New Mars

Following discussion in the '3 Shuttle Main Tanks' thread, I've come up with what I think is a reasonably realistic proposal:

Using the Ares V as a starting point, increase everything on it by a factor of 1.5.

1.5 x 2 = 3 SRB's, mounted equi-spaced.

1.5 x 60m = 90m main tank if possible, otherwise the longest possible that can be assembled in the VAB.

1.5 x 5 = ~7 RS-68b engines.

(edit) 1.5 x 130t = ~195t launch capacity, perhaps slightly less if the upper stage is not extended aswell.

We'll call it the Ares VII.

Why stop at only 1.5 times? Well, I'd imagine 3 SRB's could be accomodated most easily because when mounted equi-space, there remains a flat side where the SRB's don't intrude into the launch tower. The third SRB will then reside where the Orbiter normally sits.

Also, 7 RS-68b's are probably the absolute maximum that will fit under a 10m tank.

I reckon its do-able, what do you think?

PS: Considering this will be an inline launch vehicle, the 90m tank might make assembly in the VAB difficult. Therefore my question is: what is the maximum height you can get away with in the VAB?

I've been away from newmars for about a year, so forgive me if this sort of thing has been discussed in any length before. Actually, this would be a good place to post info on 3 and 4 SRB Ares-V derived vehicle configurations. Just now I've found gaetanomarano's page suggesting a 3 4-segment SDV would be quicker route to a 120+ tonne heavy lift capability. http://www.gaetanomarano.it/articles/006_superSLV.html.

However, now that the Ares development plan is in full steam, its seems fully shuttle-derived vehicles are out of favor, however unfortunate that may be.

If only it were so simple, rockets don't scale like this.

BTW Ares V currently has a lift capacity of 131.5 mT so even if your factor of 1.5 worked, which it doesn't, it would be 196.6 mT

They don't? Why not?

Damn, all this time I've been thinking it lifted 150t. Okay, I'll accept that (the wikipedia article says approximately 130t). I'l update the pics in a minute too.

Seriously though, as I discussed in the '3 shuttle main tanks' thread, I can't see any difference between launching two rockets in parallel, or scaling a rocket by a factor of two. Infact, as GCNRevenger suggested, if anything payload should be slightly increased, due to better aerodynamics and tank efficiencies.

Michael,
thank you for your words about my proposal
I've voted in favour of a (surely useful) bigger rocket despite (I feel) NASA will have not the funds to build it
about the Ares VII concept, I always think it's better to use the (ready available and cheaper) 4-seg.SRB with all Ares

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While I like the way you think, gaetanomarano, you do seem a little biased against the current plan. Perhaps I can persuade you by attempting to sum up some of the considerations to be made when contemplating future HLV's:

1. 5-segment SRB's have been part of Thiokols plans for some time. Most importantly, I think NASA seems them as necessary for the development of the Ares I. Because this is the case, they may as well be used for the Ares-V aswell. In this case, the increased thrust from the 5-seg SRB's will require re-design of attachment points, and reinforcement of that section of tank.Unless 'The Stick' is scrubbed (which is not completely unlikely), I imagine 5-seg SRB's are inevitable.

2. Going with an inline launch configuration will require reinforcement down the whole length of tank, to support the weight of the upper stage and payload.

These first two points already start to make a case for a clean-sheet main tank. However, it is the third point which is the final nail in the coffin:

3. Switching to RS-68 engines requires more tank volume to achieve the same payload. Therefore, a larger tank diameter is required if the vehicle is not to be unduly high.

I believe all three points have worked together to justify the current Ares V design.

However, if we're going to invest so much in re-design, we should not limit the potential of the end product. Personally, I would like to see NASA over-design their new main tank to allow for future additions, infrastructure permitting. That should include 3 or 4-SRB configurations, and extended tank lengths. Also, I'm not convinced that the step from an 8.4 to only 10m diameter is justified. Apollo-era tooling will have to be atleast re-built. Perhaps it would be convient to scale the tooling aswell. I'd imagine 12m or more would be favorable; I'm not sure where the limit exists.

As you can see, this is quite a lot of work. I can definately see where your coming from. But from my point of view, you can squander your pennies and get something whcih doesn't quite meet your needs, or you can spend big and get exactly what you want. Whether NASA's eyes are too big their wallet, I don't know.

The other problem with anything more than a 10m diameter tank, apart from the obvious increased tooling costs, is that it becomes harder to justify for those smaller loads.

Here's what a 4 x SRB, with a 13m diameter and 70m high core tank, would look like. Seeing as this would amount to twice the size of Ares V, we'll call it Ares X:

However, at this point I don't think 10 RS-68b's are practical. Perhaps you could settle for a cluster of 7 and live with the reduced payload.

no, I only suggest to use ready avilable hardware to save time and money


I think they (absolutely) must do that (to survive the giant weight atop)


too much different tank's dimensions may increase costs (for rockets' factories and assembly, transport, launch pad, etc.) so, a "standard" 10 m. diameter tank is the right choice (also, it's large enough to fit four SRB)

about bigger Ares... I'm in favour of them, but the problem (everytime) come from "funds"

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If it wasn't for 'The Stick', you'd be right. And you may still be right yet. They may be unnecessary, but the development of 5-segment SRB's are an opportunity. If that be the case, perhaps they should be up-scaled to 6-segments before work has begun?

As it is today, with a 10m tank and RS-68's, I personally think Ares-VII is about the biggest you could go without requiring a prohibitively large step up in development costs.

after the Ares IV announcement, I'm sure that NASA officials and engineers are aware they need a bigger rocket for moon missions, but there are (at least) two reasons why they insist to build the Ares-I:
1. both AresIV and AresV are too big, too heavy and too expensive for orbital missions (that NASA may reduce but not abandon)
2. after the Shuttle retirement in 2010, they ABSOLUTELY need "something" 100% american able to send astronauts in orbit" (mainly for political problems...)


add the 5th segment will be very expensive, so, if they need a "6-seg.SRB" the best solution is to buid only the latter and use it in all rockets (of course, I always think the best choice is the 4-seg.)

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I'm not sure about this, but I think it is because NASA knows it can't kill the shuttle army so easily, that it chooses to go the Non-SDV route. This may seem ironic at first, but I believe NASA would rather overwork them with these new projects, rather than risk underutilizing them. This will be especially important when less frequent lunar launch rates, and the ~4-year launch gap are considered. With that logic, it seems to me as though the development costs give the wrong impression as to the true costs, as most of the cost remains whether the ever-present employees are given new projects or not.

Exactly. Conceivably, the greatest leap in development costs will be from 4 to 5 segments. If thats the case, we might get more bang for buck if we jump to 6 instead; forgetting the 5-segment SRB altogether.

Of course, this is assuming a 6-segment SRB can be designed without requiring a prohibitively expensive redesign of any component (e.g. a clean-sheet nozzle) over the 5-seg. In the end, if the current 5-segment CLV is proved to underperform, then a 6-segment may be exactly what NASA needs anyway.

Once we've got a (suitably reinforced) 90m tank and the cluster of 7 RS-68's necessary for the Ares VII, we could conceivably make more use of this new tank by going the Delta IV heavy route, as outlined in my 'Really big rockets' thread: http://www.newmars.com/forums/viewtopic.php?p=96268



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Good lord You people are designing the USS Monstrosity.

The Ares VII, compared to the insane design of Paris, is a HELL of alot more doable. Have you people even taken into account the transport vehicle? No way in hell anything could move something of that scale and I doubt assembling it on the launch pad will be anywhere near simple. Although I suppose either Ares VII or X are possible to at least design if not implement and fabricate, but I wonder how an even simpiler design could perform.

Call this conept the Ares VI:

-Same central core and upper-stage as Ares V
-4 5-stage SRVs; same as on Ares V but two more (1 more than Ares VII)

What would the performance of this conceptual vehicle be compared to Ares V and then to Ares VII? 4 SRBs versus 3 allow for something more symmetrical which I assume is easier to handle and maintain. Are there any US boosters that use 3 rockets like that? Only one I can think of is the Atlas V.

Summarizing I think it'd be easier to implement than Ares X and slightly less troublesome than Ares VII - more hardware heritage from Ares V and more stable on the launch pad. If it lifts a good 5 tons more than Ares V for just a hundred million of development verses several billion for 15 tons or whatever I'd take the former since it saves more.

a real progress in space is to have more assembly and an increased experience in building everything we need at zero-G/low-G ...unfortunately, after the Shuttle retirement in 2010, we will have (near) ZERO assembly in space (losing soon the 25+ years Shuttle's experience) so, the only way to launch "big things" in space with a single-shot technique, will be build that kind of iper-rockets

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That is exactly what we don't need. See how long ISS is taking to construct. For Moon missions the Ares 1.5 launch is ideal. Everything can be checked out on the ground where it's so much easier, cheaper and better!

For Mars probably each vehicle will need 2 x Ares V, and an extra Ares I for crew. And maybe three such vehicles will be needed. Assembling that much mass in LEO is risky, tine consuming and expensive with smaller pieces. What's worse is that it may need astronauts as well. The more launches the higher the risk of failure. Two shuttle failures have delayed ISS by over 4 years. One failure assembling a Mars mission would cancel it.

but (without space-assembly) in the next 30+ years we will have ONLY moon missions and SMALL objects in space

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"4 SRBs versus 3 allow for something more symmetrical which I assume is easier to handle and maintain"

There was a lot of discussion at the nasaspaceflight forums about the prohibitively heavy weight of 4 SRB's, versus an extended unfilled main tank. I'm not sure of the weight of the 5-seg SRB's, but the transporter max payload was mentioned as under 18MT. Because SRB's are always stuffed full with fuel, they're way heavier than even huge empty cryogenic tanks. I'll try and find some numbers.

Basically though, what this rocket should be, is the tallest, heaviest rocket that can be accomodated in the VAB and on the MLP. Though preferably with as few modifications to either as possible.