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SLS launches likely delayed



 
 
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  #1  
Old April 17th 17, 03:46 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,817
Default SLS launches likely delayed

Looks like NASA's first two launches of the SLS for their lunar tests
will be delayed by a year or more. That means SpaceX will almost
certainly be there before them.




--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
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  #2  
Old April 17th 17, 12:51 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,761
Default SLS launches likely delayed

In article ,
says...

Looks like NASA's first two launches of the SLS for their lunar tests
will be delayed by a year or more.



Why am I not surprised? And of course, the OIG says that the problem is
"all of the programs supporting these first couple of flights are not
being funded at recommended levels". On the one hand I can see why
they're saying this. But on the other, with the kind of money we're
throwing at SLS, you'd think that NASA would be getting "enough".

That means SpaceX will almost certainly be there before them.


Possibly, but SpaceX isn't immune from schedule slips. They have lost
one Falcon 9 in flight and one during fueling for a hot fire test. Both
of these incidents delayed the program quite significantly.

Also, while I'm rooting for them, they still have not had a successful
Falcon Heavy test. Parallel staging is different enough from serial
staging that I'm not going to count my chickens before they hatch on
this one.

I've been labeled a "fan boy" who "drinks the kool-aid" many times with
regards to SpaceX, which confuses me since I think I usually have a
fairly healthy dose of skepticism whenever they do anything new. My
theory is the SpaceX "haters" just wish SpaceX would magically disappear
and everything would go back to "normal". But "normal" wasn't, and
still isn't, cutting it at either ULA or with SLS. With launch costs
far too high, we're never going to Mars, except for maybe a flags and
footprints mission. Hell, look at ULA's dwindling commercial launch
manifest.

Jeff
--
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These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #3  
Old April 17th 17, 05:25 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,761
Default SLS launches likely delayed

In article om,
says...

On 2017-04-16 22:46, Fred J. McCall wrote:
Looks like NASA's first two launches of the SLS for their lunar tests
will be delayed by a year or more. That means SpaceX will almost
certainly be there before them.



The announcement of the first flight being manned may have more to do
with the delay than budgets.


I don't think so. As far as I know, no firm decision has been made to
man the first flight. This article essentially admits that there are no
reserves in the budget to handle anything unexpected. So, anything
unexpected will simply push the schedule further to the right.

In fact, making EM-1 manned would also push the schedule further to the
right independent of anything else that's unexpected. For starters, the
"interim upper stage" is not "man rated" (it's a one-off stage which
won't be used for EM-2). That and there is considerable ground
infrastructure which would need to be in place for a manned flight that
wasn't planned to be in place for the currently unmanned EM-1.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #5  
Old April 17th 17, 06:07 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,817
Default SLS launches likely delayed

JF Mezei wrote:

On 2017-04-16 22:46, Fred J. McCall wrote:
Looks like NASA's first two launches of the SLS for their lunar tests
will be delayed by a year or more. That means SpaceX will almost
certainly be there before them.


The announcement of the first flight being manned may have more to do
with the delay than budgets.


What announcement? They haven't decided that yet. There is a delay
in the CURRENT schedule, which assumes the first launch is unmanned.
There is an even bigger delay if they decide to fly the first launch
manned.


That article had a link to a NASA web page which describes its concept
for Mars. That page does not paint Orion/SLS as sending man to Mars.


Then you must not have read it very carefully. You think they're
going to get there on the wings of butterflies, perhaps?


NASA wants to build ISS-2 in lunar orbit to test the transit ship there.
So SLS/Orion act as shuttles to/from the vehicle in lunar orbit.


Wrong. Go read it again.


NASA admits Orion isn't big enough to being crews on months long mission
to Mars and back.


Of course not. That's why there's a hab module that flies with it.
Again, go read it again.

snip


Question: when the expedition returns from Mars, it is easier to park
the big ship in Earth orbit or Moon orbit? (no aerobraking on Moon).


You don't 'park the big ship' because there is no 'big ship'. There's
an Ares capsule with a hab module. You punt the hab module and
reenter directly in the Ares capsule.

No, I don't think that's a great plan, but it is the plan. Go read it
again.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #6  
Old April 17th 17, 06:08 PM posted to sci.space.policy
Alain Fournier[_3_]
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Posts: 358
Default SLS launches likely delayed

On Apr/17/2017 * 12:07 PM, JF Mezei wrote :
On 2017-04-16 22:46, Fred J. McCall wrote:
Looks like NASA's first two launches of the SLS for their lunar tests
will be delayed by a year or more. That means SpaceX will almost
certainly be there before them.



The announcement of the first flight being manned may have more to do
with the delay than budgets.

That article had a link to a NASA web page which describes its concept
for Mars. That page does not paint Orion/SLS as sending man to Mars.

NASA wants to build ISS-2 in lunar orbit to test the transit ship there.
So SLS/Orion act as shuttles to/from the vehicle in lunar orbit.

NASA admits Orion isn't big enough to being crews on months long mission
to Mars and back.

If you will assemble a transit ship in lunar orbit, you might need
something like SLS to bring modules up there.

Assembling in LEO costs less in module launches, but more in fuel to
escape from Earth. Assembling in Lunar orbit costs more in launches of
modules, but less to escape earth/moon orbit. Does the balance tip
heavily on one of those or is it more or less even ?


It is cheaper to do most of your acceleration low in the gravity well.
You can read on the Oberth Effect, for instance:
https://en.wikipedia.org/wiki/Oberth_effect


Alain Fournier

  #7  
Old April 17th 17, 06:09 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,817
Default SLS launches likely delayed

JF Mezei wrote:

On 2017-04-17 12:25, Jeff Findley wrote:

man the first flight. This article essentially admits that there are no
reserves in the budget to handle anything unexpected.


Fair enough.

But by now, wouldn't SLS and Orion each be well into the
tests/validation period so that the major flaws have already been found
and dealt with?


How many times have they flown a full up SLS with a full up Ares?

Hint: Zero.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #8  
Old April 17th 17, 11:50 PM posted to sci.space.policy
Alain Fournier[_3_]
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Posts: 358
Default SLS launches likely delayed

On Apr/17/2017 at 6:07 PM, JF Mezei wrote :
On 2017-04-17 13:07, Fred J. McCall wrote:

That article had a link to a NASA web page which describes its concept
for Mars. That page does not paint Orion/SLS as sending man to Mars.


Then you must not have read it very carefully. You think they're
going to get there on the wings of butterflies, perhaps?



I was refering to this:
https://www.nasa.gov/feature/deep-sp...t-destinations


(It was linked to in the artciel your refered to).

It calls ISS-2 "Deep Space Gateway".

##
build a crew tended spaceport in lunar orbit within the first few
missions that would serve as a gateway to deep space
##

##
For those destinations farther into the solar system, including Mars,
NASA envisions a deep space transport spacecraft. This spacecraft would
be a reusable vehicle that uses electric and chemical propulsion


In an earlier post, you asked about the fuel impact of doing assembly
in Lunar orbit vs in LEO. I had replied that it is cheaper to do your
acceleration low in the gravity well, meaning your better in LEO,
because of the Oberth effect. Well, if electric propulsion is used,
that's another story. Because electric propulsion can be very weak
but very efficient. So you might not be able to do all your acceleration
low in the gravity well, but the very high efficiency of electric
propulsion can compensate for the gravity loss of not using the Oberth
effect.

So if electric propulsion is used, building your spaceship in Lunar
orbit might make sense. I'm saying might, not does, because it depends
on many details. But there can be some mission architectures were
building in Lunar orbit is the best way to go.

and
would be specifically designed for crewed missions to destinations such
as Mars. The transport would take crew out to their destination, return
them back to the gateway, where it can be serviced and sent out again.
##

It odesn't mention SLS used to get to mars, it mentions its cargo
capacity to that Deep Space Gateway.



Alain Fournier

  #9  
Old April 18th 17, 01:20 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,817
Default SLS launches likely delayed

JF Mezei wrote:

On 2017-04-17 13:07, Fred J. McCall wrote:

That article had a link to a NASA web page which describes its concept
for Mars. That page does not paint Orion/SLS as sending man to Mars.


Then you must not have read it very carefully. You think they're
going to get there on the wings of butterflies, perhaps?



I was refering to this:
https://www.nasa.gov/feature/deep-sp...t-destinations


(It was linked to in the artciel your refered to).


I know what you were referring to.


It calls ISS-2 "Deep Space Gateway".


No, it doesn't, since ISS and the Deep Space Gateway are about as
similar as the White House and an outhouse.


##
build a crew tended spaceport in lunar orbit within the first few
missions that would serve as a gateway to deep space
##

##
For those destinations farther into the solar system, including Mars,
NASA envisions a deep space transport spacecraft. This spacecraft would
be a reusable vehicle that uses electric and chemical propulsion and
would be specifically designed for crewed missions to destinations such
as Mars. The transport would take crew out to their destination, return
them back to the gateway, where it can be serviced and sent out again.
##


Well, that seems to answer your question, doesn't it? So why were you
asking, again? Bait and switch, anyone? Wasn't Orion (I keep calling
that thing 'Ares' for some reason) advertised as needed to go beyond
the Moon? They're going to 'service' their transit vehicle using
space walks?


It odesn't mention SLS used to get to mars, it mentions its cargo
capacity to that Deep Space Gateway.


So no need for Orion, then, and SLS can and should be replaced by a
cheaper launcher (like SpaceX Super Heavy or Blue Origin New Glenn).

This is the typical NASA plan; be all things to all people so that
it's a lousy plan for almost everything. Put your interplanetary way
station in lunar orbit, even though that makes little sense, just so
you get something to let you change directions and do 'Moon First' in
case someone changes their mind. You have no decent capability to
check out or repair your Mars vehicle (which is only a glimmer in
someone's eye for additional funding right now), since it is always on
orbit. That means it will get flown until something in the engine(s)
goes 'poof' and you lose a mission. NASA used to say a Mars ship
should have thermal nuclear propulsion and I'm pretty sure their
reference mission still says that, but this thing is "electric and
chemical". And it better be mostly chemical, or your transfer orbit
is just going to be too slow. They presumably also need some way to
get down from Mars orbit to the service, since you certainly aren't
going to land this thing on Mars - which means you need to haul enough
fuel to Mars for the whole trip.

At least their Orion plus Hab plan had some small hope of actually
getting people to Mars. This thing will never get built.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
 




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