LIVE: SpaceX Falcon 9 (Flight 2) - COTS-1 - Launch Updates - December 8, 2010

[TrueBlueWitt]

Hmm, if they'd sent up a cake they could have given Shelby a piece of space cake. How's that for a double entendre?

To me a "Who MOVED my cheese" metaphor seems more apropos when it comes to Senator Shelby!

[TrueBlueWitt]

You want the solution to be a lot better than the alternatives, but parachutes set a pretty low bar for competition, reliability-wise.

~Jon

Yeah...but they kick butt ISP-wise.

Is that still true if your propulsive Landing Thrusters also double as your LAS?

[zaitcev]

How feasible do you think it is?  I'd be curious about the mass penalty, especially with a parachute backup.  And even if feasible, I wonder how costly it would be to implement.  On the other hand, I have to think that it would help with reusability.

In case of PTK/GVK (the outcome of PPTK NP program), the parachutes were added under the excuse of the mass deficit. They reduce the necessary mass as long as you want the reliability, because the acceptable reaction time demands you lit the landing engines too high. A factor was that PTK uses solid landing motors, which burn at the same rate once lit. A liquid-fueled landing system could use deep throttling to save the fuel and perhaps achieve acceptable landing reliablity without parachutes, but that's water under the bridge now (until Dragon is redesigned). As you can see the mass minimum depends quite a bit on the external parameters. As far as costs go, that's as good as anyone's guess. The Preliminary Design for the whole ship costed about 26 million U.S. dollars (800 million roubles). Also, Mr. Perminov quoted the overall cost as "1/6th of Orion", which could be simply a political statement.

[zaitcev]

Is that still true if your propulsive Landing Thrusters also double as your LAS?

I do not understand. How are you going to land after an abort if you expended the landing fuel to perform the abort?

[TrueBlueWitt]

Is that still true if your propulsive Landing Thrusters also double as your LAS?

I do not understand. How are you going to land after an abort if you expended the landing fuel to perform the abort?

You've got me there..  As I chuckle..  With the Parachute?

Although at Launch you'd still have all the Maneuvering and OMS propellant you could use.. Far more than you have at landing.  Is that enough for a high thrust "low ISP" burn for separation, and to still land?  I don't know.

[sdsds]

Is that still true if your propulsive Landing Thrusters also double as your LAS?

I do not understand. How are you going to land after an abort if you expended the landing fuel to perform the abort?

Hard.

[hop]

Is that still true if your propulsive Landing Thrusters also double as your LAS?

I do not understand. How are you going to land after an abort if you expended the landing fuel to perform the abort?

Elon talked about keeping the parachutes as a backup to propulsive landing anyway, so that would be an obvious option.

Almost all Dragon aborts would be over water, so what would be a hard landing under parachute on land shouldn't be as bad.

[TrueBlueWitt]

Is that still true if your propulsive Landing Thrusters also double as your LAS?

I do not understand. How are you going to land after an abort if you expended the landing fuel to perform the abort?

Elon talked about keeping the parachutes as a backup to propulsive landing anyway, so that would be an obvious option.

Almost all Dragon aborts would be over water, so what would be a hard landing under parachute on land shouldn't be as bad.

Elon said they could successfully splash the Capsule on even a single chute.. so maybe you only have one Chute on board to cover this case.. 

Not sure if ONE was for Cargo only, or would allow survivable landing with crew?

[Nascent Ascent]

So, I'm wondering if Elon cut the cheese?   

[Steven Pietrobon]

Assuming the image is cropped (rather than scaled), an 800mm lens on a Canon 5D Mark II (as listed in the EXIF) subtends 1.653 arcseconds per pixel
http://www.howardedin.com/articles/fov.html

The Dragon in the image is about 16 pixels across, so 26 arcseconds for the 3.6m wide capsule.

S=O/H,  H=O/S, distance = 3.6m/sin(26/3600) = 29km

Intuitively that seems too far to me. Please could someone check my maths?

Two small errors. Rounding 16*1.653 = 26.448 to 26 and using sine instead of tan. I get 3.6m/tan(26.448/3600) = 28.1 km.

Also, from the press conference I thought I heard the spacecraft land within "a 100 metres" instead of "800 metres" of the target point.

[marsavian]

He's an American citizen now, and I believe that gives him the right to have pride / patriotism, etc.

Never said it doesn't, but if someone can spend his formative years in another country and later adopt another as his own, imo it makes him more of a "citizen of the world".

His mother was Canadian as well.

[marsavian]

  Mr. Musk stated that he doesn't quite know where he would spend $2.5B.  I fear that he'll find out just where it all goes, and the profit margin, and public value, will get eaten away.

He doesn't have a HLV lower stage or engine, HLV upper stage or engine, HLV pad or facilities. That figure he is quoting is just hot air without specific context on what part of the HLV he is referring to and is definitely not apples to apples compared to say SLS as he can't build a 125mT HLV from where he is now with only $2.5bn.

p.s. great job btw on very successful initial Dragon operation. The ISS maintenance people can breathe a big sigh of relief now as can all the organizations who want to do full fruitful research on it, Shuttle can RIP now after 2011, its job is well done ! .

[Comga]

Also, from the press conference I thought I heard the spacecraft land within "a 100 metres" instead of "800 metres" of the target point.

It sounded like that in some versions through some speakers, but on the clearest I have heard Ms. Shotwell definitely says "800 meters."

[Robotbeat]

  Mr. Musk stated that he doesn't quite know where he would spend $2.5B.  I fear that he'll find out just where it all goes, and the profit margin, and public value, will get eaten away.

He doesn't have a HLV lower stage or engine, HLV upper stage or engine, HLV pad or facilities. That figure he is quoting is just hot air without specific context on what part of the HLV he is referring to and is definitely not apples to apples compared to say SLS as he can't build a 125mT HLV from where he is now with only $2.5bn.
...

I think he very well thinks he can build a 125 mT HLV from where he is right now with only $2.5 billion. That's his point.

He may or may not be able to do that, but that's what he claims.

[Hanol]

Assuming the image is cropped (rather than scaled), an 800mm lens on a Canon 5D Mark II (as listed in the EXIF) subtends 1.653 arcseconds per pixel
http://www.howardedin.com/articles/fov.html

The Dragon in the image is about 16 pixels across, so 26 arcseconds for the 3.6m wide capsule.

S=O/H,  H=O/S, distance = 3.6m/sin(26/3600) = 29km

Intuitively that seems too far to me. Please could someone check my maths?

Two small errors. Rounding 16*1.653 = 26.448 to 26 and using sine instead of tan. I get 3.6m/tan(26.448/3600) = 28.1 km.

Also, from the press conference I thought I heard the spacecraft land within "a 100 metres" instead of "800 metres" of the target point.

The whole point is wrong.  Yes, image was scaled by the web server upon rendering.  May be 10 times, may be more.  You never know.  So all the math doesn't make any sense.

[Robotbeat]

I never bother using "sine" or "tangent" for these kinds of small angles and rough estimates. Close enough that sin(x) ~= tan(x) ~= x (using radians, of course)

[butters]

There was something in his $2.5B SHLV claim about assuming that a portion of the contract would be fixed-cost and a portion would be cost-plus. It read to me as if the $2.5 would be development cost assumed by NASA for the Falcon X Heavy type vehicle, whereas SpaceX would assume additional development cost under the fixed-cost portion of the contract in order to pursue the commercial market they believe exists for Falcon X single-core.

Put another way: Musk may be saying that if NASA wants Falcon X Heavy, then SpaceX will fund Falcon X, and lots of things would have to go wrong for the evolution from FX to FXH to cost the full $2.5B.

This also reflects the other main thrust of that Aviation Week article, where Musk was riffing on the idea that the economics of an SHLV for manned exploration don't work unless there is an application for commercial launch services. The idea is that SpaceX will fund the heaviest launch vehicle they believe they can market for commercial payloads, and NASA would only have to pay for the triple-core variant, dramatically improving the economics of developing that SHLV capability.

[marsavian]

  Mr. Musk stated that he doesn't quite know where he would spend $2.5B.  I fear that he'll find out just where it all goes, and the profit margin, and public value, will get eaten away.

He doesn't have a HLV lower stage or engine, HLV upper stage or engine, HLV pad or facilities. That figure he is quoting is just hot air without specific context on what part of the HLV he is referring to and is definitely not apples to apples compared to say SLS as he can't build a 125mT HLV from where he is now with only $2.5bn.
...

I think he very well thinks he can build a 125 mT HLV from where he is right now with only $2.5 billion. That's his point.

He may or may not be able to do that, but that's what he claims.

No, what he is saying is that he could build it for $12.5bn which is still very good. The $2.5bn only refers to his fixed-price rocket development/integration costs on top of the $10bn cost-plus for development of the constituent parts but it is disingenuous to just quote it by itself. It may also not include Raptor.

http://web02.aviationweek.com/aw/mstory.do?id=news/awst/2010/11/29/AW_11_29_2010_p28-271784.xml&channel=space&headline=NASA%20Studies%20Scaled-Up%20Falcon,%20Merlin

Based on a roughly evenly split $10 billion budget for heavy lift, with half for the boost stage and half for the upper stage, “we’re confident we could get a fully operational vehicle to the pad for $2.5 billion—and not only that, I will personally guarantee it,” Musk says. In addition, the final product would be a fully accounted cost per flight of $300 million, he asserts. “I’ll also guarantee that,” he adds, though he cautions this does not include a potential upper-stage upgrade.

[mikes]

Assuming the image is cropped (rather than scaled), an 800mm lens on a Canon 5D Mark II (as listed in the EXIF) subtends 1.653 arcseconds per pixel
http://www.howardedin.com/articles/fov.html

The Dragon in the image is about 16 pixels across, so 26 arcseconds for the 3.6m wide capsule.

S=O/H,  H=O/S, distance = 3.6m/sin(26/3600) = 29km

Intuitively that seems too far to me. Please could someone check my maths?

Two small errors. Rounding 16*1.653 = 26.448 to 26 and using sine instead of tan. I get 3.6m/tan(26.448/3600) = 28.1 km.

Also, from the press conference I thought I heard the spacecraft land within "a 100 metres" instead of "800 metres" of the target point.

The whole point is wrong.  Yes, image was scaled by the web server upon rendering.  May be 10 times, may be more.  You never know.  So all the math doesn't make any sense.

I downloaded the full image and worked from that, not the inline server-scaled version. It could also have been scaled, but that generally strips the EXIF data so I'm guessing it wasn't.

Steven: Thanks for the confirmation. Given the vagueness of pixel counting, I'm comfortable with the rounding! Precision is likely +/- 2km.

[blazotron]

Probably more important than a quick fix to the nozzle problem is that they flushed out a design fault in the vehicle in the process of root cause analysis.

Agreed. Maybe you can debate with Jim whether it was a "process failure" or a "design fault." I'll stand by with some popcorn.

No debate needed, it was both.  A design flaw that should have been fixed after the first flight

I agree it was a design flaw and I take the point about it being a process failure, but I think the argument there is very weak.  Yes they had a design flaw that became apparent on the first flight where the turbopump drain plume expanded in vacuum to impinge on and freeze the roll control system, where it does not at sea level.  And for the record I do not consider this anomaly a process failure either because of SpaceX's conscious decision to flight test the second stage rather than paying to test in an altitude test facility (i.e. their process).  The obvious recovery from that anomaly should have been to scrub the design for any other altitude effects, especially as relates to plume expansion and impingement.   

As I understand the nozzle crack, some sort of oscillatory behavior from what I presume is an interstage conditioning/purging vent interacted with the nozzle extension and caused high cycle fatigue cracking.  This aeroelastic/materials phenomenon can cause a failure even if the average conditions (which they may well have analyzed) are quite mild, but it might take a long time to become apparent, and is completely and utterly of a different nature than the roll control altitude-induced thermal failure.  Unless the hypothetical "process" for recovering from the roll control problem was something so broad as to encompass every possible effect of every fluid system on the rocket, this non-obvious failure can reasonably be labeled an unlucky design flaw.  But such a process is at best useless anyway as it would be equivalent to saying something like "examine every system containing or interacting with fluids for every possible failure mechanism".  At worst, it could provide false confidence in a flawed design. 

After all, the failure on Falcon 1 flight 3 was at heart a purge failure as well since the thrust transient caused as the residual propellant was purged from the regen chamber cause the stages to recontact.  By the thinking above, that should have prompted them to create a process that would prevent them from ever again having a "purge induced failure," which is silly.  But why stop there?  Just create a process that prevents anyone from ever designing something with a design flaw in the first place. 

Considering that they presumably did not see similar cracks on first flight so had no reason to investigate further, I think this one is pretty comfortably in the "unfortunate design flaw" and not the "process failure" category.  In fact, it was discovered through a success of the closeout inspections process.

Finally, I should add that if you disregard the above and still consider this a process failure, it is at worst a design process failure and says little to nothing about any sort of materials certification, fabrication, or quality control processes of theirs, which is more typically what is referred to when the term "process failure" is used.