Heavy Lift an unnecessary impediment?

[EarthlingX]

But why would they want to use (for example) three 50-tonne launches instead of eight 20-tonne launches? If orbital assembly is such a piece of cake and LOM don't rise, they surely would prefer not to stick more SRB's to the existing Ariane. Tell me then, why do they propose upgrading Ariane instead of making do with what they have?

Orbital assembly is not such a piece of cake, because there was not enough development done. Instead of more SRBs they could also make architecture based on Common Booster Core, like everyone else in their evolution plans. They are proposing upgrading Ariane, because they assume only one launch pad.

More efficient and less riskier with new untested rocket for which there is no money and no market demand ? How did you get to that ?

How many 20t launches were this year in USA, not counting STS ?

Yes, once the "untested" rocket has been tested, it will be less risky in the long run. The EELV's were also "untested" at the beginning, yet they were designed, built and flown and now they are very useful.

How long would than run be with politics designing and paying for 1B$+ launches ? One per year ?

EELV's are based on older rockets, they have evolutionary path which builds on marketable infrastructure, which gets improved to add capability.

What benefit to industry is having a Super Heavy Launcher if there is no market for it ? What kind of technology transfer would you expect from that ?

It is much easier to answer what kinds of benefits you get from orbital assembly, orbital fuel transfer, orbital servicing, radiation protection, closed loop environments, ISRU, ..

You can dream big and keep dreaming, or take little things and make the most of it - not that i think technology advances, which are holding back anything beyond LEO are little things. They are big things, but would cost less than HLV which nobody but politics needs. That's why they even design it on their own

 

[RVHM]

Orbital assembly is not such a piece of cake, because there was not enough development done. Instead of more SRBs they could also make architecture based on Common Booster Core, like everyone else in their evolution plans. They are proposing upgrading Ariane, because they assume only one launch pad.

Exactly. Everyone wants to evolve their rockets because they are seeing that many small rockets instead of few big ones is a bad idea.

How long would than run be with politics designing and paying for 1B$+ launches ? One per year ?

We have been launching the Space Shuttle for three decades, and the cost of a SDHLV will be in the same region (remove the maintenance-intensive orbiter, add an expendable capsule). We can afford several flights per year.

EELV's are based on older rockets, they have evolutionary path which builds on marketable infrastructure, which gets improved to add capability.

The same goes for SDHLV.

What benefit to industry is having a Super Heavy Launcher if there is no market for it ? What kind of technology transfer would you expect from that?

Going where commercial space cannot go yet and will not go in the near future. BEO exploration.

It is much easier to answer what kinds of benefits you get from orbital assembly, orbital fuel transfer, orbital servicing, radiation protection, closed loop environments, ISRU, ..

I agree radiation protection, closed loop environments and ISRU are useful. However, that has nothing to do with HLV vs. EELV.

You can dream big and keep dreaming, or take little things and make the most of it - not that i think technology advances, which are holding back anything beyond LEO are little things. They are big things, but would cost less than HLV which nobody but politics needs. That's why they even design it on their own

We haven't been dreaming for the last 30 years. We already have an affordable HLV, the Shuttle stack. We just need to modify it for BEO exploration.

 

[EarthlingX]

Orbital assembly is not such a piece of cake, because there was not enough development done. Instead of more SRBs they could also make architecture based on Common Booster Core, like everyone else in their evolution plans. They are proposing upgrading Ariane, because they assume only one launch pad.

Exactly. Everyone wants to evolve their rockets because they are seeing that many small rockets instead of few big ones is a bad idea.

Not really. This are options given to potential costumers. No takers, no research.

How long would than run be with politics designing and paying for 1B$+ launches ? One per year ?

We have been launching the Space Shuttle for three decades, and the cost of a SDHLV will be in the same region (remove the maintenance-intensive orbiter, add an expendable capsule). We can afford several flights per year.

Obviously not. You don't read news ? They can't even agree to add one more launch, with everything at the ready and no development - no dinero.

EELV's are based on older rockets, they have evolutionary path which builds on marketable infrastructure, which gets improved to add capability.

The same goes for SDHLV.

If they don't launch a single Shuttle per year, it still costs 2,5 B$, and this infrastructure will remain. I fail to see how this is affordable, when you have launchers which can do the same for much less, as shown a couple of times in this thread, and many others on this forum.

What benefit to industry is having a Super Heavy Launcher if there is no market for it ? What kind of technology transfer would you expect from that?

Going where commercial space cannot go yet and will not go in the near future. BEO exploration.

Yea, using 40 year old technology, like it's going to happen. There are no plans for financing anything but launcher to nowhere.

It is much easier to answer what kinds of benefits you get from orbital assembly, orbital fuel transfer, orbital servicing, radiation protection, closed loop environments, ISRU, ..

I agree radiation protection, closed loop environments and ISRU are useful. However, that has nothing to do with HLV vs. EELV.

It has everything to do with existing launchers against some hypothetical, most likely on first possible occasion cancelled, new money hole.

You can dream big and keep dreaming, or take little things and make the most of it - not that i think technology advances, which are holding back anything beyond LEO are little things. They are big things, but would cost less than HLV which nobody but politics needs. That's why they even design it on their own

We haven't been dreaming for the last 30 years. We already have an affordable HLV, the Shuttle stack. We just need to modify it for BEO exploration.

LOL Shuttle has been used for years to show how Reusable Launch Vehicles are unaffordable, but you probably didn't notice that, like many other things that you manage to miss.

 

[RVHM]

Not really. This are options given to potential costumers. No takers, no research.

The same happens with the SDHLV, except that this time there is a potential customer who wants to make use of the SDHLV's unique capabilities: the US government.

Obviously not. You don't read news ? They can't even agree to add one more launch, with everything at the ready and no development - no dinero.

This is a unique situation caused by the fact that much of the Shuttle chain has begun to shut down. This has not happened during the years Shuttle was operated normally.

If they don't launch a single Shuttle per year, it still costs 2,5 B$, and this infrastructure will remain. I fail to see how this is affordable, when you have launchers which can do the same for much less, as shown a couple of times in this thread, and many others on this forum.

EELS cannot do the same for much less. They can do much less for much less.

EELV's also have overhead costs, which are shared by the Air Force and military launches. Since both military launches and NASA launches are paid by tax money, I don't see why one is preferable above the other.

Yea, using 40 year old technology, like it's going to happen. There are no plans for financing anything but launcher to nowhere.

That's not the rocket's problem, that's the EDS's problem. In a deep gravity well, the only way out is either good old chemical propulsion or nuclear propulsion. Good luck with the latter.

It has everything to do with existing launchers against some hypothetical, most likely on first possible occasion cancelled, new money hole.

Pray, what exactly has it got to do? Does radiation shielding somehow stop working if you launch it on an HLV?

LOL Shuttle has been used for years to show how Reusable Launch Vehicles are unaffordable, but you probably didn't notice that, like many other things that you manage to miss.

That's a strawman argument, we're discussing HLV vs. EELV's here, not reusables against expendables. Once you take the Reusable Orbiter out of the equation, you've removed the biggest problem and the stack is no longer unaffordable.

 

[EarthlingX]

Well, we can obviously only agree that we disagree.
Government is actually the only customer for American rockets, even American broadcasters fly satellites on Russian rockets. That's how you get such great flight rate for Atlas and Delta, which again drive costs up. Export regulations are another nice add-on.

How many 20t launches did you say were in USA this year ?

 

[RVHM]

Well, we can obviously only agree that we disagree.

Agree.

Government is actually the only customer for American rockets, even American broadcasters fly satellites on Russian rockets. That's how you get such great flight rate for Atlas and Delta, which again drive costs up. Export regulations are another nice add-on.

I wonder what the effects of ITAR relaxation would be on foreign demand for EELV's. Would it drive costs down noticeably?

How many 20t launches did you say were in USA this year ?

None. But SDHLV is meant to carry out science and exploration, not to compete in the commercial market.

 

[oldAtlas_Eguy]

How many 20t launches were this year in USA, not counting STS ?

US - Last Atlas V 551 20MT was April 2006. The last Delta IV Heavy 22MT was January 2009. The next Delta IV Heavy is October 2010.
US - 1(0 launched,1 scheduled) Delta IV Heavy
ALL Others - 11(8 launched,3 scheduled) Proton, 5(2 launched, 3 scheduled) Ariane 5

 

[EarthlingX]

Orbital refuelling and servicing tests in 2007 :
Wiki : Orbital Express

About docking in orbit (rather common, check Missions&Launches) and more complicated stuff :
http://www.esa.int : New testbed simulates space's formation flying future

9 September 2010
Any space mission is difficult, docking a pair of spacecraft is tough but flying multiple satellites in formation is the real cutting edge. A new software testbed allows ESA and industrial teams to get to grips with multiple-satellite missions to come, starting with Proba-3.

 

[jimoutofthebox]

Back to the original question about heavy lift. I think to be most cost effective we need a booster that is just large enough to deliver the largest descrete element of any projected mission. For example, A new trip to the moon could be done with two launches. One launch would deliver a space craft with astronauts and TLI booster to low earth orbit. The 2nd launch would consist of the moon lander and TLI booster to low earth orbit. Both spacecraft would go to the moon independently. In lunar orbit the crew would transfer to the lander and land on the moon. After the mission the crew would lift off and link up with the return spacecraft just as Apollo for the return to earth.

A back-of-the-envelope caculation tells me that we need a booster that can deliver a minimum of 55 tons to low earth orbit to make this work. The same booster could be used to deliver the components of a mars ship to earth orbit. In an earlier post on this thread I outlined a booster that should be able to do this using a cluster of four falcon 9s with a Saturn IV stage for the final boost to orbit. A Centaur would be used for a TLI booster.

This way we can perform any projected mission using flight proven hardware while getting the best economy of scale.

 

[oldAtlas_Eguy]

Back to the original question about heavy lift. I think to be most cost effective we need a booster that is just large enough to deliver the largest descrete element of any projected mission. For example, A new trip to the moon could be done with two launches. One launch would deliver a space craft with astronauts and TLI booster to low earth orbit. The 2nd launch would consist of the moon lander and TLI booster to low earth orbit. Both spacecraft would go to the moon independently. In lunar orbit the crew would transfer to the lander and land on the moon. After the mission the crew would lift off and link up with the return spacecraft just as Apollo for the return to earth.

A back-of-the-envelope caculation tells me that we need a booster that can deliver a minimum of 55 tons to low earth orbit to make this work. The same booster could be used to deliver the components of a mars ship to earth orbit. In an earlier post on this thread I outlined a booster that should be able to do this using a cluster of four falcon 9s with a Saturn IV stage for the final boost to orbit. A Centaur would be used for a TLI booster.

This way we can perform any projected mission using flight proven hardware while getting the best economy of scale.

A 110MT capability seems to be the magic Lunar mission number, whether using one Saturn V booster equivalent, two 55MT, or four 32MT Falcon 9 Heavy. You still have to get to 100+MT.

 

[jimoutofthebox]

A 110MT capability seems to be the magic Lunar mission number, whether using one Saturn V booster equivalent, two 55MT, or four 32MT Falcon 9 Heavy. You still have to get to 100+MT.

The point was that 55 tons to LEO is probably the most cost efficent booster that should be considered. Using smaller boosters would add excessive weight and complexity to any mission while a larger booster would not have the economies of scale.

 

[rockett]

The point was that 55 tons to LEO is probably the most cost efficent booster that should be considered. Using smaller boosters would add excessive weight and complexity to any mission while a larger booster would not have the economies of scale.

Problem with that is seen in the ISS. With 10+ years of launching, using a variety of launchers, we are just now going operational. If we are going for ambitious projects, we are going to need the 100+mt

 

[EarthlingX]

Brain is needed, not muscle.

 

[oldAtlas_Eguy]

The point was that 55 tons to LEO is probably the most cost efficent booster that should be considered. Using smaller boosters would add excessive weight and complexity to any mission while a larger booster would not have the economies of scale.

Just because it is larger doesn't make it cheaper. A government developed booster will probably be more expensive per kg than a smaller commercial developed booster. We have seen that NASA doesn't do good operational cost estimates. Commercial focuses its design based on the impacts to operations costs. A little more development cost and maybe a slight lowering of capability can have huge operation cost savings. Example SpaceX and Falcon 9 design decisions vs NASA and Ares I.

An interesting dicotomy to this is SpaceX use of composits wherever they can reduces costs and increases performance. There is no substitue for good inovative engineering when it comes to cost reductions.

 

[jimoutofthebox]

Just because it is larger doesn't make it cheaper. A government developed booster will probably be more expensive per kg than a smaller commercial developed booster. We have seen that NASA doesn't do good operational cost estimates. Commercial focuses its design based on the impacts to operations costs. A little more development cost and maybe a slight lowering of capability can have huge operation cost savings. Example SpaceX and Falcon 9 design decisions vs NASA and Ares I.

I agree 100% with what you posted. Again my point is that to perform the missions we need to be doing we have to size a booster that will perform the mission at the lowest cost. For example the moon mission I talked about in my earlier post could be done with four smaller boosters rather than the two that I proposed but there will be tradeoffs.

The TLI boosters would have to be launched separately which means that it would need its own navigation system, thruster system, radar, docking mechanism, and power supply to perform the linkup with the lunar payload. The extra equipment would require extra fuel which would than require larger fuel tanks. If the thrust load was carried through the docking mechanism of the lunar module and the command module than extra structure would have to be added to carry the loads. All this adds cost and weight. In the case of the lunar lander the extra structure might make the difference between having a 3 man crew or a 4 man crew. There are other costs of coodinating 4 launches at the same time. Also all the time you are spending linking modules in space you LH2 fuel is boiling off.

A 55 ton to LEO booster can be built using existing technologies such as a 4 cluster Falcon 9 for the main booster and a 2nd stage based on the Saturn IV with a TLI booster based on the centaur. All of this technology proven and can be made flight ready quickly

 

[oldAtlas_Eguy]

Just because it is larger doesn't make it cheaper. A government developed booster will probably be more expensive per kg than a smaller commercial developed booster. We have seen that NASA doesn't do good operational cost estimates. Commercial focuses its design based on the impacts to operations costs. A little more development cost and maybe a slight lowering of capability can have huge operation cost savings. Example SpaceX and Falcon 9 design decisions vs NASA and Ares I.

I agree 100% with what you posted. Again my point is that to perform the missions we need to be doing we have to size a booster that will perform the mission at the lowest cost. For example the moon mission I talked about in my earlier post could be done with four smaller boosters rather than the two that I proposed but there will be tradeoffs.

The TLI boosters would have to be launched separately which means that it would need its own navigation system, thruster system, radar, docking mechanism, and power supply to perform the linkup with the lunar payload. The extra equipment would require extra fuel which would than require larger fuel tanks. If the thrust load was carried through the docking mechanism of the lunar module and the command module than extra structure would have to be added to carry the loads. All this adds cost and weight. In the case of the lunar lander the extra structure might make the difference between having a 3 man crew or a 4 man crew. There are other costs of coodinating 4 launches at the same time. Also all the time you are spending linking modules in space you LH2 fuel is boiling off.

A 55 ton to LEO booster can be built using existing technologies such as a 4 cluster Falcon 9 for the main booster and a 2nd stage based on the Saturn IV with a TLI booster based on the centaur. All of this technology proven and can be made flight ready quickly

A four booster Falcon 9 Super Heavy with 52MT capability would take a redesign of the core to beef up its structure. Plus to handle the payloads the core diameter needs to be larger. It all comes down to being the same cost as developing the Falcon X. To get to the 55MT you would need the Merlin 2 engine to get from 50MT to 55MT. The Merlin 2 engine is the primary cost of the development of the larger Falcon X Heavy which is capable of much larger than just 55MT. So if you are going to develop a new core vehicle develop something that can truly grow.

For the near term using LH2 in a constructed TLI booster would probably not happen. Using storable Bi-propellant in multiple 30MT or even 50MT stages would be cheaper to design, build and have a higher reliability. The mass fractions of engines and tanks of the higher density fuel give a good tradeoff for the lower ISP. With a three stage 90MT TLI booster can deliver to the Moon a large payload. A single 55MT LH2 TLI booster could not deliver the same size payload.

 

[neutrino78x]

Problem with that is seen in the ISS. With 10+ years of launching, using a variety of launchers, we are just now going operational. If we are going for ambitious projects, we are going to need the 100+mt

That just proves that non-military government agencies are inefficient. If Bigelow had the level of funding that NASA had, I bet he could put his space hotel up in 3 years.

When we talk about using commercial rockets to put space stations up, we don't intend for it to take 20 years. We're talking about one module going up every week or so, in the future. The delays you're talking about are because of low funding and other government issues, not because the physics or engineering makes it impossible to do it faster.

--Brian

 

[jimoutofthebox]

Just because it is larger doesn't make it cheaper. A government developed booster will probably be more expensive per kg than a smaller commercial developed booster. We have seen that NASA doesn't do good operational cost estimates. Commercial focuses its design based on the impacts to operations costs. A little more development cost and maybe a slight lowering of capability can have huge operation cost savings. Example SpaceX and Falcon 9 design decisions vs NASA and Ares I.

I agree 100% with what you posted. Again my point is that to perform the missions we need to be doing we have to size a booster that will perform the mission at the lowest cost. For example the moon mission I talked about in my earlier post could be done with four smaller boosters rather than the two that I proposed but there will be tradeoffs.

The TLI boosters would have to be launched separately which means that it would need its own navigation system, thruster system, radar, docking mechanism, and power supply to perform the linkup with the lunar payload. The extra equipment would require extra fuel which would than require larger fuel tanks. If the thrust load was carried through the docking mechanism of the lunar module and the command module than extra structure would have to be added to carry the loads. All this adds cost and weight. In the case of the lunar lander the extra structure might make the difference between having a 3 man crew or a 4 man crew. There are other costs of coodinating 4 launches at the same time. Also all the time you are spending linking modules in space you LH2 fuel is boiling off.

A 55 ton to LEO booster can be built using existing technologies such as a 4 cluster Falcon 9 for the main booster and a 2nd stage based on the Saturn IV with a TLI booster based on the centaur. All of this technology proven and can be made flight ready quickly

A four booster Falcon 9 Super Heavy with 52MT capability would take a redesign of the core to beef up its structure. Plus to handle the payloads the core diameter needs to be larger. It all comes down to being the same cost as developing the Falcon X. To get to the 55MT you would need the Merlin 2 engine to get from 50MT to 55MT. The Merlin 2 engine is the primary cost of the development of the larger Falcon X Heavy which is capable of much larger than just 55MT. So if you are going to develop a new core vehicle develop something that can truly grow.

For the near term using LH2 in a constructed TLI booster would probably not happen. Using storable Bi-propellant in multiple 30MT or even 50MT stages would be cheaper to design, build and have a higher reliability. The mass fractions of engines and tanks of the higher density fuel give a good tradeoff for the lower ISP. With a three stage 90MT TLI booster can deliver to the Moon a large payload. A single 55MT LH2 TLI booster could not deliver the same size payload.

What I propose would be 4 Falcon 9s in a quad arrangement. At lift off two of the boosters would feed all four engine clusters. When the tanks run dry the boosters would be dropped and the two remaining boosters would continue to fire with full tanks. This would be much like the Atlas system except the tanks and the engines would be dropped instead of the just the engines. There should be no need to redesign the Falcon since all the load from the booster is going into the 2nd stage adapter. There would be no core booster to carry the load.

Concerning the LH2 stage. Every thing I've read indicates that there is no storable fuel the will give even close to the same performance as a LH2 booster even considering the extra structure to hold the LH2. Thats why the Centaur is the standard booster for high performance missions. That also why I propose a "fat" Centaur as a TLI booster.

While it would be nice to be able to afford a new monster booster I would rather use what we already have so that I might see the day when we are going to the moon and mars on regular basis.

 

[oldAtlas_Eguy]

Concerning the LH2 stage. Every thing I've read indicates that there is no storable fuel the will give even close to the same performance as a LH2 booster even considering the extra structure to hold the LH2. Thats why the Centaur is the standard booster for high performance missions. That also why I propose a "fat" Centaur as a TLI booster.

A UDMH/Nitric Acid engine ISP 290 to 310. RP1/LOX engine ~350 and LH2/LOX ISP ~450. In order to keep the LH2 and LOX for extended periods > 1 day a regenerative cooler would be needed adding its weight and the solar cells to power it. Why do you think that Apollo used Hydrazine for the command module and Lunar Lander?

For a construct in LEO BEO mission where parts and fuel may be in orbit for months without a buildup of an orbiting LH2/LOX fuel depot, use of LH2/LOX for the TLI booster is not practical. But if you build a fuel depot first then the problems of boil off can be handled.

What I propose would be 4 Falcon 9s in a quad arrangement. At lift off two of the boosters would feed all four engine clusters. When the tanks run dry the boosters would be dropped and the two remaining boosters would continue to fire with full tanks. This would be much like the Atlas system except the tanks and the engines would be dropped instead of the just the engines. There should be no need to redesign the Falcon since all the load from the booster is going into the 2nd stage adapter. There would be no core booster to carry the load.

A Falcon 9 first stage is currently designed to operate in the Heavy configuration with all the attach points liftoff loads calculated for a max payload of ~35MT with some margin. That margin is not going to cover a 55MT payload. The first stage would have to be redesigned. One of the main design policy items of SpaceX is economy of scale and not making things overly complex. Boosters that are different than the core increase complexity and lessen the economy of scale.

While it would be nice to be able to afford a new monster booster I would rather use what we already have so that I might see the day when we are going to the moon and mars on regular basis.

I agree that a redesign of the Falcon 9 first stage core would not be as costly as a whole new booster with a new Merlin 2 engine, but the effort does not lead to a capability that can evolve to even larger payload capability. That makes it a “no-go” for a business decision. A Falcon 9 Heavy with 32MT will cost very little to become operational; mainly pad mods and a first flight / flight test. Same would be true of a Falcon X Heavy once the Falcon X core is developed. You get two vehicle classes for the price of one.

An upgrade path for the Falcon 9 going from the Merlin to the Merlin 2 gives more performance for both Falcon 9 and Falcon 9 Heavy with a small redesign of the thrust supports and piping on the aft end of the first stage. The tanks would not be redesigned. Like the Falcon 1 it would give an inexpensive way to prove out the Merlin 2 before clustering it on a Falcon X.

Once the COTS flights get going in earnest, SpaceX will have enough profits to reinvest in the Merlin 2 development on the order of $50 to $100 mil a year. If someone expresses a desire to purchase a Falcon 9 Heavy flight in the next year, then these reinvestment moneys would go to the pad mods and other items not done yet to support a Falcon 9 Heavy, which would delay start of the Merlin 2 development. At the possible development rate for the Merlin 2 it will be ~10 years before Space X rolls out a Falcon X, unless the US government subsidizes the Merlin 2 development on the tune of $100 mil or more per year. Then the earliest for a Falcon X would be 2016, followed a year or more later by the Falcon X Heavy ~2018.

So why aren’t we doing that? NASA wants detail control over the HLLV design customizing it to their mission, not designing the mission to fit an “off-the-shelf” HLLV generic booster.

 

[Valcan]

.

Yes sometimes it seems Nasa is not thinking very logicly. They want everything to the highest performance and design possible. This is good for a test or experiment not so much for a cost wise thing. From the Mercury to the shuttle to constellation it has seemed they always want to make every launch a experiment.

Nasa needs to balance cost with performance. Shuttle is a perfect example. Awesome performance, horrible cost.



BUT<---------------------That word again.!!!

Nasa isnt all to blame congress uses the nasa budget as a lever to power. They keep the high paying jobs in a district for votes (if that isnt buying votes i dont know what is) instead of doing what is best for the space program and Nasa in general. Of course this is in keeping with the rest of there political carrers so why ruin a good thing.

Me i say go with falcon X. SpaceX seems to have shown a ability to get things done with the least amount of cost for the most performance and safety.

 

[jimoutofthebox]

A UDMH/Nitric Acid engine ISP 290 to 310. RP1/LOX engine ~350 and LH2/LOX ISP ~450. In order to keep the LH2 and LOX for extended periods > 1 day a regenerative cooler would be needed adding its weight and the solar cells to power it. Why do you think that Apollo used Hydrazine for the command module and Lunar Lander?
There is a big difference between an ISP of 350 and 450 when every gram of vehical weight counts. The other point is that with my proposal the vehicals would not have to spend more than a few hours in orbit. Thats the advantage of my proposal is that you don't have to wait for multiple stages to be assembled. The lunar lander would still need LH2 for landing but they would still use storable fuels for the command module and the assent module. NASA chose storable fuels for the lunar activity because of there reliability. The fuels ignite on contact and all you need is to open the valve to make them work

 

[jimoutofthebox]

A Falcon 9 first stage is currently designed to operate in the Heavy configuration with all the attach points liftoff loads calculated for a max payload of ~35MT with some margin. That margin is not going to cover a 55MT payload. The first stage would have to be redesigned. One of the main design policy items of SpaceX is economy of scale and not making things overly complex. Boosters that are different than the core increase complexity and lessen the economy of scale.
My proposal would drop 2 of 4 Falcon 9s boosters once they ran dry, but the other two would fire until they ran out of fuel. The load would not be transferred through one booster but be shared between them. The Falcon 9s should be able to be used as is. Think of my proposal as a russian R7 booster without the core booster. Only four boosters attached to the upper stage.

 

[oldAtlas_Eguy]

.

Yes sometimes it seems Nasa is not thinking very logicly. They want everything to the highest performance and design possible. This is good for a test or experiment not so much for a cost wise thing. From the Mercury to the shuttle to constellation it has seemed they always want to make every launch a experiment.

Nasa needs to balance cost with performance. Shuttle is a perfect example. Awesome performance, horrible cost.



BUT<---------------------That word again.!!!

Nasa isnt all to blame congress uses the nasa budget as a lever to power. They keep the high paying jobs in a district for votes (if that isnt buying votes i dont know what is) instead of doing what is best for the space program and Nasa in general. Of course this is in keeping with the rest of there political carrers so why ruin a good thing.

Me i say go with falcon X. Space X seems to have shown a ability to get things done with the least amount of cost for the most performance and safety.

Yes, the politicizing of NASA started way back. Remember about the VP requiring NASA put its new Manned Spaceflight Mission Control in Houston in 1960’s. Other than the VP there was no reason to locate it there. So to insure the NASA budget NASA appeased the VP and located the center in Houston.

 

[Valcan]

A.
My proposal would drop 2 of 4 Falcon 9s boosters once they ran dry, but the other two would fire until they ran out of fuel. The load would not be transferred through one booster but be shared between them. The Falcon 9s should be able to be used as is. Think of my proposal as a russian R7 booster without the core booster. Only four boosters attached to the upper stage.

:shock: Dude thats !!!!36!!! Motors that all need to fire thats not including any on the underside!

Meh just invest the money for FalconX. For the price of a single Ares I launch you could fund the entire engine R&D. Then you wouldnt need to juryrigg it.

 

[rockett]

Good example of what can happen when you try to synchronize too many engines (Soviet N1 with 30 engines):

N1 showing the 30 rocket engines of its first stage

Liftoff of the second N1 flight, and its subsequent explosion

Credit: Soviet N1 Lunar Rocket http://www.aerospaceweb.org/question/spacecraft/q0196.shtml