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#51 2005-02-22 23:33:21

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,934
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Re: New Space Shuttle

Nuclear engines for everyday reuseable ground launch don't make sense. Mainly because nuclear engines, while efficent, have difficulty making much thrust without the reactor becomming very big and heavy.

There is also the radiation problem, that the reactors would produce huge amounts of radiation that you would need a very heavy shield to protect the crew during flight, and heavy shields around the engines to protect the ground crew after flight. A nuclear reactor still produces vast quantities of radiation for several months after being shut down.

Nuclear rocket engines will also probobly leak small quantities of radioactive material naturally, even during normal operation. This will present a sizeable environmental issue that the enviro-mentalists (they really are mental) use to easily stop the project in the courts like they do commertial power plants.

And if the thing blew up... well... that would be a a bad thing.

What about Timberwind? That was a particle bed reactor with much lower reactor mass. Yea, the radial flow particle bed had the problem of creating hot spots between particles that boiled liquid propellant to gas, then the gas bubble prevented coolant from reaching that spot so the particles melted together. There must be more reason for dramatically reduced reactor mass than particles vs. hexagonal rods. I think it used highly enriched uranium that didn't require a moderator, so it didn't need all that graphite of Nerva. Couldn't you design a reactor as light as Timberwind with controlled flow channels that don't melt?

The best radiation shielding is liquid hydrogen, which is propellant for a nuclear thermal rocket. The propellant tanks themselves are shielding, you don't need more shielding. Ground crew? How about launch from Jackass Flats?

Nerva encased all its uranium in ceramic so strong that it could fall out of the sky and strike the ground without cracking the ceramic capsules open. Spew capsules all over the debris field, but each capsule intact. Using that same ceramic capsule, how much radiation would leak?

Blow up and environmentalists? I remember when Cassini launched people were screaming and crying. (sigh) I like to keep our environment clean, manage resources responsibly, and all that, but let's separate fact from fiction. Uranium safely encased in such capsules wouldn't be more dangerous than debris from an airline crash. Do you really want to poke around with sharp jagged metal all about. With an airliner full of fuel soaked into the ground, do you want to smoke or poke around wiring harnesses still connected to live batteries? Neither poke around uranium fuel capsules strewn around. But I do expect activists to panic. (Ooh! Someone said the word "noockyoular"! Flagellate yourself and say 100 Hail Marry's to cleans yourself.)

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#52 2005-02-23 00:48:20

Euler
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From: Corvallis, OR
Registered: 2003-02-06
Posts: 922

Re: New Space Shuttle

I still have to work out the hyd/oxy storage and useage.  It very well may not work.

For a typical SSTO using O2/H2, the fuel and oxydiser take up close to 90% of the total vehicle weight.  Basically you will need 100x more fuel than you were expecting to use.

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#53 2005-02-23 07:18:29

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

No no Robert, that post was about reuseable NTR engines for ground launch, deagle here is talking about an expendable NTR engine to boost cargo from mid-suborbital to Lagrange to save on vehicle mass. But anyway...

But I stand by my old post. The biggest problem for both ground launch and suborbital TLI injection are the consequences of failure... There are different levels of radioactive, the Plutonium in RTGs isn't so bad and there is not enough of it to pose much of a hazard. A fresh, new, nuclear reactor that hasn't ever be activated is even less radioactive, since Uranium-235 has such a long, long half life.

BUT, there is one thing that does scare me, and that is a nuclear reactor that has been activated and either is or had been running recently. The nuclear reaction itself produces a veritable sea of hard gamma and neutron radiation and even after the reactor is shut off it continues to produce extremely large amounts of radiation.

"Nerva encased all its uranium in ceramic so strong that it could fall out of the sky and strike the ground without cracking the ceramic capsules open. Using that same ceramic capsule, how much radiation would leak?"

The answer is too much, for example... If you were to be in the same room as a recently spent fuel rod of HEU, you would die. If you were close enough to touch it, you'd be dead inside of the month, if not by the end of the week. If you walked within a few feet, you would have debilitating radiation poisoning. If your house was within a block of the rod for a few weeks it might also sicken you or at least render you sterile or kill fetuses. It makes me even more nervous if only a few of the capsules did fail on impact, and their contents were dispursed.

This is a whole different level of radioactivity, far beyond the pansy whining of environmentalists concerns about RTGs and even beyonds the pins-and-needles of power reactor rods... enough to make me (N = Nuclear) wary of the idea. This amount of radiation does have to potential to kill hundreds outright. This is doubly bad for NTR engines, since they use HEU and have such high fuel burnup they produce lots of waste very fast.

This is a little different from pebble-bed power reactors, like the ones in Germany, South Africa, and China, because it uses pure HEU and not 3-5% enriched, and hence each pellet produces and contains an order of magnetude more radiation. If the hundreds of pellets were dispursed over a populated area, and they did remain intact, I fear that you would at least have many cases of severe radiation poisoning... And if the pellets failed, well, you are going to need a bigger mourge.
---

"The best radiation shielding is liquid hydrogen, which is propellant for a nuclear thermal rocket. The propellant tanks themselves are shielding, you don't need more shielding."

Not true, liquid hydrogen is a good shield per pound, but a lousy shield per volume, and is better suited to particle radiation. So even if you made a very complex tank shape with a "cup" for the engine, the tank itself won't be big enough to block much radiation from the sides, nor would it block radiation from the bottom of the engine. It gets better, that when you have nearly expended the fuel and the tank is almost empty, the crew won't have any shielding left now would they? You definatly wouldn't have any for the ground crew if you recoverd the spent engine.

But most of all, NTR engines don't offer a compelling advantage for launch versus chemical fuels because of the high mass of the reactor versus a chemical engine of comperable thrust and the size of the tanks involved for all-LH2 flight. Its just not worth it, you might as well use a bigger LOX/LH2 rocket then a smaller NTR one for launch duty. The radiation & handling procedures for an NTR RLV kill that idea completly too.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#54 2005-02-23 12:02:32

RobS
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From: South Bend, IN
Registered: 2002-01-15
Posts: 1,701
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Re: New Space Shuttle

Dook, regarding your masses, those question marks for hydrogen and oxygen are the killers, believe me. So far, you've built a huge airplane basically to lift NASA's space shuttle to 200,000 feet. The space shuttle's mass, however will not decrease as much as you have increased it by adding airplane wings and turbojet engines.

I agree with GCN regarding nuclear thermal engines; you can't use them below LEO.

By the way, do you know about the use of natural logs to compute the relationship between fuel mass and specific impulse? You'll need that to come up with semi-credible numbers.

         -- RobS

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#55 2005-02-23 14:31:52

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

Its much much worse then that Rob, Dook wants the whole shuttle and the LOX/LH2 tank to come down as a one-piece lift body.

Plus have enough fuel to put the whole vehicle in a highly eliptical orbit ~50,000-75,000mi high at apogee.

And have enough left over to put a payload at Lagrange with only a modest expendable kick stage.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#56 2005-02-23 17:25:59

Dook
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From: USA
Registered: 2004-01-09
Posts: 1,409

Re: New Space Shuttle

Since you love to sit back and snidely criticize rather let me point out some of YOUR MISASSUMPTIONS. 

The mass of my vehicle was in the very first post and has been stated many times.  Also the masses of every component, except the hyd/oxy fuel.

It would be a lifting body so it would have a lot of room for fuel.

I said the vehicle would turn around, fire it's engines to slow before re-entering the atmosphere plus it could fly in with the engines at an increasingly shallower angle to lessen the re-entry heating.

SpaceShipOne went over 300,000 feet then came straight back in with no ceramic tiles.

GCN Geek Boy:  Why don't you come up with a new idea for once?  Contribute to the improvement rather than rant and rave like a spoiled 17 year old with nothing better to do than jump on every post like you know it all.  You obviously know more about space launch systems than many of us but this is just a once in a while hobby for us while it's your entire life and what have you done?   

RobS:  Yeah a quick check on the weight of the Hyd/Oxy tank is coming in at over 300,000 pounds, so it's too heavy.  It would provide 2.5 minutes of total thrust, say 1.25 min up, coast, deploy cargo, coast back, then fire for 1.25 minutes to slow on re-entry. 

I may look at using some kind of lifting vehicle to see if that is better.

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#57 2005-02-23 18:09:32

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

Then you have designed your ship all wrong. You do not design the ship, and then decide how much fuel you need. The first thing you do is characterize your payload, and then figure out how much fuel you need, and then figure out how big a space ship you need to hold it. Then you recalculate the whole thing to take into account the vehicle empty mass plus an estimate for how much more you need for the fuel/engines to carry the additional fuel needed to carry the vehicle without payload.

In essence, designing the rocket from the payload down, not the first stage up. This is how it works. It is a consequence of the rocket equation, which states basically that the mass of your ship empty + payload is a constant fraction of total vehicle mass (ship/payload/fuel) for a given specific impulse and Delta-V (velocity, corrected for atmospheric and gravitational losses).

Even a lift body shaped like the X-33, which is about as big as it practically gets, is not all that big compared to the insatiable demand for bigger hydrogen tanks. You also want your vehicle to be as small as possible to reduce how expensive it is to build and to waste as little of its empty mass (theres that rocket equation again) on fuel tanks and support beams.

Remember this: the rocket equation does not treat the payload mass and vehicle mass seperatly, it tells you only how much total empty vehicle mass you can push for a given mass of fuel to a certain speed. So, your payload is simply whatever you have left over from your empty vehicle mass "budget."

"SpaceShipOne went over 300,000 feet then came straight back in with no ceramic tiles."

Space Ship One's reentry speed was about the same as its top airspeed, or about Mach 2.5-3.0 aproximatly. A spaceplane like yours on the other hand would reenter at Mach Twenty-Five to Thirty. You would obviously need a pretty good heat shield.

You can't really use rocket engines to slow your reentry because that would take too much fuel. Mathematically, it would greatly increase the Delta-V requirement for your ship, since instead of letting the Earth's atmosphere slow you down, you instead have to burn rocket fuel to do it.

Your spaceplane would simply be too huge to pack all this extra fuel, and since your mass would decrease compared to your surface area, your ship would be so light that it would experience very high deceleration loadings during reentry, and crush it like a tin can. Also, since you will be reentering from such a high speed, you can't reenter on a very shallow trajectory, because you will simply skip right off the atmosphere and back into space.
---
As far as what I suggest, I think that a two-stage spaceplane is the best bet with today's technology. Something akin to Germany's Saenger-II concept, where a large supersonic carrier plane would carry a modest lift-body spaceplane on top to a fairly high altitude & speed, then seperate and send the spaceplane to orbit.

The carrier plane would have two possible propulsion schemes: either powerd by a larger, higher performance version of the SR-71 Blackbird's engines which combined turbine and ramjet engines in the same package, perhaps boosted with liquid oxygen... or, stick with advanced turbine engines, and include a small number of large LOX/Kerosene reuseable rocket engines in the rear of the plane for the sprint to seperation.

The spaceplane would be a pointy lift-body, powerd by conventional-style bell nozzle hydrogen rocket engines, except the hydrogen would be stored as a slush to improve density to reduce vehicle size. The heat shield would be all metal except on the nose and leading edge, and two models would be built, one purely for cargo (Proton sized) and one for crew (12 w/ airlock).

The carrier plane would also make a truely devestating, almost-unstoppable bomber for the USAF with its huge possible payload. Something like a hypersonic B-52, only with even more bombs.

Much has been touted about Scramjet engines, but it is generally agreed that they cannot reach speeds much beyond Mach 15, which isn't fast enough for a practical single-stage spaceplane. An advanced concept, a regenerative scramjet which uses the vehicles' own air friction to boost efficency, would be extremely difficult to do and is beyond our technology. If you go two-stage, you might as well use regular rocket engines instead of Scramjets for the upper stage.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#58 2005-02-23 18:27:37

Euler
Member
From: Corvallis, OR
Registered: 2003-02-06
Posts: 922

Re: New Space Shuttle

Dook, you won't be able to make any useful contributions to discussions about launch vehicles until you familiarize yourself with the http://en.wikipedia.org/wiki/Rocket_equation]rocket equation.  The constraints placed on rockets by the rocket equation mean that an orbital launch vehicle’s mass will always consist mostly of fuel.  In fact, there has to be so much fuel that most of the non-fuel weight will be taken up by fuel tanks.  If you ignore fuel and fuel mass ratios and instead only concentrate on engines and thrust, your designs probably won’t be capable of reaching orbit.

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#59 2005-02-23 18:31:55

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: New Space Shuttle

So for a spaceplane idea how about this
http://www.bristolspaceplanes.com/proje … l]Spacecab

Still will anyone put the cash to develop such a plane especially as there will still be a need for a heavy launch cpacity that TSTO spaceplanes just cannot deal with.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#60 2005-02-23 18:42:18

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

Its the right idea, but it is too limited in performance, probobly because it doesn't use the latest, best technology available.

I think it is plausable for a TSTO spaceplane to be built that could carry a similar payload as the Proton or Atlas-V 55X rockets. It would not be intended for heavy lift, instead making up for it by repeated rapid turn-arounds for a very small per-flight cost.

The secret will be to keep the upper stage dry mass down with advanced composits and using slush hydrogen to reduce tank and structure mass. SpaceCab's upper stage is of the same order of magnetude required, but it would need to be bigger, and use the best of what we have available today.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#61 2005-02-23 18:48:08

John Creighton
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From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: New Space Shuttle

Gypd, I like the space plan concept. I do wonder why this plane could survive reentry and not space ship one. They sound like they know what they are talking about. If the development cost is only a billion like stated, the vehicle meats human rated safety stands and considerably lowers the cost LEO it could be worth while it will to develop. Such a vehicle would lower the cost of space tourism and might make it practical to build silicon chips in space for the next generation of computers. I am more interested in reaching mars then being able to ferry a few hundred kilograms to LEO but considering how many billions were spent on the ISS and it cost a billion dollars for each shuttle flight to the ISS it should be obvious how such a vehicle could conceivably make the science on the ISS cheap enough to make sense. I would suggest that NASA guarantee a contract for a company that could develop such a vehicle provided it lowers the launch cost by atleast an order of a magnitude and has acceptable safety margins. Perhaps 800 flights contracted per year at a 100 thousand dollars per flight.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

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#62 2005-02-23 18:57:00

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

SpaceShipOne doesn't have the swept delta/lift body shape, and since it is so small, it can't use a metal heat shield.

The SpaceCab people are dreaming (a little too) big, but they have the right idea. The problem is, that going through all that trouble to build a huge supersonic plane and the delicate upper stage don't make sense for just a few crew at a time or a few hundred kilos.

The problem with simply offering big contracts is that no company will put up only their own money to take a shot at it, that the risk is far too high.

Eight hundred flights a year? No way. Perhaps a hundred for early Lunar development and another 50-100 more for mid-term Mars base flights if it were as big as it should be (Proton sized payload) and another 50-100ish for commertial flights... 50-100 for military... Maybe 400-500 tops. With weekly flights, that means 8-10 copies of the vehicle.

The target price being $20-25M a flight or lower, including all operational costs and amoratizing development & construction over the life of the vehicle, minus whatever the government is willing to chip in to get the thing fly.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#63 2005-02-23 19:41:21

John Creighton
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From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: New Space Shuttle

The problem with simply offering big contracts is that no company will put up only their own money to take a shot at it, that the risk is far too high.

Well, that is a problem because I don’t think NASA should take the risk because it has enough challenges with the vision for space exploration. With such a limited capacity for delivering mass to LEO the vehicle does not fit into the vision for space exploration. It is more suited for space tourism, ISS science, and small light zero G material production. NASA could provide grants or loans or even promise some contracts upon completion but I don’t think it should absorb too much of the risk. If this thing can do what they claim it should have commercial applications. Perhaps some public subsidiary could be created with an initial public offering to absorb some of the risk and raise part of the required equity.


Eight hundred flights a year? No way. Perhaps a hundred for early Lunar development and another 50-100 more for mid-term Mars base flights if it were as big as it should be (Proton sized payload).

At a billion dollars for development cost, in order to reduce the cost by an order of magnitude or more the development cost must be amortized over many flights, either via one vehicle or many. For a billion dollars development the vehicle must take in a revenue of 100 million dollars a year. For 10 flights a year that would be 10 million dollars a flight. Doesn’t Soyaze already cost 10 million dollars a flight. So in order to drop the cost be an order of a magnitude at least 100 flights are required per yer. 1000 flights per year would do a much better job of amortized the development cost and keeping the launch cost near the marginal operating cost. If NASA did purchase 800 flights a year then it could deliver 240 tons of fuel to LEO per year. Maybe that would not be required for a moon mission but would be fairly useful for a mars mission. If NASA is not exploring mars at this stage perhaps it could set aside a billion dollars a year for ISS science until mars exploration begins.


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#64 2005-02-23 20:02:07

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

Oh no, NASA shouldn't even be dreaming about an RLV any time soon. Large expendable rockets are much better suited to setting us up on Moon/Mars/etc to have a destination to fly an RLV to in the first place. VSE with expendable rockets is probobly cheaper from a development point of view too, as far as technology per dollar you get.

I think that a weekly flight schedule is a good benchmark. A persuit orbit to get from the ground to an orbiting rendevous point will take a day or two to get up, a day on station, another day to allign orbits in order to deorbit back to the launch spaceport. One day for systems check to reload consumeables, one more day for integration to the carrier plane and payload loading, and then one more day for misc. preperations for rollout and fuel tank prechilling. Once or twice a year, the vehicle would be taken out of service for one to two weeks for maintenance and a more thurough systems inspection.

I think that the SpaceCab $1Bn estimate is a little low, and the true cost to build a worthwhile RLV that is rugged, efficent, and not absurdly big will be much higher, probobly in the $15Bn range if built by "typical" government procurement methodology. Each copy would probobly be in the $1-2Bn range too (if you count that you need fewer carrier planes then space planes).

Assuming that a spaceplane combo would last ~10 years (500 flights) each and ten such spaceplanes are flying weekly, then that is $10.0-12.5Bn per year in revenue at $20-25M per flight. Its doable.

For the reccord, Soyuz-TMA costs somewhere around ~$40M a pop or around $30M for the all-kerosene R-7 rocket by itself.
---
Unless something extremely valuble were discoverd that could only be made in space, SpaceCab doesn't make much sense. It can't deliver much payload or crew, and a vehicle not much bigger with more advanced technology could deliver much more payload. There also isn't much need for launching that many people or little satelites or tiny ISS payloads... payloads even smaller then the Progress cargo capsule Russia launches.

SpaceCab is little more then a copy of the Concorde airliner with a rocket bizjet on top, it would definatly need to be bigger to support a useful payload.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#65 2005-02-24 01:18:10

John Creighton
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From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: New Space Shuttle

You numbers look reasonable. It is interesting to see with all those flights that the reusable launch vehicle concept proposed wouldn’t do any better then the soyaze. Your suggestion that it would cost a billion dollars to produce each vehicle is also discouraging. I think the b2 bomber might of cost a billion a piece but that must of partly included development cost.

If the goal is to truly lower the cost to space the cost of producing the vehicle most also be lowered. I believe this can be done, but I agree that at present NASA should focus on the VSE first. Then once it has a place to go it can build a better reusable launch vehicle that is equipped with scram jets and aro spike engines. Such a vehicle would probably not even need the two stages.

Away it is a shame though the ISS was built and there is no reusable launch vehicle to properly utilize its potential for industry, science and tourism. It is not the station I would of built if I would of even built a station but it is there. Hopefully before it burns up in the atmosphere some private industry will build a RLV.

Since the markets are largely unknown the risk is probably too big for a private business to independently build a reusable launch vehicle. Bellow I am quoting some information about material production in space. Just think how many microchips could be produced with 300 kg of silicon that formed a perfect crystal. If such a crystal could be produced within the turnaround time of a reusable launch vehicle(about a week)  and the chips made from the perfect silicon crystals had a market and superior performance then I think the chips produced could be enough to justify a space industry. What do people pay for each Pentium chip 500 dollars? How big is each chip? The size of a thumbnail?

I do think there is potential for a zero g fabrication industry. I do think a space station could help sustain such an industry. However, I think that the ISS was badly designed and built at the wrong time. It should have been built after the moon and mars bases and after a reusable launch vehicle. It should have been lifted via a heavy launch vehicle, it should have had larger more independent modules and it should have had its own engines so it could lift its own orbit if desired. Anyway, I degrees.


In order to fully allow and facilitate the commercialization of the tremendous potential market
of space, the cost of the basic space infrastructure must be reduced dramatically. The government
will also be required to play a role to promote, entice, and aid the development of a private sector
presence in space. The Commercial Space Center for Engineering (CSCE) examines the experiment
options and costs for industry clients, always keeping the clients’ constraints in mind. The
main focus of the CSCE is to utilize the platforms of the ISS to experiment on new or emerging
technologies for industry payload research.
The unique near-zero gravity of space would allow industries to manufacture new materials
simply due to the fact that the absence of gravity allows for the creation of perfectly even and consistent
mixtures of materials with vastly different mass and densities. These alloys would have
“unique physical properties no nation on Earth could duplicate” and could lead to the production
of much faster computers, smaller and much more powerful batteries that could power future electric
cars, and many other new products.
It would be useful at this point to summarize a sample of the potential advantages and products
that may be produced in a microgravity environment.
1. Immune response understanding leading to viral infection antibodies or vaccines
2. Synthetic production of collagen for use in constructing replacement human organs (e.g.,
corneas)
3. Manipulated differentiation of plant cells to produce desired chemicals (e.g., cancer-killing
drugs)
4. Production of targetable pharmaceuticals (cancer cures)
5. Protein crystal formation for structure identification (structured biology)
6. Protein assembly
7. Growth of large pure electronic, photonic, and detector crystal materials (computer chips,
quantum devices, infrared materials)
8. Ultrapure epitaxial thin film production in very high vacuum (e.g., wake shield facility)
9. Production of perfect solid geometric structures
10. Manufacturer of pure zeolite crystal material for filtration applications (pollution control)
11. Manufacture of polymers with unique characteristics
12. Electrophoresis for separation of microscopic components within fluids

http://techreports.larc.nasa.gov/ltrs/P … ...ev1.pdf


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#66 2005-02-24 07:26:06

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: New Space Shuttle

I agree with you GCNRevenger on "the target price being $20-25M a flight or lower, including all operational costs and amoratizing development & construction over the life of the vehicle, minus whatever the government is willing to chip in to get the thing fly." But why has Nasa not gone after that very same issue with the cost of the currently available launchers that they have at there disposal(Delta,Atlas, ect..).

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#67 2005-02-24 08:33:49

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

I don't believe you fully appritiate how good of a deal the EELV rockets are versus their older counterparts. You do get quite a bit of payload per dollar versus older launch vehicles. The price for a single Titan-IV was pretty high. The EELVs are also still in their early years, and could become much more powerful without a corresponding price increase.

Ultimatly, I don't think its practical to make the rockets themselves far cheaper, with Elon Musks' Falcon rockets probobly skirting the bottom edge of whats possible for an American company.

NASA shouldn't be working on any Shuttle-II at the moment since you would need some place to fly it to first. Either fuel for a large Mars ship (powerd by a GCNR engine?) refueled in Earth orbit, sending mining equipment to a Lunar base via ion tug to, a fuel depot in LEO maybe, that sort of thing... which are better set up by large expendable rockets


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#68 2005-02-24 11:16:20

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: New Space Shuttle

Seems NASA is now looking for a more cheaper option for its flights to the ISS and into LEO.
http://www.space-travel.com/news/rlv-05a.html]Spacerace 2

Still for any TSTO RLV to make a real commercial reason for existence it must have a place to go. But frankly I find that the ISS will not require such a creation. Still hopefully in the future with the increased launches of people needed a decision to build such a spaceplane will come.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#69 2005-02-24 17:25:49

publiusr
Banned
From: Alabama
Registered: 2005-02-24
Posts: 682

Re: New Space Shuttle

I am one of the few who likes a big orbiter.

Mini-spaceplanes on top of EELVs will be torn off from pitch-loads and bending moments. Take a look at page 55 of this months Pop Sci (with Bigelow's 2010 station on the cover)

You will note that the orbital version of Dream Chaser is SIDE mount, and looks very like a mini hybrid version of Energiya Buran.

I loved Energiya myself. The liquid fueled strap-ons (ZENITS) were EELVs in their own right in 1985, when they first flew.

With RD-0120s on the ET, the orbiter was a parasite that could be exchanged with large payload pods.

With side mounting allowing outsized articles to be carried (within reason) large disk shaped aerobrakes could be carried.

Five 100 ton pods and ISS would be done.

If we had that design, we could release orbiter sized X-43 hypersonic boilerplates from the back of 747 orbiter ferry, then release in space from the ET--allowing the ET to stay in orbit for spacehab use--as the hypersonic boilerplate re-enters for prolonged test with active cooling.

Seymour Bogdonoff at Princeton--a hypersonics guru--under stands the need for large scale tests.

In other words--Energiya should have been our STS.

Imagine if we had been flying that since 1981--with Columbia in Gorky park.

We'd probably have 14 astronauts still with us.

Energiya did not bankrupt the USSR, contrary to what some may say. N-1 cost as much, and the Soviets survived it and got stronger.

The CCCP went bankrupt when they fought Muslims in parts of the world where they had no business.

Sound familiar?

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#70 2005-02-24 18:56:42

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

I disagree:

A big orbiter is a horrible idea, launching 80MT of spaceplane for only 20-30MT of cargo or a single crew makes no sense at all.

The DynaSoar program, the HL-20/42, the Russian BOR, and today's OSP concepts would all fly this way, and surely it would not have been a show-stopper for all of them. The "pitch load show stopper" is a myth just like the "twenty-six gee seperation" if CEV had to emergency seperate from EELV. There are plenty of disgruntled engineers who would be happy to tell anonymous bald-faced lies to gullible reporters, politicans, and managers if they had something to gain.

Energia wasn't a terrible idea for a rocket, but side-mounting is not the optimum panacea you make it out to be... actually, it reduces the total efficency by increasing drag and requiring nonperpandicular thrust vectoring to account for the off-centerline weight of the payload. The most powerful version of Energia, the "M" model, actually would have had a top-mounted payload and eight Zenit boosters.

ACTIVE reentry cooling?? For a manned vehicle!? Are you MAD?

"We'd probably have 14 astronauts still with us."

Thats being terribly unfair. Both times that Shuttle has failed has primarily been because of bad management not willing to accept Shuttle's technical issues, not so much that Shuttle had them. Energia with an orbiter on the side has no escape options either, and Energia with a damaged heat shield would have burned up just like Columbia.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#71 2005-02-24 19:35:08

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: New Space Shuttle

In other words--Energiya should have been our STS.

Imagine if we had been flying that since 1981--with Columbia in Gorky park.

We'd probably have 14 astronauts still with us.

That's a very pompous and callous assertion to make.

I do agree that liquid boosters like those on Energia would have avoided a Challenger-style accident.  Yet if Challenger hadn't happened, some type of major shuttle accident would have happened in 1986.  The system was just too complex, and NASA was pushing too hard to meet an unrealistic flight rate.  Many engineers thought that the accident would occur on the Vandenberg launch or the Centaur flights.  The complexity of the orbiter is common to the US space shuttle and the Buran.

As far as Columbia goes, I doubt that Energia-Buran would have been able to avoid a foam-strike incident like Columbia suffered.  I haven't been able to get a good answer for this, but I'm assuming that Energia was covered in insulating foam, just like the Shuttle ET.

The major problem is that the shuttle's designers had unrealistic expectations for their ship when nobody had ever built a reusable, orbital spacecraft before.  They went straignt from the X-15 to the massive shuttle without taking intermediate steps like the smaller X-20 in between.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#72 2005-02-25 16:19:46

publiusr
Banned
From: Alabama
Registered: 2005-02-24
Posts: 682

Re: New Space Shuttle

"Yet if Challenger hadn't happened, some type of major shuttle accident would have happened in 1986."

I find that assertion pompous an callous.

Buran is simpler and can be switched out with other payloads. There is no doub that 100 ton station modules would have been had--and with American quality control

"As far as Columbia goes, I doubt that Energia-Buran would have been able to avoid a foam-strike incident like Columbia suffered.  I haven't been able to get a good answer for this, but I'm assuming that Energia was covered in insulating foam, just like the Shuttle ET."

Buran flys heads up--out of the way.

"They went straignt from the X-15 to the massive shuttle without taking intermediate steps like the smaller X-20 in between."

Buran at least, unlike our STS--had the BOR boilerplates.

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#73 2005-02-25 17:52:17

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: New Space Shuttle

"Buran is simpler"

No it isn't, it simply moves the main engines to the external tank.

Neither does Bruan sit "above" the insulation on the external tank and "heads up" (or whatever that means) as the entire tank is coverd with insulation top-to-bottom.

The BOR would not have been a suitable "boilerplate" and nor would you waste an Energia to fly one.

Your bias against NASA is getting tiresome.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#74 2005-02-25 18:06:21

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: New Space Shuttle

The point I was trying to make about the X-20 is that it was supposed to be both manned and reusable (unlike the BOR-4 and BOR-5.)  X-20 would have taught us that launching, recovering, and turning around a manned spacecraft would be more difficult than we believed at the time.  The shuttle never achieved a launch rate greater than nine flights per year, although NASA had hoped for over twenty per year when the program started.

In regards to my conviction that a shuttle accident was inevitable in 1986, I suggest you read books like "The Challenger Launch Decision" or talk to the shuttle personnel who worked during that period.  Challenger was the product of the NASA culture at the time, which put its schedule ahead of the well-being of the astronauts.  Look at STS-61C, launched just 16 days before Challenger (which was almost launched after somebody started to accidentally drain the LOX tank,) or STS-51F in 1985 (where a main engine shut down early after a sensor problem, and the mission was aborted to a lower orbit.)

Regardless of what technology is available, accidents will happen when you insist on pushing too hard and ignoring the concerns of your engineers.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#75 2005-02-25 20:28:17

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: New Space Shuttle

This is the best that I could do.  I made some changes, no SRB's, but it really can't do much.  The on board hyd/oxy would run the SSME's for only 23 seconds.  I don't know how high and fast it could get on just 23 seconds worth of liquid fuel.

The main body (excl high V tail) is 24' shorter than the current shuttle, the height is one foot less, but the wingspan is 42' wider.  Built with carbon composite construction and one less SSME engine it's empty weight should be about the same mass as the current shuttle.
 
                                            Mass         
Vehicle mass incl 2 SSME's       230,000 lbs   
Payload desired                            63,500 lbs
4 F-119's with SR-71 intakes      16,000 lbs   

Hydrogen (slush) 13,379 cu ft = 56,910 lbs
LOX                       4,890 cu ft = 340,484 lbs 
Jet fuel                                          20,000 lbs
Maximum (Launch) Weight        726,894 lbs


Launch Profile        Altitude             Thrust                         
4 F-119's                  0-40k            140,000 sea level
4 F-119's/2 SSME's    40k-120k      976,000 to 1,024,600
2 SSME's             120k and up        1,024,600

I still like the horizontal takeoff with the F-119's, no having to move a heavy shuttle from horizontal to vertical and they could be used to 'fly' the empty shuttle to new launch locations rather than having to load it onto a 747 to maybe launch from a runway close to the equator for certain missions.  Also I have not included the mass of a helium propellant tank pressurization system.

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