the case against HLV

[john_316]

I am sorry but I think that HLV not only outweights MLV but also allows room if the initial package is less than optimum and thus can be reconfigured to add compensation weight such as another component or added fuel etc etc.<br /><br />I can't see 6-7 MLV's as a cheaper alternative to 1 HLV. I just dont see the cost savings nor the weight increase in the MLV being surperior to the HLV design.<br /><br />Just 2 cents worth....<br /><br /><img src="/images/icons/smile.gif" /><br /><br /><br />

 

[mattblack]

You're correct. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[josh_simonson]

The ESAS report does sorta pull the wool over folks eyes by quoting the launch cost of the HLV assuming 6 launches/year. Realistically I'd expect about 3, 2 to the moon and 1 for something else (telescope, spysat...).

 

[nacnud]

Well there are six HLV launched in a good year, it's just that we call them STS.<br /><br />You could easily find use for four+ HVLs a year in support of a Moon base, plus any that would be needed for Mars missions.

 

[JonClarke]

Please read what I said more carefully. I wrote:<br /><br />"while a Mars mission is possible without a HLV it is very complex and ugly business. "<br /><br />In other words I agree with you.<br /><br />However, it may be worth noting that ESAS has limited orbital assembly of two launches per mars-bound spacecraft.<br /><br />Jon<br /><br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[gunsandrockets]

"However, it may be worth noting that ESAS has limited orbital assembly of two launches per mars-bound spacecraft."<br /><br />Actually it is three launches in the case of the manned Mars-Transfer-Vehicle, 2 x HLV + 1 x CLV.<br /><br />"Please read what I said more carefully..."<br /><br />Now that's an ironic request. <br /><br />

 

[gunsandrockets]

"The ESAS report does sorta pull the wool over folks eyes by quoting the launch cost of the HLV assuming 6 launches/year. Realistically I'd expect about 3, 2 to the moon and 1 for something else (telescope, spysat...). "<br /><br />Six HLV per year?! That's shocking. Are you sure it isn't six of the stick-CLV per year?<br /><br />Please tell me which page of the ESAS report this is on so I can download the relevant part. I don't have a high speed connection.

 

[gunsandrockets]

"I can't see 6-7 MLV's as a cheaper alternative to 1 HLV. I just dont see the cost savings nor the weight increase in the MLV being surperior to the HLV design. "<br /><br />If you don't mind the 10 billion dollar development cost for HLV. Plus having the exploration architecture dependant on a single type of launch vehicle with no backup.

 

[gunsandrockets]

"It's essential to consider development cost, development risk, and the vast uncertainties in both development and operating cost."<br /><br />I pretty much fully agree with you. Except for this...<br /><br />" Why not continue to work toward a long-term solution, a practical and reusable launch vehicle?"<br /><br />I think NASA should leave launch vehicle development and much of LEO activity to the private sector. NASA should buy launch services instead of developing launch vehicles.<br /><br />Where I think NASA should be spending it's limited resources, and that's the key to the whole issue - NASA's limited resources, is on the costs of actual missions to deep space and developing the technology that aids deep space exploration. <br /><br />One key technology to aid deep space exploration is advanced propulsion. Propulsion superior to chemical propusion can cut the mass budget of deep space missions in half or more. That would mean less than half the launch capacity from Earth would be needed. Why bother developing HLV to lift more mass to orbit, when you can reduce the mass needed in orbit instead?

 

[nacnud]

<font color="yellow">One key technology to aid deep space exploration is advanced propulsion. Propulsion superior to chemical propulsion can cut the mass budget of deep space missions in half or more. That would mean less than half the launch capacity from Earth would be needed. Why bother developing HLV to lift more mass to orbit, when you can reduce the mass needed in orbit instead?<br /><br /><font color="white">Well if you're going to factor in the cost of HLV development then how about the cost of developing this advanced propulsion. Also what’s the cost of the flight hardware, if advanced propulsion costs a lot per unit mass then a single launch of a complex machine might cost more that two launches, one of already developed technology and one of propellant.<br /><br />I agree long term NTR, BNTR, NEP etc show advantages over chemical but chemical might be enough for the first mission. <br /><br />Fun this devils advocate stuff, isn't it <img src="/images/icons/laugh.gif" /><br /></font></font>

 

[josh_simonson]

>Six HLV per year?! That's shocking. Are you sure it isn't six of the stick-CLV per year? <br /><br />Both were investigated at 6/year. Section 6 and 12 has the info. Specifically table 12-16 in section 12 lists the cost at 6/year being only 391M for the HLV. But using their (more efficient 6/year) numbers at 2/year you get more like 800M. Loss of efficiency due to a low flight rate might boost that all the way up into the 1bln range. <br /><br />Of course, once the HLV is on the horizon, NRO and NASA will start planning payloads, huge spysats (or clusters of them), space telescopes, big deep space missions, ect. I'd expect at least one extra mission per year for this kind of thing, but I doubt they'd afford 4. At 3 launches/year you get 600M, which is a commonly mentioned price. But that's calculated at the economy of scale of 6 launches/year, so it's actually on the low side. NASA can afford 6 launches, but they can't afford to build 750 tons of space equipment as cargo at the same time without an increase in budget.

 

[john_316]

I understand your point but the the EELV wasn't originally planned as a civilian satellite launcher or for NASA for that matter. And even if they use them for satellite launchers then that money goes to the rocket maker and partially to the launch facility. <br /><br />The Delta and Atlas Heavies are to replace Titan IV.<br /><br />But was is going to become the new defacto satellite launcher for satellite launches in the USA? Atlas? Delta? both?<br /><br />I could see a modified Atlas and Delta Heavy for CEV launch as a secondary launch vehicle. I think this would be wise if you ask me. But are they going to do it? Probably not.<br /><br />But once we have CEV operational we will have a faster turnaround than a STS mission as we can have more capsules ready and more SRB sticks online in the time it requires to launch a Delta or Atlas.<br /><br />I support all American made rockets for NASA and DOD missions and even redundant uses and cross-use from one system to another. <br /><br />But A HLV for Mars and Moon exceeds the weight that MLV (ie EELV) can provide. To use the Zubrin case for Mars using EELV/MLV is not going to happen unless you want a small crew of 3 crew going to Mars on a chemical ride for 6 months out and 6 months back on the same equipment.<br /><br />A HLV will be able to launch a larger vessel with better crew and crossrange ability and it beats being in a soup can day in and day out for a long ride if thats decided.<br /><br />Plus a HLV can launch a Nuclear Propulsion stage for a MTV while the MLV can't.<br /><br />Besides we will have all these items anyways if need be. (ie we will actually have access to space and possibly multiple vehicles to launch them instead of just one sole rocket to get there. We need multiple platforms to achieve our space access. Even if the CEV is the only thing for a crew we will have at least 2 vehicles to launch it most likely. Why not 4? Thats up to the NASA people and funding to use Delta-4H and Atlas-5H.......<br /><br /><br /><img></img>

 

[JonClarke]

Picky picky picky. Pots should not call kettles black.<br /><br />You know what I meant. 1) MLV is not a good way to go, and, 2) at least some orbital assembly is required.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[gunsandrockets]

Well done.<br /><br />As you have noted the EELV are already used for both military and commericial applications. Plus NASA has formally agreed to use EELV for unmanned exploration missions. The Delta II is now dead.<br /><br />Your point..."That's the key - if military and NASA and the private sector are all using the same vehicles then they're going to be cheaper for everyone. That means more money can be put in the assets on top."...is well taken. Isn't it interesting how this time around the USAF and commercial interesests are going to be allowed to continue using existing boosters wheras during the STS era everything was forced to fly via the Shuttle, at least until Challenger blew up. <br /><br />But in my opinion it isn't so much NASA's underutilization of existing assests that is so wasteful as much as the huge development budgets for the new launch vehicles are wasteful. 15 billion dollars to develop two new launch vehicles! Imagine how much 'assets on top', as you put it, could be bought for 15 billion dollars.<br /><br />Your point..."I'm skeptical about 100 metric tonnes (m.t.) being a real must-have need and not just a strong case of really like to have." That is exactly right. And this nice to have HLV is going to drain NASA of money for years to come.<br /><br />Wouldn't it be ironic, if after spending 5 billion dollars developing the CEV and another 5 billion dollars developing the CLV, plus the constant drain of the STS and the ISS programs NASA had to cancel the HLV? Then NASA might turn around and redesign it's exploration architecture to fit around the MLV class CLV-stick launcher! In a weird way the high cost of the CEV + CLV might save NASA from the even higher cost of the HLV. <br />

 

[gunsandrockets]

"Both were investigated at 6/year. Section 6 and 12 has the info. Specifically table 12-16 in section 12 lists the cost at 6/year being only 391M for the HLV. But using their (more efficient 6/year) numbers at 2/year you get more like 800M. Loss of efficiency due to a low flight rate might boost that all the way up into the 1bln range."<br /><br />"Both were investigated at 6/year. Section 6 and 12 has the info. Specifically table 12-16 in section 12 lists the cost at 6/year being only 391M for the HLV. But using their (more efficient 6/year) numbers at 2/year you get more like 800M. Loss of efficiency due to a low flight rate might boost that all the way up into the 1bln range." <br /><br /><br />Very interesting. I had heard that NASA had plans for two missions to the moon per year once the HLV and the rest of the moon mission architecture was up and running. And that would equal only two HLV launches per year. Even with other missions added to that launch rate, I'd bet the average launch rate would remain at two per year. Imagine how much ground infrastructure it would take to launch more than that!<br />

 

[josh_simonson]

>Imagine how much ground infrastructure it would take to launch more than that! <br /><br />That's the problem, the ground infrastructure has to be paid for wether you use it once or 6 (or sixty) times. The table says the HLV will cost 1.27bln/year plus 179 million per launch at 6/year. The 1.27 bln is the infrastructure cost.<br /><br />Amusingly, according to their numbers, if you launch 17 HLVs/year it'll be the same price as an Atlas V heavy. <br /><br />It's also kind of curious that rocketdyne claims the new SSMEs will be ~40M, so 240M in SSMEs on each hlv, and then add ~60M for the SRBs. That adds up to 300M in expended hardware/launch right there, but NASA's claimed unit cost is 179M. They must have some kind of squirrely contract with these companies where they gurantee a large, fixed, amount plus a small marginal unit cost. If these contracts are decided at the 6/year rate, NASA will be getting fleeced by their suppliers until they get up to 6 launches/year.

 

[john_316]

The MLV point is mute. <br /><br />HLV will be used for the Moon and Mars missions as required. <br /><br />EELV will be used as needed in any mission configuration but HLV will be here to stay for quite some time once its in place.<br /><br />MLV will not be taking crews to Mars or the moon for the USA.<br /><br />MLV has its merits for certain case by case launches but as far as I know HLV will do the job.<br /><br /><img src="/images/icons/smile.gif" /><br /><br />

 

[shoogerbrugge]

Just nit picking here, but the Delta 4 isn't available for commercial payloads. Boeing decided not to bother with competiting, and they got SeaLaunch which is in the same category.<br /><br />I'd prefer a MLV system myself, mass production makes things cheaper and safer because of greater standardisation. But I guess the choice has been made. At least the VSE is going to use existing hardware instead of starting with a clean sheet again. So there is a reason to be positive.

 

[gunsandrockets]

"The MLV point is mute."<br /><br />I am not the only one who thinks the issue is far from over. <br /><br />"HLV will be used for the Moon and Mars missions as required."<br /><br />Maybe. There is a huge lump of spending, 10 billion dollars worth, between now and HLV deployment. And NASA has many other spending priorities competing for the same money. <br /><br />"EELV will be used as needed in any mission configuration but HLV will be here to stay for quite some time once its in place."<br /><br />Key phrase, 'once its in place'. And even then HLV only hangs around as long as hefty payloads are required. Unlike MLV, the HLV has a single customer. <br /><br /><br />"MLV has its merits for certain case by case launches but as far as I know HLV will do the job."<br /><br />The question is which launcher can do the manned exploration job for the least amount of money. I still think the answer is the MLV. <br /><br /> <br />

 

[barf9]

The big problem with space tourism is where do you go. Billionaries will want a nice big playground if their going to keep shelling out $10-$20 Million for a week in orbit. Mir is gone and the ISS has work to do. Bigalow's inflatable habitat has alot of promise, but it's not a system with a long history of actual use (insurance?). But what if there was a brand new 100+ ton skylab like station to play in? What if more new 100+ ton sections could be added to this station, with large private rooms and a friendly staff? The private sector might be able to reach orbit by 2010 but only some agency like NASA could give them a place to go.

 

[barf9]

The HLV could also finish lifting the ISS. Weren't most of the remaining modules designed only to fly in the shuttle? A new HLV could be designed w/ a shuttle cargo adapter, something I guess the MLVs we have now can't be modified to do. This would lower pressure to spend all the remaining shuttle flights on the ISS (fix the Hubble?), how many missions did they say the SHuttle was going to fly last May? I'm sure that number is going down.

 

[josh_simonson]

The first HLV flight will occur after NASA plans to bow out from the ISS. Unless this changes, HLV will not be used for the ISS. It's unlikely ESA would pay for an HLV launch to the station after that point unless they were offered a good deal on a test launch.<br /><br />OTOH, a HLV launched inflatable could be 55ft in diameter.

 

[barf9]

if you build it they will come!!

 

[publiusr]

The anti-HLLV people just don't appreciate the need for engine out. It takes five-6 Delta IVs to place 120 tons in LEO. Magnum can do it in one shot with 3-5 hydrogen engines and only one upper stage.<br /><br />It would cost you 15-18 RS-68s to do it with Delta, and five to six upper stages.<br /><br />With 15 hydrogen engines expended with five-6 HLLV flights, I have 500-600 tons in Orbit, for Moon Mars, space factories, etc.<br /><br />All the things we would have had if we had the SSMEs on the ET like Energiya.<br /><br />Imagine if we had flown 100 Energiya HLLVs instead of 100 or so STS missions!

 

[john_316]

Good point but what if we had orginally built STS as a 100 ton launcher not a taxi and cargo hauler or continued with Saturn then we wouldnt need the Energia and well we still dont. Besides its not American.... We like to fly our own rockets as needed. I cant help the morons in the old whitehouse/congress/nasa that did away with assured space access.<br /><br />I always thought they had a requirement from DOD or someplace were we always where supposed to have assured space access (manned).......<br /><br />Besides until the return of Energia to production I dont see it flying either. When was its last launch? Like 1988 almost 20 years ago?<br /><br /><img src="/images/icons/smile.gif" /><br />