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Space X 2nd stage recovery



 
 
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  #51  
Old April 28th 18, 05:30 PM posted to sci.space.policy
Jeff Findley[_6_]
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Default Space X 2nd stage recovery

In article ,
says...

In article ,
says...
Oh, I agree. SpaceX has no reason to undertake the diversion of
developing and certifying a Service Module for Dragon V2 any more than
they need to undertake the diversion of man rating Falcon Heavy.
Dragon V2 is intended to be a purely LEO system, which means that
Falcon 9 is more than adequate. SpaceX direction for deep space work
is BFR/BFR Spaceship. Anything that distracts from that that isn't
needed or part of the long range plan is wasted time and money.


Agreed. Now is not the time for them to get distracted by developing
hardware that's a dead end. Falcon 9, Falcon Heavy, and Dragon 2 are
"good enough". Spending additional development resources on expanding
their capabilities just doesn't make any sense when they have BFR/BFS
development ahead of them.


Yeah, I know, replying to myself. Bad netiquette. Sorry...

I suppose the exception for SpaceX is hardware recovery. After the last
Falcon 9 launch from Cape Canaveral, there were pictures at Port
Canaveral showing what looked like two fairing halves. And we know
they're working on 2nd stage recovery.

The exceptions are easy to explain. They are tests performed *after*
the primary mission objectives have been met for the hardware being
tested. The fairings and 2nd stage will continue to perform their
primary mission before attempts to recover them.

Adding a service module to Dragon, in place of the simpler trunk, would
be possible, but it would be adding to Dragon's primary mission
capabilities and the crew's lives would depend on the proper functioning
of the service module. As such, it would have to be fully "crew rated"
in a way that relatively benign recovery devices simply do not.

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.
  #52  
Old April 28th 18, 08:35 PM posted to sci.space.policy
David Spain
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Default Space X 2nd stage recovery

On 4/28/2018 2:29 PM, JF Mezei wrote:
On 2018-04-28 12:30, Jeff Findley wrote:

Adding a service module to Dragon, in place of the simpler trunk, would
be possible, but it would be adding to Dragon's primary mission
capabilities and the crew's lives would depend on the proper functioning
of the service module. As such, it would have to be fully "crew rated"
in a way that relatively benign recovery devices simply do not.



Yeah but what does "crew rated" mean outside of NASA? If say SpaceX were
flying it's own customers not NASA astronauts? Also I fear "crew rating"
when NASA is a primary customer is a bit of a political tool that can be
used to hammer contractors in line in case they get too far out in front
of SLS.



Since BFR/BFS are being built in separate facility, would it really hurt
BFR/BFS if NASA were to send mega pork money for SpaceX to build an
upgraded Dragon with service module to do moon excursions? If the later
is built at Hawthorne facility that is focused on Falcon/Dragon, it
shouldn't hinder BFR/BFS much.


Well I'm not going to speak for SpaceX. If such a thing were to happen
it would be up to SpaceX to respond in a fashion that makes sense for
SpaceX. My blathering about it without any knowledge of what is
transpiring within SpaceX is pointless. Blathering about it WITH
knowledge of what is transpiring within SpaceX (outside of being a
journalist) probably would get me fired.

Yes, it makes more sense for SpaceX to respond to RFP with BFR/BFS
proposal for moon. The mega pork from NASA would help fund BFR/BFS
development.


Yes it does. I wouldn't call it pork. I'd call it a "public investment
in the future". :-)


But if BFR/BFS proposal would not win, then it is better for SPaceX to
win with Dragon/Falcon so at least profits from that work go to fund
BFR/BFS. (aka: better than nothing)


Depends. Maybe, maybe not. Distraction of an engineering organization
has its own costs.

Longer term though, if BFR/BFS do to manned space travel what Fan[/l]con9
reusability has done for cargo costs, then eventually, it will win
any/all NASA contracts for manned space travel.


Maybe. Depends upon how the RFP is written. Sometimes they can be pretty
specific and exclusionary. "Contracted vendor must be able to legally
display "Boeing" name and insignia in highly visible portion of
vehicle."... Well, usually not this bad...

Dave



  #53  
Old April 29th 18, 12:42 AM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 2,307
Default Space X 2nd stage recovery

In article , says...

On 2018-04-28 12:30, Jeff Findley wrote:

Adding a service module to Dragon, in place of the simpler trunk, would
be possible, but it would be adding to Dragon's primary mission
capabilities and the crew's lives would depend on the proper functioning
of the service module. As such, it would have to be fully "crew rated"
in a way that relatively benign recovery devices simply do not.



Yeah but what does "crew rated" mean outside of NASA? If say SpaceX were
flying it's own customers not NASA astronauts? Also I fear "crew rating"
when NASA is a primary customer is a bit of a political tool that can be
used to hammer contractors in line in case they get too far out in front
of SLS.


I believe the FAA has to sign off on crewed vehicles not flown by NASA.
So, there will be a certification process, but it will be independent of
NASA. NASA, of course, doesn't have to FAA certify anything because
they're a government agency (like DOD). NASA gets to write their own
rules and their own waivers to the rules! NASA gets to have their cake
and eat it too!

Take the failure to develop vertical landing of Dragon 2 as an example.
NASA didn't want SpaceX testing vertical Dragon 2 landings on cargo
delivery missions to ISS. To be fair to NASA, this sort of testing
would have had a non-zero chance of NASA losing some of its hardware and
experiments it was returning from ISS. This effectively killed
propulsive landing because paying for a completely separate test
campaign would have been completely on SpaceX's dime.

They developed Falcon 9 booster landing in such a way, so SpaceX thought
it reasonable for Dragon 2 as well. But booster landings have
absolutely zero impact on the customers if they fail. Not so for Dragon
2 propulsive landings. So NASA wanted to stick with what they know,
which arguably stifles innovation in the process.

The moral of the story is that you have to do things "the NASA way" when
NASA is paying the bills.

BFR/BFS, however, is going to be developed on SpaceX's dime (and their
investors, of course), so NASA won't have any say in the matter like
they did with Dragon 2 and Falcon 9 Block 5. If BFR/BFS is successful,
NASA will simply be a customer. If they don't like it, they don't have
to fly on BFR/BFS, now do they?

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.
  #54  
Old April 29th 18, 03:42 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Space X 2nd stage recovery

JF Mezei wrote on Sat, 28 Apr 2018
14:15:42 -0400:

On 2018-04-27 23:32, Fred J. McCall wrote:

Oh, I agree. SpaceX has no reason to undertake the diversion of
developing and certifying a Service Module for Dragon V2 any more than
they need to undertake the diversion of man rating Falcon Heavy.


This week saw VP Pence name the new NASA administrator. In all the PR I
heard, going back to the moon was mentioned. Also mentiond, working with
commercial suppliers.

Whether going to the Moon makes sense or not, if NASA wants to go and is
willing to pay, should SpaceX pass on such an opportunity?


Of course not.


The bigger question is whether SpaceX should bid for such a project with
Dragon and a glorified trunk/service module or bid with BFR/BFS.


BFR/BFR Spaceship. For lunar missions, BFR Spaceship could (with an
LEO refuel) fly to the Moon with enough cargo and personnel to
establish a base, land, offload, and return to Earth without
refueling.

More likely 'commercial' application is for cargo. NASA is going to
want to put people on SLS/Orion. I don't think they're going to pay
for developing another manned system to replace their pet. Dragon V2
weighs about 6.4 tonnes 'dry' and around 10 tonnes loaded with cargo.
That's what you need to get to TLI. Could the Super Dracos be used
for a TLI burn? I don't know if they have enough fuel for that. If
not, you need some sort of 'high energy upper stage' or a real Service
Module engine to get you there. Falcon 9 doesn't have enough grunt,
nor does Falcon Heavy in reusable mode (unless the Super Dracos are
good enough, in which case it MAY be able to get 10 tonnes to TLI in
reusable form). So you're likely using Falcon Heavy and throwing away
three cores with every launch. Musk says this would take launch cost
up to around $150 million (plus the cost of Dragon for cargo). Could
'Falcon Super Heavy' do the job in reusable mode? Maybe. NASA
*SHOULD* ask what that would cost to develop, but they won't because
it would probably wind up being a direct competitor to SLS if you're
willing to expend the cores.


From a components point of view (big picture) should SpaceX decide to
get Dragon to the moon and back, would it be easier modify a 2nd stage
to have bigger tanks and perhaps its own solar panels for longer
autonomy as opposed to making a separate service module?


No, and that wouldn't get the job done in any case. The problem isn't
electrical power, although Dragon only produces about a fifth of what
Orion Service Module does. The problem is all the consumables (water,
air, etc). And before you say it, no, you can't just stuff all that
in the trunk (and you don't have as much 'cargo capacity' as you
think, anyway, since part of that is consumed by your 'people' cargo).

Any connections of any size to the 'trunk' are going to require
punching holes in the Dragon heat shield, which is probably NOT
something you want to do, particularly on lunar returns. So even with
a 'real' service module, you're going to have to do some reengineering
on the Dragon capsule itself if you're sticking your extra consumables
outside the capsule.


Doesn't it become much easier to man-rate and upgraded man-rated model
vs man rating something new?


No. When you start making big modifications to hardware and how
you're going to use it, that is "something new". And they'd still
have to go down the road of 'man rating' Falcon Heavy AND assume they
were throwing it away (because it can't get to the Moon with
sufficient payload in anything but expendable mode).


--
"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
  #55  
Old April 29th 18, 03:45 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Space X 2nd stage recovery

JF Mezei wrote on Sat, 28 Apr 2018
14:29:09 -0400:

On 2018-04-28 12:30, Jeff Findley wrote:

Adding a service module to Dragon, in place of the simpler trunk, would
be possible, but it would be adding to Dragon's primary mission
capabilities and the crew's lives would depend on the proper functioning
of the service module. As such, it would have to be fully "crew rated"
in a way that relatively benign recovery devices simply do not.


Since BFR/BFS are being built in separate facility, would it really hurt
BFR/BFS if NASA were to send mega pork money for SpaceX to build an
upgraded Dragon with service module to do moon excursions? If the later
is built at Hawthorne facility that is focused on Falcon/Dragon, it
shouldn't hinder BFR/BFS much.


Engineering talent to do designs for such things is just floating
around available.


Yes, it makes more sense for SpaceX to respond to RFP with BFR/BFS
proposal for moon. The mega pork from NASA would help fund BFR/BFS
development.

But if BFR/BFS proposal would not win, then it is better for SPaceX to
win with Dragon/Falcon so at least profits from that work go to fund
BFR/BFS. (aka: better than nothing)


You're assuming they're looking for 'commercial crew'. Given that
that would compete directly with SLS/Orion, you probably shouldn't
hold your breath waiting for that.


Longer term though, if BFR/BFS do to manned space travel what Fancon9
reusability has done for cargo costs, then eventually, it will win
any/all NASA contracts for manned space travel.


Don't bet on it. They'll have some reason for wanting to use
SLS/Orion.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #56  
Old April 29th 18, 06:12 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Space X 2nd stage recovery

JF Mezei wrote on Sat, 28 Apr 2018
22:08:48 -0400:

On 2018-04-28 19:42, Jeff Findley wrote:

BFR/BFS, however, is going to be developed on SpaceX's dime (and their
investors, of course), so NASA won't have any say in the matter like
they did with Dragon 2 and Falcon 9 Block 5. If BFR/BFS is successful,
NASA will simply be a customer. If they don't like it, they don't have
to fly on BFR/BFS, now do they?


If NASA sends some of its EMPLOYEES on a SpaceX ride, it is legally
responsible for the safety of its employees and wants to ensure that
ride is safe.


No it isn't. Cite said law.


This is different from SpaceX selling seats directly to tourists who are
solely responsible for their own life when they sign the contract with
SpaceX.


Not so much, no.


So the minute NASA buys transport for its employees, it will likely
insist on "man rated" standards. How flexible NASA becomes in ensuring
the transport meets standards is likely the bigger question.


No. It will do that long before it 'buys transport' in order to avoid
buying said 'transport' and keep funding SLS/Orion. If BFR/BFR
Spaceship is flying commercial passengers when it does this it becomes
pretty transparent and opens NASA up for a really big lawsuit for
slandering a SpaceX business.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #57  
Old April 29th 18, 01:42 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 2,307
Default Space X 2nd stage recovery

In article ,
says...

On 2018-04-28 19:42, Jeff Findley wrote:

BFR/BFS, however, is going to be developed on SpaceX's dime (and their
investors, of course), so NASA won't have any say in the matter like
they did with Dragon 2 and Falcon 9 Block 5. If BFR/BFS is successful,
NASA will simply be a customer. If they don't like it, they don't have
to fly on BFR/BFS, now do they?



If NASA sends some of its EMPLOYEES on a SpaceX ride, it is legally
responsible for the safety of its employees and wants to ensure that
ride is safe.


Of course it is.

This is different from SpaceX selling seats directly to tourists who are
solely responsible for their own life when they sign the contract with
SpaceX.


No, it's not. NASA pays for flights for its employees all the time on
FAA certified passenger jet aircraft. NASA does not have a separate
certification process for passenger jet aircraft that are certified for
its employees to fly on.

So the minute NASA buys transport for its employees, it will likely
insist on "man rated" standards. How flexible NASA becomes in ensuring
the transport meets standards is likely the bigger question.


They can insist all they want, but with an FAA certification, SpaceX
can, politely of course, tell NASA where to stick it.

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.
  #60  
Old April 29th 18, 08:22 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Space X 2nd stage recovery

JF Mezei wrote on Sun, 29 Apr 2018
01:52:03 -0400:

On 2018-04-28 22:42, Fred J. McCall wrote:

More likely 'commercial' application is for cargo. NASA is going to
want to put people on SLS/Orion.


If politicians send a message to NASA that after they run out of
budgetted engines, they won't get additional money and that they should
seek commercial launches, you'll find NASA will have a contest to pick 2
or 3 launch providers.


If unicorns **** magic pixie dust we'll all be eating steak.



Any connections of any size to the 'trunk' are going to require
punching holes in the Dragon heat shield, which is probably NOT
something you want to do,


Don't they already have connections for power. As I recall they "wrap"
around the heat shield and penetrate the capsule higher up.


Yes, they do, AND THOSE ARE DESIGNED IN. You're now talking about
doing the same thing with stuff like hypergolic fuel lines. All that
stuff burns when you fire the Super Dracos, which kind of defeats the
purpose of putting fuel down there in the trunk (and destroys the
vehicle on engine fire into the bargain).



have to go down the road of 'man rating' Falcon Heavy AND assume they
were throwing it away (because it can't get to the Moon with
sufficient payload in anything but expendable mode).


SpaceX would likely compare the economics of multiple re-usable flights
to assemble/fuel the lunar ship versus single flight which sacrifices a
falcon heavy. (2 Falcon9 stages)


You cannot refuel a Dragon capsule anywhere but on the ground. So
you're now postulating an entirely new 'trunk', an entirely new
capsule, an entirely new refueling vehicle, ...


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
 




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