Big Dumb Boosters revisited

Tom Kalbfus · 2006-12-27 00:57:00

Big Dumb Boosters?
Where the astronauts use a sextant and a pocket watch while manually aiming the spaceship and timing the controlled burns with frequent course corrections for the trans-lunar injection.

Tom Kalbfus · 2006-12-27 01:01:50

Give me a Sea Dragon, and place some large modules on the lunar surface. If some automated craft can slowly grow (assemble) mass-drivers, then you need no spacecraft at all once your infrastructure is up and independant.

The oceans have been well explored enough to virtually rule out the existance of sea dragons, and even if we could capture one, I doubt it would do us much good for getting to the Moon. Sea dragons are mythological creatures, just like unicorns and pixies, I doubt fairy tales offer us any avenue of approach for exploring the moon, the cow thing has been tried, there jumping skills are highly over-rated in such books.

RobertDyck · 2006-12-27 01:12:29

The oceans have been well explored enough to virtually rule out the existance of sea dragons, and even if we could capture one, I doubt it would do us much good for getting to the Moon. Sea dragons are mythological creatures, just like unicorns and pixies, I doubt fairy tales offer us any avenue of approach for exploring the moon, the cow thing has been tried, there jumping skills are highly over-rated in such books.

It's a launch vehicle. A space fan should be able to look this stuff up.
Sea Dragon from Encyclopedia Astronautica

Ps. If you're trying to be funny, comments like this come across as a moron.

Tom Kalbfus · 2006-12-27 09:30:26

The oceans have been well explored enough to virtually rule out the existance of sea dragons, and even if we could capture one, I doubt it would do us much good for getting to the Moon. Sea dragons are mythological creatures, just like unicorns and pixies, I doubt fairy tales offer us any avenue of approach for exploring the moon, the cow thing has been tried, there jumping skills are highly over-rated in such books.
It's a launch vehicle. A space fan should be able to look this stuff up.
Sea Dragon from Encyclopedia Astronautica
Ps. If you're trying to be funny, comments like this come across as a moron.

Yes, I was trying to be funny. You shouldn't be so testy about someone trying to insert a little humor here. In part I was poking fun at the point that you brought up this Sea Dragon without explaining it. I'm sure if I googled Sea Dragon, I would have gotten a number of hits including one about the legendary sea monster. You shouldn't assume that the reader has read everything you've read. You don't have to be a moron not to know what is meant when the term Sea Dragon is brought up with out further explaination! Instead of complaining, I decided to make a joke instead. Ah, but I see you are a dour and humorless person, too bad.

This thing was designed in 1962 for Christ sake, that is 5 years before I was born, it was never built, and how am I supposed to know what it is when someone brings it up out of the blue?

RobertDyck · 2006-12-27 10:08:08

I was poking fun at the point that you brought up this Sea Dragon without explaining it.

I didn't bring it up, publiusr did. I have other favourites.

Tom Kalbfus · 2006-12-27 10:30:32

I was poking fun at the point that you brought up this Sea Dragon without explaining it.
I didn't bring it up, publiusr did. I have other favourites.

Ok, you didn't, but my point is still valid. There were so many concepts out there, it is foolish to expect the reader to know what one is talking about when you bring up an old concept from 1962 that was never actualized. I know there were many more launch vehicles on paper then their were in reality. In 40 years, probably few people will know what a NASP is. If I say NASP in 2047, someone will say, what is that, he won't automatically know what a NASP is, and I'd be expected to explain further if I wanted to talk about it.

RobertDyck · 2006-12-27 10:39:34

A couple web sites that have been referenced in posts on this board and I expect everyone here has already read:
Encyclopedia Astronautica
NASA's Shuttle & Station website
Mars Society
Space Adventures
Mars Direct

And if you haven't read the book:
The Case for Mars

dicktice · 2006-12-27 19:49:39

Big Dumb Boosters?
Where the astronauts use a sextant and a pocket watch while manually aiming the spaceship and timing the controlled burns with frequent course corrections for the trans-lunar injection.

Well Tom, if you haven't read what I meant by Big Dumb Booster, go back and do so instead of wasting any more of your time misrepresenting what was meant to revisit the concept (after an appreciable time), which was to imagine the cheapest way to get supplies from Earth to Moon in the future by direct ascent, using single- or two-stage rockets to reach L1 with zero velocity, from which to choose the desireable orbital plane around the Moon to pass over any already arrived-at location, and then land tail-first under remote-presense control from that location.

So ... why not pull up an e-chair, if you're really interested, and participate a serious discussion of the pros and cons regarding this as a feasible (or not) mode of supply using today's know-how. Or at least stop playing silly-buggers with the topic. That is, if you don't want to be thought of as a mere spoiler, eh?

Tom Kalbfus · 2006-12-29 09:53:11

Big Dumb Boosters?
Where the astronauts use a sextant and a pocket watch while manually aiming the spaceship and timing the controlled burns with frequent course corrections for the trans-lunar injection.
Well Tom, if you haven't read what I meant by Big Dumb Booster, go back and do so instead of wasting any more of your time misrepresenting what was meant to revisit the concept (after an appreciable time), which was to imagine the cheapest way to get supplies from Earth to Moon in the future by direct ascent, using single- or two-stage rockets to reach L1 with zero velocity, from which to choose the desireable orbital plane around the Moon to pass over any already arrived-at location, and then land tail-first under remote-presense control from that location.
So ... why not pull up an e-chair, if you're really interested, and participate a serious discussion of the pros and cons regarding this as a feasible (or not) mode of supply using today's know-how. Or at least stop playing silly-buggers with the topic. That is, if you don't want to be thought of as a mere spoiler, eh?

Give it a break, stop beating a dead horse, it was only meant as a joke, jeeze! I can't believe your such a sour puss, that you can't take a single joke!

As for large boosters, as I can't attest to their stupidity, I think if you can't make a fully reusable space vehicle, then the other way to go is in single use giant boosters. A single Sea Dragon can lift the equivalent of 15 Shuttle missions into Low Earth orbit, if I recall the payload of the Shuttle correctly.
500 tons to orbit is also the equivalent to five Saturn V rockets. The economic question to ask, is how much would it cost to make and launch a single Sea Dragon vs 15 Shuttle flights and in orbit assembly.

publiusr · 2006-12-29 17:10:02

You certainly save on pad time.

More on BDBs here:
http://www.spacefellowship.com/Forum/vi … 2868#22868
http://forum.nasaspaceflight.com/forums … 11&start=1
http://uplink.space.com/showflat.php?Ca … art=1&vc=1

Or you can go and waste time with the dreamer-RLV thing--one more time--with feeling.

http://www.astrox.com/ http://spacecraft.rsevproject.com/

And that is so much better than a plain simple rocket right?

WRONG!!

dicktice · 2006-12-29 20:11:06

It'll take some time to review all those references. I'd hoped to stimulate a little original thought regarding one-way direct ascent to L1, but I guess that'll have to wait until after the New Year festivities, eh? In the meantime, "Happy New Year" to all of you old Mars-or-bust types, out there in cyperspace!

Tom Kalbfus · 2006-12-29 21:42:29

There is an upper limit to how large you make a launch vehicle though. I doubt you can make space travel as cheap as an airplane ticket per passenger by building really huge boosters.

RobertDyck · 2006-12-30 00:28:11

The Reusable Space Exploration Vehicle from your rsevproject link is a truly beautiful craft. Not at all practical, but truly beautiful. They call it a "Blackbird Class Science Ship" and its wing and chine are definitely Blackbird design. However, a large wing like that is only practical for atmospheric flight. The delta wing with embedded large engines is practical for mach 1.6+ speeds, and addition of the fuselage chine and the chine on the outboard side of the engines is practical for mach 3+ speed. I question the canard though; practical for subsonic and even mach 2 flight, but above mach 3 it provides significant drag. You don't want that amount of drag on the front of the vehicle at hypersonic speed; it could make the aircraft unstable.

In space you want to minimize surface area and maximize internal volume. Volume holds the crew and life support while a large surface hull is just mass to push around. On atmospheric entry a large surface area requires that much more heat shield. More heat shield means still more mass. Actually, the flattened sphere of a Soyuz descent module, or the descent module of an Apollo D2 or Northrop-Grumman's original proposal for CEV is the optimal. However, that capsule design does not provide for any atmospheric "flying" to control descent. The Apollo command module as flown is a wide cone, which does provide some "flying" at hypersonic speed. This provides a little control during entry, but it's very slight. The parafoil of X-38 provides much more control, and that's at the subsonic final descent stage where control is most important. A lifting body is the optimal compromise between a vehicle able to truly fly with complete aerodynamic control over its flight path at hypersonic and supersonic speed, while at the same time keeping surface area down and internal volume up. The surface area of a lifting body is greater than a capsule, but much less than a delta wing. The X-38 is based on the X-24A, which has control problems at low speed such as landing; that's why X-38 used a parafoil. HL-20 has a better lifting body; ever so slightly heavier but able to control flight at low speed so it lands on wheels on a runway. Its glide slope is just as steep as the Shuttle, but its lifting body and control fins are much smaller than Shuttle's fuselage and delta wing so it's lighter. The smaller heat shield also helps reduce weight. Lack of a parafoil reduces weight, compensating for a body heavier than an X-38. Most importantly, the HL-20 incorporated internal de-orbit engines, making it much more reusable; as opposed to X-38's expendable de-orbit package. The ability to land with wheels on a runway make it much more practical to operate. If you want an RLV.

Operate any sort of winged spacecraft on Mars? Hah! No! An interpanetary spacecraft must be very light and efficient. Mars thin atmosphere means the only aircraft that can operate at all use a glider (sail plane) wing. You need an aeroshell to enter Mars atmosphere. An RLV for Mars would be based on the Delta-Clipper, the DC-X.

All in all the "Blackbird Class Science Ship" could be used as the mother ship for a TSTO, but not as a spacecraft. But it is pretty.

GCNRevenger · 2006-12-30 00:48:19

A huge rocket could probably serve VSE-era exploration needs well enough, when we don't need but a large payload shot every year or two.

But later on, when you want to tend bases on the Moon, Mars, (and later LEO, L1, etc), or you want to mine the Moon or asteroids, or you want to tend space hotels, or small zero-g factory platforms...

...and later on, the other things, colonization of Mars, construction of prototype free-flying space colonies, regular exploration to the outer planets. The future.

We can't do any of these things in any practical way with expendable rockets. If we can't build a space elevator, then we are going to have to build an RLV. Thats all there is to it.

You can't fly a rocket often enough with a giant capsule to stuff passengers in, so an RLV is essential for crew. We'll also need small (relatively) flights to and from LEO for mining or factory platforms, which you don't get in a big rocket.

And in general, its not practical to pack a huge number of little payloads into one monster package, its too much trouble to plan and pack and stuff all of it into just one shot. Plus putting all your eggs in a rocket designed to be cheap and not reliable might be okay for exploration, but not for other things. And RLV will be reliable because its dynamics aren't as violent, and because it will have to be to work.

Not to mention when we do eventually get a good RLV cargo ship to work, then the economies of scale will slap expendable rockets silly, and make launch cheap enough for regular flights to the outer planets as we talk about regular flights to Mars now.

Tom Kalbfus · 2006-12-30 08:45:25

A huge rocket could probably serve VSE-era exploration needs well enough, when we don't need but a large payload shot every year or two.
But later on, when you want to tend bases on the Moon, Mars, (and later LEO, L1, etc), or you want to mine the Moon or asteroids, or you want to tend space hotels, or small zero-g factory platforms...
...and later on, the other things, colonization of Mars, construction of prototype free-flying space colonies, regular exploration to the outer planets. The future.
We can't do any of these things in any practical way with expendable rockets. If we can't build a space elevator, then we are going to have to build an RLV. Thats all there is to it.

The launch window to Mars occurs once every two years. Seems to me that when such a window occurs, you would want to launch a whole bunch of passengers all at once, a "Shuttle" that could ferry passengers into low Earth Orbit once per week, would only ferry Mars bound passengers for a small percentage of its time and would need to find other payloads to keep itself in business between Mars launch windows. A Launch Vehicle capable of delivering 500 tons to low Earth orbit could probably launch the entire Mars bound craft all at once, complete with Hab, nuclear transfer vehicle and Earth return vehicle all at once. You would have 2 years to build each one before each launch window occurs.

For a Space Elevator, you might want a huge heavy lift vehicle to lift the cable into orbit, they say they can do it with the shuttle, but a larger vehicle could launch a more robust cable. First we got to make the cable and the quality of the cable will determine how much of it we have to lift into orbit. Less tensile strength means more taper and more mass to lift.

You can't fly a rocket often enough with a giant capsule to stuff passengers in, so an RLV is essential for crew. We'll also need small (relatively) flights to and from LEO for mining or factory platforms, which you don't get in a big rocket.
And in general, its not practical to pack a huge number of little payloads into one monster package, its too much trouble to plan and pack and stuff all of it into just one shot. Plus putting all your eggs in a rocket designed to be cheap and not reliable might be okay for exploration, but not for other things. And RLV will be reliable because its dynamics aren't as violent, and because it will have to be to work.
Not to mention when we do eventually get a good RLV cargo ship to work, then the economies of scale will slap expendable rockets silly, and make launch cheap enough for regular flights to the outer planets as we talk about regular flights to Mars now.

RobertDyck · 2006-12-30 10:28:36

One complaint about "Star Wars" development of laser weapons was their attempt to go big. Researchers pointed out that initial development is always done with something small, then once it works you scale up. A riffle size laser weapon has to be developed first before you attempt a ground based laser that can shoot down a satellite. Ronald Regan's SDI (Star Wars) attempted to build a ground based laser with a 1 metre diameter mirror. They did end up building one that could burn out the optics of a spy satellite without destroying the satellite itself. However, doing initial development on the full size weapon was very expensive, and that cost took away money and resources that could have been used to refine a more sophisticated weapon. Later the air force developed a laser that could burn through the hull and fuel tanks of a SCUD missile in flight, and the laser would completely fill a 747. Notice the anti-missile laser that was developed after the big ground based laser emplacement was so big it required the largest aircraft that America currently makes. A more refined design should be smaller, enabling a smaller aircraft to act as its platform. A smaller aircraft would be more affordable, permitting a greater number to be built, which would permit more aircraft to patrol a protected area, and the laser protection system could be deployed in more locations. Finally, a small enough laser defence system could be truck mounted, enabling ground defence system using laser instead of Patriot missiles. A laser fires at the speed of light and fires in a straight line, easier targeting and multiple shots. If the first shot doesn't hit the incoming ballistic missile, just keep firing until you do hit it. A laser has a much longer range than a Phalanx close-in-weapon-system, but has the same continuous fire capability. Without the sophistication to make it small, you can't do any of that.

All this because some dumb-ass decided to do initial development big. Let's learn from this and not repeat that mistake. Initial development of a fully reusable spacecraft should be small. Once it works you can scale up. So built the first one as a 4 astronaut space taxi with no cargo capacity what so ever. It would still permit some flexibility: one or more of the seats could be replaced with a duffle bag for cargo, or a rack to hold drawers from science racks on ISS. This small space taxi would make ISS operation cheap enough to be practical. A frequent flying, inexpensive space taxi. If you really insist on a large RLV, then consider the small space taxi to be the development platform for the big one.

GCNRevenger · 2006-12-30 11:37:39

The launch window to Mars occurs once every two years. Seems to me that when such a window occurs, you would want to launch a whole bunch of passengers all at once, a "Shuttle" that could ferry passengers into low Earth Orbit once per week, would only ferry Mars bound passengers for a small percentage of its time and would need to find other payloads to keep itself in business between Mars launch windows. A Launch Vehicle capable of delivering 500 tons to low Earth orbit could probably launch the entire Mars bound craft all at once, complete with Hab, nuclear transfer vehicle and Earth return vehicle all at once. You would have 2 years to build each one before each launch window occurs.

No, the launch window for lowest energy opposition-type transits open biannually. Flying both opposition and conjunction, and later when high-energy nuclear drives are available (and they will, there will never be colonization without them) then you can leave almost any time you please. You can fly directly to Mars most any time of the year you like, but the most fuel-efficient window only opens every year or two. If you have a superhigh efficiency engine though, fuel efficiency is not so critical.

As for earlier times, when building the foundation for a base, town, colony, there is plenty of reason to have an RLV then too. Putting all your eggs in one big basket is a sure fire way to knee-cap the whole operation when one cheaply built SeaDragon et al finally does blow up, and there is the impracticality of making an aerobrake shield or lander so huge to put down >100MT class payloads. With a fuel condenser in Earth orbit to store the Earth-Mars boosters, smaller mass-produced cargo delivery vehicles bring payloads to Mars orbit, where they are then landed my a Mars-based RLV in turn.

There is something to be said for granularity of cargo, that you can send what you need, when you need it instead of having to count that what you need will be manifested on a future flight. Otherwise, you will have to reserve a significant portion of each flight to "last minute" payloads which will adversely impact the efficiency overall.

In the first landings for exploration, a giant rocket would probably be less efficient than a number of smaller ones, if for no other reason than they are easier to manufacture and handle than one massive rocket. There is also the problem that even 500MT wouldn't be enough without nuclear propulsion, and even then you would have to plan on the Mars Ascent/Earth Return vehicle landing on Mars with its fuel tanks empty, which is a major risk factor, unless of course you intend to land all the exploration missions in one spot. Chemical propulsion is doubly out too if you intend to fly direct using the upper stage for TMI, since its efficiency will suffer due to its size.

GCNRevenger · 2006-12-30 12:23:27

One complaint about "Star Wars" development of laser weapons was their attempt to go big. Researchers pointed out that initial development is always done with something small, then once it works you scale up. A riffle size laser weapon has to be developed first before you attempt a ground based laser that can shoot down a satellite. Ronald Regan's SDI (Star Wars) attempted to build a ground based laser with a 1 metre diameter mirror. They did end up building one that could burn out the optics of a spy satellite without destroying the satellite itself. However, doing initial development on the full size weapon was very expensive, and that cost took away money and resources that could have been used to refine a more sophisticated weapon. Later the air force developed a laser that could burn through the hull and fuel tanks of a SCUD missile in flight, and the laser would completely fill a 747. Notice the anti-missile laser that was developed after the big ground based laser emplacement was so big it required the largest aircraft that America currently makes. A more refined design should be smaller, enabling a smaller aircraft to act as its platform. A smaller aircraft would be more affordable, permitting a greater number to be built, which would permit more aircraft to patrol a protected area, and the laser protection system could be deployed in more locations. Finally, a small enough laser defence system could be truck mounted, enabling ground defence system using laser instead of Patriot missiles. A laser fires at the speed of light and fires in a straight line, easier targeting and multiple shots. If the first shot doesn't hit the incoming ballistic missile, just keep firing until you do hit it. A laser has a much longer range than a Phalanx close-in-weapon-system, but has the same continuous fire capability. Without the sophistication to make it small, you can't do any of that.
All this because some dumb-ass decided to do initial development big. Let's learn from this and not repeat that mistake. Initial development of a fully reusable spacecraft should be small. Once it works you can scale up. So built the first one as a 4 astronaut space taxi with no cargo capacity what so ever. It would still permit some flexibility: one or more of the seats could be replaced with a duffle bag for cargo, or a rack to hold drawers from science racks on ISS. This small space taxi would make ISS operation cheap enough to be practical. A frequent flying, inexpensive space taxi. If you really insist on a large RLV, then consider the small space taxi to be the development platform for the big one.

What? What are you talking about Robert? Don't you have any clue that sometimes its often times much harder to miniaturize something than to enlarge it? There is also the problem of putting too many milestones between the bench-top demo in the lab and the actual system, which can also lead to huge costs and long delays. Time was of the essence in the Regan years to develop counters to the Soviets, and now time is of the essence again to develop counters to Iranian and North Korean missiles.

The reason why the ABL is so large is since it uses an older and bulkier technology, but one that is more reliable and proven unlike newer technologies (older chemical versus new diode or free electron). The USAF picked the one they knew would work and accepted the tradeoff of a less efficient arrangement. There is also a major learning curve for turning the thing into an effective weapon, which wouldn't have been very helpful to do on lab bench.

The older laser you spoke, that "little" 1m gizmo, was also a chemical laser and required a few semi trucks worth of equipment to operate. Getting that that same weapon to fit, upgraded large enough to hurt missiles, would never fit in in a 747! You don't give the ABL system enough credit for what an advance it is over older iterations of the technology nor how hard it was to shrink it down to fit.

A more "refined design" like a diode or compact resonator-type free electron laser are years if not a decade away, and so they simply aren't an option for the ABL that needs to enter service sooner not later. These exotic lasers are still little more than laboratory demos... "you go to war with the laser you have, not the laser you wished you had."

I bet an FEL imparticularly would have trouble due to charge-up times, especially since mounting it on the ground with the Earth's curvature or terrain would limit the number of times it could fire. Good thing we're putting a more reliable one on an airplane...

If I had to choose who the dumbass is, you or the military laser brass, I wouldn't have to burn much effort in deciding...

And you, being this lofty engineer, should have heard of this little thing called the cube/square law at one time or another: it will in fact be easier to make a relatively large RLV compared to making a small one, at least as far as what technologies involved can accomplish. Remember that mass efficiency is critical (at least for the upper stage of a TSTO), and so a larger vehicle would actually have a better time of it than a small-as-possible one. Witness how the X-33 was always a suborbital prototype, and only the bigger (and more efficient) VentureStar was the orbital version.

An RLV with no cargo capacity is a complete waste of time, thats not what we need it for most, we need it most for carrying small-to-modest payloads (~10-20MT) efficiently, so we can establish commercial spaceflight and markets in Earth orbit and on the Moon, then later to replace expensive VSE expendable rockets where possible. Carrying a crew is a secondary concern really, and besides it needs to be a large crew and hence a large vehicle for orbital tourism anyway. A duffel bag or a pair of ISS racks is totally immaterial for anything practical too.

And my stance on the ISS is well known, no vehicles should be built to tend it. Ever. Since the station is completely worthless even if you did tend it. Not that it will even be there in a usable condition by the time the RLV is ready anyway.

If we absolutely have to have a smaller version as a technology testbed then fine, but having to develop and built twice as many vehicles will be a total waste otherwise, especially since the aerodynamics of the lifting-body vehicles would have be re-tailored for the larger ship(s) later anyway most likely, limiting commonality.

RobertDyck · 2006-12-31 03:40:27

What? What are you talking about Robert? Don't you have any clue that sometimes its often times much harder to miniaturize something than to enlarge it?

Perhaps I should stop equivocating and simply state that I believe we need a crew taxi to transport astronauts to LEO, and a big expendable launch vehicle (big dumb booster) to launch bulk cargo. That BDB can (should) also launch a manned mission to Mars. One mission every 26 months, argue for 2 launches for Mars Direct or 3 launches for NASA DRM, or some other number for another architecture, but that's still too few to justify an expensive big RLV. These other missions you mention are "down the road". First we need to get there. Of course I would like to start asteroid mining, but that can be accomplished with a BDB as well. A reusable architecture like my "Mars Orbit Rendezvous" can be accomplished with a BDB to launch modules for assembly, and a small space taxi to ferry astronauts up and down.

If you don't want to listen to me, then I point out that the investigation boards for both the Challenger and Columbia accidents strongly recommended separating cargo from crew. A reusable space taxi and separate BDB for cargo accomplish that.

There is also the problem of putting too many milestones between the bench-top demo in the lab and the actual system

I don't see it as a mile stone, it's the actual system.

Time was of the essence in the Regan years to develop counters to the Soviets, and now time is of the essence again to develop counters to Iranian and North Korean missiles.

No, neither Iran nor North Korea are threats. North Korea has stated several times that they will not let themselves be invaded, and they will do what ever is necessary to defend themselves. They don't have any intention of invading USA or anyone else. The sole exception is South Korea. They want to reunify the Koreas. How that will be accomplished is in question, but American threats to invade North Korea simply result in their developing effective defences. If you feel their defences are an effective threat to USA, then that is exactly what they intended. They fully realize that if they use a nuclear weapon against US soil, American will retaliate by saturation bombing them with strategic thermonuclear bombs. Their country will become a radioactive hole in the ground. Consequently they will never mount a first strike against the US, no matter what. However, if the US invades North Korea with a force as strong and as effective as the one that took out Iraq, they will launch a revenge attack as the last gasping breath of their government. North Korean government officials also know that if America invades their country, they personally will either be killed during the attack, or if they survive there will be a trial like Saddam and they will be executed. Consequently they have nothing to loose by taking out as many Americans as they can in their defeat. This means their nuclear weapons are a colossal waste of money, they can't ever use them. Well, not unless you invade North Korea first. Are you the treat? Are you the invader? Do you really intend to use military force to conquer/occupy/subjugate North Korea? If so you are the enemy of the world. If not, then sit back in the knowledge that North Korea's weapons are a paper tiger. They can't ever use them. The more they waste on such weapons, the less they have to build their economy. By wasting money on such weapons they only damage themselves.

The same applies to Iran. They see their immediate enemy as Israel; a nation that already has 200 nuclear warheads. If Iran builds just one they will still be in a significantly inferior position. If they use just one such weapon on America's ally, they again will be converted to a radioactive hole in the ground. They can't ever use it, so who cares if they waste money on one.

ABL is so large is since it uses an older and bulkier technology... There is also a major learning curve for turning the thing into an effective weapon

A reason to do it right before spending millions of dollars to build a giant bulky ineffective device.

"you go to war with the laser you have, not the laser you wished you had."

Better not to go to war at all. Wasn't I one of those who said on this message board that it's a very bad idea to invade Iraq? I did write the MP I supported in the 2004 election, and asked him not to let Canada enter the war in Iraq. I said "Afghanistan yes, Iraq no". Al-Qaeda attacked our ally so we have to take out al-Qaeda; they're in Afghanistan, not Iraq. Americans didn't listen to me but luckily someone in Canada did. Is this "I told you so"? Yes it is.

I've read things from several scientists who said laser technology was no where near ready when the ground-to-satellite weapon was developed. It needed a lot of basic research first. If that money was spent on basic research instead of building a giant weapon now, then a refined system would be available today.

cube/square law ... Witness how the X-33 was always a suborbital prototype, and only the bigger (and more efficient) VentureStar was the orbital version.

Yes, X-33 was a suborbital technology demonstrator. If all the technology was known to be reliable, it would have been a multi-million dollar waste of money. It was an insurance policy, ensuring the technology works before committing to the big vehicle. It would only prove to be a sound investment if something failed. Well, something did fail. Although most of the technology was proven, there was a last minute change from solid wall composite fuel tanks to hollow wall. The first test of these tanks failed. That did prove the X-33 was worthwhile. The intelligent solution would be to change the tanks, but some greedy corporate executives wanted money. That killed the project. It wasn't a question of scale or of technology, it was simply money.

An RLV with no cargo capacity is a complete waste of time, thats not what we need it for most, we need it most for carrying small-to-modest payloads (~10-20MT) efficiently

This reminds me of Adolf Hitler's decision to use the then-new jet engine for big bombers. Military planners said the fast engine is best used for fast fighter escort planes and continue to use propellers for the big bombers. But no, Hitler insisted on putting the new technology on the big vehicle. Tell me again, who won World War 2?

it needs to be a large crew and hence a large vehicle for orbital tourism anyway.

Let's see, aircraft was developed by first building small aircraft that could transport mail cost effectively. One and two person fighters were built, observation aircraft, and then "barn stormers" used one and two person aircraft for demonstration shows. Only after all that was economically viable did aircraft expand to carry passengers. At first passenger travel financial loss for the airline. The first aircraft to transport passengers at a profit was the Ford Trimotor, which carried at most 8 passengers. After they established a market the Douglas Corporation built the DC-1, DC-2, and finally the DC-3 aircraft. They were the first truly successful airliners. The Douglas Corporation followed that with aircraft though the DC-10, and many aircraft by several corporations were developed after the DC-3. But you want to skip all these steps and jump straight to the end. Without developing technology or learning necessary lessons, you want to skip the early phases and jump straight to large scale production of big vehicles. Tell me, how successful was the Hindenburg?

What I'm saying is if you skip the small vehicles and jump straight to a large one, you'll get a Zeppelin instead of a DC-3.

GCNRevenger · 2006-12-31 08:51:59

Oh come on, you aren't that obtuse, so I assume that you are conveniently forgetting stuff to try and make me look dumb.

As I have said many times, an RLV is a project for a later date, well after we are established on the Moon at least, and probably not until a Mars base is started too. An RLV isn't good for much if you don't have a place or reason to fly it to, which are better built by expendable rockets.

Second, if you will notice I have also spelled out in my vision for an RLV that there will be different, separate, discrete versions of upper stage with the same mold lines for carrying crews and cargoes; after all, since mass efficiency is so critical, carrying a crew that you don't need makes a big difference. Perhaps even a third version as a pure tanker too. I'm not willing to believe that you simply forgot this, so stop acting.

I don't see it as a mile stone, it's the actual system.

A system without a use, being too small to launch satellites and not having any space station to fly to, is just a milestone.

Oh please, I'm not going to debate your empty-headed broken-moral-compass evil drivel. Yes thats right, evil, which is what happens when you throw away your belief in either good or evil. Because if there is no evil then there is no need to fear, right? There's no problem if you just redefine our enemies away. Pathetic.

Anyway, your assumptions rely on the idea that these people with ballistic missiles and either the possession or the capability to produce WMDs are rational actors. Regardless of all the moral questions, this is an objectively and historically bad assumption to make, and so if there is a way through technology to create a counter to these weapons, then it is worthwhile. As an added bonus, such defenses not only protect us, but also decrease the deterrent value of TBMs/ICBMs against our allies & interests. Given the current state of the world, we need anti-missile weapons sooner, not later.

And I think you need to compare the effective destructive killing power of nukes or CWs to the land area of Israel.

A reason to do it right before spending millions of dollars to build a giant bulky ineffective device.

The development cost to go from lab to weapon would be relatively the same for a practical antimissile laser no matter what type you used. You being an engineer obviously know that there is a lot of work involved with taking something from the labs that works good on steel plates meters away right in front of the emitter to a 100km+ missile buster on an airplane. There is no "do it right" before hand in a lab, because the task itself is to take it out of the lab and make it work. Which is a separate development step than developing the laser itself.

Better not to go to war at all

See above about rational actors. If the time comes to use anti-missile weapons, chances are it won't be by choice.

I've read things from several scientists who said laser technology was no where near ready when the ground-to-satellite weapon was developed. It needed a lot of basic research first. If that money was spent on basic research instead of building a giant weapon now, then a refined system would be available today.

No it really wouldn't, the ABL chemical laser is the refined laser, this "basic research" would have to be into an entirely different technology. These other two types of lasers, diode and FEL, were hardly laboratory gizmos at the time and being electrically driven also suffer from charge times.

Witness how the X-33 was always a suborbital prototype, and only the bigger (and more efficient) VentureStar was the orbital version

You really have trouble with reading context I think Robert; the point was the X-33 was not an orbital vehicle, but the larger VentureStar which was based off the same technology would have been. The only difference being the size, where the larger vehicles' cube/square efficiency made the difference over the smaller one.

This reminds me of Adolf Hitler's

I feel Godwin's Law coming on. Your point about jet engines and bombers versus fighters is irrelevant, because they were for so much different purposes than for space vehicles. I call out your analogy as being worthless.

My point was that a small vehicle isn't going to be a whole lot easier than a bigger one, and since the former will be useless for anything practical, that if we don't absolutely need it to prove the technology then it is a waste of time. The crew taxi won't even be that much smaller probably, carrying a ~10MT crew cabin.

And absolutely I want to jump to the end, we are much better at developing things on the drawing board before we ever build things anymore. And, since the dynamics are going to be different (lift body shapes are very sensitive to details) or the useless ten-billion-dollar taxi then its not so much a vehicle in the path of a larger cargo carrier, but a divergent distraction.

RobertDyck · 2006-12-31 11:45:57

You've based everything on the assumption that a space station is useless. I disagree. You also claimed maintaining the Hubble space telescope was also useless. Again I disagree. The Shuttle did science in LEO before the station was built, but NASA originally intended it to service a station. As many people pointed, a reusable shuttle is a waste of time and money if it doesn't have a destination. That station can now do the science so reusable shuttle now has a purpose. However, the per launch cost of the shuttle is greater than a Proton or Ariane launch vehicle, each of which as similar cargo capacity, which is one reason I argue to replace the big expensive shuttle with a small one and use a BDB for cargo. Again, sensitive experiments built to fit in a science drawer can go on the mini shuttle.

Alternatively, use a BDB to lift modules for orbital assembly of a fully reusable interplanetary spacecraft. The Mars orbit rendezvous architecture uses a reusable spacecraft to go from LEO to Mars orbit, parks in Mars orbit until the mission is over, then comes back to LEO. Initially it uses expendable TMI/TEI stages, but that can later be replaced with a reusable one. Getting crew to that interplanetary spacecraft is a key part of the architecture. So the space taxi is part of a manned mission to Mars.

Do you want more examples? The principle is simple; use a BDB for bulk cargo because it's cheap, and a small taxi for crew because crew is not expendable and life support systems are expensive.

dicktice · 2007-01-03 18:14:04

THE current space station may not be practical or economic in the long run, GCNR. But the concept of space stations per se, orbiting any planetary bodies that possess potential for exploitation for a generation or more in future, will be obvious necessities if spreading ourselves across the Solar System is to progress rapidly. The same goes for space colonies, when we're ready, in order to utilize the volume of space above and below the ecliptic. There's always been a first of any aerospace hardware we've developed in the past. They've almost always been "abortions," as we used to call 'em, even if they worked. They were never anything like optimum. Live and learn, eh? The money, compared with the cost of the present war (another abortion?), is a rotten excuse ... that is, of course, unless it puts Congressmen off enough to cause them to kill the budget. Bad reason.

Tom Kalbfus · 2007-01-04 03:08:25

One complaint about "Star Wars" development of laser weapons was their attempt to go big. Researchers pointed out that initial development is always done with something small, then once it works you scale up. A riffle size laser weapon has to be developed first before you attempt a ground based laser that can shoot down a satellite. Ronald Regan's SDI (Star Wars) attempted to build a ground based laser with a 1 metre diameter mirror. They did end up building one that could burn out the optics of a spy satellite without destroying the satellite itself. However, doing initial development on the full size weapon was very expensive, and that cost took away money and resources that could have been used to refine a more sophisticated weapon. Later the air force developed a laser that could burn through the hull and fuel tanks of a SCUD missile in flight, and the laser would completely fill a 747. Notice the anti-missile laser that was developed after the big ground based laser emplacement was so big it required the largest aircraft that America currently makes. A more refined design should be smaller, enabling a smaller aircraft to act as its platform. A smaller aircraft would be more affordable, permitting a greater number to be built, which would permit more aircraft to patrol a protected area, and the laser protection system could be deployed in more locations. Finally, a small enough laser defence system could be truck mounted, enabling ground defence system using laser instead of Patriot missiles. A laser fires at the speed of light and fires in a straight line, easier targeting and multiple shots. If the first shot doesn't hit the incoming ballistic missile, just keep firing until you do hit it. A laser has a much longer range than a Phalanx close-in-weapon-system, but has the same continuous fire capability. Without the sophistication to make it small, you can't do any of that.
All this because some dumb-ass decided to do initial development big. Let's learn from this and not repeat that mistake. Initial development of a fully reusable spacecraft should be small. Once it works you can scale up. So built the first one as a 4 astronaut space taxi with no cargo capacity what so ever. It would still permit some flexibility: one or more of the seats could be replaced with a duffle bag for cargo, or a rack to hold drawers from science racks on ISS. This small space taxi would make ISS operation cheap enough to be practical. A frequent flying, inexpensive space taxi. If you really insist on a large RLV, then consider the small space taxi to be the development platform for the big one.
What? What are you talking about Robert? Don't you have any clue that sometimes its often times much harder to miniaturize something than to enlarge it? There is also the problem of putting too many milestones between the bench-top demo in the lab and the actual system, which can also lead to huge costs and long delays. Time was of the essence in the Regan years to develop counters to the Soviets, and now time is of the essence again to develop counters to Iranian and North Korean missiles.

I think RobertDyck is somewhat confused. George Lucas didn't develop any real laser weapons systems in producing his films. No planets were distroyed in the making of the films either.

dicktice · 2007-01-04 09:18:23

You know, Tom, you were a real pill to interject that crap--about a MOVIE, for God's sake--into what is a deeply important debate between two contributors who really know what they're talking about. So withhold the sideline levity, please, until they've had their say and we've all had a chance to contribute. Sorry to be so frank, but you asked for it.

Tom Kalbfus · 2007-01-04 10:28:50

You know, Tom, you were a real pill to interject that crap--about a MOVIE, for God's sake--into what is a deeply important debate between two contributors who really know what they're talking about. So withhold the sideline levity, please, until they've had their say and we've all had a chance to contribute. Sorry to be so frank, but you asked for it.

You brought up the subject of Star Wars, not I.
Yeah, I know what your trying to do, your trying to discredit an idea by using a perjoritive, by calling it names if you will. By associating missile defense with light sabers, X-wing fighters, and the Force, you hope to discredit the idea.

New Mars Forums

Announcement

#26 2006-12-27 00:57:00

Re: Big Dumb Boosters revisited

#27 2006-12-27 01:01:50

Re: Big Dumb Boosters revisited

#28 2006-12-27 01:12:29

Re: Big Dumb Boosters revisited

#29 2006-12-27 09:30:26

Re: Big Dumb Boosters revisited

#30 2006-12-27 10:08:08

Re: Big Dumb Boosters revisited

#31 2006-12-27 10:30:32

Re: Big Dumb Boosters revisited

#32 2006-12-27 10:39:34

Re: Big Dumb Boosters revisited

#33 2006-12-27 19:49:39

Re: Big Dumb Boosters revisited

#34 2006-12-29 09:53:11

Re: Big Dumb Boosters revisited

#35 2006-12-29 17:10:02

Re: Big Dumb Boosters revisited

#36 2006-12-29 20:11:06

Re: Big Dumb Boosters revisited

#37 2006-12-29 21:42:29

Re: Big Dumb Boosters revisited

#38 2006-12-30 00:28:11

Re: Big Dumb Boosters revisited

#39 2006-12-30 00:48:19

Re: Big Dumb Boosters revisited

#40 2006-12-30 08:45:25

Re: Big Dumb Boosters revisited

#41 2006-12-30 10:28:36

Re: Big Dumb Boosters revisited

#42 2006-12-30 11:37:39

Re: Big Dumb Boosters revisited

#43 2006-12-30 12:23:27

Re: Big Dumb Boosters revisited

#44 2006-12-31 03:40:27

Re: Big Dumb Boosters revisited

#45 2006-12-31 08:51:59

Re: Big Dumb Boosters revisited

#46 2006-12-31 11:45:57

Re: Big Dumb Boosters revisited

#47 2007-01-03 18:14:04

Re: Big Dumb Boosters revisited

#48 2007-01-04 03:08:25

Re: Big Dumb Boosters revisited

#49 2007-01-04 09:18:23

Re: Big Dumb Boosters revisited

#50 2007-01-04 10:28:50

Re: Big Dumb Boosters revisited

Board footer