Back to the Future, Past, or Something

John · Senior Member

Back to the Future, Past, or Something

Dusty · Veteran Member

Perhaps the something like the BAC Mustard might fit the bill! wink

http://en.wikipedia.org/wiki/MUSTARD

John · Senior Member

The MUSTARD concept is really a little more advanced than what I was addressing. I actual came up with that one myself with the idea of putting two X-33 type vehicle together and sharing fuel mustard style. But, then I later recalled that I had seen a newspaper clipping about the MUSTARD vehicles when I was a kid. (Could this have been subconscious input?) One nice thing about this is that you can have a high parts commonality between the multiple vehicles to get economies of scale.

What I was discussing is a vehicle that is almost identical the actual U.S. space shuttle system in terms of techology-- just a different use of the items. I have little orginal here: take the actual Shuttle, Shuttle C (HLV), and the HL-20 and you able a basis for my concept. It doesn't have the issues with having the big engines in the orbiter (and making them reusable) like the HL-20, it does still have a large payload bay and arm like the shuttle (about 40% of payload), and the booster stack can serve as a medium to heavy lift vehicle without modification (both like and unlike Shuttle-C).

NUKE ROCKY44 · Senior Member

A future winged orbiter will rest in a commercial space venture. Primarily the distinct advantage being deliberate piloted re-entry will carry passengers from one corner of the earth to the other in record time and of course the added feature where passengers witness the 'black sky' of space.

Rather than a tee-off on old arguments why NASA dropped the Shuttle. I'll just
say, main tank issues on all counts is NOT insurmountable by any engineering standpoint. NASA just wants to get rid of Shuttle.

Storage techniques has come a long way since X33. With the help of the automotive industry and X33 it has advanced see: BMW H7

I just see large scale LOX/LH storage of aerospace fuels use on earth and in space as reusable engineering a non-issue.

It's do-able. And it's only gonna get better from a technical standpoint. blankstare

John · Senior Member

That BMW hydrogen tank is interesting. These technologies well be useful in next generation systems when ever we get around to it or when someone does (China?).

I was really discussing an alternative past and looking at something between the shuttle we made versus just expendables. Orion basically just has the crew module somewhat reusable. It has no real cargo capacity. I have I lot less cargo capacity but has reusable crew, support and OHMs (service module). But I use an expendable "second stage" booster.

Of course the past is the past so we won't do this but maybe a good idea for China or Japan.

G R L Cowan · Veteran Member

The BMW liquid-hydrogen tank masses 145 kg empty, 154.5 kg full, so it is not relevant to any hydrogen-consuming flying vehicle.

(How fire can be domesticated)

John · Senior Member

Good point GRLC but they are planning to use LH2 on the new Lunar lander. I'm amazed a the latter.

My point isn't to push a "save the shuttle thread" (I've already done that and Obama is President...even Bush wasn't going my way on that.) Rather I interesting the issue what is that optimium solution for 1970s technology between 100% expendable and 100% reusable. This isn't just theoretical because emerging space programs like China's (perhaps the future in space) are still trying to get to our 1970s level. It also possible if Japan can get over America worship and start to take a stand for themselves even they might do something.

I think the mix I proposed above is a good ROM on that solution. The main point is to take the final stage propulsion out of the orbiter and to scale it back in size. I wonder what the percentage of shuttle missions that really required the 25+ ton capacity? What percent could have been accomplished with 10 tons. Yet, I'd suggest there are good reasons to save some of the shuttle type capabilities. One is the ability to bring things back down. Another is the "arm" to work our on things, i.e. assembly, repair, etc. Finally the long term future is no in expendablies regardless of the near term cost-effectiveness. I think that one thing of values is to get experience with flying a spaceplane type vehicle to get experience with it. Also, my plan would also give a medium to heavy left booster by default.

-- Edited by John on Saturday 27th of June 2009 03:44:37 PM

GoogleNaut · Guru

The machine I envision is similar in many respects to Ares V, however, I am looking at a design that uses two equal volume tanks: the top tank carries 2833 m^3 of liquid oxygen, and bottom tank carries 2833 m^3 of liquid hydrogen. It uses a cluster of 6 or 7 RS-68 fully regeneratively cooled rocket engines for core stage burn, and uses 4 strap on boosters engined with a pair of Russian RD-171M LOX/Kerosine engines. The strapons only contain kerosine onboard (and helium for pump purge,) and the oxygen comes from the core tank atop the liquid hydrogen tank: the amount of kerosine is carefully selected to burn all of the excess oxygen in that core stage (beyond what the RS-68's will burn.) The core tanks are carefully and specifically designed with hatch knockouts so that the whole core tank assembly can be delivered and used as part of the delivered payload of the vehicle to an orbital depot/construction yard.

Delivered payload should be in excess of 200,000 kg in addition to a 100,000 kg core tank.

The strapon boosters, incidently, are single tank vehicles which tends to make simpler the notion of creating a 'flyback' booster concept with them. As single tank vehicles (they don't carry oxydizer) they will be easier to service and propell using a cluster of turbofan engines...

John · Senior Member

Googlenaut,

That is a heavy-left vehicle but I like that concept. I have to admit that I didn't think of that one, i.e. the kerosene only tanks in the strapon boosters. I guess that you could use a common tank for both LOX and LH2 on the core. That should reduce costs (learning curve). The strapons would even be better economically.

Of course in the historical scenario we could use the Saturn V or a close derivative. Presently NASA is committed to Ares V. Your concept has even a greater left capability.

By the way one twist I've been looking at on my system would be to use a modified S-II stage for the core launch vehicle. The idea here would be the same stage except it would only have 3 J-2 engines. Mine is basically medium-left. But, what is nice is that you have the orbiter launch vehicle and the medium-left unmanned in one system giving economies of scale.

GoogleNaut · Guru

The Saturn S-II had five J-2's, so I don't really understand. The stage would have been incapable of lifting itself (and the S-IV and apollo stack) off the ground (its thrust to weight ratio was about 0.9.) Stripped down maybe...

I once read that the S-IC (the Saturn 5 1st stage) with its mass ratio of 15:1 would have been more or less "easily" capable of achieving orbit in one shot...but it could only carry an aerodynamic fairing---and the burnout acceleration (close to 20 g's) would have been tremendous! From ground to orbital velocity in 238 seconds!

My concept vehicle--which I call Antares VI (because it has six RS-68's on the core stage, just like Ares VI) is specifically designed to deliver its core stage propellant tanks as part of its payload. What is specifically challenging is to design the tankage to be 'easily' taken apart on orbit and relatively easily to cut out the hatch blanks and install the hatch bulkheads. Also, surface insulation may have to removed in certain spots and added to others. And then there is the 'pyromechanical' safing--safing and removal of range safety pyromechanisms--that must be done on orbit which has never been done before on any vehicle in history. Because of this, new pyromechanical devices will need to be designed in order that they may be easily and safely removed from a vehicle in orbit once they are no longer needed. And then there is the question of safe disposal of such inherently high energy material...probably by stuffing it into a Soyuz-like vehicle for reentry and burnup in Earth's atmosphere...

The whole idea of delivering the tankage to a space depot facility is so that the tanks can be used as modular components for expanding that facility and as core components for assembling large, space bourne vehicles. The tanks are already designed to handle large forces (pressure and thrust loading) so it would be a cinch to use them as the core building block for a much larger, nuclear powered vehicle intended for deep space missions. The design of this modular, expandible vehicle architecture is already underway.

And then there is the design of vehicle RCS/OMS (reaction control system/ Orbital Menuvering System.) I think that reusable pods could be used, and that these systems will probably rely on perhaps gasseous Hydrogen and Oxygen for propellant, although a LOX/Ethanol, or LOX/LCH4 system isn't out of the picture either. I'd like to get away from N2O4/MMH (nitrogen tetroxide and monomethyl hydrozine) both of which are corrosive, toxic, and very expensive ($500+ per gallon.) The necessary complexity of ground service needed to inspect and repair the vehicle plumbing for leaks caused by propellant corrosion is a substantial labor demand for the Space Shuttle. NASA has wanted to eliminate or atleast reduce the demands for these hypergolic propellants for a long time.

-- Edited by GoogleNaut on Sunday 28th of June 2009 04:59:43 PM

John · Senior Member

To answer your question, the reason to reduce to 3 engines is the needs the "second stage" through requirements. The vehicle has two large SRBs strapped on just like the Shuttle to give lift off. The arrangment is much like the Titan III & IV. I was just speculating if the tankage of the S-II would be usable. It very likely that we just need a new stage for this vehicle.

That's a good question as to how much the hypergolics thrusters cause maintenance problems vs. the fuel pumps and main propulsion system on the orbiter. If you are going to use non-hypergolics isn't there and ignition issue with thrusters used repeatedly. The tile damage would be greatly reduced by having the orbiter above the LH2/LOX booster which be expendable.

Really our concepts are for two different purposes. You really have an alternative to Ares V or a future replacement. I'm looking at an alternative history. In that context I would have abandoned Saturn V or Apollo. But, the Apollos would be for Moon missions. Large space station components would be put up by Saturn Vs. The small module could be launched with the vehicle I propose sans orbiter. Orbital missions would use the orbiter, which would carry supplies for the station, packages up to 10 tons, and stand alone missions.

-- Edited by John on Sunday 28th of June 2009 05:43:11 PM

G R L Cowan · Veteran Member

GoogleNaut wrote:

... And then there is the 'pyromechanical' safing--safing and removal of range safety pyromechanisms--that must be done on orbit which has never been done before on any vehicle in history. Because of this, new pyromechanical devices will need to be designed in order that they may be easily and safely removed from a vehicle in orbit once they are no longer needed. And then there is the question of safe disposal of such inherently high energy material...probably by stuffing it into a Soyuz-like vehicle for reentry and burnup in Earth's atmosphere...

More likely one would go to pyromechanical devices based on a mixture of coarsely particulate fuel and frozen or liquid oxygen. They would not need to be removed, just their refrigeration -- if they have it -- turned off. If they are cool only because they have stored coolness, their self-disarming is just a matter of time.

(How fire can be domesticated)

GoogleNaut · Guru

Those fuel-oxygen mixtures tend to be extremely sensitive to shock. A single spark, friction, or crinkling motion of the shifting tank could set it off.

This is why typical linear charges for range safety and stage seperation are typically composed of something like PETN (pentaerythritol trinitrate) in a thin, hollow plastic tube (like det chord) which is used to initiate a slightly larger, roughly triangular shaped charge of similar formulation, molded into a metal tube, bonded to the part of the stage to be cut. The det chord is itself intiated from both ends simulataneously by two NASA Standard Initiators--explosive power cartriges that are electrically fired. This affords a good deal of redundancy. The charge is designed to slice through a tank, fairing, or other structural load bearing component on a rocket. The charge is surgical and much testing determines the minimum amount of explosives needed to accomplish the job--and it is usually a suprisingly small amount...typically no more than 20-50 grains per foot: or to put in another way, a linear charge used to seperate the 33 foot diameter Saturn IC first stage from the Saturn S-II second stage was less than 12 ounces of explosive!

PETN is a very stable, if not forgiving explosive. It can be rubbed, pinched, and even burned, but detonation will not occur unless one or both NASA Standard Initiators are fired. The technology of explosive bolts and linear shaped charges is a very mature and safe technology. Just for my purposes, a way needs to be found to safe the unexploded ordenance, remove safed initiators, and then remove the linear charges. Only then can a tank be safely used for human habitation...

John · Senior Member

Googlenaut, Im coming around to having some appreciation for your idea of strap on kerosene/LOX boosters that get the LOX out of the main vehicle. I understand that the old Soviet Union had a big project using this concept before their collapse. I also understand that they had a plan to recover and reuse the central LH2/LOX stage. Since the whole thing didnt get that far into the flight test program its a little unclear to me how well it would work.

Another, claim (at this point I hesitant to use the work fact for this) is that although the Space Shuttle SRBs are reusable that the total cost of recovery, refurbishment, etc. make this process as expensive as just using throw-away SRBs. Has anyone any thing on this?

On balance I still think that my alternative to the Space Shuttle would have been a totally feasible and more cost-effective approach. It could have been done with the 1970s technology or by China today. It would even be better than the Orion/Ares I if Obama doesnt go forward with the Ares V/return to the Moon. Obviously my orbiter would be too heavy for the Moon vehicle and it is not for that purpose.

-- Edited by John on Saturday 18th of July 2009 02:38:05 PM

GoogleNaut · Guru

Just yesterday I used some stress calculations to find a good pocket size of 20 cm (along circumference) by 26.58 cm (along X axis length of vehicle) by 1.9 cm thick plate for the skin of the vehicle. Each orthogrid plate will be composed of 14 wide by 15 long pockets (each 20cm by 26.58 cm) machined into an Al 2195 T4 plate about 3 cm thick. 12 plates are welded together to form a 'barrel' segment, and five 'barrels' will make up the body of the propellant tank.

Of course, not being an engineer, I have to say I don't know what I am doing. But I am learning by doing, and having fun trying! :)

Ty Moore
"GoogleNaut"

NUKE ROCKY44 · Senior Member

ET assembly

...found link recycling of Shuttle ET. This pic is from Dave Hunt site. I still think ET can be recycled it would mean more expense initially but the trade offs would gain later.

The other modification to ET from a blog is the use of a faring (cap) covering the tip of ET down to upper boundary of intertank and a collar covering the tank-orbiter forward attachment this they say, effectively can divert turbulence (tank foam debris) away from orbiters tiles all together. I thought they had tested these modifications ideas awhile back in wind tunnel tests.
I guess if the side saddle approach like what John Franz posted was adopted then wouldn't ET need to be re-designed??

GoogleNaut · Guru

I've seen this proposal for ET use, and have heard of the 'aerospike' method too.

A long time ago, NASA publically stated that if anyone or any company could find a way to use an ET on orbit, then they could have them for free.

The catch: The ET becomes the sole property of the person or organization using it. That sole person or organization is entirely responsible for anything that can happen as a result of the ET falling back to Earth. And so--the organization that posesses the ET must demonstrate the ability to control it at all times, and dispose of it in a controlled and safe manor.

NASA goes to great lengths to ensure that each ET is safely disposed of, which is why none has been allowed to enter orbit at all (all trajectories intersect the atmosphere over the Indian Ocean.) The OMS must perform a 'circularization burn' to raise the altitude of the perigee (or periapsis as it is sometimes referred.)

The fact that no ET has infact been used in this manner is indicative of the tall order of safety that must be applied, and liability that is necessarily assumed by the controlling organization. Also, there is the question of long term stability of the polyurethane foam insulation in vacuum conditions: no one knows how long it can last in vacuum, but everyone knows that millions of hunks of foam floating around in low Earth Orbit is very, very bad! Orbital debris mitigation right now is a high priority of any mission planner.

The side saddle approach is the main problem resulting in debris strikes: it places the fragile vehicle (the orbiter) in an area where any debris is likely to cause multiple strikes (ricocheting between vehicle and tank) and more damage. Placing the orbiter vehicle on top of the stack is the only way to wholly eliminate debris strikes from the tank. This would require redesigning the whole 'stack.' Interestingly enough, one of the early designs for the Space Shuttle using a Saturn 5 booster placed the shuttle on the side of the ET, but the ET was on top of the Saturn 5 booster. I'm not sure if the Shuttle's engines ran concurrently with the booster or were 'air ignited' at altitude when the booster was jettisoned--it was a strange concept though...

NUKE ROCKY44 · Senior Member

I can understand the safety issue of ET in space with the present design. But what I don't understand is why the design of the ET can only be used with an external insulation configuration. My take on the issue is not enough engineering work is applied to the ET and is shouldn't be an issue of ET engineering weakness.

For your FYI NASA did a study for the side-mount proposal [view here] NASA WATCH. If the Shuttle HLV were adopted some modifications would have to be made to the ET anyway. So why not provide some shielding to prevent foam debris and in the future allow for redesigned ET to be released at a predetermined orbit and allowed to go in orbit for a space tug to begin collecting this vital structure for future uses. That for all practical purposes is already in space.

GoogleNaut · Guru

In actuality--a side mount cargo pod could be designed to be 'tough enough' to withstand expected strikes from foam and ice, and still deliver a nice, hefty payload to low earth orbit: the thing is not designed to come back anyways, so basically, who cares if the aeroshell has a big, fat dent in it. It's gonna burn up anyways!

Simply by removing the orbiter, with its fragile, precision, human carrying flight surfaces, you have removed essentially 100% of the risk associated with debris strikes. So no further mod of the tank is needed...

As far as internal structural modifications to the tank: I think they will be pretty slight because the cargo pod will have a similar mass to the payload carrying orbiter: the primary difference will be the payload to cargo-pod mass ratio. The main mass difference will be from the lack of heat shield and wings (and landing gear.)

On a side note, on the launch vehicle I am working on, I am looking at an integrated semi-rigid external insulation panel which will double as a an orbital Whipple Shield for micrometeoroid protection...I always try to think of multiple uses for the same intrinsic system: the savings in mass and the economy of simplicity dictate that if a system can be used for multiple purposes, then it makes sense to do so.

NUKE ROCKY44 · Senior Member

Well I guess your Whipple suggestion seems to advance the dual or triple use of space equipment hurled into space .

I just see a clear separation and philosophy distinction.

I'm more of an in-orbit constructionist to achieve human access in space since it's more than a one shot contract with the commercial satellite aspect of civilian/military EELV's.

Yes, EELV's has a spot lower cost component compared to the dual use engineered in-orbit space equipment. EELV's tend to increase recyclable debris at LEO.

I think if you're in the in-orbit constructionist camp no dual use equipment is expendable and allowed to float freely in space. And costs will be reduced because you're maximizing delivery of quality equipment on every launch, increasing mission efficiency, employment opportunities and contracts for private companies who can service space recyclables.

The complexity of human missions demands this equipment be made available.

GoogleNaut · Guru

That is the essence of my philosophy: I try to seek ways to design things so that they can serve other purposes once the primary mission is accomplished. For instance, the five 32 inch (.99 m diameter) liquid oxygen supply lines will be designed to serve as pressurized human companionways: with the addition of bolted flanges, it becomes possible to use these LOX conduits to become service corridors, accessways, and passeges between pressurized modules. Once one starts thinking in terms of reusability, then it becomes fairly straightforward to design for reusability. In this way, every launch to an orbital station will bring a basic 'kit' of construction supplies. Not all components may be reused, but things can be taken apart, modified, refabricated or machined, and welded back together. Ultimately scraps too small to be usable for much of anything could be melted in a solar furnace and spin cast into something else entirely...the idea is to maximize the delivered mass.

NUKE ROCKY44 · Senior Member

"...LOX conduits to become service corridors, accessways, and passages between pressurized modules."

Googlenaut, this is a good example of reusable dual purpose space equipment.

"...the idea is to maximize the delivered mass."

I agree. But why can't NASA and its contractors or RSA, ESA project develop this equipment??

Answer: the brain freeze of status quo space politics.

"Sources familiar with the review say U.S. outreach and cooperation with international partners on space activities is an area ripe for study, as is reform of the U.S. export control regime with regard to commercial communications satellites. In June, the U.S. House of Representatives approved legislation that would give the administration authority to remove commercial satellites and components from rigorous State Department export licensing requirements.

Other topics on the table include commercial remote sensing, technology industrial base and acquisition reform, the need to maintain two expendable launch vehicles and a review of the Bush administrations stance on weapons in space."

[LINK]

It seems clear the area of dual use in-orbit recovery of equipment for future use between the international private and public space organizations would benefit all involved. Effectively distributing the expense around without one company or nation having to do most of the heavy expense.

In order to build in-orbit infrastructure to moon, mars, asteroids and beyond ITAR will have to be changed to reflect a new dynamic in space.

"...a review of the Bush administrations stance on weapons in space."

Wonder if nuclear space technology will again come under the misguided category of 'weaponization' of space thus forcing politicos to disapprove of peaceful reactor uses in space.

But I've heard the over used word 'change' before-not too hopeful.

GoogleNaut · Guru

Well, this is an instance where I believe it will take an organization with leadership to simply state: "we're going to do it anyways." It takes guts and it means taking risks, not just with developing new hardware, but also taking financial risks probably on a scale never before possible. If an organization can do that, then perhaps the 'Leaders" will follow. Afterall, change sometimes happens only because someone spearheads an effort, and the "legislators" then --sometimes reluctantly-- follow to catch up. We have always lived in an age of "relevence," and if We (humanity in general; US in particular) wish to continue to be 'relevant' then we'd better get onto the business of relevent things!

I would like to see a commercial entity form that can do just that. We've recently seen some absolutely vast failures and similarly epoch swindles (Bernies Maddof) that are literally threatening the national security of the US because they are so huge. The space program has always been thought of as inspiration for the younger generation--but it has to be much more than that: it has to be the new generator of future wealth for the economy. To do that--it must have a much larger budget: atleast 5 times bigger than what it currently has, 10 would be better. The idea is to start something akin to a new "Hudson Bay Company" to build that space infrastructure. This will stimulate the economy, it will create jobs, and it will create wealth for all.