At 09:31 PM 2/18/2003 -0800, Jim Richardson wrote:
As a side issue, how hot is the vehicle going to be when it lands? Will
it need time to cool down?
Depends heavily on the TPS system. Re-radiative systems will be
very hot and will require substantial cool down. Transpiration systems
On Tue, Feb 18, 2003 at 01:01:42PM -0500, Henry Spencer wrote:
> On Tue, 18 Feb 2003, Buddha Buck wrote:
> > > that's slack time for all of the ground crew except the guy driving the
> > > transporter,
> >
> > I) Why does the transporter need a driver? It seems to me that some
> > current-day
On Wed, 19 Feb 2003, Ian Woollard wrote:
> >>...aeroplanes are starting to be unpiloted...
> >And their reliability record, so far, makes expendable launchers look
> >wonderful. And it's not because people haven't been trying hard.
> >
> I don't believe that this is going to be true in the long r
Henry Spencer wrote:
On Mon, 17 Feb 2003, Ian Woollard wrote:
...quite a lot
of new aeroplanes are starting to be unpiloted, or capable of being
flown that way anyway right now.
And their reliability record, so far, makes expendable launchers look
wonderful. And it's n
Well, if we're going for extremes anyway...
Start by magnetizing the launch pad, or something near
it, such that a rocket hovering (or, at least, moving
slowly) near by will be drawn to land right on the
pad.
If that's not enough, make the mile or so around the
pad
sloped and slippery such that a
On Tue, Feb 18, 2003 at 08:48:12AM -0800, Tony Fredericks wrote:
> The problem I see with this technology is that it reduces drag. That's
> your primary braking for spacecraft returning from orbit. You could end up
> lithobraking.
>
>
> >From: Jim Richardson <[EMAIL PROTECTED]>
> >
> >On Sat,
At 04:33 PM 2/18/2003 -0500, Henry Spencer wrote:
On Tue, 18 Feb 2003, Pierce Nichols wrote:
> It's hard to beat ablative for cheap reliability. Transpiration
> might beat it, but it's going to require substantial development work.
Ablators take development work too, you know -- you can'
The next meeting of the Experimental Rocket Propulsion Society will be
held this THURSDAY evening at the South Sunnyvale Coco's starting at 8:00pm.
Items for meeting #254 (20 Feb 2003):
This meeting will be the 10th Anniversary meeting of the Society,
formed February 18th, 1993 at the home of Mic
[EMAIL PROTECTED] wrote:
> The hard part of SSTO is mass ratio, which is essentially a passive
> design feature for a true SSTO. The flight systems should be, and IMHO may
> need to be, less complicated than those of much human-rated stuff that is
> already operational.
I can't see TH
On Tue, 18 Feb 2003, Michael Wallis wrote:
> ...American Airlines doesn't care what the 777 R&D costs are -
> they care about how fast it can be turned and back in the air earning
> income.
Of course, one reason they care so much about that is the size of the
mortgage on the bird... The old rule
Randall Clague wrote:
> And so what? The biggest driver of operations cost for a commercially
> developed RLV is debt service on the R&D budget. Four man hours per
> flight is so lost in the noise that it's like looking for pennies at
> Fort Knox.
First, 4 man-hrs is a long term goal not somet
Andrew Case wrote:
> I can see the argument for this, but I can also see arguments for what
> is effectively a mobile stand. I suspect that the problem space is not
> well enough defined to come to a firm conclusion, though I'm open to
> arguments either way.
Let's be clearer then ... think p
On Tue, 18 Feb 2003, Pierce Nichols wrote:
> It's hard to beat ablative for cheap reliability. Transpiration
> might beat it, but it's going to require substantial development work.
Ablators take development work too, you know -- you can't buy a complete
reentry-rated ablative heatshiel
At 12:36 PM 2/18/2003 -0800, Michael Wallis wrote:
To get to 4 man-hrs turnaround you can't be swapping heatshields (or
any other major component). At 40 man-hrs your turn might be able to
hand that if it's designed for quick release/replacement (original
Alpha was) but it was a stop-gap design t
On Tue, 18 Feb 2003, Pierce Nichols wrote:
> >And their reliability record, so far, makes expendable launchers look
> >wonderful. And it's not because people haven't been trying hard.
>
> What about Global Hawk and Predator? They are remotely piloted as
> opposed to autonomous, but my i
Henry Spencer wrote:
> In any case, the point may be moot. Bear in mind that if your heatshield
> swap operation takes four guys for fifteen minutes -- which seems
> plausible as a first guess, given a vehicle big enough to need power
> handling of the heatshield plate -- that's one of your four
At 03:25 PM 2/18/2003 -0500, Henry Spencer wrote:
On Mon, 17 Feb 2003, Ian Woollard wrote:
> ...quite a lot
> of new aeroplanes are starting to be unpiloted, or capable of being
> flown that way anyway right now.
And their reliability record, so far, makes expendable launchers look
wonderful. An
On Mon, 17 Feb 2003, Ian Woollard wrote:
> ...quite a lot
> of new aeroplanes are starting to be unpiloted, or capable of being
> flown that way anyway right now.
And their reliability record, so far, makes expendable launchers look
wonderful. And it's not because people haven't been trying har
Henry Spencer wrote:
> Note, though, that the original comment was in the context of the
> long-term feasibility of turnaround using only four *man-hours*. Unless
> your base-cap-refurbishment shop is highly automated, you won't be able to
> do that with ablators.
With a TPS that doesn't requi
At 01:46 PM 2/18/2003 -0500, Andrew Case wrote:
In the initial stages, while building up operational experience, it seems
sensible to me to keep speeds low enough that a sudden stop imposes loads
no larger than those encountered during launch (bearing in mind that the
loads in question are side
On Tuesday, February 18, 2003, at 01:22 PM, Pierce Nichols wrote:
I agree on the need, but I don't see why it has to be slow and
ponderous. Personally, I think the ideal vehicle would be a specially
adapted travel lift, like they use to transport and launch boats from
large dinghies up
At 12:29 PM 2/18/2003 -0500, Andrew Case wrote:
On Tuesday, February 18, 2003, at 12:05 PM, [EMAIL PROTECTED] wrote:
Since by definition, the engine thrust support structure (TSS) must take
something like 1.5 times the load of the fully fueled vehicle, the ground
support structure could be somet
We pretty readily moved the Rotary ATV around in the manner you described,
and at faster than walking speed. We didn't quite need struts or cables
between the gear legs, but that wouldn't have been a huge issue and would
have reduced the likelyhood of overstressing the gear with tow vehicle
accele
On Tue, 18 Feb 2003, Buddha Buck wrote:
> > that's slack time for all of the ground crew except the guy driving the
> > transporter,
>
> I) Why does the transporter need a driver? It seems to me that some
> current-day robotic technologies would do a decent job of seeking a
> transponder on t
On Tue, 18 Feb 2003, Jerry Durand wrote:
> >There's an argument to be made against moving it based on the fact that
> >that's slack time for all of the ground crew except the guy driving the
> >transporter...
>
> Some reason you couldn't be working on it (other than fueling) WHILE it's
> on the
On Tue, 18 Feb 2003, Andrew Case wrote:
> There's no reason you can't build a huge transporter that can gently
> pick up the ship and trundle it up to a mile or so over well prepared
> surfaces to a dedicated launch stand...
It doesn't need to be anything huge. A little wheeled dolly that locks
[EMAIL PROTECTED] wrote:
>There will likely be a somewhat soft physical limit in how rapidly one can
> push fuel and oxidizer into the vehicle, but by the standards of an
> operational air base, or a Daytona 500 pit crew, 4 hours turnaround would
> seem generous, and both involve vehicles argua
Andrew Case wrote:
There's an argument to be made against moving it based on the fact that
that's slack time for all of the ground crew except the guy driving the
transporter,
I) Why does the transporter need a driver? It seems to me that some
current-day robotic technologies would do a dec
At 09:29 AM 2/18/2003, you wrote:
There's an argument to be made against moving it based on the fact that
that's slack time for all of the ground crew except the guy driving the
transporter, but it's not clear that you can't make that time up by
improved efficiency once you get to the launch s
On Tuesday, February 18, 2003, at 12:05 PM, [EMAIL PROTECTED] wrote:
Since by definition, the engine thrust support structure (TSS) must
take
something like 1.5 times the load of the fully fueled vehicle, the
ground
support structure could be something as simple as a robust single leg
(or
jack
The title of the article was "At NASA, Concerns on Contractors"
http://www.washingtonpost.com/wp-dyn/articles/A18236-2003Feb16.html
--
<
Alex Fraser N3DER .
. [EMAIL PROTECTED] ...
[~]_><
___
ERPS
Gentlefolk,
Brainstorming Since the vehicle is unlikely to have shuttle-like cross
range, it should be designed to fly from where it lands. I think a mobile
service vehicle is a necessity.
Since by definition, the engine thrust support structure (TSS) must take
something like 1.5 times t
At 08:48 AM 2/18/2003 -0800, Tony Fredericks wrote:
The problem I see with this technology is that it reduces drag. That's
your primary braking for spacecraft returning from orbit. You could end
up lithobraking.
Well, it's being investigated to reduce drag. However, a brief
skim of
The problem I see with this technology is that it reduces drag. That's your
primary braking for spacecraft returning from orbit. You could end up
lithobraking.
Tony Fredericks "Mind that bus!"
Amateur Rocket Scientist"What Bus?"
E.R.P.S. Member SPLAT!!
On Tue, 18 Feb 2003, Randall Clague wrote:
> I think a total four man-hours per flight is not so much out of reach
> as out to lunch. Where did this figure come from?
That was umpteen zillion messages ago, you expect us to remember that far
back? :-)
It was arbitrary, and clearly something that
Gentlefolk,
One imagines that, like most other thing, turnaround time would be subject to
cost-benefit trades, design, and experience.
There will likely be a somewhat soft physical limit in how rapidly one can
push fuel and oxidizer into the vehicle, but by the standards of an
operational
On Sun, 16 Feb 2003 21:48:45 -0800, David Weinshenker
<[EMAIL PROTECTED]> wrote:
>I'm looking forward to seeing what XCOR's next generation looks like: the one
>where they apply "lessons learned" from EZ-Rocket... are they building the "Xerus"
>configuration they displayed a while back? That loo
On Sun, 16 Feb 2003 22:13:38 -0500, Andrew Case <[EMAIL PROTECTED]>
wrote:
>to me the four man hours of on-pad effort is possible, but once you
>take into account the time to install the payload on the pallet and
>time in the hanger for periodic maintenance, a total of four man hours
>per fligh
38 matches
Mail list logo
