CEV PDQ

On Tue, 10 May 2005 14:30:42 -0500, in a place far, far away, Herb
Schaltegger made the
phosphor on my monitor glow in such a way as to indicate that:

Actually, you're incorrect about this. Few if any of the
U.S./European/Japanese segment for ISS have been truly volume limited.
They've all been mass-limited, especially at the inclination chosen for
ISS.

I'm referring to Shuttle-C, not Orbiter.

And if you'd actually read my post you'd see that your typically
snarky one-liner is a non sequitur. You're bitching that Shuttle-C is
volume limited, just like an STS orbiter

No, I'm pointing out that Shuttle-C is volume limited, *unlike* an STS
orbiter.

and I'm pointing out that
Station modules have been mass-limited, not volume limited so your
argument that Shuttle-C is deficient due to volume limits is
irrelevant.

It would seem that your argument is the one that's irrelevant. The
point is that Shuttle-C would not have reduced the number of assembly
flights enough to make it worth the money, which (one more time) is
why it wasn't built.

On Tue, 10 May 2005 14:28:12 -0500, in a place far, far away, Herb
Schaltegger made the
phosphor on my monitor glow in such a way as to indicate that:

On Tue, 10 May 2005 13:53:14 -0500, Reed Snellenberger wrote
(in article ):

I've actually been pleasantly surprised at how little EVA work has been
required for the station (apart from the truss components, which are
unlikely to be used in a ship). The CBM design seems to have worked out
very well...

If you only knew how many headaches the CBM's were to design from a
mechanical and fluid/electrical standpoint!

Yes, it's a shame that all of the effort/millions invested in this
didn't go instead into decent EVA equipment.

On Tue, 10 May 2005 19:44:16 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:
On Tue, 10 May 2005 19:14:32 GMT, in a place far, far away, Reed
Snellenberger made the phosphor on my
monitor glow in such a way as to indicate that:


Until it leaves Earth Orbit, it's just ISS/USS (take your pick) #2


Only in a very gross sense. It's not designed for weightless
research, for example. The only requirements it shares with ISS are
the ability to support some number of people for several months.
Also, it's likely to have nuclear power, even if the reactor doesn't
get activated until after departure.

Even in a detailed sense, it's like ISS...

Until it leaves Earth Orbit, it'll be identically equal to ISS (a
habitat orbiting a planet), with the same requirements (zero-g
facilities, among other things).

There are many potential space station designs that are not even
slightly, let alone identically equal to ISS.

On Tue, 10 May 2005 16:47:51 -0400, in a place far, far away, "Jeff
Findley" made the phosphor on my monitor
glow in such a way as to indicate that:


...it's a shame that all of the effort/millions invested in this
didn't go instead into decent EVA equipment.

Unless we plan on exploring the Moon and Mars from inside the lander, you'd
think that better EVA hardware would be a long term goal of the Moon/Mars
program.

Canceling the development of better space suits for the space station
program, and then subsequently spending quite a bit of time, effort, and
money trying to reduce EVA time, seems to have been a very short sighted
decision.

NASA is famous for those.

(Henry Spencer) wrote in
:

In article ,
Jorge R. Frank wrote:
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.

If memory serves, it is still the case that there are "black zones" in
the shuttle ascent trajectory where a multiple SSME failure is not
survivable, because the orbiter is too high and too slow to reenter at
an acceptably shallow angle.

For multiple SSME failures, yes, I agree. Let me see if I can clarify this
a bit:

For a single SSME failure at *any time* during ascent, the shuttle is
capable of intact abort, but the abort cannot be initiated until after SRB
sep.

For multiple SSME failures at *most times* during ascent, the shuttle is
capable of a contingency abort, which may or may not allow intact return of
the vehicle but which will support a bailout by the crew. At other times
("black zones"), a contingency abort is outside the shuttle's certification
limits and will likely result in loss of vehicle, but procedures have the
crew attempt it anyway since they have nothing to lose by trying.

We all on the same page now, I hope...?

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

Derek Lyons wrote:

P

Presumably the designers lack your propensity to see a conspiracy
around every corner and an equal propensity to blame every ill on the
current administration.


From Cheney and the boys must-read "Rebuilding America's Defenses":
http://www.newamericancentury.org/Re...asDefenses.pdf



"Space and Cyberspace

No system of missile defenses can be fully effective without placing
sensors and weapons in space. Although this would appear to be creating
a potential new theater of warfare, in fact space has been militarized
for the better part of four decades. Weather,
communications, navigation and reconnaissance satellites are
increasingly essential elements in American military power. Indeed, U.S.
armed forces are uniquely dependent upon space. As the 1996 Joint
Strategy Review, a precursor to the 1997 Quadrennial Defense Review,
concluded, “Space is already inextricably linked to military operations
on land, on the sea, and in the air.” The report of the National Defense
Panel agreed: “Unrestricted use of space has become a major strategic
interest of the United States.”
Given the advantages U.S. armed forces enjoy as a result of this
unrestricted use of space, it is shortsighted to expect potential
adversaries to refrain from attempting to offset to disable or offset
U.S. space capabilities. And with the proliferation of space know-how
and related technology around the world, our adversaries will inevitably
seek to enjoy many of the same space advantages in the future. Moreover,
“space commerce” is a growing part of the global economy. In 1996,
commercial launches exceeded military launches in the United States, and
commercial revenues exceeded government expenditures on space. Today,
more than 1,100 commercial companies across more than 50 countries are
developing, building, and operating space systems.
Many of these commercial space systems have direct military
applications, including information from global positioning system
constellations and better than-one-meter resolution imaging satellites.
Indeed, 95 percent of current U.S. military communications are carried
over commercial circuits, including commercial communications
satellites. The U.S. Space
Command foresees that in the coming decades, an adversary will have
sophisticated regional situational awareness. Enemies may very well
know, in near real time, the disposition of all forces….In fact,
national military forces, paramilitary units, terrorists, and any other
potential adversaries will share the high ground of space with the
United States and its allies. Adversaries may also share the same
commercial satellite services for communications, imagery, and
navigation….The space “playing field” is leveling rapidly, so U.S.
forces will be increasingly vulnerable. Though adversaries will benefit
greatly from space, losing the use of space may be more devastating to
the United States. It would be intolerable for U.S. forces...to be
deprived of capabilities in space.
In short, the unequivocal supremacy in space enjoyed by the United
States today will be increasingly at risk. As Colin Gray
and John Sheldon have written, “Space control is not an avoidable issue.
It is not an optional extra.” For U.S. armed forces to
continue to assert military preeminence, control of space – defined by
Space Command as “the ability to assure access to space, freedom of
operations within the space medium, and an ability to deny others the
use of space” – must be an essential
element of our military strategy. If America cannot maintain that
control, its ability to conduct global military operations will be
severely complicated, far more costly, and potentially fatally compromised.
The complexity of space control will only grow as commercial activity
increases. American and other allied investments in
space systems will create a requirement to secure and protect these
space assets; they are already an important measure of
American power. Yet it will not merely be enough to protect friendly
commercial uses of space. As Space Command also
recognizes, the United States must also have the capability to deny
America's adversaries the use of commercial space platforms for military
purposes in times of crises and conflicts. Indeed, space is likely to
become the new “international commons,” where
commercial and security interests are intertwined and related. Just as
Alfred Thayer Mahan wrote about “sea-power” at the beginning of the 20th
century in this sense, American strategists will be forced to regard
“space-power” in the 21st.
To ensure America's control of space in the near term, the minimum
requirements are to develop a robust capability to transport systems to
space, carry on operations once there, and service and recover space
systems as needed. As outlined by Space Command, carrying out this
program would include a mix of reuseable and expendable launch vehicles
and vehicles that can operate within space, including “space tugs to
deploy, reconstitute, replenish, refurbish, augment, and sustain" space
systems. But, over the longer term, maintaining control of space will
inevitably require the application of force both in space and from
space, including but not limited to antimissile defenses and defensive
systems capable of protecting U.S. and allied satellites; space control
cannot be sustained in any other fashion, with conventional land, sea,
or airforce, or by electronic warfare. This eventuality is already
recognized by official U.S. national space policy, which states that the
“Department of Defense shall
maintain a capability to execute the mission areas of space support,
force enhancement, space control and force application.”
(Emphasis added.)
In sum, the ability to preserve American military preeminence in the
future will rest in increasing measure on the ability to operate in
space militarily; both the requirements for effective global missile
defenses and projecting global conventional military power demand it.
Unfortunately, neither the Clinton Administration nor past U.S. defense
reviews have established a coherent policy and program for achieving
this goal.

Ends and Means of Space Control

As with defense spending more broadly, the state of U.S. “space forces”
– the systems required to ensure continued access and eventual control
of space – has deteriorated over the past decade, and few new
initiatives or programs are on the immediate horizon. The U.S. approach
to space has been one of dilatory drift. As Gen. Richard Myers,
commander-in-chief of SPACECOM, put it, “Our Cold War-era capabilities
have atrophied,” even though those capabilities are still important today.
And while Space Command has a clear vision of what must be done in
space, it speaks equally clearly about “the question of
resources.” As the command succinctly notes its long-range plan: “When
we match the reality of space dependence against resource trends, we
find a problem.”
But in addition to the problem of lack of resources, there is an
institutional problem. Indeed, some of the difficulties in
maintaining U.S. military space supremacy result from the bureaucratic
“black hole” that prevents the SPACECOM vision from
gaining the support required to carry it out. For one, U.S. military
space planning remains linked to the ups and downs of the
National Aeronautics and Space Administration. America’s difficulties in
reducing the cost of space launches – perhaps the single biggest hurdle
to improving U.S. space capabilities overall – result in part from the
requirements and dominance of NASA programs over the past several
decades, most notably the space shuttle program. Secondly, within the
national security bureaucracy, the majority of space investment
decisions are made by the National Reconnaissance Office and the Air
Force, neither of which considers military operations outside the
earth's atmosphere as a primary mission. And there is no question that
in an era of tightened budgets, investments in space-control
capabilities have suffered for lack of institutional support and have
been squeezed out by these organization’s other priorities. Although,
under the Goldwater-Nichols reforms of the mid-1980s, the unified
commanders – of which SPACECOM is one – have a greater say in Pentagon
programming and budgeting, these powers remain secondary to the
traditional “raise-and-train” powers of the separate services.
Therefore, over the long haul, it will be necessary to unite the
essential elements of the current SPACECOM vision to the
resource-allocation and institution-building responsibilities of a
military service. In addition, it is almost certain that the conduct
of warfare in outer space will differ as much from traditional air
warfare as air warfare has from warfare at sea or on land; space
warfare will demand new organizations, operational strategies, doctrines
and training schemes. Thus, the argument to replace
U.S. Space Command with U.S. Space Forces – a separate service under the
Defense Department – is compelling. While
it is conceivable that, as military space capabilities develop, a
transitory “Space Corps” under the Department of the Air Force might
make sense, it ought to be regarded as an intermediary step, analogous
to the World War II-era Army Air Corps, not to the Marine Corps, which
remains a part of the Navy Department. If space control is an essential
element for maintaining American military preeminence in the decades to
come, then it will be imperative to reorganize the Department of Defense
to ensure that its institutional structure reflects new military realities."
(pages 54-57 in the report; 66-69 in the pdf)

So there you have it in a nutshell- the United States Space Force is to
rule space, and fight battles in space with its new assets including a
"space tug", (which I think is the CEV) NASA, and even the Air Force and
NRO are impediments to that plan, and must have control of any space
activities taken away from them for the national strategic good.
You don't see much about going to Moon or Mars in there, do you?

Pat

Pat Flannery wrote in
:

Rand Simberg wrote:

And they do seem to be in a rush about all this.

Too much so, in my opinion.

Which I can't quite figure out- they seem to be wanting to get this
done overnight (by government standards) rather than put some thought
into it before they start sticking stuff together. But impatience with
thinking anything over seems to be a hallmark of this administration

Pat, does *everything* have to be a Bush administration conspiracy to you?

Do you pay *any* attention to current events before rushing to the
keyboard?

The Bush VSE plan under O'Keefe was *slow*; first manned flight of the CEV
wasn't scheduled until 2014. It's *Griffin* who has accelerated everything.
He is doing so not because of Bush, but because of certain powerful
senators (Hutchison, et al) who consider the four-year gap between shuttle
retirement and CEV to be unacceptable.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

In article ,
Pat Flannery wrote:
Besides which, the Apollo CM was designed for use with a low pressure
pure O2 atmosphere, with our current oxygen/nitrogen atmosphere at
higher pressure, a closer to spherical form makes more structural sense...

Makes very little difference with modern materials, actually. Spherical
pressure vessels have a mass advantage when built in metal, but not in
composites.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

"Derek Lyons" wrote in message
...
"Jeff Findley" wrote:

"Derek Lyons" wrote in message
...
h (Rand Simberg) wrote:

Assuming that the cheap booster is available in a reasonable time
frame, and a complete second set of hardware is sitting around checked
out and ready to go in a reasonable timeframe.

You mean like how we had a *complete* backup Skylab along with a
*complete*
backup Saturn V? We also had backup CSM's and Saturn IB's for all of the
Skylab missions and for ASTP.

Which we had mostly because there was a considerable amount of excess
material and production capacity from the lunar program available
cheaply. It's a different matter when you have to pay for everything
from scratch.

The Saturns were surplus, but the Skylab program built two copies of Skylab
as flight hardware (and at least one other copy for use on the ground).
That's quite a bit of redundancy, given that there was no guarentee that the
backup hardware would ever fly.

Now if the first mission to Skylab hadn't been successful in saving the
station, there is the possibility that modifications could have been made to
the micrometeorite bumber on the backup Skylab and it could have flown.

The ISS program has, on occasion, turned test hardware into flight hardware
due to a shortage of cash. Needless to say, there is little in the way of
backup (US) hardware in the ISS program. As for the launcher, we all know
how many backup shuttles are left.

If you stop and think about it, having backup hardware isn't that
expensive
if you're talking about a *sustained* program where you're going to have
many missions. The backup hardware for mission 1 just becomes the flight
hardware for mission 2 and so forth and so on. If you accept that your
last
mission may fail, you don't need a backup for that mission at all.

Which can lock you into a series of missions with near identical
hardware.

It worked for the six successful moon landings.

Otherwise some additional expense will be involved in updating the
equipment as you learn it's characteristics (I.E. Lessons Learned)
and/or to incorporate additional equipment or remove existing
equipment. On top of this you have the non trivial costs of storage
and the additional costs of building out each module for an extended
lifetime. (I'm am *not* saying these things are good or bad, merely
pointing them out as considerations.)

As usual, the tradeoffs and considerations are not nearly as simple as
you handwave.

Certainly the hardware will evolve over time (as the LEM did). However, as
an example, I wouldn't expect every mission to the moon to use a completely
new design for the lander. That's a recipe for extremely high costs and low
reliability since each mission is essentially flying a new lander design for
the very first time.

Building custom hardware for each mission clearly isn't what NASA is after.
If it was, we wouldn't be seeing the CEV program looking like it's going to
be made of several modules instead of one big one. The CEV component used
for launching and landing of the crew will surely evolve over time, but it
also looks like it will be reused for multiple missions, so it's evolution
would be slow, like the shuttle's.

Finally, there's no reason you can't make multiple copies of CEV modules as
backup hardware and still vary some of the equipment inside (e.g. in much
the same way you can change out ISS experiment racks). Note that the LEM's
varied what they carried to the lunar surface.

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

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

On Tue, 10 May 2005 16:00:11 -0500, in a place far, far away, Herb
Schaltegger made the
phosphor on my monitor glow in such a way as to indicate that:

No, I'm pointing out that Shuttle-C is volume limited, *unlike* an STS
orbiter.

Go back and re-read your own posts. You're not making any sense.

Well, if I said that Orbiter was volume limited, I mistyped. My point
remains about Shuttle-C, which was.

and I'm pointing out that
Station modules have been mass-limited, not volume limited so your
argument that Shuttle-C is deficient due to volume limits is
irrelevant.

It would seem that your argument is the one that's irrelevant. The
point is that Shuttle-C would not have reduced the number of assembly
flights enough to make it worth the money, which (one more time) is
why it wasn't built.

No, *I* stated it wasn't built due to money, in response to your
comment that volume limitations (irrelevant volume limits, by the way)
were a main reason (which they were not).

Due to the fact that *it wasn't worth the money*. If it had been, the
money would have been found, by using the savings that it would have
resulted from fewer SSF launches.