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I'd say what this says to Huntsville in plain English, but it's a family forum, so I'll leave the two-word statement as an exercise for the reader.

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44 minutes ago, RealKerbal3x said:

Updated design, with new landing legs!

Interesting... I’m not seeing any side-firing mini-Raptors... maybe there’s a ring of even-mini-er engines? The mythical hot-gas thrusters, perhaps, spammed around enough to land in lunar grabbity?

2 hours ago, tater said:

That's the least likely thing I can imagine.

Wow.

Did I say wow?

FromOuttaNowhere!.gif

Wonder if this’ll end up being one of those tiny decisions that ends up having world-changing implications down the road? I mean, even if not intended they just “legitimized” (for want of a better term) the whole Starship program. 

Prolly not, I imagine we’ll see more funding for a second lander eventually. 

2 hours ago, cubinator said:

not only that, on the NASA event page it seems to imply that only two astronauts will land on the first mission. Can you imagine having an entire Starship to share with just one other person?

I’ve seen horror movies that start exactly like that... <_<

 

2 hours ago, tater said:

Orion holds 4, so it's risk mitigation I guess. Halves the possible lost crew if there was a LOC landing event—I was going to say that it allows Orion to rescue crew in case of some issue, but Orion is so awful, that's not actually possible. They can watch from NRHO, and do nothing at all.

The irony that Starship could just land the whole dang Orion capsule on the moon anyway...

3 minutes ago, tater said:

I'd say what this says to Huntsville in plain English, but it's a family forum, so I'll leave the two-word statement as an exercise for the reader.

Good day, sir! ?

er, wait that’s three words...

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56 minutes ago, RealKerbal3x said:

Updated design, with new landing legs!

Close view on the legs.

worse.png

This just looks like a really ridiculously sloppy render to me.

See how the feet clip through the fairing on one side but not the other?

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7 minutes ago, CatastrophicFailure said:

Interesting... I’m not seeing any side-firing mini-Raptors... maybe there’s a ring of even-mini-er engines? The mythical hot-gas thrusters, perhaps, spammed around enough to land in lunar grabbity?

 

In the darker ring above and to the left of the flag and the NASA logo.

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7 minutes ago, CatastrophicFailure said:

I’m not seeing any side-firing mini-Raptors... maybe there’s a ring of even-mini-er engines? The mythical hot-gas thrusters, perhaps, spammed around enough to land in lunar grabbity?

Looks like four banks of six engines each for a total of 24.

worse.png

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I notice they went for the more sensible array on the cylinder vs dealing with the nose compound curvature.

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Just now, sevenperforce said:

Looks like four banks of six engines each for a total of 24.

worse.png

Wow, I didn't spot the ones above and to the right.

24 landing engines then. What do we reckon, somewhere in the region of 25kN per engine? That's quite a bit smaller than superdraco.

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Crew-2 progressing.

 

 

SpaceX's announcement tweet.

 

 

And of course what we will knew but old-space is extremely slow to acknowledge:

If you're just trying to copy F9 you're destined for failure. Starship may not work reusably, but there's no serious reason not to think Superheavy won't even so be by far the cheapest ride to space on a per kg basis.

 

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20 minutes ago, RCgothic said:

If you're just trying to copy F9 you're destined for failure. Starship may not work reusably, but there's no serious reason not to think Superheavy won't even so be by far the cheapest ride to space on a per kg basis.

This.

As I was trying to say up the thread, the mere existence of the GSE tanks implies SS/SH production is absurdly inexpensive, not matter how you do the math. The only assumption required is that SpaceX would not spend more than some multiple of off the shelf propane tank cost. Pick a number and work from there? Think SpaceX would happily spend 100X off the shelf tank cost? Then a SS costs ~$10M. Would they not burn money in that way, and only spend 10X tank cost? $1M. Etc.

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5 minutes ago, tater said:

This.

As I was trying to say up the thread, the mere existence of the GSE tanks implies SS/SH production is absurdly inexpensive, not matter how you do the math. The only assumption required is that SpaceX would not spend more than some multiple of off the shelf propane tank cost. Pick a number and work from there? Think SpaceX would happily spend 100X off the shelf tank cost? Then a SS costs ~$10M. Would they not burn money in that way, and only spend 10X tank cost? $1M. Etc.

I think SpaceX will always go for the cheaper option. If you can buy a GSE tank for cheaper, why make it yourself? One possibility is that they’re at a point when the bulk of their tank costs is worker salary and machine maintenance, so there isn’t a huge financial difference between building a tank or not. Might as well build something. 

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7 minutes ago, sh1pman said:

I think SpaceX will always go for the cheaper option. If you can buy a GSE tank for cheaper, why make it yourself? One possibility is that they’re at a point when the bulk of their tank costs is worker salary and machine maintenance, so there isn’t a huge financial difference between building a tank or not. Might as well build something. 

I'm open to them thinking spending more is OK... but not past a certain amount.

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Um...why cannot Elon just run computer simulations of what could go wrong BEFORE it does?

 

Might save some metal from becoming scrap?

 

What? Some stuff you cannot predict? Cannot pressure and propellant flow be calculated for? That's what computers do best!

No offense really, RUD's are entertaining, but watching Starship do what it was meant to do would be more so.

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From SpaceX updates: https://www.spacex.com/updates/starship-moon-announcement/index.html

Quote

SpaceX is rapidly advancing Starship development, drawing on an extensive history of launch vehicle and engine development programs. Since January 2020, SpaceX has built 10 Starship prototypes, with production and fidelity accelerating on each build. SpaceX has manufactured and tested more than 60 of Starship’s Raptor engines, accumulating nearly 30,000 seconds of total test time over 567 engine starts, including on multiple Starship static fires and flight tests. We have conducted six suborbital flight tests, including two 150-m hops and four high-altitude flights. SpaceX has also built a full-size Super Heavy booster as part of a pathfinder effort, and currently has five vehicles in production.

Italics mine. That's impressive. It seems as though they've slowed down Raptor development from last summer, and are taking their time with the more recent Raptors. If last year's tweet updates were anything to go by, it sounded like they were moving through ~10 engines per month or so, and would likely have hit SN50 by early fall. Since that's supposed to have been a major milestone for the Raptor, could they have started to slow down around the same time?

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47 minutes ago, Spacescifi said:

What? Some stuff you cannot predict? Cannot pressure and propellant flow be calculated for? That's what computers do best!

You actually think they don't do simulations?

They do BOTH.

If simulating real world complex systems for a single SN# hop took 2 months to code, and run, and took 99% of all possible real world issues into account, you'd still miss that 1%, but hey, it's easy to change and fix, right? What if it took 6 weeks to build the thing and actually fly it? Faster to fly the real thing.

52 minutes ago, Spacescifi said:

Might save some metal from becoming scrap?

Metal is cheap.

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1 minute ago, tater said:

You actually think they don't do simulations?

They do BOTH.

If simulating real world complex systems for a single SN# hop took 2 months to code, and run, and took 99% of all possible real world issues into account, you'd still miss that 1%, but hey, it's easy to change and fix, right? What if it took 6 weeks to build the thing and actually fly it? Faster to fly the real thing.

Metal is cheap.

 

I see. I was beginning to think all the crashes were due to stuff he could have caught.

 

But it seems he has a deadline so he is going ASAP so if crashes cannot be avoided and that is the price of fast learning so be it.

 

Did not know comp testing was more tedious than actual spaceship flight tests LOL.

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4 minutes ago, Spacescifi said:

 

I see. I was beginning to think all the crashes were due to stuff he could have caught.

But it seems he has a deadline so he is going ASAP so if crashes cannot be avoided and that is the price of fast learning so be it.

Did not know comp testing was more tedious than actual spaceship flight tests LOL.

There is no deadline other than actually doing it in a time frame that is not decades.

Testing is not necessarily more difficult than actual testing, but you have to then simulate everything. Look at Starliner—they simulated everything on Starliner, but in the real world it failed because they didn't simulate the 2 vehicles talking to each other (though they simulated each alone).

The very first flip for Starship looked... exactly like the SpaceX simulation video I presume you have seen—and that was from a couple years prior.

What that does not tell them is about the unknown unknowns. You can't simulate things you have not thought of already.

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57 minutes ago, Spacescifi said:

 

Um...why cannot Elon just run computer simulations of what could go wrong BEFORE it does?

 

Might save some metal from becoming scrap?

 

What? Some stuff you cannot predict? Cannot pressure and propellant flow be calculated for? That's what computers do best!

No offense really, RUD's are entertaining, but watching Starship do what it was meant to do would be more so.

Simulations aren't perfect.

So many equations, especially in aerospace engineering, have pieces that aren't actually mathematically derived. Jet engines have a "manufacturer's constant" that goes in an exponent to calculate thrust. All kinds of numbers are decided on by real-world testing because there's no way to derive them mathematically. Even when you plug it all into a simulation, you have to check and compare with real world data to make sure the simulation is predicting things correctly, not in some alternate universe where drag or flow works slightly differently. So simulation will never totally match a real system when making something as complicated as a rocket.

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8 hours ago, Ultimate Steve said:

There's a lot of speculation that this award is because the SpaceX option was the only one they could afford, and even then they had to talk SpaceX down in price a bit.

There is further speculation that, because Congress probably won't be happy with this choice, that this also serves as a play to say "We'll have two landers, we'll give you what you want, if you properly fund us."

SpaceX has the benefit that they only need their hot gas landing engines who they need anyway for accurate landing on earth. Yes they need new legs but they don't have to retract or be hidden by heat shields,  an nose docking port. 
In short this will be pretty cheap for SpaceX, Main cost is probably the procedures for the operation

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7 minutes ago, cubinator said:

Simulations aren't perfect.

So many equations, especially in aerospace engineering, have pieces that aren't actually mathematically derived. Jet engines have a "manufacturer's constant" that goes in an exponent to calculate thrust. All kinds of numbers are decided on by real-world testing because there's no way to derive them mathematically. Even when you plug it all into a simulation, you have to check and compare with real world data to make sure the simulation is predicting things correctly, not in some alternate universe where drag or flow works slightly differently. So simulation will never totally match a real system when making something as complicated as a rocket.

 

I see...so real flight testing is the ultimate proving ground for success or failure.

 

Kind of like life. One can guess all day about what COULD happen or just do a real test and write out the test results for future reference.

 

The scientific test method could be useful in life for all kinds of unknowns one may wish to try.

 

Data derived from resl tests never lies. That you can bank on.

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So many shake-my-head issues here. Let's start with one:

15 minutes ago, Spacescifi said:

Data derived from resl tests never lies. That you can bank on.

Please meet my little friend, Mr. Bar. First name Error. Error Bar gets a lot of work in science, because data derived from real tests abso-f'ing-lutely can lie. For all sorts of reasons.

Next is the question of computational engineering (or even physics). The results of any model are only at best as good as the model. Model has a bug in it? Bad results. Model is perfectly coded but makes a simplifying assumption that wasn't true? Bad results. Model is great at jobs X and Y, but you use it for Z? Bad results. You see where I'm going with this?

Now real-world testing. What happens when you have some experimental error? Same as "model has a bug in it". What happens when your test fails to match real-world conditions? Same as "wrong assumptions". How about when you take this test data and use it for something it wasn't designed to test? Same as "X and Y but not Z".

What happens when you run a test and get 10 data samples, but the part you are testing has a low-cycle fatigue issue that makes it break after 20-30 cycles? Well, that's a problem, right? What happens when you tested it 10,000 times in the lab, but never when it was -15C, and yet you need to fly on a cold winter day?

There are reasons why computational CFD has mostly replaced wind tunnel testing, but there are also reasons why there are still wind tunnels.

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20 minutes ago, mikegarrison said:

So many shake-my-head issues here. Let's start with one:

Please meet my little friend, Mr. Bar. First name Error. Error Bar gets a lot of work in science, because data derived from real tests abso-f'ing-lutely can lie. For all sorts of reasons.

Next is the question of computational engineering (or even physics). The results of any model are only at best as good as the model. Model has a bug in it? Bad results. Model is perfectly coded but makes a simplifying assumption that wasn't true? Bad results. Model is great at jobs X and Y, but you use it for Z? Bad results. You see where I'm going with this?

Now real-world testing. What happens when you have some experimental error? Same as "model has a bug in it". What happens when your test fails to match real-world conditions? Same as "wrong assumptions". How about when you take this test data and use it for something it wasn't designed to test? Same as "X and Y but not Z".

What happens when you run a test and get 10 data samples, but the part you are testing has a low-cycle fatigue issue that makes it break after 20-30 cycles? Well, that's a problem, right? What happens when you tested it 10,000 times in the lab, but never when it was -15C, and yet you need to fly on a cold winter day?

There are reasons why computational CFD has mostly replaced wind tunnel testing, but there are also reasons why there are still wind tunnels.

 

Got it, so a combo of forethought and real test result review is vital to see what worked and what did not.

Compare notes as it were. DO let your right hand know what your left did...at least when it comes to evaluating unknown potential.

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1 hour ago, tater said:

You actually think they don't do simulations?

Yes, but do they have installed RO? RealFuels? RSS? Principia?

We know they have MechJeb or TCA (cuz they land), and Hangar Extended, but what about realism?

1 hour ago, tater said:

If simulating real world complex systems for a single SN# hop took 2 months to code, and run, and took 99% of all possible real world issues into account, you'd still miss that 1%, but hey, it's easy to change and fix, right?

And Kraken.

1 hour ago, tater said:

Metal is cheap.

Metal itself. But the hardware manufacturing, including precise equip and staff salaries.

1 hour ago, tater said:

but in the real world it failed because they didn't simulate the 2 vehicles talking to each other (though they simulated each alone).

Iirc, Starliner had problems with clock and so on before it could fail also the meeting.

Anyway, if the talking was not simulated, then it raises a question, how did they test the equipment for that. Kinda, one hand clap.

1 hour ago, Spacescifi said:

Did not know comp testing was more tedious than actual spaceship flight tests

Of course, it is.
For the comp testing you first need code the code, debug it, run beta-testing,
While the rocket is just a pipe with flammables which flies on its own. It either bursts, or not.

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