Payload to orbit if all US main launchers launched simultaneously

[savuporo]

The beauty of assembling at a Lagrange point is that the majority of the Delta V for a Trans Mars Injection burn  is delivered before boil off becomes a concern ....

Right. What about other burns ?

[Robotbeat]

Ed for space emperor.

But for hydrolox depots (or in-space fueled stages), it's important to realize that oxygen is the vast majority of the mass... you can keep it from boiling off entirely using essentially passive techniques (though a modest amount of active cooling may be more practical), then launch the relatively small amount of hydrogen in the last few months... And use hypergolics for maneuvering for later parts of the mission. ISS uses hypergolic propellant transfer fairly routinely, by the way!!!

I'm also a big fan of electric propulsion as a sort of very-high-Isp stage, it makes sense for pre-placing assets at the exploration site. You could enormously multiply the in-Mars-orbit capability of Delta IV Heavy or especially Falcon Heavy by using a 100kW electric stage to slowly spiral a big hypergolic stage or lander or even a small space station to low Mars orbit, or a whole series of supply pallets or modular exploration elements to the Martian surface. Such an electric stage would make supplying a permanent Mars base require no more launches than supplying ISS (though you'd need to use the heavier versions of EELVs and Falcon 9). And the technology is all incredibly well-proven now by commercial comm-sats and unmanned missions.


But there are all sorts of ways of skinning this cat. You don't have to use a very large HLV to do it (or a huge increase in launch infrastructure and launch rate).

[john smith 19]

But there are all sorts of ways of skinning this cat. You don't have to use a very large HLV to do it (or a huge increase in launch infrastructure and launch rate).

This was sort of my point starting this thread. To give people an idea of what the whole of the US launch industry could put up in 1 salvo over (I think) less than a week, with launchers that are available (and racking up safety stats) now.

And I think it's pretty impressive.

Thinking about it the idea of standard sized payload "pods" sized to the smallest launcher with mounting hardware to join pods together came (literally) off the top of my head.

Note this is not the optimal mass efficient solution, with everything perfectly  fitted to it's assigned LV (and rather clumsy elsewhere  ) but I'd guess it would save quite a bit of development money. 

On a liquid note. If it can store LOX I'm pretty sure Xenon would not be a problem. Of course 5000 Kg or thereabouts makes for a pretty big Xenon tank. 

[notsorandom]

The beauty of assembling at a Lagrange point is that the majority of the Delta V for a Trans Mars Injection burn  is delivered before boil off becomes a concern ....

Right. What about other burns ?

Entering and leaving a L-point takes much less Delta V. Even after three or so days of flight getting there boil off isn't too bad. So a spacecraft can still slow down to settle into the L-point using an LH2 stage if minimal steps are taken to mitigate boil off. To leave for Mars or any other deep space destination a spacecraft doesn't need a lot of Delta V. Lower ISP engines like hypergolic or lower thrust like electric ion work just fine.  The rest of the burns like entering and leaving Mars orbit can be handled with electric, storable methane and/or aerobreaking. I think that solar electric propulsion and staging out of an L-point is a pretty good solution. SEP can even be used to move bigger hardware to an L-point from LEO if time is not a factor.

[savuporo]

Thinking about it the idea of standard sized payload "pods" sized to the smallest launcher with mounting hardware to join pods together came (literally) off the top of my head.

That would be somewhere in 14ton to LEO range, including the "pod" of course, if you wanted to include as many companies with launchers as possible, worldwide. Incidentally, thats around what most ISS modules came in at.

I'm long convinced that this is how any bigger architecture should be put together, be it the next space station or a lunar base, or even mars sample return.

[savuporo]

The rest of the burns like entering and leaving Mars orbit can be handled with electric, storable methane and/or aerobreaking. I think that solar electric propulsion and staging out of an L-point is a pretty good solution. SEP can even be used to move bigger hardware to an L-point from LEO if time is not a factor.

Methane is not storable, not currently, the tech does not exist and is not validated. No immediately obvious plans anywhere to get it done in next decade.
SEP only works for payloads that have plenty of time to get where they need to be, years.
For everything else, hydrazine seems to be the morning fresh dairy for spacecraft for years to come.

[john smith 19]

That would be somewhere in 14ton to LEO range, including the "pod" of course, if you wanted to include as many companies with launchers as possible, worldwide. Incidentally, thats around what most ISS modules came in at.

Well since this was originally targeted at US launchers that would the Antares at 5000Kg. But I asked the question on an SLS thread that if you exclude propellant what indivisible l loads are there? I could only come up with a) Humougous telescope lens system. b) big nuclear reactor IE 100MW range.

Beyond that. Not much.

I'm long convinced that this is how any bigger architecture should be put together, be it the next space station or a lunar base, or even mars sample return.

Agreed.

Sadly the history of this subject suggests the sensible approach is the last thing that will be done. 

Methane is not storable, not currently, the tech does not exist and is not validated. No immediately obvious plans anywhere to get it done in next decade.

Although logically Methane should be not much harder than Lox if someone wants to do it.

Five decades from the first Apollo landing and still  the only serious work on on orbit cryo storage seems to be that from LM for the Centaur stage.   

SEP only works for payloads that have plenty of time to get where they need to be, years.
For everything else, hydrazine seems to be the morning fresh dairy for spacecraft for years to come.

Well there is that green propellant that they are testing on the ISS

AJ10-118K had a 319 sec specific impulse, but that's pressure fed and only 4.45 tonnes thrust.  The Titan 4 second stage LR91-AJ-11 engine was pump fed.  It produced 48 tonnes thrust at 316 sec ISP, but of course was not restartable.  Ariane 5 has Aestus, with its 321 sec ISP and restart ability.  Russia has more modern hypergolic pump fed engines, including some with staged combustion cycles.  They have proven specific impulses of up to 327 seconds. 

Trouble is most of them are out of production or small. The engines on Titan II were very impressive but are long gone (and the only ones that have run RP1, LH2 and A50 as the fuel). The R&D project with rocketedyne to pump feed the Aestus (IIRC called RS72 in the US) was impressive but again relatively small.

Compare that to something like 450secs+ on an RL10 or an SSME at about 512Klb of thrust.   

Hypergolics are the pragmatic solution but there is no big engine to use them. 

[savuporo]

Although logically Methane should be not much harder than Lox if someone wants to do it.

LOX isnt being used on any long duration mission either, so that doesnt get you further than methane.

The proven technologies for deep space propulsion ( i.e beyond earth departure kick ) right now are
- hydrazine
- small SEP thrusters
- solid kick stages

Hypergolics are the pragmatic solution but there is no big engine to use them.

You may want to ask Russians about that.

[Robotbeat]

Although logically Methane should be not much harder than Lox if someone wants to do it.

LOX isnt being used on any long duration mission either, so that doesnt get you further than methane.

The proven technologies for deep space propulsion ( i.e beyond earth departure kick ) right now are
- hydrazine
- small SEP thrusters
- solid kick stages

Hypergolics are the pragmatic solution but there is no big engine to use them.

You may want to ask Russians about that.

No, not just hydrazine but nitrogen tetroxide as well. The main propulsion systems on the larger probes like Cassini are bipropellant.

[savuporo]

No, not just hydrazine but nitrogen tetroxide as well. The main propulsion systems on the larger probes like Cassini are bipropellant.

Yes of course,  i should  keep saying "hypergolic with hydrazine". The key being "hypergolic" because of the reliability and longevity.

[john smith 19]

No, not just hydrazine but nitrogen tetroxide as well. The main propulsion systems on the larger probes like Cassini are bipropellant.

True. However for a full stage you need attitude control and pressurization and power.

I started a thread on what it would take to do IVF for a storable stage in advanced concepts but it went nowhere.

Apparently no one considered it worthwhile.  However without something like it the only option that does not need such support is a solid, which would make a trip to say Mars (or any other planetary body) much heavier for the same payload). The option would be to do it through the payload power and computer systems, but that's likely to change with every mission.

1.  2 ranges.  KSC and CCAFS are the Eastern Range (one range).  But depending on the orbit, Wallops may use resources of the Eastern Range.

Noted. I guess the question then becomes what orbits Wallops can launch to that don't need Eastern range support so they can work in parallel.

2.  No, it is pad/vehicle dependent. so no difference.

I guess I'm a bit surprised at that given the EELV's were designed to the same spec. I take it the range interfaces at the pad level, rather than the vehicle.

3.  The issue isn't the supply of physical roadblocks.  It is setting up and clearing out the areas that the roadblocks are to protect.

Is there anything specialized about the people who do this? It sounds like anyone from the National Guard to a hired security firm could handle it on a one off basis. BTW if you knew you were doing 3 launches back to back could you not seal common areas for the whole week?

faster  voice and data channel re-configuration processes are still limited by having to do physical voice checks on on all the channels at all the positions.

You mean someone has to physically speak some kind of message on each channel ? 
There is no "test" mode that connects a single microphone to all channels for a quick pass/fail test on them in one go?

Don't get me wrong. I believe all 4 vehicles could launch a single payload each within a normal working week but I'm not an expert and I'm trying to seen what the "roadblocks" are.

Right now I'm picturing.
1)Configure both Eastern and Wallops range on previous Thur/Friday.
2)Monday morning. Launch Antares and 1st LV from Eastern
3)Reconfigure Eastern for 2nd LV
4)Launch 2nd LV Wednesday.
5)Reconfigure for 3rd LV
6)Launch 3rd LV Friday.

Although depending on when you want to do the Antares launch you could postpone Wallops work to Monday or later and launch later in the week.

Your insight is valuable. I still don't think it's impossible, but as always there are the "unknown unknowns" (well unknown to me  that can make such an idea fail.

[john smith 19]

Regarding large storable stages.

I note the Indian GSLV incorporates a storable stage using a single 160 Klb engine.

Something to think about for those interested in such options.

[Jim]

I guess I'm a bit surprised at that given the EELV's were designed to the same spec. I take it the range interfaces at the pad level, rather than the vehicle.

The spec was for payloads and not range interfaces.

Range interfaces are at the pad and the vehicle.  (Has to be at least the vehicle, because most of the range resources are in flight).  Also, there is a difference between the range and the launch base resources.

[Jim]

You mean someone has to physically speak some kind of message on each channel ? 
There is no "test" mode that connects a single microphone to all channels for a quick pass/fail test on them in one go?

Yep.  Because there are dozens of channels and dozens of consoles positions in many facilities.  Not every channel goes to each console, nor can most consoles handle more than 20 channels.

[Jim]

Is there anything specialized about the people who do this? It sounds like anyone from the National Guard to a hired security firm could handle it on a one off basis. BTW if you knew you were doing 3 launches back to back could you not seal common areas for the whole week?

It is a security firm that does it, the same one that handle base security.   And no you can't seal off the common areas for a week because other facilities need to accessed, like other pads.  People still need to their day jobs.

[john smith 19]

It is a security firm that does it, the same one that handle base security.   

Would it be fair to say a bit specialized (govt security contractor) but not exactly Special Forces? 

And no you can't seal off the common areas for a week because other facilities need to accessed, like other pads.  People still need to their day jobs.

Pity.  It was an obvious optimisation.

That said I guess to do this properly would require building a comprehensive description across all services and specialties needed to change vehicles and to find the critical path (and hence reduce its length).

Yep.  Because there are dozens of channels and dozens of consoles positions in many facilities.  Not every channel goes to each console, nor can most consoles handle more than 20 channels.

It still sounds an awfully clunky way to do things.  I'm sure it pass the KISS test and I guess no one has ever bothered about the time lost. 

My instinct is that range turnaround has much in common with the shift to changing the major press tools for a new car within 10minutes.

All ot the techniques used could have been implemented a century earlier if someone had the incentives and therefor the will to do so. 

I don't think I'm seeing any of the real show stoppers yet, although I guess the voice channel tests would probably need some serious co ordination to speed up.

In your opinion what's the long pole in the tent if you wanted to swap LV's in (say) 1 day instead of two?

[Jim]

In your opinion what's the long pole in the tent if you wanted to swap LV's in (say) 1 day instead of two?

manning to cover more than 5/40 per week

[Robotbeat]

In your opinion what's the long pole in the tent if you wanted to swap LV's in (say) 1 day instead of two?

manning to cover more than 5/40 per week

In other words, if they just added a shift or two, it would probably take care of the problem?

Sounds like a rather mundane issue. It'll cost more, sure, but you'll also be spreading that cost over many more launches. (Assuming we ever get to the point that it makes sense to swap LV's in 1 day vs 2 days.)

[john smith 19]

In your opinion what's the long pole in the tent if you wanted to swap LV's in (say) 1 day instead of two?

manning to cover more than 5/40 per week

I think that's the one option that's not going to be available given how staff costs grow budgets exponentially.

I guess my question is what is the biggest task that those people would do?

[Robotbeat]

What? That looks like the easiest problem to solve. Add another shift. Your rent and capital costs don't increase, just staffing, so your overall cost per launch is likely to go down, not up.