John Hare has an interesting Ares I alternative:
Suppose that instead of stretching and totally redesigning the SRB, they had shifted to a two SRB first stage with the exact same units as used for the last hundred and something shuttle launches. These rockets are fully developed and tested with an extensive flight history of operating in pairs over the last three decades. The purchase costs, handling , and performance are known quantities. Development consists of building an attachment structure, upper stage adapter, and vibration dampening gear. With the considerably more lift performance available from eight segments compared to five in Aries I, the problem fixing payload hits could be absorbed without sacrificing the flavor de jour safety systems NASA would like to have. They wouldn’t even have to game the requirements to match the competition from ULA, Direct, and various upstarts. While it’s possible that this would cost as much as the projected Ares I, it shouldn’t, and if it did, it would be for a system nearly twice as capable.
The first thought, of course, is that it increases the marginal costs quite a bit, but as Jon notes, you can buy a lot of extra SRBs for the billions you might save in trying to tart up the pig. As I noted in comments, one other advantage is that it would allow the first stage to do its own roll control with the SRB gimbals (something that Ares I is incapable of, necessitating a roll-control system for the entire stack on the second stage). But thrust asymmetries could be a big problem. Shuttle can compensate by gimballing the SSMEs, but this configuration wouldn’t have that capability.
***billions you might save in trying to tart up the pig***
Don’t candy coat it Rand, it’s a lipstick turbopump.
Add a side mount pod and SSME’s and it all works!
🙂
What is this going to do for the g-forces? Seems like that much extra thrust would cause it to accelerate like a bat out of hell.
Sounds too much like SRB-X to me.
Of course, if you ditched the upper stage and put a heavy ET in the middle with say three or four SSME’s on the bottom, I bet it would DIRECTLY avoid any excessive acceleration issues.
Hey Dennis, what did you think of ‘not’ Shuttle-C?
Did you have a hand in that?
His diagram is misleading in that he labels J-2S as a “major development project” but does not do the same for the air-start SSME. That is itself a major project in its own right.
The development headaches of an air-start SSME is one of the things that resulted in NASA switching to the J-2X in the first place.
Nemo,
I was corrected in comments on that one.
I would say finishing the J-2S would be far easier than an air start SSME.
Still, let us note the Jupiter 130 and the Not Shuttle-C do not need any upper stage to do earth orbit.
Sure, sounds interesting. But how many jobs would it keep/create in whose districts? You left out the most important technical criteria of all.
Mike
First round. The points that needed to be made were made, and were made by NASA, not some unknown group that claims NASA support.
However, that being said, this is much more about the destination and what we are going to do there rather than the rocket.
Will be addressing this formally soon.
Still, let us note the Jupiter 130 and the Not Shuttle-C do not need any upper stage to do earth orbit.
They still need the payload or some support vehicle to do the circularisation burn.
Martin,
So does the shuttle and the Orion SM uses a cariant of that same engine as did the Delta II US and the old Apollo Service Module.
That engine already exists.
“I would say finishing the J-2S would be far easier than an air start SSME.”
Make that J-2X
Dennis,
It seems to me that the not Shuttle-C would work better if it left the Orion lifting to the Delta IV and used one launch for a big horizontal lunar lander and another for the TLI stage.
It would houwever make for a three launch solution.
Later, if your lander and transfer stage is reusable, you could simply launch the Orion on the Delta and fuel and cargo for the moon on one Shuttle-C-not.
Mike
Absolutely.
I heard rumblings from sources that they were going to mix crew and cargo on this version but that is not what we are supporting. There is a huge tug of war going on inside the beast right now as at least one of the presenters the other day (you figure out who) basically lied through their teeth. This creates a limb that they will not easily climb back off from.
already said three years ago
“already said three years ago”
That in and of itself is enough to discredit it if the Ralph Wiggum of the internet is in favor of it.
The Not-Shuttle-C argument essentially vindicates Dennis who has been proposing something similar for ages. They’ve even managed to get rid of most of the complexity in the cargo element. Note that they are still proposing a NASA in house upper stage. Drop that and make it uncrewed and you have what I believe to be the cheapest SDLV possible, not counting silly things like an unmanned 4 seg Ares I variant. Like any SDLV it’s still a tremendous waste of money, but it may be the smallest waste possible.
Note that an uncrewed version doesn’t even need shuttle flight computers, it can just emulate them on modern hardware. All you would need is an emulator for IBM S/360 microcode, a license from IBM and you have a cycle-perfect emulator. Much less need for extensive validation (which would be most of the work) if all you’re launching is an EDS.
It would houwever make for a three launch solution.
Mass-wise it’s two launch. If you remove Orion to be launched on Delta-IV Heavy, you end up with one EELV, one Not-Shuttle-C launch and then some. And with propellant depots, fractional launches actually make sense. I did some sums the other day, and with L1 rendez-vous and a hypergolics depot you can make this work with two Not-Shuttle-C launches or equivalent. I’d prefer to have the Altair dry-launched and to use Not-Shuttle-C only for launching an EDS together with some hypergolic propellant to fill up any excess payload capacity.
Martijn
It is funny that a single FPGA or ASIC based piece of silicon can completely replicate the STS computer system. You could use all the same software and hardware interfaces, though there are several upgrades that you could put into the sensor system.
Though the STS computer is a 370/148 hardware wise, at least that is what I was told by one of the original programmers back in the 70’s.
A trade would have to be done relative to that type of configuration vs a new DSP based computer. Probably due to the huge embedded software base for STS it would be good to reuse what they have. A 50-50 bet one way or the other.
Shannon’s presentation on Not-Shuttle-C appeared to me to be a very subtle, calculated and brilliantly executed attack on DIRECT, without even mentioning it by name. He undermined the credibility of DIRECT’s claims J-130 can help close the gap by showing Not-Shuttle-C is more direct than DIRECT itself and still cannot close the gap. He also suggested that anything less than Ares V (in particular Not-Shuttle-C, but including Jupiter by extension) would lead to a less capable lunar architecture. This invites the conclusion that if you are willing to wait longer for an inline SDLV you might as well go for Ares V.
The attack also appears to have been closely coordinated with Cooke and company. Take a look at the only backup slide in his presentation: it’s a chart that suggests Not-Shuttle-C is much simpler than both Ares and DIRECT, whereas DIRECT is about as complex as Ares. This is very misleading, DIRECT is more like halfway between Not-Shuttle-C and Ares. I cannot help but think this was done deliberately.
The claim that Not-Shuttle-C would require a smaller lander is false by the way.
The reason I say three lauch is I would like to see Dennis get his reusable mega horizontal (Space 1999 Eagle?) Lander.
If you are going to make it reusable for years in space with minimal servicing, you want it overengineered and robust as hell. You only gotta move it to an L point or LLO once.
This would leave one whole launch for the TLI stage.
When your reusable archatecture is in place, you can go to two launches.
I’m in favour of this as well and it likely even works better with my old favourite the hypergolic lander. Simple, single stage, compact because of the density of hypergolics, pressure fed, hypergolic so no igniter that can wear out and fail, lower pressures and temperatures. Plus you get plenty of propellant launches to an L1 hypergolics depot straight away, without needing to wait for cryogenic depots. The boost to commercial launchers could be significant.
In my mind, whatever lander that is produced (yes I like the horizontal lander for many operational reasons) be built with the earliest possible reuse in mind. With a robust ISRU in place we can at least eliminate oxygen as something that has to be lifted from the Earth. Many many studies have shown the dramatic improvement in architecture sustainability and lower cost that this creates.
I really am not supportive of hypergolics over the long haul, though they may be cheaper to implement until you get ISRU up and running.
I’m in favour of MMH/NTO in the short run because it would allow for early depots without the risk (likely overblown) of cryogenic depots, which remain a high-priority technology to be developed, together with ISRU and aerobraking.
Dense propellants would remain nice in the long term, but those include kerolox as well. Hypergolicity is also nice, though that doesn’t have to mean MMH/NTO.
I’m very interested in higher silanes + H2O2. This is non-cryogenic, hypergolic, dense, much less toxic than MMH/NTO, has better Isp and combustion properties than hydrocarbons and has significant ISRU potential, much more so than MMH/NTO. Of course even NTO could benefit from lunar oxygen. If you use gel propellants and metal loading you improve Isp and density further as well as ISRU potential. This means you could potentially produce much more propellant from the same amount of regolith or ore, essentially producing no slag. This potentially means much more efficient excavation.
BTW Dennis, is there any chance of you appearing before the commission?
*** M Puckett Says:
June 21st, 2009 at 1:15 pm
“already said three years ago”
That in and of itself is enough to discredit it if the Ralph Wiggum of the internet is in favor of it.***
You sir, owe Ralph Wiggum an apology.
John, you realize I was comparing him to GM, not you….wait…..I see your point.
If there has to be a HLV, then a Not-the-Shuttle-C (NTSC) type vehicle seems the best of all current options. But only for cargo not crew launch. (Though if one did use a side mount configuration vehicle to launch Orion, the capsule launch escape system shroud and Orion service module completely protect the capsule heat shields from debris shed during launch)
Since reusability of SSME is no longer a factor with NTSC, then considerably more efficient staging is possible than used by the STS, (something which the Soviet Buran shuttle benefitted from too because the Energia core engines were expendable). There is great benefit it not having to drag 14 tons of main engines and 30 tons of tankage up to full orbital velocity. So a side mount configuration shouldn’t suffer too badly in comparison with an inline configuration. Much better payload than the original Shuttle C concept (which reused the SSME) should be possible.
I guess that If one substitutes two RS-68 for the three SSME on a NTSC, then the vehicle would reach 90% of orbital velocity by the time the External Tank runs dry and staging commences. If one subsitutes a pair of RL-10b for the OMS, then 20 tons of propellant (only 10 tons more than the OMS prop) should be enough to complete final 10% to LEO.
NTSC, I like it. For those who want to see the shuttle stack disappear: The NTSC is not your PAL. Thank you, I’ll be here all week.