Launch News SpaceX Falcon 9 launch with Jason-3, January 17, 2016

[Urwumpe]

I was responding to Captain Klonk calling it "the difficult way". He seems to be under the impression that wings and control surfaces capable of withstanding supersonic flight are going to weigh less than the propellant required to decelerate a (nearly) empty stage. The rocket equation says otherwise.

Sorry, I seemingly mixed up the social context there then. I agree, the rocket equation is the judge there. Its not without a price and of course, there are also factors beyond the rocket equation that have an effect.

Software issues aside the "easy way" being discussed is actually way harder, and removes the existing option to say "screw recovery, give me dV!" should the need arise.

Yes, it makes flexibility hard. Not that it matters much, if you can achieve more with two specialist boosters for example. But building the same base stage and just use different software and different extras for it is of course more economic initially (at higher flight rates, the differences become less important)

 

[Col_Klonk]

I was responding to Captain Klonk calling it "the difficult way". He seems to be under the impression that wings and control surfaces capable of withstanding supersonic flight are going to weigh less than the propellant required to decelerate a (nearly) empty stage. The rocket equation says otherwise.

You demoting me.. I'm a Colonel :lol:
I'm under no impression, and left that option open.
One would look to the SR71 and F104 aircraft for different construction and configs at high mach numbers. Titanium is a good material option, although I think there are newer materials... must look it up.

---------- Post added at 10:23 PM ---------- Previous post was at 06:10 PM ----------

Remember for the Falcon 9 that the wings would need to be robust enough to fly back something the size of the Statue of Liberty with the CG back near the engines, so you have some awkward aerostability issues to deal with. The tanks and interstage would effectively form a 100 ft "nose" that has little weight but big surface area, so weathervane instability is a big problem.

Yup.. already thought of that..

Fuel and weight wise, SpaceX's nearly spent 1st stage just has to continue its arc into the ocean (mostly). It's not burning a lot of fuel to decelerate because it is very light. Most of the stage dV is going toward pushing the 2nd stage to orbit, not returning. Even flyback to the landing site is not so bad energy wise. Again - you're decelerating a light stage, and once you get it moving back to the pad you're "flying" the stage with the grid fins.

At the end of the day, the Falcon 9 is a largely conventional rocket, with some low mass amendments (fins, legs, control software) to enable return.

It'll be a weigh-up between a stage (liberty size) and it's return fuel load landing on a barge, compared to an empty stage gliding back in on a wing system to a runway.

The Barge thing is like repeating the same experiment and hoping for a different result.

 

[Urwumpe]

The Barge thing is like repeating the same experiment and hoping for a different result.

The same experiment with slightly changed parameters. After all, they do some modding on the Falcon 9 1.2.

Also it is not like it fails always the same way... :lol:

 

[C3PO]

The same experiment with slightly changed parameters. After all, they do some modding on the Falcon 9 1.2.

Also it is not like it fails always the same way... :lol:

Wasn't the R7--->Soyuz designed in roughly the same manner? Build, fly, analyze, change, repeat.

 

[Andy44]

Wasn't the R7--->Soyuz designed in roughly the same manner? Build, fly, analyze, change, repeat.

Pretty much. But SpaceX gets paid every time they launch, so long as the payload reaches orbit, so the model works well for them.

As for Col. Klonk, you do realize that somewhere at SpaceX's corporate headquarters some well-paid guys did a trade study about this stuff resulting in the decision to go with this configuration, right? If you are an investor or a customer I'm sure they could produce a Powerpoint slideshow that would explain it all.

 

[Urwumpe]

Wasn't the R7--->Soyuz designed in roughly the same manner? Build, fly, analyze, change, repeat.

Sort of. But then, this had been a time, where nothing else existed to replace flight testing and the failure rate had been astronomic.

The Soyuz launcher was a slow evolution over various other launchers, which each had a purpose... and there was still a LONG gap with more evolutions because the prime payload was not ready in time.

 

[boogabooga]

As for Col. Klonk, you do realize that somewhere at SpaceX's corporate headquarters some well-paid guys did a trade study about this stuff resulting in the decision to go with this configuration, right?

Actually, from what I heard the boost-back first stage was Elon's brainchild and he fired all the engineers that said otherwise or told him stuff he didn't want to hear.

So, I wouldn't assume right away that their method is best/most practical or that other companies can't come up with better ideas.

 

[RisingFury]

Actually, from what I heard the boost-back first stage was Elon's brainchild and he fired all the engineers that said otherwise or told him stuff he didn't want to hear.

Oh, you heard! Where did you hear that from? SpaceGossip.net?

 

[boogabooga]

Was an article about Elon Musk. But it was a while ago.

 

[MaverickSawyer]

Oh, you heard! Where did you hear that from? SpaceGossip.net?

More likely some of the burnt out engineers fleeing to Virgin Galactic or Blue Origin.

 

[Thunder Chicken]

Actually, from what I heard the boost-back first stage was Elon's brainchild and he fired all the engineers that said otherwise or told him stuff he didn't want to hear.

Citation please.

I highly doubt this. If Elon Musk were this much of a dictatorial , they'd be blowing up rockets on the pad and he'd have engineers making for the doors like rats on a sinking ship.

I've worked in such engineering firms and they are the antithesis of energy and productivity. The old engineers are trying to hide in the corners like fat kids playing dodgeball, hoping to stay out of trouble until retirement. The young engineers get enough years on their resume, also trying not to draw trouble, and bail out as soon as something better comes along. You do not have a dynamic, progressive organization willing to take risks when the CEO is a meddling egotistical prick.

I'm sure Elon Musk has his hangups, like everyone. But he seems to have lofty goals, reasonable expectations, an understanding of the occasional need to fail to learn and succeed, and enough brains to hire smart people and let them shine.

 

[Col_Klonk]

Citation please.
.. You do not have a dynamic, progressive organization willing to take risks when the CEO is a meddling egotistical prick.

:rofl:
I was 'chief electronic design engineer' (title oh for a title ) for a small instrumentation firm for a mere 12 months... The CEO was an accountant who had all these ideas, most which I rejected due to economic viability.
You could buy the things (more mature products) from next door for half the price than what we could make it... and our design time hardware/software would take a minimum of 1 year (we were multitasking). I suggested smaller, more unique products.

Well, he refused to listen.. even argued to death with me that Accuracy and Precision were the same thing. After a year I desperately gave up and resigned - I think he wanted this as he got really nasty. A year later I found out through a colleague, he'd finally taken my advice, but I'd already moved on.

So i wouldn't be surprised about Elon 'the dictator' :rofl: as it will not be in the public eye, but shady rumours - No smoke without a fire !
You probably find that the first engineers advised against what he wanted - 'fired' them and the new people would come in and do what they're told.
The problem with this is that those new engineers will get a 'bad rap' due to the CEO 'barking up the wrong tree', which might be this case.
If it does go bad, Elon will drop them for something else.. if it goes well they're heroes of the people.. a bit of a yoyo existence ?
:thumbup:

 

[Urwumpe]

I also doubt that Musk is really more tyrannical than other start-up CEOs.

He has his ideas and the CEO sets the strategical goals. That contains also the strategic product planning and if the CEO says that in the next 5 years, SpaceX will have a first stage that lands again by boost-back as product, that is a command. It might be silly, but its still his right to demand it.

You can of course tell him "With all due respect, Sir, you are an as........le", but that won't bring you any gains and will not make your CEO feel better at all. Nor will it help the company.

I can only recommend the old lesson about "Lead your leaders" there.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080014349.pdf

And yes, any CEO of a startup company recently is a tyrant. He may be friendly, talking about involvement and personal fulfillment, etc. But deep down in his core, he has his vision of the company, his story how the history of the company shall be written and does not permit his employees to have any word into it. They are there to fill the gaps in his plot. Not more, not less. You can accept this. Or leave.

 

[Col_Klonk]

... Not more, not less. You can accept this. Or leave.

Exactly.. so when I saw his 'vision' being implemented the wrong way, resulting in the staff taking flak for incompetent 'leadership'... I left.

Now take my wife's company.. 3 incompetent managers prior to her could not get anything right. Without applying for the position they gave it to her.
5 years later they have a fully certified (world) lab bringing in excess of 6 figure numbers. They just let her do her thing, no direction or ordering around!!

I also was looking after a funded research lab that was 50% busy and suggested doing external work to bring in $$$.. Management refused.. the lab closed down after 2 years.. reason..No money !!:facepalm:

Damm i must be ugly as no-one believes me... well at least the wife does

SpaceX is probably looking good at the moment as it has the $$$... It just has to maintain the $$$ flow by good management - We'll see.

 

[movieman]

And as it looks right now, it does not have any advantages over classic aerospace development models at all.

How much money, and how many years, would NASA have spent to build a non-reusable Falcon 9 with a traditional aerospace development model? Let alone one that could land on a barge at sea?

If I remember correctly, they spent about as much to put a dummy second stage on top of a shuttle SRB and launch it into the ocean as Musk did to develop Falcon 9 and launch it into space.

For that matter, how quickly would aviation have developed, if the engineers of the time weren't willing to try a lot of things and crash a lot of planes?

 

[Col_Klonk]

That is essentially the difference between a business and a government department.
But I think you're mixing the fruits here ! Nasa's program has been with sending live humans.... costs a lot more than just sending a box of nuts and bolts into orbit.
Although there is a possibility NASA bent the story a bit.. to get more money. Elon has done the same thing wrt the Mars thing.

If one looks at pre-Nasa and even the Russian early rockets programs.. a lot of their stuff just blew up.
From all that we have the benefit of what works, with refinements and innovations to improve efficiency and safety.

 

[Urwumpe]

How much money, and how many years, would NASA have spent to build a non-reusable Falcon 9 with a traditional aerospace development model? Let alone one that could land on a barge at sea?

NASA would first of all have the problem that its shareholders are not wanting it to build rockets, but to provide jobs in states of some selected senators.

Then it would have to please scientific interests as well beyond the initial mission.

But then for a good comparison, look at the development of the Atlas V, which started effectively in 1994 with the EELV program and the first requirements getting formulated. It took Lockheed 8 years until the first launch from that point on.

SpaceX officially started to develop the Falcon 9 in 2005 and needed 5 years until it flew first. Lets forget the fact that a heavy launcher was already in development as Falcon 5 when SpaceX was founded in 2002. The Falcon 9 1.1 was done in 2013, 8 years later. First successful landing was in 2015, ten years after the Falcon 9 program started, four years after the Grasshopper program of SpaceX was discovered by journalists and afterwards confirmed by SpaceX - it is not known when SpaceX started to develop the landing technology.

Important other factor: SpaceX been awarded contracts worth 4.2 billion USD since 2008 from NASA. That is a whole lot of money. SpaceX was supposed to deliver 12 CRS resupply missions to the ISS, now its only 10, and one of those was a failure. Still NASA will pay for it. And those NASA contracts allow SpaceX to get a lot of loans from banks because of that.

We will never really know how much. SpaceX must not do a public annual financial statement. Would SpaceX have been a German corporation, it would have been required to do so. US laws allow keeping the reports secret until international laws apply and full public financial statements are mandatory every year.

 

[Andy44]

EELV (Atlas V and Delta IV) was driven mainly by the Air Force, not NASA, for those that don't know.

The USAF wastes money, too, but they generally don't worry as much about getting funding cut because they are less publicly visible and considered vital to "national security", so the USAF gets more stuff done in space, sooner, than NASA does. Of course the USAF isn't going to explore Mars, either.

 

[RGClark]

Talking about return journey...
The fuel weight required for the current return trip could be replaced by fold out (or extendable) wing surfaces sitting flush, similar to the current legs.
Current landing struts replaced by shuttle type gears, only lighter.
Control done by the smaller canards up front (which may extend for the return trip)
The nose section of the stage has an ejection part revealing a nose cone for reducing resistance.
Depending on materials used and implementation it might weigh the same, or lighter with more fuel for Tsiolkovsky
The return trip uses the staging speed and position for the target runway. It could even turn back to the original launch base.
If necessary use drogue chutes to slow it down.

Instead of full-sized wings could used fixed fins that also serve as the landing legs:

Destination Moon.

Bob Clark

 

[Col_Klonk]

Was thinking along these lines....
Deployment time vs structural strength would be the obvious questions for the return trip.

---------- Post added 01-25-16 at 09:19 AM ---------- Previous post was 01-24-16 at 02:46 PM ----------

Come to think of it.. this configuration would be more stable..