Ares vs DIRECT

On Mon, 19 Nov 2007 00:38:10 -0600, in a place far, far away, "Jorge
R. Frank" made the phosphor on my monitor glow
in such a way as to indicate that:

Michael Gallagher wrote:

Even if they stuck with LOR, it seems to me launching both vehicles on
the same booster would again necessitate a slightly bigger launch
vehicle. I'm guessing the advantage of having the crew launch on an
Ares 1 and eveything else on an Ares V would be to keep the V as small
as possible but still do the job. I know I could be wrong. Anyone
crunch the numbers on this?

No, just the opposite. It was to keep the I (not the V) as small and as
simple as possible to drive up the reliability numbers for crew launch.

Yes, even though launch is the least risky part of a lunar mission.
Jon Goff had a good post on this potential misallocation of risk.

http://selenianboondocks.blogspot.co...imization.html

On Nov 19, 8:18 am, (Rand Simberg)
wrote:
On Mon, 19 Nov 2007 00:38:10 -0600, in a place far, far away, "Jorge
R. Frank" made the phosphor on my monitor glow
in such a way as to indicate that:

Michael Gallagher wrote:

Even if they stuck with LOR, it seems to me launching both vehicles on
the same booster would again necessitate a slightly bigger launch
vehicle. I'm guessing the advantage of having the crew launch on an
Ares 1 and eveything else on an Ares V would be to keep the V as small
as possible but still do the job. I know I could be wrong. Anyone
crunch the numbers on this?

No, just the opposite. It was to keep the I (not the V) as small and as
simple as possible to drive up the reliability numbers for crew launch.

Yes, even though launch is the least risky part of a lunar mission.
Jon Goff had a good post on this potential misallocation of risk.

http://selenianboondocks.blogspot.co...-overoptimizat...

So, what would it take for NASA to say, "Hey, we've come up with this
great way to make Ares work" and then simply incorporate Direct as the
new Ares design?

h (Rand Simberg) wrote:

On Mon, 19 Nov 2007 00:38:10 -0600, in a place far, far away, "Jorge
R. Frank" made the phosphor on my monitor glow
in such a way as to indicate that:


No, just the opposite. It was to keep the I (not the V) as small and as
simple as possible to drive up the reliability numbers for crew launch.

Yes, even though launch is the least risky part of a lunar mission.
Jon Goff had a good post on this potential misallocation of risk.

http://selenianboondocks.blogspot.co...imization.html

The problem is his evaluation is that he is discussing a strawman Ares
I (which exists only to go to the moon) vice the real Ares I, which is
used to boost both lunar missions and space station missions. In the
latter role, optimization for launch safety is rather important.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

"Michael Gallagher" wrote in message
...
On Sat, 17 Nov 2007 05:42:50 GMT, Brian Thorn
wrote:

.... NASA would simply have to rename the DIRECT vehicles "Ares II" and
"Ares III" and the general public will hardly notice. Ares V would
still be a possibility for Mars farther down the road.

You get pretty much the same answer if you ask what happened to Saturn II,
Saturn III, and Saturn IV. ;-)

Seriously though, I'm as against Direct as I am against Ares. NASA ought
not design *any* new launch vehicles. The architecture ought to be changed
to use EELV's, so we could actually learn how to do these huge programs with
the launch vehicle's we've got.

Jeff
--
"When transportation is cheap, frequent, reliable, and flexible,
everything else becomes easier."
- Jon Goff

On Mon, 19 Nov 2007 11:17:48 -0500, "Jeff Findley"
wrote:


.... NASA would simply have to rename the DIRECT vehicles "Ares II" and
"Ares III" and the general public will hardly notice. Ares V would
still be a possibility for Mars farther down the road.

You get pretty much the same answer if you ask what happened to Saturn II,
Saturn III, and Saturn IV. ;-)

Seriously though, I'm as against Direct as I am against Ares. NASA ought
not design *any* new launch vehicles. The architecture ought to be changed
to use EELV's, so we could actually learn how to do these huge programs with
the launch vehicle's we've got.

I'm on the fence, EELV vs. SDLV. But I strongly suspect EELV is off
the table at the behest of Congress. There is also the problem of the
high cost of shutting down Complex 39 if we go the EELV route.

If we're stuck with Shuttle heritage, DIRECT looks vastly more
promising than Ares I/V.

Brian

"Brian Thorn" wrote in message
news
I'm on the fence, EELV vs. SDLV. But I strongly suspect EELV is off
the table at the behest of Congress. There is also the problem of the
high cost of shutting down Complex 39 if we go the EELV route.

If we're stuck with Shuttle heritage, DIRECT looks vastly more
promising than Ares I/V.

Agreed, but I'm not sure the fight is really over. It could be that once we
get a new administration that this whole business is revisited. If that
does happen, I'd expect that there would be heavy lobbying from the EELV
folks since they need the business. And what's better than a cost plus
contract to "man rate" your existing EELV's? They'd be more than happy to
take NASA's money to do this.

Certainly the switch to EELV's would impact jobs, but those aerospace jobs
would be replaced by new aerospace jobs (building the CEV, new lunar lander,
and etc.). Getting NASA to focus on those new jobs, instead of keeping
saturn/shuttle heritage jobs, would be a *good thing* for the agency and the
country.

Jeff
--
"When transportation is cheap, frequent, reliable, and flexible,
everything else becomes easier."
- Jon Goff

On 17 Nov, 00:35, wrote:
I am sure y'all have beat this topic to death but I was not paying
attention. However, is NASA completely committed to ARES/ARESV or is
there still some chance they may choose DIRECT?
It looks to me as if they could still choose DIRECT if they wanted cuz
they havent started any sig work on Ares. I do not have enough info
to decide which is better.

What if Hilary concludes she doesn't want to spend much money on new
launch vehicles, whilst at the same time SpaceX is making progress.

Could they adopt the "Rack".

With this NASA launches one truss, one Canadian arm, and a low power
electrodynamic tether drive to maintain orbit.

Then, Kerosene / Lox Earth Departure stages are brought up. Each
weighs about 20-25 tons, so they can be launched by Atlas V, Delta IV,
Falcon 9, Progress, Arianne.

Once enough are on the "rack", the lunar lander is launched. The
lander might need to be scaled down, which can be done if ED Stages
take it to low Earth Orbit. Or the lander cargo can be taken up
separately. The components from the "Rack" are put together, and
finally, Orion is launched on a Falcon 9H. (If NASA really needs to
put astronauts on a solid stick of explosives, then they could do that
as well).

This requires three to four launches for a cargo mission landing 10
tons in a smaller lander, or 8 launches to deliver and return a crew
of about 4 astronauts. Even at current prices for Atlas V or Delta IV,
its a lot cheaper than Ares I and V. At SpaceX prices, a manned
mission would have launch costs of $480 million.

There's no role for ATK or the Shuttle army in this scenario.

Alex Terrell wrote:

On 17 Nov, 00:35, wrote:
I am sure y'all have beat this topic to death but I was not paying
attention. However, is NASA completely committed to ARES/ARESV or is
there still some chance they may choose DIRECT?
It looks to me as if they could still choose DIRECT if they wanted cuz
they havent started any sig work on Ares. I do not have enough info
to decide which is better.

What if Hilary concludes she doesn't want to spend much money on new
launch vehicles, whilst at the same time SpaceX is making progress.

Assuming Hilary gets elected and SpaceX starts making progress.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL