technical knowledge to know that he really couldn't make it from
that point to a winning test flight before the X-Prize deadline.

Mike Walsh

"Rand Simberg" wrote in message
...
On Tue, 17 May 2005 16:40:57 -0700, in a place far, far away, "Michael
P. Walsh" made the phosphor on my monitor glow
in such a way as to indicate that:

Or are you referring to what decisions Armadillo made after the
X-Prize as far as continuing their program?

No.

This is not backed up by anything I read on the Armadillo
web site. Do you have a source for your claim, perhaps
something I missed on the Armadillo test site?

Frankly it sounds very much like you are blowing smoke.

Regardless of what it sounds like (this is based on what John said at
Space Access last year), it's a result of the fact that White Sands
couldn't get their environmental impact statement settled to allow
them to launch from there, absent a lot of money (more than John was
willing to pay) from Armadillo.

OK, I concede you have a source I can't verify but seems valid since
George Herbert confirmed that this type of discussion had occurred.

It remains true that Armadillo had not progressed sufficiently technically
to have any reasonable chance of winning the X-Prize at the April
time period of last year's Space Access Conference.

Mike Walsh

"Pete Lynn" wrote in message
...
"Michael P. Walsh" wrote in message
news

Personally I believe the big problem with Armadillo
was attempting to their own engine development from
scratch. Something they are still doing.

It would not surprise me if their lack of high purity hydrogen peroxide,
(regulatory reasons?), cost them a year. Switching to LOX earlier might
have been another way around this.

Buying in engines would have been quicker, but excepting the unforseen
delays, not cheaper, I expect it would have also constrained them
designwise. They can make and develop the less sophisticated type of
engines they need much cheaper and faster than anyone else, including
XCor.

Cheaper quite possibly. Cheaper and faster than anyone else, including
XCOR?

Not proven by their progress so far. I believe that Armadillo is finding
engine development to be a lot harder than they believed it would be
when they started.

I also note that if you are trying to win a time constrained prize then
you need to avoid getting into long lead time R&D programs and that
is typical of engine development.


Personally I think they are doing it exactly right. This is the type of
integrated incremental design and build typical of serious low cost
development in other fields. The one off design mentality more typical
in this industry has very high costs and achieves very low levels of
refinement, though it is very appropriate within the fixed contract,
waste everything but time context.


Doing it right for what? In the context of winning a time limited program
it is not the way to go and I believe Armadillo's experience shows that.

Scaled Composites took the high end. They (with the help of Paul Allen's
money)
competed a new hybrid engine development from two separate contractors.
Throwing more resources into the program reduces the risk of not making
a fixed deadline in time, although buying an already available LO2-kerosene
engine might have provided an even lower time risk, assuming a suitable
engine was available on the market.

Armadillo seemingly reached a dead end on the monopropellant H2O2
engine and has moved on to LO2-kerosene. I suspect they have a long
program of engine development ahead of them. This is due quite a bit
to their limited resources and available expertise. I assume John Carmack
is too intelligent to risk his financial health on some kind of attempt to
provide a low cost propulsion system or manned operating space
vehicle.

If it happens, I am sure he will post the results on his website.

Mike Walsh

"George William Herbert" wrote in message
...
Pete Lynn wrote:
"Michael P. Walsh" wrote:
Personally I believe the big problem with Armadillo
was attempting to their own engine development from
scratch. Something they are still doing.

It would not surprise me if their lack of high purity hydrogen peroxide,
(regulatory reasons?), cost them a year. Switching to LOX earlier might
have been another way around this.

If they had a sufficient supplier of high concentration peroxide,
their monoprop engine work was plenty successful and would have
gotten them to X-prize performance regimes.

The supply failure was due to one vendor exiting the business
and then the big one (FMC) refusing to sell to Armadillo,
as I understand it, not due to legal / regulatory ones.

The regulatory issues are unrelated to that.


I should clarify that my remark about a small organization such as Armadillo
trying to do their own engine development is based on unexpected factors
that seem to always crop up. It is possible that if you were to go back in
time and have John Carmack find a reliable supplier of high concentration
peroxide early enough to get through the problem areas that he has reported
so fully earlier that he might have successfully completed his monoprop
engine work. X-Prize performance doesn't require high ISP, but does
require a safe, controllable engine capable of meeting the thrust and time
requirements needed for an X-Prize vehicle.

I note that vehicle development also takes time, and so far Carmack
hasn't reported much progress on that front. Of course, if you complete
the vehicle except for the propulsion system you still don't go anywhere.

If you care to comment I would appreciate it because I respect your
knowledge of the field.

I also want to say that I am quite impressed by what John Carmack and
Armadillo Aerospace have accomplished.

My only criticism is I believe they bit off a lot more than they could chew.

Mike Walsh

On Wed, 18 May 2005 14:04:03 -0500, George William Herbert wrote
(in article ):

Herb Schaltegger wrote:
George William Herbert wrote:
EVA is really hard, granted.

Orbital assembly for deep space spacecraft is not proven,
but is not necessarily, as a complete problem, as hard as EVA is.

All the more reason NOT to use, or use it absolutely minimally, for a
present-day CEV architecture.

Unless the estimated cost to develop and prove it is less
than the cost of developing heavy lift alternatives.

Only if you presume the requirement to develop heavy lift boosters in
the first place.

Which is a usefully arguable argument, with "traditional vendor"
answers on both sides being in the billions of dollars.

My opinion on this matter is that orbital assembly can
be simplified and looked at as a special case of the orbital
docking or berthing problem.

Yes, I agree.

Not all docking/berthing mechanisms
under consideration are suitable for high accelleration flight,

Yes, I agree on this point as well.

but many are, and the problem is simplified if you don't have to
run a pressurized hatch connection between the vehicles.

Very true, although IVA assembly is certainly do-able. Consider the
U.S., European and Japanese modules of SSF/ISS as a proof-of-concept,
if you will.

You need to connect a control run of some sort, but merely
plugging in one cable bundle manually in a minimal EVA
after the docking is not a high risk EVA activity,

True, however . . . once you set the ground rules to allow for EVA
assembly tasks of any kind, designers often start adding on other
tasks. "Since the crew is going to be outside anyway, why can't they
ALSO do . . . " It's a very slippery slope.

and there
are credible unmanned ways of doing it as well (short arm with
a plug on the end...).

Think "piston" and you've got the right idea.

Orbital assembly at that level is not nearly as mass efficient
as more labor intensive options, but does get you around having
to build and buy a HLV.

Yes, hence my comment above.

It's adequate for Moon/Mars missions.

Exactly.

-george william herbert
/


--
Herb Schaltegger, GPG Key ID: BBF6FC1C
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." - Benjamin Franklin, 1759
http://www.individual-i.com/