Falcon reusability

Am I missing something, or is SpaceX, whose openness in many ways is
praiseworthy, simply not talking about any progress toward
demonstrating the resuability of Falcoln 1e and Falcon 9 first stages?

On 2/6/2011 3:06 PM, Matt wrote:
Am I missing something, or is SpaceX, whose openness in many ways is
praiseworthy, simply not talking about any progress toward
demonstrating the resuability of Falcoln 1e and Falcon 9 first stages?

I never found them very open in discussing what they were doing; in
fact, they once threatened to sue me when I mentioned a posting by
someone else that one of their early Merlin rocket engines had puked up
its replaceable ablative coating on the inside of its combustion chamber.
I noted that on the last launch, they were saying that weather in the
first stage recovery zone was unacceptable a few minutes before launch,
but launched anyway.
Musk has stated that they would like to get the first stage recovery
system to work at some future point, but it doesn't seem to be a
super-pressing issue at the moment for them.
At some point, they are going to look at the recovery system problems
and weigh them off against the increase in vehicle payload they could
get if they just ditch it and its weight, and make the Merlin engines
in a form that doesn't need to be reusable. The recovery system always
seemed to be at philosophical odds with the rest of the Falcon concept
to me, which seemed to be was to build as simple and low cost launch
system as was possible.
In the case of the Falcon 1, the problem seemed to be that the recovery
parachutes were getting damaged by the exhaust of the second stage
Kestrel engine as it ignited.
In the case of Falcon 9, it sounds like the first stage is structurally
failing as it descends back into the atmosphere; that would be a lot
harder to fix that just adding thermal protection to the parachutes,
like on Falcon 1.


Pat

Pat Flannery wrote:
In the case of Falcon 9, it sounds like the first stage is structurally
failing as it descends back into the atmosphere; that would be a lot
harder to fix that just adding thermal protection to the parachutes,
like on Falcon 1.

Hmm. Interesting. I agree I think the "plan" as of today it just get the
frickin thing to orbit payload, worry about recovery (aka cost reduce) later.
Musk is essentially on record with that comment...

However, your observation brings up an interesting question. Why on earth are
they trying to recover the entire stage? What's the value of recovering
tankage? Couldn't the engines be ejected and recovered separately or as a unit
and just let the tankage sink?

Or is it less complex/costly to recover the entire stage? That seems
counterintuitive on first examination. But maybe they need/rely on the empty
tankage to keep the system buoyant and thus it's cheaper that way than to add
inflatables to the engines or engine section separately to keep it afloat.

Another thought. How far downrange does this stage splashdown? If it's still
on the continental shelf, it might be recoverable w/o buoyancy if the internal
structure can either withstand to hold out sea water long enough for an
undersea recovery assuming most of its decent velocity is shed with parachutes.

But as you point out it's a rocket not a boat, nor a floor wax nor dessert
topping...

Dave

In article 41748521-7420-4fbd-84e9-6bdeaf477c72@
24g2000yqa.googlegroups.com, says...

Am I missing something, or is SpaceX, whose openness in many ways is
praiseworthy, simply not talking about any progress toward
demonstrating the resuability of Falcoln 1e and Falcon 9 first stages?

Any progress they are making is proprietary. I doubt they want to share
any of the details.

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011

On 2/6/2011 9:47 PM, David Spain wrote:

However, your observation brings up an interesting question. Why on
earth are they trying to recover the entire stage? What's the value of
recovering tankage? Couldn't the engines be ejected and recovered
separately or as a unit and just let the tankage sink?


That was my thought also; they may want the electronics on the stage as
well as the engines, but the value of the tankage is bound to be far
less than the nine Merlin engines.
NASA worked on concepts for recovering the first stages of both the
Saturn I and Saturn V intact also, but neither idea went anywhere.
I don't know about Saturn I, but the Saturn V first stage used to
break up during descent also.


Or is it less complex/costly to recover the entire stage? That seems
counterintuitive on first examination. But maybe they need/rely on the
empty tankage to keep the system buoyant and thus it's cheaper that way
than to add inflatables to the engines or engine section separately to
keep it afloat.


You could probably add something inflatable to the parachutes it
descended on to keep it afloat without too much trouble; it could even
be filled by ram air pressure using one-way valves as the chute descended.


Another thought. How far downrange does this stage splashdown? If it's
still on the continental shelf, it might be recoverable w/o buoyancy if
the internal structure can either withstand to hold out sea water long
enough for an undersea recovery assuming most of its decent velocity is
shed with parachutes.


On the June 2010 flight, the Falcon 9 first stage came down at 32 deg
07'N, 069 deg 15'W
http://www.nasawatch.com/archives/20...n-9-nails.html
A quick check with Google Earth shows that it came down _way_ off the
edge of the continental shelf in water over 17,000 feet deep, over 700
miles from the launch point.

Pat

On Feb 7, 8:31*am, Jeff Findley wrote:
In article 41748521-7420-4fbd-84e9-6bdeaf477c72@
24g2000yqa.googlegroups.com, says...



Am I missing something, or is SpaceX, whose openness in many ways is
praiseworthy, simply not talking about any progress toward
demonstrating the resuability of Falcoln 1e and Falcon 9 first stages?

Any progress they are making is proprietary. *I doubt they want to share
any of the details.

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011

It is a simple cost trade-off. Recovery is just not economically
feasible. Why does this bother people?

In article c32190f6-9c5e-4b22-9e60-e97c83380648
@m16g2000prc.googlegroups.com, says...

On Feb 7, 8:31*am, Jeff Findley wrote:
In article 41748521-7420-4fbd-84e9-6bdeaf477c72@
24g2000yqa.googlegroups.com, says...



Am I missing something, or is SpaceX, whose openness in many ways is
praiseworthy, simply not talking about any progress toward
demonstrating the resuability of Falcoln 1e and Falcon 9 first stages?

Any progress they are making is proprietary. *I doubt they want to share
any of the details.

It is a simple cost trade-off. Recovery is just not economically
feasible. Why does this bother people?

SpaceX is still working on recovery of the first stage. Even if they
don't re-use any hardware, it will give them a chance to inspect the
first stage engine for wear and tear. It's possible the flown engines
are holding up well, but it's also possible that the flown engines were
near failure. Without recovering and inspecting the engines, it's hard
to tell how they're holding up.

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011

Thanks. Obviously proprietary information is close-hold for any
company, but I was looking at their published materials and trying to
determine whther they had in fact recovered Stage 1 from any of their
launches so far.

Matt

On 2/7/2011 11:08 AM, Matt wrote:
Thanks. Obviously proprietary information is close-hold for any
company, but I was looking at their published materials and trying to
determine whther they had in fact recovered Stage 1 from any of their
launches so far.

They've never succesfully recovered the first stage of a Falcon 1 or
Falcon 9.
They didn't even put the chutes aboard Falcon 1 flight five.

Pat

In sci.space.history message 43d05881-d3f7-4000-88c6-a34b123fd5ea@k38g2
000vbn.googlegroups.com, Mon, 7 Feb 2011 11:08:18, Matt
posted:

Thanks. Obviously proprietary information is close-hold for any
company, but I was looking at their published materials and trying to
determine whther they had in fact recovered Stage 1 from any of their
launches so far.

Recovery status, for anything that might be recoverable of anybody's
launch system, will have been reported in the relevant media.

Try Wikipedia.

Falcon 1 #1 was I think sort-of recovered, for local tidiness. At least
I hope so.

Falcon 1 #2-5 not recovered.
falcon 1e not yet launched.
Falcon 9 #1-2 not recovered.

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