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32 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.

As I understand much of the problems with the landings has been sloshing in the header tank. First they used pressurized methane but the sloshing created an pressure drop. 
Next try with helium pressurization and you got bubbles in the  methane.  Now they know this they can simulate it at least with helium and design baffles who reduce sloshing but don't trap gas while flipping. 

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What i wonder when seeing the pictures of Dragon ontop of the Falcon 9: How exactly is it fixed to the service module? Any hardpoint would be a gap in the heatshield while the umbilical arm that reaches around the heatshield surely isnt enough to hold it in place...

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5 minutes ago, Elthy said:

What i wonder when seeing the pictures of Dragon ontop of the Falcon 9: How exactly is it fixed to the service module? Any hardpoint would be a gap in the heatshield while the umbilical arm that reaches around the heatshield surely isnt enough to hold it in place...

Its bolts trough the heat shield as I understand. this is not an problem with say an 1 cm bolt, yes it will be hot but the heat would spread out pretty fast.  Cabling and cooling pass the umbilical arm on the side to avoid heating as this is stuff who can not handle heat and its also an much larger hole. 
Pretty sure all capsules use an variant of this. 

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All of them are attached by piercing the shield, afaik.

Gemini for MOL, TKS, and Soyuz VI also have successfully tested man-sized hatches in it.

And Shuttle together with Buran both had at least three huge doors for wheels underneath.

And it was never a source of problems.

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17 hours 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?

Actually you are solving the problem that NASA always did: How to get a single rocket up there.

That was never the intention of Elon Musk: He wants a Mars colony with hundreds of rockets flying, so his vision is a rocket and a factory. He takes a lot of expierence from automotive engineering where a lot of test vehicles are built while building up the factory.

Although these prototypes are work intensive and do cost more than final versions, their cost is less than it seems because you need to build them anyway to master the production process. And even if they are not perfect for orbital flight and landing, they might be good enough for some hop tests. So build them early and they are useful to engineering. Build them later and they are just scrap.

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51 minutes ago, kerbiloid said:

Lunar missions became commercial?

All US space efforts are "commercial." NASA builds nothing, contractors do. Most look at the USAF and NASA as the customer, then design capability to exactly service that customer in a "commercial" setting as we commonly talk about it. Others design specific thing to a NASA spec, bespoke—SLS for example.

Mueller (designer of the Merlin engine) was referring to the case for SpaceX. If they built it, aside from Mars (which doesn't generate revenue, it costs money), what is it good for? One use case is selling lunar missions to someone with deep pockets... the US government. SpaceX was gonna build SS anyway, if they can sell a couple flights for $2.9B, that's great for them.

Note that the contract is for 2 flights, one uncrewed demo, and one crew mission.

The 2 losing submissions are entirely free to build their landers anyway—the difference between them and SpaceX is that minus the government throwing money at them, they won't do it.

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8 hours ago, tater said:

All US space efforts are "commercial." NASA builds nothing, contractors do. Most look at the USAF and NASA as the customer

I thought "commercial" is not the same as "paid from budget", but "paid by non-budget customers, paying taxes into the budget".
So, then all Soviet launches, including Laika, were commercial.
And submarines with SLBM, too.

8 hours ago, tater said:

Mueller (designer of the Merlin engine) was referring to the case for SpaceX. If they built it, aside from Mars (which doesn't generate revenue, it costs money), what is it good for? One use case is selling lunar missions to someone with deep pockets... the US government. SpaceX was gonna build SS anyway, if they can sell a couple flights for $2.9B, that's great for them.

The same could be said about Voskhod, if they were selling the seats for space tourists.
Then anything at all can be called "commercial", because you can sell tickets to watch  it.

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28 minutes ago, kerbiloid said:


So, then all Soviet launches, including Laika, were commercial.
 

In the soviet Union all "companies" were owned by the state. Afaik the us government doesn't have a majority stake in SpaceX.

 

 

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3 minutes ago, Flying dutchman said:

Afaik the us government doesn't have a majority stake in SpaceX.

When SpaceX sells launches for commercial sats, it's of course, commercial flights,

But yet haven't heard about lunar landings sold to somebody but budget.

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44 minutes ago, kerbiloid said:

I thought "commercial" is not the same as "paid from budget", but "paid by non-budget customers, paying taxes into the budget".

The difference in this case is more one of speculation.

If a home builder builds a house for a client, they have a budget (which they generally exceed, lol, one $1000+ change order at a time), and they make it. They know at the start of the project how much the client is obligated to pay them.

Home builders can also work on spec. They build a house, and after it is complete, it is sold to someone—if they chose the site, design, market conditions poorly—they are out the cost of the home with no one wanting to buy it.

SpaceX and Starship in this case (the Mueller quote) is the latter. They were going to build Starship anyway—but once it exists at some level, there is a very likely buyer—NASA.

Edited by tater
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1 hour ago, tater said:

They were going to build Starship anyway—but once it exists at some level, there is a very likely buyer—NASA

Currently the only lunar customer is NASA, and unlikely it will change in SpaceX lifetime.

So, it looks like a dedicated, budget-aimed activity.

USSR was building T-72 for its own needs, no matter if somebody else buys.
Does it mean that the Soviet tank building industry was commercial, if they sold some of them to random customers?

Will the SpaceX lunar things be ever sold if NASA won't buy them (paying from budget)?

Edited by kerbiloid
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17 minutes ago, kerbiloid said:

 

USSR was building T-72 for its own needs, no matter if somebody else buys.
Does it mean that the Soviet tank building industry was commercial, if they sold some of them to random customers?

 

it does mean that the soviet state sold tanks to a friendly (to them) nation. i'm pretty sure that if the US wanted to buy one at the time they wouldn't sell. 

now did that make the soviet state a commercial organisation?

 

not a clue honestly.

Edited by Flying dutchman
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In my head canon there have always been two definitions of the concept commercial in this context.

1. If (US) gov wants a rocket, and they (directly or through NASA, doesn't matter, since in this context I consider NASA to be gov) pay a private company to build it for them then it is commercial. On the other hand if it's NASA that does the building, then it's not commercial contract.

2. If a private company builds a rocket and sells it to gov, it's a government contract. On the other hand, if they sell it to some other private company, then it's commercial.

So the same contract can be both commercial and government depending on which side I'm looking from.

(Something like "borrow" and "lend").

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My opinion on the difference between commercial and govt contacts:

1) A govt agency has a design. It wants the design built, so it goes out to contractors. The contractors haven't necessarily built this before, so because the govt has responsibility for the design, any problems that crop up are the govt's responsibility. The contract is cost+.

2) A govt agency has a requirement. Suppliers bid their own designs to meet that requirement. The supplier has responsibility for the design and any obstacles it might face. The contract is fixed cost.

 

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1 hour ago, Flying dutchman said:

it does mean that the soviet state sold tanks to a friendly (to them) nation. i'm pretty sure that if the US wanted to buy one at the time they wouldn't sell. 

The US tank builders were commercial companies performing also state orders among others.
The SU tank builders had the only customer - the state (or govt)  They were also producing civil tech, but only for the same only customer.
SpaceX currently has the only lunar customer - the state (or govt).
So, the lunar program is as commercial as a federal agent on salary. The state pays - it works. The state doesn't pay - it doesn't work. No other lunar customers are seen.

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25 minutes ago, RCgothic said:

My opinion on the difference between commercial and govt contacts:

1) A govt agency has a design. It wants the design built, so it goes out to contractors. The contractors haven't necessarily built this before, so because the govt has responsibility for the design, any problems that crop up are the govt's responsibility. The contract is cost+.

2) A govt agency has a requirement. Suppliers bid their own designs to meet that requirement. The supplier has responsibility for the design and any obstacles it might face. The contract is fixed cost.

 

I kind of think your view is the "correct" one.

Mercury was designed by NASA and they simply contracted McDonnell to build it. NASA still did all of the testing and launched it. It was not a commercial contract.

Crew Dragon was designed by SpaceX, built by SpaceX, tested by SpaceX, and correct me if I am wrong, but is launched and operated by SpaceX too (SpaceX does mission control from Hawthorne). It is a commercial contract.

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6 hours ago, kerbiloid said:

Currently the only lunar customer is NASA, and unlikely it will change in SpaceX lifetime.

So, it looks like a dedicated, budget-aimed activity.

SpaceX would have continued building Starship had they lost the contract—in fact by far the most likely outcome, their win was completely surprising.

SpaceX is not building Starship to serve the only lunar customer. They are building it speculatively.

5 hours ago, kerbiloid said:

The US tank builders were commercial companies performing also state orders among others.
The SU tank builders had the only customer - the state (or govt)  They were also producing civil tech, but only for the same only customer.
SpaceX currently has the only lunar customer - the state (or govt).
So, the lunar program is as commercial as a federal agent on salary. The state pays - it works. The state doesn't pay - it doesn't work. No other lunar customers are seen.

The current procurement system for military hardware tends to be that they have a contract for a specification. Say a tank of certain mass and dimensions with some capability (the first 2 so it can be shipped using existing military logistics). Say 3 companies want the contract, they pitch ideas. The Army picks 2 to go on, and both are paid to develop prototypes. The prototypes are then tested, and a final selection is made, the winner of which gets the B$ contract. The people bending metal get paid, and no one has to bend metal without knowing ahead of time they will be paid.

If I had a great idea for a tank, and simply built it—then tried to sell it to the Army, that would be purely speculative.

SpaceX is building a tank (flying tanks), and only then selling it for the lunar use case. They tried for a smallsat contract (not a constellation, I think FIVE) and bid Starship a few weeks ago.

 

Starship exists for two reasons, IMO, and neither has to do with the Moon. One, SpaceX wants to colonize Mars (kooky, but there you go). Two, SpaceX wants to continue to have the ability to lower cost to orbit—not out of altrusim, but because slow as they may be, BO is plodding along towards having NG in service, and NG has more capability than F9 in every way, and is being specifically designed to be able to compete on cost with F9. If not Starship, they would need to make a LV that is at least 7m in diameter, puts FH-like mass in LEO, and is as cheap to fly as F9. Such dev takes time, so they had to start before BO is flying.

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38 minutes ago, tater said:

SpaceX would have continued building Starship had they lost the contract—in fact by far the most likely outcome, their win was completely surprising.

I'm particularly about the lunar stuff. Obviously, Starship is a launch vehicle of common purpose, including commercial.

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11 minutes ago, kerbiloid said:

I'm particularly about the lunar stuff. Obviously, Starship is a launch vehicle of common purpose, including commercial.

While I think this contract obviously helps them, they were doing it anyway.

I was also surprised when BO first announced the "National Team," vs their previous "Blue Moon" presentations, for sort of the same reason. Bezos wants to go to the Moon personally (from interviews I have read). I always assumed they'd be designing their own vehicle—they they would simply build and present to NASA as a fait accompli. It was odd (IMHO) for them to team up with partners that would literally not build that particle board mockup in Houston without getting paid for it first.

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14 hours ago, kerbiloid said:

Currently the only lunar customer is NASA, and unlikely it will change in SpaceX lifetime.

 

I thought SpaceX already sold the 'Dear Moon' mission to a rich guy.  It may not be a lunar landing, but looping around the moon does sound rather lunar to me...

14 hours ago, kerbiloid said:

Will the SpaceX lunar things be ever sold if NASA won't buy them (paying from budget)?

Once they have demonstrated the capability(and possibly even before), I rather expect that there will be at least a few non US gov buyers for payload to the moon.

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Starship really does change everything if/when they get it working.

Even without crew safety established for SS liftoff and Earth EDL, they can fly distributed launch missions to the Moon and back from LEO. Both Commercial crew vehicles are actually capable of holding 7 crew, and there's no need to worry about crowding for a short launch to meet SS in LEO (and zero reason to launch to ISS inclination, so a fast rendezvous should be possible). With just a single CC taxi flight to load it, we'd nearly double the number of astronauts to the surface on any given mission.

 

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