SpaceX long-term stage processing goal = 48 hour turnaround

[Jim]

Nope, it was an engine problem.  See http://heroicrelics.org/info/j-2/augmented-spark-igniter.html for details.  And you could certainly find problems like this by looking for parts on the returned engine that are stretched, bent, or otherwise deformed in ways you have not seen on the test stand.

Not really, would be hard to discern whether the issue came from the launch or the return.

[sublimemarsupial]

Nope, it was an engine problem.  See http://heroicrelics.org/info/j-2/augmented-spark-igniter.html for details.  And you could certainly find problems like this by looking for parts on the returned engine that are stretched, bent, or otherwise deformed in ways you have not seen on the test stand.

Not really, would be hard to discern whether the issue came from the launch or the return.

Who cares whether it came from the launch or the return? It would be a problem that could be readily identified after flight via inspection and fixed, making the reusable vehicle more reliable long term

[Jim]

Who cares whether it came from the launch or the return? It would be a problem that could be readily identified after flight via inspection and fixed, making the reusable vehicle more reliable long term

All this is in the context whether returning the booster is useful without the intent of reuse.

[sublimemarsupial]

Who cares whether it came from the launch or the return? It would be a problem that could be readily identified after flight via inspection and fixed, making the reusable vehicle more reliable long term

All this is in the context whether returning the booster is useful without the intent of reuse.

Ok change reusable for returnable, vehicle reliability is still imroved if there is a chance the defect was from ascent - which for this problem it was.

[RDMM2081]

WRT to engine re-use, aren't we missing the fact that the engines on an F9 do experience something that is not able to be replicated on the test stand?  Specifically, the supersonic retro burn.  What effect does engine startup and ignition in a supersonic environment have on engine components?  Well, now there are engines back on land which have experienced this and the engineers can check them out and see!

[Senex]

The economics of reuse will overwhelm "disposable." 

Based on what data?

You want data.  I respect that.  That was the purpose of my original post — to identify another data point.

Look at the data points we have regarding reusable boosters:

• The Shuttle, both the Orbiter and SRB's
• DC-X
• Masten, Armadillo, etc.
• XCor's rocket planes
• You mention the X-37
• Falcon 9, Blue Origin (They're not talking.  That's why we are having this discussion.)

DC-X, Masten, Armadillo, the rocket planes . . . different flight regime.  The X-37 has more in common with a reusable Dragon capsule than a booster.

Of these, only the Shuttle components operated in a relevant flight regime.

And the X-15:

"In November 1966, James Love and William Young, engineers at the NASA Flight Research Center at Edwards Air Force Base, completed a brief report in which they noted that the reusable suborbital booster for a reusable orbital spacecraft would undergo pressures, heating rates, and accelerations very similar to those the X-15 experienced."

      - from:  Survey of Operation and Cost Experience of the X-15 Airplane as a Reusable Space Vehicle, NASA Technical Note D-3732, James Love and William Young, November 1966.

And they concluded that re-use was economically very practical.

Again, I encourage people to read David Portree's article in Wired referencing the study:

http://www.wired.com/2013/05/the-x-15-rocket-plane-reusable-space-shuttle-boosters-1966/

[LouScheffer]

Nope, it was an engine problem.  See http://heroicrelics.org/info/j-2/augmented-spark-igniter.html for details.  And you could certainly find problems like this by looking for parts on the returned engine that are stretched, bent, or otherwise deformed in ways you have not seen on the test stand.

Not really, would be hard to discern whether the issue came from the launch or the return.

Who cares whether it came from the launch or the return? It would be a problem that could be readily identified after flight via inspection and fixed, making the reusable vehicle more reliable long term

This was not Jim's point.  Others were claiming that inspecting a returned vehicle could lead to better quality engines, even if the vehicle is never re-used.  Jim was pointing out that in that scenario, you don't care about margins on the way down, just on the way up, and it might be hard to tell where the margin excursion happened.

In practice, if a margin is found to be exceeded, but not to failure, it would be subject to additional analysis to see if it happened on the way up, the way down, or both.  There is at least some chance it happened on the way up, and hence it's possible that examining landed engines could find flaws that are relevant to even expendable use.  How common this is remains to be seen.

[JamesH]

So, according to most, even Jim, the engines are reusable without major refurb, because they were designed that way, and have been thoroughly tested on the stand.  Cool. Something we can leave out of the refurb costs (except for expected refurb costs already identified, expected to be minimal)

That leaves the airframe, avionics and plumbing.

That's good, isn't it? Those are the 'less' complicated parts of the craft, can be relatively easily examined, and are also the least expensive to replace. Electronics can self test (to get most possible problems), tanks can be pressure tested, legs can be checked, grid fins can be examined.  Sounds good to me.

Even if the whole airframe is a total loss (seems unlikely, as it's designed to be reusable), there are still those 9 engines that ARE reusable (because Jim said so).

[Jim]

The engines still have to be inspected since they now have experienced a reentry, supersonic retro burn and landing.

[Lars-J]

The engines still have to be inspected since they now have experienced a reentry, supersonic retro burn and landing.

And here I thought I just read from your elsewhere that this stage provided no new information about the engines, and that all testing could be done on the ground. 

[chipguy]

Falcon 9 v1.1 FT is a reusable rocket and designed like one.

no, it is an expendable rocket that is being converted/upgraded to a reusable one.

It is a reusable rocket initially deployed to service an expendable business model while
the kinks in the reusable regime of operation are engineered out.

By your logic could ULA "convert/upgrade" Atlas V to a reusable rocket?

[Herb Schaltegger]

The engines still have to be inspected since they now have experienced a reentry, supersonic retro burn and landing.

And here I thought I just read from your elsewhere that this stage provided no new information about the engines, and that all testing could be done on the ground. 

In the absence of plans to re-fly them operationally, he's right.

[Jim]

It is a reusable rocket initially deployed to service an expendable business model while
the kinks in the reusable regime of operation are engineered out.

By your logic could ULA "convert/upgrade" Atlas V to a reusable rocket?

No, the first version of Falcon 9 was expendable and not reusable.

[sunbingfa]

Reusability aside, the short turnover time may be attractive to military customer, who has been pushing the short notice launch with little success. Unless XS-1 has huge success within the next 3-5 years.

[nadreck]

Falcon 9 v1.1 FT is a reusable rocket and designed like one.

no, it is an expendable rocket that is being converted/upgraded to a reusable one.

No, with all due respect the whole reason why (see the thread: http://forum.nasaspaceflight.com/index.php?topic=37390.0) there is a controversy between the statement from Elon that one reflight of a Falcon Core justifies its reusability vs George Sowers saying you need 20 in the ULA universe is because the F9 was designed to be reusable.

If I went to Ford and asked them how much cheaper they could make an expendable car than say a Ford Focus but with similar performance, after they stopped laughing, they could probably settle down to engineer something but the design and manufacturing setup costs would probably dictate that you needed a market of millions of units before you could get the price much lower than half that of a Ford Focus and it would still be at least as reusable as 3rd party refilled print cartridges.

Reuse was being designed in (it didn't work for the whole system but components were being designed for it) in the Falcon 1 even. So what is the hard to believe part is that SpaceX did all this designing in for something that still has a unit cost to manufacture below the same class of launchers that never had reuse considered for any part.  Even more amazing is that it took them a tiny fraction of the development costs (adjusted for today's dollar) to do the same thing.

The sad thing is that ULA has convinced itself that taking all their existing engineering and adding reuse to it is the same process as SpaceX starting from scratch and designing systems for reuse.  ULA keeps carrying its own 'expendable experience' baggage forward with the Vulcan and worse seems to presume that SpaceX has the same baggage which is not the case.

[Robotbeat]

This whole discussion reminds me of something I read on Twitter.

There are two reasons something new (supposedly) can't work:
1) It's been done before.
2) it hasn't been done before.

[Dante80]

The economics of reuse will overwhelm "disposable." 

Based on what data?

You don't need data, just common sense.

It could happen in 5 years, or 20, or even a century. It is going to happen though (barring a breakthrough in exotic space transport methods or a thermonuclear war).

[Jim]

Falcon 9 v1.1 FT is a reusable rocket and designed like one.

no, it is an expendable rocket that is being converted/upgraded to a reusable one.

No, with all due respect the whole reason why (see the thread: http://forum.nasaspaceflight.com/index.php?topic=37390.0) there is a controversy between the statement from Elon that one reflight of a Falcon Core justifies its reusability vs George Sowers saying you need 20 in the ULA universe is because the F9 was designed to be reusable.

snip

Reuse was being designed in (it didn't work for the whole system but components were being designed for it) in the Falcon 1 even. So what is the hard to believe part is that SpaceX did all this designing in for something that still has a unit cost to manufacture below the same class of launchers that never had reuse considered for any part.  Even more amazing is that it took them a tiny fraction of the development costs (adjusted for today's dollar) to do the same thing.

Wrong.  Just adding a parachute does not qualify as designing for reuse.

Other than tank diameter and domes, there is little hardware that the early F9 first stages share with the current ones.  Thrust structure, avionics, propulsion system, pressure systems, are all different.  Even launcher.

[schaban]

Wrong.  Just adding a parachute does not qualify as designing for reuse.

Other than tank diameter and domes, there is little hardware that the early F9 first stages share with the current ones.  Thrust structure, avionics, propulsion system, pressure systems, are all different.  Even launcher.

I think engines and perhaps other parts were designed to withstand salt water, no?

[abaddon]

Jim, the original quote you are responding to was "Falcon 9 v1.1 FT is a reusable rocket and designed like one."  Why are we discussing the original F9?