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First flight of Block 5 successful launch and landing



 
 
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  #1  
Old May 14th 18, 11:23 AM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,715
Default First flight of Block 5 successful launch and landing

The first flight of SpaceX Falcon 9 Block 5 has happened. Both the
launch (the first communications satellite for Bangladesh) and the
landing of the first stage was successful.

I also saw a picture on Twitter of a recovery ship with what looked like
a fairing half under a tarp. This would have been fished out of the
water since Mr. Steven is on the west coast.

What we saw has been described as the end of the beginning for SpaceX.
At this point Block 5 should be standardized as much as possible so that
NASA will certify it for crewed flights. NASA really won't tolerate the
sort of continuous tweaking that SpaceX did on the first 50+ flights.

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.
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  #2  
Old May 15th 18, 04:00 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default First flight of Block 5 successful launch and landing

JF Mezei wrote on Mon, 14 May 2018
17:00:27 -0400:

On 2018-05-14 06:23, Jeff Findley wrote:

What we saw has been described as the end of the beginning for SpaceX.
At this point Block 5 should be standardized as much as possible so that
NASA will certify it for crewed flights. NASA really won't tolerate the
sort of continuous tweaking that SpaceX did on the first 50+ flights.


During launch commentary, the commentator mentioned no planned major
changes for Falcon 9 anymore, but that tweaks would likely continue to
be done for minor improvements.


Want to bet they won't be flying those tweaks on manned missions until
they're proven in?


Does NASA require "brand spanking new" Stage I for crewed flights or
tolerate re-used stages ?


Unknown, since there are no crewed flights to date. They 'tolerate'
previously flown stages and capsules on cargo missions. There's no
known reason to not do the same on manned flights. They'll probably
fly new until there have been 7 or so 'reused' launches that are
successful.


It should be noted that the very first Block 5 not only managed to land,
but landed on "I still love you" for its very first flight.


That's not a 'but'. I Still Love You is the name of the barge. It's
the only thing out there to land on, so if the stage successfully
landed that would be where.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #3  
Old May 15th 18, 12:13 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,715
Default First flight of Block 5 successful launch and landing

In article ,
says...

On 2018-05-14 06:23, Jeff Findley wrote:

What we saw has been described as the end of the beginning for SpaceX.
At this point Block 5 should be standardized as much as possible so that
NASA will certify it for crewed flights. NASA really won't tolerate the
sort of continuous tweaking that SpaceX did on the first 50+ flights.



During launch commentary, the commentator mentioned no planned major
changes for Falcon 9 anymore, but that tweaks would likely continue to
be done for minor improvements.


Sure, as long as NASA approves of the "minor improvements".

Does NASA require "brand spanking new" Stage I for crewed flights or
tolerate re-used stages ?


Last I heard they still want new stages for crewed flights. They have
said that eventually they may approve of the use of flight proven
stages.

It should be noted that the very first Block 5 not only managed to land,
but landed on "I still love you" for its very first flight. Shows
landing software/expertise has matured and still worked despite new
engines, new fins, new landing gear.


The "new" titanium grid fins have flown before. Cite:

Falcon 9 rocket launching Sunday sports fin upgrade
June 25, 2017
https://spaceflightnow.com/2017/06/2...nching-sunday-
sports-fin-upgrade/

Pretty much everything you say is new is an incremental upgrade over
previous versions, so the likelihood of failure is rather low, IMHO.
Also, I'd bet that all of these changes have been reviewed by NASA as
part of commercial crew. Some of the changes have been made at NASA's
request (like the Merlin 1D turbopump changes intended to eliminate
micro-fractures).

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.
  #4  
Old May 15th 18, 02:04 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Default First flight of Block 5 successful launch and landing

JF Mezei wrote on Tue, 15 May 2018
04:04:57 -0400:

On 2018-05-14 23:00, Fred J. McCall wrote:

That's not a 'but'. I Still Love You is the name of the barge. It's
the only thing out there to land on, so if the stage successfully
landed that would be where.


SpaceX has had higher success rate landing on ground than on the barges.


Well, no, not in any real sense. The only reason barge numbers are
lower is because all the development of the capability was done with
barges.


(I realise that landing on barges is also because of shortage of fuel
which limits control for landing).


Close but no cigar. Landing on land requires totally reversing the
velocity vector of the first stage after separation.


Still, a success on a barge with a "new" rocket on first time is very
impressive.


You might want to look at just how many successful barge landings they
have under their belt and when the last failure was.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #5  
Old May 16th 18, 08:20 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,773
Default First flight of Block 5 successful launch and landing

JF Mezei wrote on Tue, 15 May 2018
18:22:21 -0400:

On 2018-05-15 07:13, Jeff Findley wrote:


fins: had heard that the Falcon 9 Heavy was first to use them, but
your link proves otherwise.


What? You're not going to argue with him about it?



Pretty much everything you say is new is an incremental upgrade over
previous versions, so the likelihood of failure is rather low, IMHO.


Looking at the early failures, it was often "very close but no cigar".
So introducing lots of minor changes could be seen as major for the
landing software.


And monkeys could fly out your butt. Landing software is going to
care about physical characteristics. It's going to have tolerance for
mass changes because they need to be able to land with varying amounts
of fuel. So the only changes to really care about are CG and moment
arm changes. That's easy to design around on the ground.



Also, I'd bet that all of these changes have been reviewed by NASA as
part of commercial crew.


I have not seen the contract between NASA and SpaceX. Not sure how much
micromanagement authority they have. But for sure, they would have
specifcied a number of standards and succesful tests prior to NASA
sending their crews on SpaceX flights.


The commercial crew capability is being developed under NASA contract,
so they're going to get program reviews on changes.


If NASA is reluctant to accept on-going tweaks, that would push them to
agree to re-use of a rocket that is at a version NASA tested, instead of
insisting on always new stages which would force NASA to accept on-going
tweaks and improvements being made.


No.


--
"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
  #6  
Old May 16th 18, 01:16 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,773
Default First flight of Block 5 successful launch and landing

JF Mezei wrote on Wed, 16 May 2018
04:32:49 -0400:

On 2018-05-16 03:20, Fred J. McCall wrote:

And monkeys could fly out your butt. Landing software is going to
care about physical characteristics. It's going to have tolerance for
mass changes because they need to be able to land with varying amounts
of fuel. So the only changes to really care about are CG and moment
arm changes. That's easy to design around on the ground.


If it were that easy, they would have succeeded with their first
attempt. It took a number of attempts before they got it to work.


You're confused (as usual). Doing it the first time is hard. However,
once you've figured it out, so long as you don't make major changes in
CG or mass you don't even have to change the software.


The fact they succeeded on first attempt with a rocket where many
variables were changed shows the software has gained maturity and
reliability.


Or it shows that they took care that their changes didn't make any
significant changes in CG or moment arms.


Remember that the "revolutionary" part starts with Block 5 which can be
reused more than once, and this depends on reliable landings.


Remember that if the issue was 'reliable landings', they were already
doing that. The Block 5 changes are to reduce need for refurbishment
and make it easier when it is required.



The commercial crew capability is being developed under NASA contract,
so they're going to get program reviews on changes.


Yet, weren't you the one arguing that a commercial crew contract was no
different than putting their employees on a commercial jetliner?


No, I wasn't. Once again you are confused. What I was arguing was
that a commercial crew contract ON AN ALREADY EXISTING AND FAA
CERTIFICATED VEHICLE is no different from getting on a commercial
airliner. But this is not that. This is development of a vehicle and
system under NASA contract to carry NASA personnel AS CREW. No FAA
certificate; NASA controls the 'man rating' of the system.


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




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