NASA SLS/Orion/Payloads

[PB666]

12 hours ago, lugge said:

Completely correct answer, and completely useless.
Are you a mathematician? ;-)

Not completely useless, if you are using solar electric propulsion to go interstellar, the proplem of ISP is rather superficial, since you can consider a superconducting supercollider as a very reaction mass efficient ion drive. But the problem with ion drive with ver high efficiency is that they love power, and as you increase tangential velocity centripedal-gravity increase to the point that no amount of effort can hold you close to the sun, lose the sun, lose the power. 

[DerekL1963]

3 hours ago, tater said:

5. ISRU isn't a thing yet. It needs to be built, then tested before NASA stakes billions and lives on it.

So.Much. This.   ISRU hasn't been tested beyond laboratory bench prototypes - and it's a long and rocky road from bench prototype to flyable test hardware.  And a longer and rockier road from test hardware to something you can stake lives and billions on.  For all intents and purposes, despite decades of handwaving by Zubrin and his fact resistant acolytes, the current state of the art for ISRU is just barely this side of "vaporware".

 

[tater]

35 minutes ago, DerekL1963 said:

So.Much. This.   ISRU hasn't been tested beyond laboratory bench prototypes - and it's a long and rocky road from bench prototype to flyable test hardware.  And a longer and rockier road from test hardware to something you can stake lives and billions on.  For all intents and purposes, despite decades of handwaving by Zubrin and his fact resistant acolytes, the current state of the art for ISRU is just barely this side of "vaporware".

Yeah, this is something utterly critical to understand. Anyone who is sanguine about sending colonists (or even flags and footprints) to Mars needs to either read Scott Kelly's book, or at least listen to his interviews. If they can't have ISS life support run hands-free (or at least replacement parts and failures free) for a couple years at a stretch, what makes people think that a novel technology to produce propellants (or just their life support) is going to work the first time, perfectly, in an incredibly harsh environment?

Do I think that a 1960s brute force approach could possibly work? Sure. If they could throw enough mass, you'd just send spares, and loads of excess capacity. Also, in the 1960s, the Cold War race aspect allowed for a level of risk that would no longer be acceptable to many or most. In order to do that, you'd need a similar level of national effort, and that is simply not going to happen. As a result, any such effort will be very measured.

 

[DAL59]

4 hours ago, Bill Phil said:

I've talked to some NASA engineers working at MSFC. It'll take something like 7 SLS launches. At 3 billion per launch, plus 3 billion per payload, that's 42 billion. That's being generous (SLS will be more expensive, payloads too), but we only just got started. Adding in 15 years of paying off salaries and benefits for 10k people (about 250k per person, from what I can find), that's about 80 billion total. For the first mission, and an extra 42 per mission after that.

And that is guaranteed to be a gross underestimate. NASA has tens of thousands of contractor employees that work on NASA programs, and we've ignored the yearly SLS cost, the SLS development cost, and so on.

They're not getting funding for that, unless sunk cost fallacy.  Except, if they do decide to spend the next 15 years launching useless rockets, they wont have to send a habitat.  Because Musk will be happy to let them into the hotel.  BFR does more payload that SLS, for 1/200th the price.  1/200th.   Even if its 100 times more expensive, it would still be better than the SLS.   

1 hour ago, tater said:

If they can't have ISS life support run hands-free (or at least replacement parts and failures free) for a couple years at a stretch,

The ISS is two decades old.  Do you really think we couldn't build a far superior one, especially now we have 3-d printers?  

1 hour ago, tater said:

Do I think that a 1960s brute force approach could possibly work? Sure. If they could throw enough mass, you'd just send spares, and loads of excess capacity.

Huh.  I wonder what rocket could possibly have plenty of spare mass...  

 

[Canopus]

11 hours ago, DAL59 said:

They're not getting funding for that, unless sunk cost fallacy.  Except, if they do decide to spend the next 15 years launching useless rockets, they wont have to send a habitat.  Because Musk will be happy to let them into the hotel.  BFR does more payload that SLS, for 1/200th the price.  1/200th.   Even if its 100 times more expensive, it would still be better than the SLS.   

The ISS is two decades old.  Do you really think we couldn't build a far superior one, especially now we have 3-d printers?  

 

You keep talking about BFR as if it is already flying regularly. Yet SpaceX hasn‘t even sent people to LEO.

Also i fail to see how 3d printing would help to improve the ISS.

Edited April 6, 2018 by Canopus

[Bill Phil]

10 hours ago, DAL59 said:

They're not getting funding for that, unless sunk cost fallacy.  Except, if they do decide to spend the next 15 years launching useless rockets, they wont have to send a habitat.  Because Musk will be happy to let them into the hotel.  BFR does more payload that SLS, for 1/200th the price.  1/200th.   Even if its 100 times more expensive, it would still be better than the SLS.   

The ISS is two decades old.  Do you really think we couldn't build a far superior one, especially now we have 3-d printers?  

Huh.  I wonder what rocket could possibly have plenty of spare mass...  

 

BFR only reduces launch cost. Congrats. Now, instead of spending 42 billion per mission, you're spending maybe 30, if you're lucky. Remember, it's a NASA mission. If they use BFR (if BFR even flies, could easily be cancelled, although no one wants that) they will also use SLS. Guaranteed, unless SLS is cancelled by then, but, if there are Mars plans, they'd probably be cancelled as well. Still something like 68 billion for the first mission. Once again, massive underestimate. If missions happen every two years, that's an extra 5 billion per mission.

[PB666]

2 hours ago, Canopus said:

Also i fail to see how 3d printing would help to im[p]rove the ISS.

3D inflatable dolls?

21 minutes ago, Bill Phil said:

BFR only reduces launch cost. Congrats. Now, instead of spending 42 billion per mission, you're spending maybe 30, if you're lucky. Remember, it's a NASA mission. If they use BFR (if BFR even flies, could easily be cancelled, although no one wants that) they will also use SLS. Guaranteed, unless SLS is cancelled by then, but, if there are Mars plans, they'd probably be cancelled as well. Still something like 68 billion for the first mission. Once again, massive underestimate. If missions happen every two years, that's an extra 5 billion per mission.

Not only reduces cost, but is also supposed to reduce turn-around time . . .and also core to the strategy is a refuel-able 'gas-station' in LEO that can provide propellant for large space craft.

The trouble I see with BFR is that metholox system they are using still needs to gain efficiency or they need to think about switching to hydrolox.

 

[tater]

The presumption regarding 3d printing is the ability to print replacement parts for critical systems. This is indeed possible, and massively simplifies repair on long missions. Instead of having to take however many replacement parts for every single sub-assembly of every critical system, you bring a digital copy of everything, and print replacement parts to order. You are still limited to what can in fact be 3d printed, and how much stock you bring. Also, in many cases the 3d parts will not be as robust as the original part it replaces.

[PB666]

10 hours ago, DAL59 said:

They're not getting funding for that, unless sunk cost fallacy.  Except, if they do decide to spend the next 15 years launching useless rockets, they wont have to send a habitat.  Because Musk will be happy to let them into the hotel.  BFR does more payload that SLS, for 1/200th the price.  1/200th.   Even if its 100 times more expensive, it would still be better than the SLS.   

The ISS is two decades old.  Do you really think we couldn't build a far superior one, especially now we have 3-d printers?  

Huh.  I wonder what rocket could possibly have plenty of spare mass...  

 

This is like a woman dressed in a nighty with a cougar hopping over a car trying to sell Fords. Don't confuse an advertising campaign with a product. Buying a ford did not get you a cougar or a woman.

3 minutes ago, tater said:

The presumption regarding 3d printing is the ability to print replacement parts for critical systems. This is indeed possible, and massively simplifies repair on long missions. Instead of having to take however many replacement parts for every single sub-assembly of every critical system, you bring a digital copy of everything, and print replacement parts to order. You are still limited to what can in fact be 3d printed, and how much stock you bring. Also, in many cases the 3d parts will not be as robust as the original part it replaces.

How do you repair a 3D-printer in space.

[tater]

2 minutes ago, PB666 said:

How do you repair a 3D-printer in space.

Depends on the printer. They tend to be fairly simple, after all. It means that you bring replacement parts for the printer.

The orher issue with printed replacement parts, is that the system that failed in the first place, now is fixed, but with the same failure modes. Indeed, perhaps more failure modes (say the original part was metal, and the new one is plastic).

[PB666]

28 minutes ago, tater said:

Depends on the printer. They tend to be fairly simple, after all. It means that you bring replacement parts for the printer.

The orher issue with printed replacement parts, is that the system that failed in the first place, now is fixed, but with the same failure modes. Indeed, perhaps more failure modes (say the original part was metal, and the new one is plastic).

This is don't get actually. I go to home depot they have a little 3-D printer. Most of the stuff I have that breaks, they are much larger than the printer. What if the air-conditioning system breaks, can you build a whole new system. Or do you have to design the system with so many parts that you can then disassemble the system, replace a part, then reassemble the system. Who is going to do all this intricate workbench repair in the microgravity of space (screws and bolts floating around in your space craft?).

If you design all the actuator electronics for example to run on Raspberry Pi, then all you need to do is to bring 10 along, then any electronic system that fails replace the Pi. On  system board just have caps, resisters, transformers that can be plugged in and keep extra in stock.

[Wjolcz]

I'm only excited about Europa missions launched on SLS tbh. Feels like the only sensible thing to build and launch on it. And still even that could probably be launched on FH for a fraction of the price.

[tater]

18 minutes ago, PB666 said:

This is don't get actually. I go to home depot they have a little 3-D printer. Most of the stuff I have that breaks, they are much larger than the printer. What if the air-conditioning system breaks, can you build a whole new system. Or do you have to design the system with so many parts that you can then disassemble the system, replace a part, then reassemble the system. Who is going to do all this intricate workbench repair in the microgravity of space (screws and bolts floating around in your space craft?).

There are larger 3d printers. I saw one at Sandia Labs in their rapid prototyping lab that was being developed for the Navy. Selective laser sintering of metal parts... parts about the size of a microwave. Pipes, basically, with flanges. The electronics would ahve to be brought, but if many failure modes for life support involve screwed up plumbing, it beats dragging along every possible pipe combination that might fail. You bring a printer, and make replacement elbows, etc.

It;s a legit way to leverage the limited mass you can bring, but that doesn't mean that life support, etc is then magically fixed, either.

[sh1pman]

12 minutes ago, Wjolcz said:

I'm only excited about Europa missions launched on SLS tbh. Feels like the only sensible thing to build and launch on it. And still even that could probably be launched on FH for a fraction of the price.

FH has poor BLEO performance. For launching something to Jupiter, you really want a high Isp hydrolox stage.

[PB666]

11 minutes ago, tater said:

There are larger 3d printers. I saw one at Sandia Labs in their rapid prototyping lab that was being developed for the Navy. Selective laser sintering of metal parts... parts about the size of a microwave. Pipes, basically, with flanges. The electronics would have to be brought, but if many failure modes for life support involve screwed up plumbing, it beats dragging along every possible pipe combination that might fail. You bring a printer, and make replacement elbows, etc.

It;s a legit way to leverage the limited mass you can bring, but that doesn't mean that life support, etc is then magically fixed, either.

Do elbows fail, I have galvanized pipes, only once has an elbow failed (that was when I was tearing it out to replace it).
The other thing is that for copper pipes you can now just have a 'shark' tooth that slides over. Its a much lighter part.

For 23 years I managed a fairly large lab, here is what I typically had that failed.
2nd stage compressors on ultra-low temperature devices. One compressor fail, on hard short to ground fault on a compressor.
1 multitranformer failure (short to ground on one of the legs).
Computer power supply failures (numerous, frequent - blown capacitors)
Harddrive failures (occasionally - with ssd this is now not a problem).
neoprene belts.
Teflon seal wear out.
Refrigeration system on some equipment fails (needs new compressor)
Vacuum pump failure (needs to be rebuilt) - Much more about the rebuilding than the parts and very messy.
Electronics failure - often circuit board power transformer (typical example are microfuges).
Back in the days of overclocking, lost CPUs, switch back to Intel and never lost another CPU.
Rubber seals and gaskets for various plumbed systems.
For copper and brass valves the occasional replacement valve due to pitting (which was finally mitigated by systematic liming of the pipes to prevent corrosion).

Most things that break really require cleaning and maintenance, almost everything that has to be replaced is a complex of structure and electronics that 3-D printing does not do well.
(Actually for most things that break, the item that needs to be repaired is irreparable, the user).

BTW if you are laser sintering of parts, you are also going to have toxic vapors generated.

 

 

[Wjolcz]

38 minutes ago, sh1pman said:

FH has poor BLEO performance. For launching something to Jupiter, you really want a high Isp hydrolox stage.

What about the planned metholox stage with Raptor?

[Bill Phil]

37 minutes ago, sh1pman said:

FH has poor BLEO performance. For launching something to Jupiter, you really want a high Isp hydrolox stage.

Europa Clipper can launch on an EELV. The only reason it was proposed to be a payload for SLS was so they could get to Jupiter faster, without a bunch of gravity assists.

It can definitely be launched on FH. The question is, could it be done better with a different LV?

[DerekL1963]

5 minutes ago, PB666 said:

Most things that break really require cleaning and maintenance, almost everything that has to be replaced is a complex of structure and electronics that 3-D printing does not do well.

My experience in the Navy pretty much agrees with that.  Failures tended to be either in the power or electronics systems, or high wear mechanical items -  pretty much the things that 3-D printing doesn't do.

[tater]

7 minutes ago, DerekL1963 said:

My experience in the Navy pretty much agrees with that.  Failures tended to be either in the power or electronics systems, or high wear mechanical items -  pretty much the things that 3-D printing doesn't do.

Yeah, I expect that the military application has intentional damage in mind (done by the enemy), not routine part replacement. To limp whatever system along. Clearly anything that 3d printing can't deal with then needs to be brought along.

On topic to why life support is nothing like solved, and related, what they want to do with DSG, is that while there have been lessons learned from ISS that would result in evolved LS systems, even those improved systems need to be tested. In the case of what parts wear out/fail in some routine way, that needs to be characterized in a real life situation so that when they take that same system to Mars, they have brought the right complement of replacement parts along.

[DerekL1963]

2 minutes ago, tater said:

Yeah, I expect that the military application has intentional damage in mind (done by the enemy), not routine part replacement. To limp whatever system along. Clearly anything that 3d printing can't deal with then needs to be brought along.

Not really.  Most systems you need repaired underway in order to survive (in or post combat), you need the spares NOW.  Not in a day or two when the 3-D printer spits them out.  Assuming you have power to the printer and the printer itself is not damaged...  The military is looking at them because anything destroyer sized or up does have enough minor things go wrong that a 3-D printer can be useful in making them right.  They can also be used to keep the inventory of spares topped off (as opposed to print-on-demand.)
 

9 minutes ago, tater said:

On topic to why life support is nothing like solved, and related, what they want to do with DSG, is that while there have been lessons learned from ISS that would result in evolved LS systems, even those improved systems need to be tested. In the case of what parts wear out/fail in some routine way, that needs to be characterized in a real life situation so that when they take that same system to Mars, they have brought the right complement of replacement parts along.

Indeed.  Setting spares inventory levels is...  something of a black art.  And dealing with only a small number of installations of a given system just makes it harder because you don't really know if your statistics are truly representative.

[tater]

14 minutes ago, DerekL1963 said:

Not really.  Most systems you need repaired underway in order to survive (in or post combat), you need the spares NOW.  Not in a day or two when the 3-D printer spits them out.  Assuming you have power to the printer and the printer itself is not damaged...  The military is looking at them because anything destroyer sized or up does have enough minor things go wrong that a 3-D printer can be useful in making them right.  They can also be used to keep the inventory of spares topped off (as opposed to print-on-demand.)

That makes sense. The laser sintering rig I saw was pretty large, and printed fairly quickly for the build area. I recall the guy in the lab saying they were looking into it for CVNs because of size and power requirements. Of course a Sandia Labs dog and pony show ain't the real world, just their notional ideas about what it might get used for .

Edited April 6, 2018 by tater

[sevenperforce]

2 hours ago, sh1pman said:

FH has poor BLEO performance. For launching something to Jupiter, you really want a high Isp hydrolox stage.

FH is cheap for its LEO performance, so there's nothing to stop you from throwing Europa Clipper into LEO with a recoverable FH, then tossing up a separate transfer stage for the injection burn the following week. Much cheaper than configuring the SLS for Clipper.

[sh1pman]

Just now, sevenperforce said:

FH is cheap for its LEO performance, so there's nothing to stop you from throwing Europa Clipper into LEO with a recoverable FH, then tossing up a separate transfer stage for the injection burn the following week. Much cheaper than configuring the SLS for Clipper.

Yeah, this is probably the best option from the cost perspective. 

Requires rendezvous and autonomous docking though. And two narrowly spaced launches.

[Scotius]

3 hours ago, PB666 said:

This is like a woman dressed in a nighty with a cougar hopping over a car trying to sell Fords. Don't confuse an advertising campaign with a product. Buying a ford did not get you a cougar or a woman.

Excuse me. Do you want me to post a link to YT video of a police chase in USA, in which escaping suspect (high as a kite) took his (stolen) Ford truck offroad? That beautiful, monstrous car tore through the scenery like a beast, and took in stride abuse that would leave a lesser car wheels up and leaking fluids from every pipe. The chase ended only when that idiot drove into a pond and got the car hopelessly stuck in the mud. I think i fell in love that day Too bad i'm several thousands of dollars short of being able to buy such truck.

[sevenperforce]

37 minutes ago, sh1pman said:

Yeah, this is probably the best option from the cost perspective. 

Requires rendezvous and autonomous docking though. And two narrowly spaced launches.

Clipper only masses 5-8 tonnes, so Falcon 9 can put it into LEO with RTLS or EEO with ASDS recovery. Clipper is intended to be able to handle a six-year coast to Jupiter, so extended Earth orbit loiter isn't really a problem. The transfer stage is the only time-sensitive element and it can launch whenever you want it to.

Clipper has full independent maneuvering capabilities so rendezvous and docking to the transfer stage is a matter of software, not hardware...other than a simple IDA.

With Falcon 9 ASDS putting it into EEO, you might even be able to get away with using another ASDS Falcon 9 for the transfer stage.  You're looking at $124-150M...absolute max would be maybe $185M.

And that's for an SLS-style direct-to-Jupiter launch. If you want to do a six-year coast via gravity assist stacking, just go FHR2 for a cool $95M and call it a day.

Hmmmm........ www.rocketbuilder.com says that the cost of an Atlas V 551 is just $73M. That can't be right, can it?