RS68 confirmed for CaLV

j05h · May 18, 2006

http://www.spaceref.com/news/viewsr.html?pid=20656 You read it here first. RS-68 on CaLV, 10 meter core stage. Well, it's a DDHLV now (Delta Derived...) Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

erioladastra · May 18, 2006

"Delta Derived" I hav been told by folks that the RS-68 is an offshoot of the SSME.

john_316 · May 19, 2006

This is good news. A 650,000 lb thrust engine over a 420,000 lb thrust is a little better. A 230,000 lb difference helps out a lot.... I just hope the current tooling can do the increase for the diameter needed. No jabs at the SSME but the further away you take it away from the STS system the more practical you will be to keep up with technology. Not saying thats a bad thing but hey if they can save money then they should. After all it is taxpayers money riding on this thing... <img src="/images/icons/smile.gif" />

rfoshaug · May 19, 2006

Does anyone know what the total liftoff thrust and mass will be now? <div class="Discussion_UserSignature"> ----------------------------------My minds have many opinions </div>

john_316 · May 19, 2006

I think over 3,250,000 total lb thrust if I am not mistaken as each engine delivers 650,000 lbs of thrust and there will be 5 engines on the CaLV. Thats not including the SRB's.... I have no clue what the gross weight/total weights are or will be. <img src="/images/icons/smile.gif" />

henryhallam · May 19, 2006

Will the CaLV still use five engines? Even 4 of the RS-68 would still provide ~25% more thrust than 5 SSMEs. But maybe all five are needed to lift the new heavier tank that will be required.

rfoshaug · May 19, 2006

Yes, it looks like they're going for 5 engines. Wonder if it will be heavier than the heaviest Saturn V (Apollo 17?)? <div class="Discussion_UserSignature"> ----------------------------------My minds have many opinions </div>

edkyle98 · May 19, 2006

My guess would be yes. Total CaLV liftoff thrust is going to be roughly 4500 tonnes (9.9 million pounds). If it has the original CaLV's 1.36 thrust to weight ratio, CaLV will weigh 3309 tonnes (7.3 million pounds) at liftoff, well more than Saturn V's 3039 tonnes (6.7 million pounds). It will probably outhaul Saturn V too. If my guess is right, this is a plan for the heaviest, most-powerful launch vehicle the world has ever seen. - Ed Kyle

no_way · May 19, 2006

<blockquote>In reply to:<hr />You read it here first<hr /></blockquote> twas on Hobbyspace ( and RSS ) long before you posted it <img src="/images/icons/wink.gif" />

j05h · May 19, 2006

> twas on Hobbyspace ( and RSS ) long before you posted it LOL. Yeah, and Nasawatch.com. I'm just being dramatic or somthing. I'm psyched about the changeover. This is a much more "future-proof" engine than SSME, in my opinion. Both are flight proven, etc, but the SSME pushes to many boundaries to ever be an economical engine. $60 million dollars per engine? Way to expensive. The RS-68 sounds far more affordable, and the 10m base diameter is going to enable all sorts of new payloads. Good call, NASA. josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

trailrider · May 20, 2006

"With 4 RS68 engines and the 2 five segment SRB the L/O thrust is over 9 million pounds." So, S_G, does that mean 4 or 5 RS-68's? That illustration on the SpaceRef.com is confusing. While it LOOKS like they have a "fifth" engine hanging out in the breeze, it may only be to illustrate the configuration of a typical engine. I know the article says "5" RS-68's. Please clarify if possible! I am rather upset by the change to the 33 ft. diameter tank. It means my 1/144 scale model, carefully crafted from several Space Shuttle plastic model kits (NOT cheap) is obsolete. <img src="/images/icons/frown.gif" /> I'll either have to change the upper stage to a smaller size, make a frustum-shaped interstage, or just explain to kids I lecture to that there've been some changes made! BTW, what is the individual thrust of a 5-segment RSRB? But we do seem to be making progress! Ad Luna! Ad Ares! Ad Astra!

mattblack · May 21, 2006

Thiokol's 5-segment test motor yielded more than 3.6 million pounds thrust for a 128-second burn, 5 seconds longer than the traditional SRB. Over on NasaSpaceflight.com there is a somewhat bitter and twisted dogfight going on over EELV (Atlas V) versus Shuttle-derived. Some of these guys are getting nasty and they've already driven Dr Doug Stanley away!! I detect some political agendas in the argument and even I've weighted in on it, but I'm running out of steam, engineering wise: I think some of these guys are frustrated EELV contractors venting their spleens, even thought they do raise some good points. For what it's worth; I think they should stick to the standard 27.5 foot E.T. diameter, but with a slight stretch -- and with 4x uprated RS-68s for this corestage. I chuckle a bit ironically now, for about a year ago I used to argue on these pages for the adoption of the RS-68, not the expendable SSME (RS-25) for cost reasons. But shuttle_guy talked me round to the RS-25!!! <div class="Discussion_UserSignature"> One Percent of Federal Funding For Space: America CAN Afford it!! LEO is a Prison -- It's time for a JAILBREAK!! </div>

radarredux · May 21, 2006

> I think some of these guys are frustrated EELV contractors venting their spleens, even thought they do raise some good points./i> If you have the time for a short write up, I would be interested in reading a short summary (maybe 1-2 paragraphs) on each side.

mattblack · May 21, 2006

I'll give it a go in a day or so. <div class="Discussion_UserSignature"> One Percent of Federal Funding For Space: America CAN Afford it!! LEO is a Prison -- It's time for a JAILBREAK!! </div>

frodo1008 · May 21, 2006

That is about 1.5 million pounds of thust MORE than the venerable Staurn V (at least for the first stage)! That is a WHOLE lot of thrust!!

mikejz · May 21, 2006

I just wish they would go with a 4x5 segment SRB---now THAT would be something really impressive.

lampblack · May 21, 2006

This item says there will be five of those big boys -- five RS-68s: http://www.nasa.gov/home/hqnews/2006/may/HQ_06226_RS-68_ENGINE.html I have just spent about half-an-hour looking for information on just how much additional weight the newly configured rocket will be able to haul to low earth orbit. Presumably it will put up more than the 125 tons that everyone had been talking about? Does anyone in these parts know exactly what a rocket with five RS-68 engines coupled to a pair of five-segment solid rocket boosters can do in terms of weight to orbit? <div class="Discussion_UserSignature"> Just tell the truth and let the chips fall... </div>

lampblack · May 21, 2006

And if there is significant extra capacity, does that mean anything in terms of how the overall architecture for getting to the moon is structured? Or does it simply afford the planners more wiggle room than they had before? <div class="Discussion_UserSignature"> Just tell the truth and let the chips fall... </div>

scottb50 · May 21, 2006

The RS68 is based on the SSME and is capable of mutliple re-starts. Re-use should be a no-brainer. A cooled nozzle, like the SSME would boost performance and the design seems to be strong enough to handle somewhat higher pressures. Routine maintenance shouldn't include replacing nozzles, unless ablative designs can be made significantly cheaper and be changed in minutes. Would work great as engines for a TSTO Launcher. The only problem I see is man-rating it, at least the SSME is already man-rated. With the RS68's lower pressures and rather robust design it should be capable of multiple uses. Add a cooled nozzle with a high altitude extention and you could carry quite a bit. Two RS68's and two five segment Shuttle SRB equivelents would easily carry more than 100,000 pounds to LEO. Use 2 SSME's for upper stages and RL-10's, or other engines for LEO Tugs. SSME's would also be used on lunar and Martian cyclers. The only reliable commercial way to work in Space is to separate it into two interlinked but separate systems. One system exclusively to and from LEO and another system in LEO and beyond. Two very different realms with individual needs. The Russians get it. Soyus to LEO and back and Space Stations in LEO. All they need to do is build the hardware to go to the moon and Mars, put it in LEO and use Soyus to get to it. It's a lot easier to adapt LEO capable equipment to other tasks in Space then to adapt the Soyus. Even the bigger Soyus would carry more people and cargo, not try to be Superman. Not to say the systems couldn't be built from the same basic components, just that when put together in different combinations the components make diverse designs. <div class="Discussion_UserSignature"> </div>

john_316 · May 22, 2006

You would assume that if they go with 125 tons+ then they would be able to create an effective mission profile for the lunar lander, habitats, and even the mining equipment. They could also launch say such items as robotic haulers, drill rigs, and earth movers to begin a permanent stay on the moon. This also makes good for an earth departure stage for a manned mission to mars as they may be able to lift a nuclear core reactor on one lift. <img src="/images/icons/smile.gif" />

frodo1008 · May 22, 2006

It would depend just as much on how much thrust was generated for the upper stages. However, while I am not capable of direct mathematical calculation (as some may be on this forum) let us as they say, reason together here. The latest first stage configuration would now seem to be: Two, five segment SRB's, and five RS68.s. Now: 5 X 665 = 3.325 million pounds of thrust. And: 2 X 3.6 = 7.2 million pounds of thrust. For a total of: 10.525 million pounds of thrust. Now this much thust could probably lift a 10 million pound vehicle off the pad, or some 5,000 standard tons without too much trouble. This is easily 1.5 times as much as the Saturn V weighed. So if the second stage also had some 1.5 times the thrust as the Saturn V second stage (which was 1 million pound of thrust). Then our second stage should be capable of some 1.5 million pounds of thrust. The original J2 used for the Saturn V had a thrust of 225 K and used five such engines for a 1 million pound thrust total (actually 1.125 million, but not to quibble here). I would think that the J2S itself is at least this capable, and an increase to six or even seven such engines would not be beyond NASA's capability, I would think. At seven such engines we achieve our 1.5 million pound capability for the second stage. The third stage of the Saturn V consisted of a single 225 K thrust J2. So I would not think it too very difficult with first and second stages of this vehicle to use 2 such engines. After all, that is what the second stage of the single stick five segment SRB, CEV human carrying vehicle is going to use. So it is concievable that the new vehcle could place as much as twice the payload of a Saturn V into LEO. The Saturn V was capable of placing some 120 metric tons (or at 2,200 lbs per metric ton, some 268,000 lbs) into LEO. So it woudl seem to me that the new CALV with this confi

mikejz · May 22, 2006

I wonder if the CaLV might find itself flying minus the SRBs as a 40-50 ton launcher

frodo1008 · May 22, 2006

An easier and less expensive solution for that level of launcher would be to add more Common Booster Core units to the Delta IV Heavy. If you designed the CALV around a 33 ft in diameter central core taking off the SRB's would make for a very inefficient vehicle at best. At worst it could be a disaster! There was another thread in which advanced designs for the Delta IV Heavy were put forth for the CALV itself, but NASA wanted to go with a design that already included the SRB's (and originally the modified SSME's) to be able to at least use some of the already developed technology of the STS system. However, I personally think that using the five segment SRB's, RS68's, and J2S's is a better solution. And creates a vehicle even more powerful than the original Saturn V. A vehicle that could not only be used for moon exploration but a large build up of Earth-moon system infrastructure as well! Of course, it is eventually possible that Boeing itself might also find uses for beefed up Delta IV Heavy rockets also.

rocketwatcher2001 · May 22, 2006

I can't wait to see this one fly. <img src="/images/icons/smile.gif" /> When is this one going to be ready? <div class="Discussion_UserSignature"> </div>

rfoshaug · May 22, 2006

<blockquote>In reply to:<hr />The CaLV with RS-68's, five segment SRBs and J2X has a payload of about 18,000 pounds less than a Saturn Five.<hr /></blockquote> Why is that? It's sure going to have quite a bit more thrust and (almost certainly) be heavier on the pad than Saturn V, so why won't it carry a heavier payload than the ol' kerosene rocket? <div class="Discussion_UserSignature"> ----------------------------------My minds have many opinions </div>

RS68 confirmed for CaLV

j05h

Guest

erioladastra

Guest

john_316

Guest

rfoshaug

Guest

john_316

Guest

henryhallam

Guest

rfoshaug

Guest

edkyle98

Guest

no_way

Guest

j05h

Guest

trailrider

Guest

mattblack

Guest

radarredux

Guest

mattblack

Guest

frodo1008

Guest

mikejz

Guest

lampblack

Guest

lampblack

Guest

scottb50

Guest

john_316

Guest

frodo1008

Guest

mikejz

Guest

frodo1008

Guest

rocketwatcher2001

Guest

rfoshaug

Guest

Similar threads

TRENDING THREADS

Latest posts

Share this page