nasa wants to transport passengers to ISS

In article m,
says...

https://www.google.com/#q=NASA+Books...pace+Flig hts

Pardon my ignorance here, but that got me to a WSJ article on NASA
committing to buying seats on Boeing CST100 and SpaceX. No mention of Orion.

What is the progress of man-rating Delta 4 on which Orion is to be
launched ? (we all agree that with only 4 SLS launches, odds are low
Orion would do any mission on it, right ? )

Delta IV won't be "man rated". In fact, Delta IV is in the process of
being phased out by ULA.

I know Orion has a heatshield designed for re-entry from higher orbit.
(aka: hotter re-entry). Would CST 100- use the same tech or would they
use heat shield only capable of LEO re-entry ?

Just wondering how much mission overlap there is in reality between
Orion and CST100. (We all know CST100 won't bring men beyond LEO, won't
launch on a single SLS to mars and back and all other NASA PR)

Besides the shape and the fact that they both transport crew, they're
quite different. If they weren't different, how could CST-100 be so
much cheaper?

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

In article ,
says...

JF Mezei wrote:


Just wondering how much mission overlap there is in reality between
Orion and CST100. (We all know CST100 won't bring men beyond LEO, won't
launch on a single SLS to mars and back and all other NASA PR)


The big difference isn't in the heat shields but in the duration the
vehicles have without being docked. CST 100 is only good for about
2.5 days (60 hours). Orion is good for an order of magnitude longer
time (21.5 days). I don't find a good figure for Dragon V2, although
it is probably closer to CST 100 than to Orion. However, since all
that duration capability resides in a service module (for both Orion

That and for a Mars mission 21.5 days won't cut it. The fact is, the
crew return vehicle doesn't need much in the way of independent flight
duration since on most beyond LEO missions, it will be docked to a HAB
of some sort anyway.

The only reason Orion "needs" any sort of "long duration" at all, is
because there simply isn't any money to fund development of meaningful
hardware like a deep space HAB, moon lander, Mars lander, and etc.

Isn't Orion supposed to be designed so that a contingency EVA can be
done from Orion itself? I don't believe CST-100 or Dragon V2 were
designed with that requirement in mind. That might actually be a useful
capability, if the airlock on your HAB fails for some reason and you're
far from home and *need* to do an EVA ASAP.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

In article m,
says...

On 15-09-08 21:54, bob haller wrote:

yeah and the acoustic vibrations nearly created a disaster. building the shuttle without launch boost escape should of been proscuted criminally


In a Shuttle scenario, could the structure have widthstood premature
activation of the SRB separation pyros ? (aka: ditch the SRBs prematurely) ?

Nope. SRB separation while still firing would not have been a "clean"
event. That's why a RTLS abort included continuing to fly until the
SRBs "burned out".

And in current rockets that use SRBs can this be done ? Or does the
instant loss of thrust from SRbs create too much stress for the structure ?

It's not even planned for, as far as I can tell. I believe the large
Orion escape system can pull it away from SLS if the main engines shut
down and the SRBs are still firing. The irony here is that Orion needs
a relatively large ATK escape rocket just in case it needs to escape
from the large ATK SRBs strapped to the side of the SLS core stage.

The worst case scenario is a SRB case rupture where Orion has to escape
from a giant fireball of flaming chunks of SRB propellant.

Large solids on a manned launch vehicle is penny wise (low development
costs) and pound foolish (high per flight costs, high handling and
infrastructure costs, and obscenely dangerous failure modes).

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

"Jeff Findley" wrote in message
...

In article m,
says...

https://www.google.com/#q=NASA+Books...pace+Flig hts

Pardon my ignorance here, but that got me to a WSJ article on NASA
committing to buying seats on Boeing CST100 and SpaceX. No mention of
Orion.

What is the progress of man-rating Delta 4 on which Orion is to be
launched ? (we all agree that with only 4 SLS launches, odds are low
Orion would do any mission on it, right ? )

Delta IV won't be "man rated". In fact, Delta IV is in the process of
being phased out by ULA.

I know Orion has a heatshield designed for re-entry from higher orbit.
(aka: hotter re-entry). Would CST 100- use the same tech or would they
use heat shield only capable of LEO re-entry ?

Just wondering how much mission overlap there is in reality between
Orion and CST100. (We all know CST100 won't bring men beyond LEO, won't
launch on a single SLS to mars and back and all other NASA PR)

Besides the shape and the fact that they both transport crew, they're
quite different. If they weren't different, how could CST-100 be so
much cheaper?

I can't tell if you're being facetious or not, but in case you're not, my
answer would be:

One is designed to be a commercial for-profit craft and the other to fulfill
a government contract (presumably cost plus).

In case you are... agreed :-)


Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

In article ,
says...

"Jeff Findley" wrote in message
...

Besides the shape and the fact that they both transport crew, they're
quite different. If they weren't different, how could CST-100 be so
much cheaper?

I can't tell if you're being facetious or not, but in case you're not, my
answer would be:

One is designed to be a commercial for-profit craft and the other to fulfill
a government contract (presumably cost plus).

In case you are... agreed :-)

Different requirements, different solutions, different vehicles. It's
just that many of the requirements for Orion are made up since there are
no missions for the thing. Plus its size was dictated by the former
NASA Administrator. It's bigger than it really needs to be since any
mission longer than a few days really needs a HAB, airlock, and etc.
All of that drives up cost quite needlessly.

CST-100 is closer to what NASA really needs than Orion. But Orion is
closer to what the former Administrator wanted, so it's what we're
ultimately stuck with.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

"Jeff Findley" wrote in message
...

In article ,
says...

"Jeff Findley" wrote in message
...

Besides the shape and the fact that they both transport crew, they're
quite different. If they weren't different, how could CST-100 be so
much cheaper?

I can't tell if you're being facetious or not, but in case you're not, my
answer would be:

One is designed to be a commercial for-profit craft and the other to
fulfill
a government contract (presumably cost plus).

In case you are... agreed :-)

Different requirements, different solutions, different vehicles. It's
just that many of the requirements for Orion are made up since there are
no missions for the thing. Plus its size was dictated by the former
NASA Administrator. It's bigger than it really needs to be since any
mission longer than a few days really needs a HAB, airlock, and etc.
All of that drives up cost quite needlessly.

CST-100 is closer to what NASA really needs than Orion. But Orion is
closer to what the former Administrator wanted, so it's what we're
ultimately stuck with.

Agreed. But I suspect if Orion was done by a commercial company its costs
would still be noticeably lower, despite the requirements.

But I'm cynical that way.

I still think our next trip beyond LEO will be some sort of Dragon v2 (v3?)
or now perhaps a CST-100 and a Bigelow module or two (perhaps 2 with a BEAM
at one end to act as an airlock).

The details aren't critical as much as I suspect we'll see a commercial
attempt before NASA.

(outside chance someone other than the US goes beyond LEO next, but I doubt
it.)


Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

"JF Mezei" wrote in message
eb.com...

On 15-09-09 22:50, Greg (Strider) Moore wrote:

I still think our next trip beyond LEO will be some sort of Dragon v2
(v3?)
or now perhaps a CST-100 and a Bigelow module or two (perhaps 2 with a
BEAM
at one end to act as an airlock).

I think it is more likely to be ISS v2.0 with a Dragon, Soyuz and/or
CST100 and/pr Orion attached to it. And they will be rated for 2 years
instead of 6 months.

I can almost certainly guarantee it won't be an ISS v2.0. It'll be all
American made or nearly so and done as a private commercial flight or
something the government ends up funding.



Consider a mission to mars: one huge requirement is that the crew be fit
enough to walk in gravity after spending 6 months in space.


It won't be a mission to Mars. It may simply be a test loop around the Moon
or a visit to a near earth asteroid.
But in either case it'll be a rather short trip to test equipment and ideas
beyond LEO.


Consider storage requirements for food, water, consumables, toilet
paper, oxygen, nitrogen etc.

The advantage of ISS is that it gives us a good grasp on how much
storage is needed, how efficient water reclamation is, how often it
fails, (same for O2 generation and Co2 removal).

We know storage requirements That's pretty easy. And if you're planning
something just a week-month long like the above outlined trips, honestly,
you just throw more redundancy and mass at the problem. Something SpaceX can
do cheaper than anyone else.






--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

In article ,
says...

"JF Mezei" wrote in message
eb.com...

Consider storage requirements for food, water, consumables, toilet
paper, oxygen, nitrogen etc.

The advantage of ISS is that it gives us a good grasp on how much
storage is needed, how efficient water reclamation is, how often it
fails, (same for O2 generation and Co2 removal).

We know storage requirements That's pretty easy. And if you're planning
something just a week-month long like the above outlined trips, honestly,
you just throw more redundancy and mass at the problem. Something SpaceX can
do cheaper than anyone else.

Agreed. We had a good handle on that after Skylab, so by the mid-1970s
we could have done just about anything "deep space" with Apollo derived
hardware. But, it was not meant to be since Skylab and ASTP were done
with Apollo surplus hardware and nothing new was being built, due to
shuttle development.

Granted, Skylab style life support was a bit more "open loop" than what
we have on ISS now, but that wouldn't have been a show-stopper. For
example, you need a lot of extra water anyway to surround your storm
shelter since it serves as a radiation shield, so who really cares if
you are recycling it or not?

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer