DIRECT v3.0 - Thread 4

[dlapine]

All of this being said, would a J130 based on liquid-boosters be acceptable to the safety gods at NASA for manned flight? Or is this concept for HLV cargo only?

I would say that it depends which safety people you talked to. That said, the liquid booster-based version would be lighter and safer on the ground (the RSRMs being basically encapsulated explosives, the VAB is a high-risk environment these days).  Utilising AV cores would also allow for the development of a high degree of redundancy, using Atlas-VH as a crew-only launcher and using the J-130K as a cargo launcher, including a version with an ACES-41-based upper stage.

The real issue would be the cost and developmental risks involved for modifying the boosters to take the weight of the fully-loaded Jupiter CCB on the pad.

The latter post by dlapine on that of SRB vs CCB cost is (IMO) not the biggest concern. The points you make above are more relavent. Safety on the pad & getting more & better use out of the VAB is what I feel is more important. It also saves the crawlerway, crawler loading (which would help in a re-design for new, though I would still keep the same mass moving requirements), and save pad turnaround time.

It's more a concern getting ATK out of the picture. If we can accomplish that (politicially), we're much further along. Of course all this isn't Direct 3.0 related, so we're in dangerous (thread) territory. I think we had a thread for this somewhere way back...

edit to add where my thoughts were on this, plus comments after that:
http://forum.nasaspaceflight.com/index.php?topic=20923.msg563436#msg563436

Hey, give me a little credit, I did bring up the topic of safety as well as cost. I just don't know the answers...

77mt is nominal amount for SRB-based J-130, right?

Anybody have an idea as to the cost differential for atlas CCB's versus 2 4-seg SRB's?

It'd sure be nice to price an stubborn ATK right out of the market...

Hmmm- what about safety- would 4 liquid-fueled boosters have a safety level even close to 2 SRB's for manned flight?

You have performance, cost and safety as primary concerns for any launch system. One could argue that ignoring cost is what got Constellation into trouble.

Also,  I believe I was off on the J130 performance, it should be 71mt, not 77mt.

I'm not against this idea, just want to make sure that it's not poorer in implementation than the default. It needs to be at least as good as the stock Direct 3.0 or it's not worth putting effort into.

That being said, it looks like swapping out the SRB's for liquid boosters doesn't fail in the areas of performance, cost or safety at first glance.

I agree that getting ATK out of the Direct proposal is a win.

Unfortunately, only Ross could tell us how politically feasible this is, and being politically feasible has been a major focus of Direct all along.

[Downix]

All of this being said, would a J130 based on liquid-boosters be acceptable to the safety gods at NASA for manned flight? Or is this concept for HLV cargo only?

I would say that it depends which safety people you talked to. That said, the liquid booster-based version would be lighter and safer on the ground (the RSRMs being basically encapsulated explosives, the VAB is a high-risk environment these days).  Utilising AV cores would also allow for the development of a high degree of redundancy, using Atlas-VH as a crew-only launcher and using the J-130K as a cargo launcher, including a version with an ACES-41-based upper stage.

The real issue would be the cost and developmental risks involved for modifying the boosters to take the weight of the fully-loaded Jupiter CCB on the pad.

The latter post by dlapine on that of SRB vs CCB cost is (IMO) not the biggest concern. The points you make above are more relavent. Safety on the pad & getting more & better use out of the VAB is what I feel is more important. It also saves the crawlerway, crawler loading (which would help in a re-design for new, though I would still keep the same mass moving requirements), and save pad turnaround time.

It's more a concern getting ATK out of the picture. If we can accomplish that (politicially), we're much further along. Of course all this isn't Direct 3.0 related, so we're in dangerous (thread) territory. I think we had a thread for this somewhere way back...

edit to add where my thoughts were on this, plus comments after that:
http://forum.nasaspaceflight.com/index.php?topic=20923.msg563436#msg563436

Hey, give me a little credit, I did bring up the topic of safety as well as cost. I just don't know the answers...

77mt is nominal amount for SRB-based J-130, right?

Anybody have an idea as to the cost differential for atlas CCB's versus 2 4-seg SRB's?

It'd sure be nice to price an stubborn ATK right out of the market...

Hmmm- what about safety- would 4 liquid-fueled boosters have a safety level even close to 2 SRB's for manned flight?

You have performance, cost and safety as primary concerns for any launch system. One could argue that ignoring cost is what got Constellation into trouble.

Also,  I believe I was off on the J130 performance, it should be 71mt, not 77mt.

I'm not against this idea, just want to make sure that it's not poorer in implementation than the default. It needs to be at least as good as the stock Direct 3.0 or it's not worth putting effort into.

That being said, it looks like swapping out the SRB's for liquid boosters doesn't fail in the areas of performance, cost or safety at first glance.

I agree that getting ATK out of the Direct proposal is a win.

Unfortunately, only Ross could tell us how politically feasible this is, and being politically feasible has been a major focus of Direct all along.

Politically, it's a bigger gamble.  ATK is the main reason why the CxP has continued so far as it has.  If it was onboard with DIRECT, I suspect that our favorite option would have been put forward already.

[kraisee]

Astronautix had the SRB at $23 mil in 1989 dollars.  Adjusting for inflation, comes to around $40 million per.

Like everything else in this industry, the flight rate makes the biggest difference in per-unit cost.

Ross.

[spacenut]

So, If the Jupiter could be made modular enough to strap on four Atlas V rockets or two 4 seg solids, and you have a flight rate of about 4 per year.  That would either be 16 extra Atlas V rocket first stage cores or 8 solid rockets or 32 segments.  Would this not make the Atlas V strapons less expensive since you would be using more?  That would place the solids in the $20 mil range.  Also if they finally made the Atlas V phase II, it could launch Orion and the Jupiter could use only 2 of these phase II rockets for the 100 ton booster, or maybe four for about what 135 tons +.  You can get 4 phase II's around a Jupiter, but you can't get 4 solids because of the existing flame trenches are only rated for about 11 million lbs. of thrust right?

[dlapine]

Astronautix had the SRB at $23 mil in 1989 dollars.  Adjusting for inflation, comes to around $40 million per.

Like everything else in this industry, the flight rate makes the biggest difference in per-unit cost.

Ross.

It appears that you're not gonna get much cheaper than $10M a segment even with more than 10 flights a year and you need a minimum of 8 segments per launch (2 4-segment SRB's) at a cost of at least $80M a launch for solids.

I'd love to see the same graph with current cost info for liquid boosters.
Well, it'd be ok if you left off the numbers for Ares I.   

Hard to imagine the US of A needing 10 launches of a heavy lift vehicle under the current space plans though.

Hmmm,  5 launches a year (a reasonable number that I picked out of the air), puts the SRB cost around $15M a segment or $120M a launch. Given that the Atlas CCB is  already used by another launch system, I can't see the cost per booster going above the $20M per unit, only down. So worst case for a liquid booster-based Direct is just $80M for the boosters, and it gets better for every additional launch.

That would imply that ATK is at best a necessary political evil in the scope of Direct, and something to be discarded if at all possible.

Methinks the idea of a liquid booster-based Direct has merit.

Would it be at all unreasonable to assume the pad modifications needed to support a 4 booster configuration of light liquid boosters to be no more difficult than those for the stock J-130 with it's 2 heavy SRB's?

[dlapine]

So, If the Jupiter could be made modular enough to strap on four Atlas V rockets or two 4 seg solids, and you have a flight rate of about 4 per year.  That would either be 16 extra Atlas V rocket first stage cores or 8 solid rockets or 32 segments.  Would this not make the Atlas V strapons less expensive since you would be using more?  That would place the solids in the $20 mil range.  Also if they finally made the Atlas V phase II, it could launch Orion and the Jupiter could use only 2 of these phase II rockets for the 100 ton booster, or maybe four for about what 135 tons +.  You can get 4 phase II's around a Jupiter, but you can't get 4 solids because of the existing flame trenches are only rated for about 11 million lbs. of thrust right?

I believe the weight of the extra SRB's is the limiting factor- the transporter can't handle the extra 2.2M pounds of 2 more SRB's.  The SRB's come fully fueled at the VAB, whereas the liquid boosters can be fueled at the pad. Because you can't get a 4 SRB-based vehicle to the launch pad, the strength of the flame trenches doesn't matter much.

I suppose you could rebuild the crawler, reinforce the roadways, rebuild the pads, modify the VAB, but who's got the time?

Not to mention the money.

[notsorandom]

How well would four Delta IV CBCs work? They are even lower thrust but also have a bit less mass. I am mainly wondering since Boeing proposed a very Jupiter like rocket. In the Delta CBCs favor I have heard that there is quite a bit of spare manufacturing capability and the heavy variant is already flying. The RS-68 would have to be human rated witch is apparently more difficult then the RD-180.

This discussion is based upon the scenario that ATK completely stonewalls on the SRBs i.e Ares I or nothing. I have a suspicion that the current Direct proposal is still the least expensive to develop. If ATK see the writing on the wall and gets behind the current Jupiter design then they bring quite a bit of political backing.

[Downix]

How well would four Delta IV CBCs work? They are even lower thrust but also have a bit less mass. I am mainly wondering since Boeing proposed a very Jupiter like rocket. In the Delta CBCs favor I have heard that there is quite a bit of spare manufacturing capability and the heavy variant is already flying. The RS-68 would have to be human rated witch is apparently more difficult then the RD-180.

This discussion is based upon the scenario that ATK completely stonewalls on the SRBs i.e Ares I or nothing. I have a suspicion that the current Direct proposal is still the least expensive to develop. If ATK see the writing on the wall and gets behind the current Jupiter design then they bring quite a bit of political backing.

The issue then would be in staging, the RS-68 stages lower than the SSME, RD-180, NK-33 and Merlin-1c.  We'd need a second stage then.  Unless we're doing RD-68 on boosters, SSME on core, then it may be doable.  Want me to crunch those #'s next?

[WellingtonEast]

I believe the weight of the extra SRB's is the limiting factor- the transporter can't handle the extra 2.2M pounds of 2 more SRB's.  The SRB's come fully fueled at the VAB, whereas the liquid boosters can be fueled at the pad. Because you can't get a 4 SRB-based vehicle to the launch pad, the strength of the flame trenches doesn't matter much.

I suppose you could rebuild the crawler, reinforce the roadways, rebuild the pads, modify the VAB, but who's got the time?

Not to mention the money.

I understand the rationale on weight restrictions for transporting the fully assembled rocket to the pad.

Why not transport the SRB's separately and attach them at the pad? 

Cheers

[alexw]

I understand the rationale on weight restrictions for transporting the fully assembled rocket to the pad.

Why not transport the SRB's separately and attach them at the pad? 

    (This question comes up surprisingly often... should be put into a FAQ somewhere.)
    1) The STS stack is supported by the SRBs. Would have to (majorly) redesign the tank and orbiter attachment points on the MLP.
    2) Got a portable VAB, with high bay and crane, and room to fit that at LC-41?
    Basically, it would be a massive change in the stack engineering and KSC infrastructure. But it's not a completely theoretical question -- SLC-6 at Vandenburg would have stacked the SRB segments and built up the STS stack on the pad, and was nearly operational after tremendous expense.
    -Alex

[notsorandom]

The issue then would be in staging, the RS-68 stages lower than the SSME, RD-180, NK-33 and Merlin-1c.  We'd need a second stage then.  Unless we're doing RD-68 on boosters, SSME on core, then it may be doable.  Want me to crunch those #'s next?

I was thinking along the lines of SSME core and RS-68 powered Delta IV boosters. Since I last posted I have been toying around with that concept and it looks like even with the RS-68A the stack would have a very hard time getting off the pad. The T/W ratio is not very favorable, I'm getting about 1.06. If you have some spare time and want to double check my math please go ahead but I fear that using Delta IV CBCs as boosters might be a dead end.

[Downix]

The issue then would be in staging, the RS-68 stages lower than the SSME, RD-180, NK-33 and Merlin-1c.  We'd need a second stage then.  Unless we're doing RD-68 on boosters, SSME on core, then it may be doable.  Want me to crunch those #'s next?

I was thinking along the lines of SSME core and RS-68 powered Delta IV boosters. Since I last posted I have been toying around with that concept and it looks like even with the RS-68A the stack would have a very hard time getting off the pad. The T/W ratio is not very favorable, I'm getting about 1.06. If you have some spare time and want to double check my math please go ahead but I fear that using Delta IV CBCs as boosters might be a dead end.

That fits with what I've found.  I just cannot get RS-68 based designs to go anywhere.

[MP99]

Hmmm,  5 launches a year (a reasonable number that I picked out of the air), puts the SRB cost around $15M a segment or $120M a launch. Given that the Atlas CCB is  already used by another launch system, I can't see the cost per booster going above the $20M per unit, only down. So worst case for a liquid booster-based Direct is just $80M for the boosters, and it gets better for every additional launch.

I read 5 launches with 4-seg SRB's as ~$128m per launch. 5 launches with 5-segs puts the price up ~10% to ~$140m per launch.

cheers, Martin

[MickQ]

Would the crawlerways need to be modified   As I understand it, liquid fueling takes place on the pad so the liquid booster stack should weigh less than the SRB stack during transit to the pad.

Mick.

[clongton]

Would the crawlerways need to be modified   As I understand it, liquid fueling takes place on the pad so the liquid booster stack should weigh less than the SRB stack during transit to the pad.

Mick.

The crawlerways would be just fine as-is.

[Downix]

The issue then would be in staging, the RS-68 stages lower than the SSME, RD-180, NK-33 and Merlin-1c.  We'd need a second stage then.  Unless we're doing RD-68 on boosters, SSME on core, then it may be doable.  Want me to crunch those #'s next?

I was thinking along the lines of SSME core and RS-68 powered Delta IV boosters. Since I last posted I have been toying around with that concept and it looks like even with the RS-68A the stack would have a very hard time getting off the pad. The T/W ratio is not very favorable, I'm getting about 1.06. If you have some spare time and want to double check my math please go ahead but I fear that using Delta IV CBCs as boosters might be a dead end.

That fits with what I've found.  I just cannot get RS-68 based designs to go anywhere.

Ok, I'd messed up the Delta CBC numbers, putting in the RS-68's 57% thrust vs the RS-68A's 100% thrust capability. I realized I messed up when I took those $'s to make a normal Delta IV, and saw it was impossible, to went to figure out what I did wrong.  With this fixed, I got decent #'s:

65mT to the default orbit from Kennedy for a J-130D.

So, we have:

72mT for a J-130A
71mT for a J-130O
65mT for a J-130D

There are advantages to each one.  I prefer Orbitals solution (just something about the Taurus II makes me say "Yes"), but due to political needs, the Delta solution may be the wiser choice.

[gladiator1332]

I still find it really strange that ATK has been so relatively quiet throughout all of this. As Ross stated earlier, this is a company that stands to lose it all over the 5 seg booster.
Did they become so used to the glory days when Griffin was there to defend them to the death, that they have forgotten how to fight? Or are they so sure that congress will not allow POR / SDLV die that they see putting up a fight as unnecessary? 

[robertross]

So, If the Jupiter could be made modular enough to strap on four Atlas V rockets or two 4 seg solids, and you have a flight rate of about 4 per year.  That would either be 16 extra Atlas V rocket first stage cores or 8 solid rockets or 32 segments.  Would this not make the Atlas V strapons less expensive since you would be using more?  That would place the solids in the $20 mil range.  Also if they finally made the Atlas V phase II, it could launch Orion and the Jupiter could use only 2 of these phase II rockets for the 100 ton booster, or maybe four for about what 135 tons +.  You can get 4 phase II's around a Jupiter, but you can't get 4 solids because of the existing flame trenches are only rated for about 11 million lbs. of thrust right?

I was going to point out something obvious (HR the CCB engines), but with Orion in a state of flux, we could still press ahead with a 'HLV only' at this stage. But if you go the route of a manned capsule on top of Jupiter (as I suspect many would like to see), then we 'could' have some issues with the EELV guys not liking their engines (or CCBs) mucked up. Of course higher flight rates could offset the cost overall, so there might be a null effect, or leaning to a benefit for all.

[A_M_Swallow]

This discussion is based upon the scenario that ATK completely stonewalls on the SRBs i.e Ares I or nothing. I have a suspicion that the current Direct proposal is still the least expensive to develop. If ATK see the writing on the wall and gets behind the current Jupiter design then they bring quite a bit of political backing.

I suspect that part of the problem is different groups within ATK.
4 segment SRBs are a production contract
5 segment SRBs are initially a R&D contract

With the cancellation of Ares 1, Ares V, a rumoured own HLV and the heavy versions of Jupiter the R&D staff may suspect that they will soon be out of a job.

ATK could submit 3 bids:
a. 4 segment SRBs to form part of J-130, delivery to start within 3 years.
b. 5 segment SRBs to form part of J-140SH and J-246SH.
c. 4 segment SRBs to form part of J-130, delivery to start within 3 years.  Development of 5 segment SRBs to continue.

Part of this is when Boeing/Direct can afford to stretch the External Tank/core to make the J-140SH.

The J-130 being ready to fly within 3 years is important.  With the credit crunch getting worse NASA is asking for big trouble if it does not fly any major missions in Obama's second term.

[robertross]

I still find it really strange that ATK has been so relatively quiet throughout all of this. As Ross stated earlier, this is a company that stands to lose it all over the 5 seg booster.
Did they become so used to the glory days when Griffin was there to defend them to the death, that they have forgotten how to fight? Or are they so sure that congress will not allow POR / SDLV die that they see putting up a fight as unnecessary? 

Yes, and you would think given the FY2011 announcment they would have jumped on board with Direct by now...

Unless...Jeff Hanley had some pull left, and they finally got (used) him to spearhead this proposal, but he got shot down in the process instead? This, along with the internal (unreleased) Bolden HLV study, paints a disturbing picture.