A cheap and easy way to space.

[EarthlingX]

As I understand it, the Russian AN-225 has a payload capacity of ~550,000 lbs using 1980's materials and power plants, and using a pretty standard design.

Chris

Russian approach :

from http://www.buran.ru : Spiral Orbital Aircraft Prgramme - NPO Molniya

Wiki : Mikoyan-Gurevich MiG-105 "Spiral"

from http://www.buran-energia.com : BOR-4 Description

Caption:
1-Nasal thermal shield; 2-Electrical battery; 3-Tank for the fuel, NO3 + UDMH; 4-Parachute; 5-Navigation system and on-board electronic; 6-Radio equipment; 7-Scientific equipment; 8-Actuator of the wings; 9-Wings; 10-Vertical stabilizer; 11-Engines; 12-Central bloc of the GRD engines, pitching; 13-Steel frame.

Wiki : BOR-4

from http://www.buran-energia.com : AN-225 Mriya :

Wiki : Antonov An-225 Mriya

 

[csmyth3025]

I'm still convinced that a lifting body variant will ultimately become the reusable crew and low mass payload orbital workhorse of the future. It seems that expendable rockets will remain the only practical launch vehicle for high mass payloads for the forseeable future.

As has alrady been pointed out, getting people to orbit will be a much more frequent activity than lofting large pieces of space hardware into orbit. For this reason, reducing the cost of crew transport is of critical importance.

I like the idea of replacing LH2 with RP-8 as a fuel. This would reduce the complexity and cost of frequent flights. In terms of the SKYLON/Sabre engine concept, the reduced thrust might be offset by the advantages of air launch. In terms of cooling the compressed air for the Sabre engine, I wonder if an extra allowance for LOX might be made so that LOX can be uilized for cooling the helium inter-loop rather than LH2. These thoughts are, of course, considerations for the engineers to work out. I have no idea if they are practical or not.

Chris

 

[halman]

csmyth3025,

Although this is not widely known, helium is becoming extremely scarce, and technologies which rely on it are not a good bet, in my opinion. From my perspective, liquid oxygen is not a difficult material to work with, does not require a great deal of space, and is fairly cheap. The additional complexity of compressing atmospheric oxygen within a launch vehicle does not, to me, seem worthwhile when lox is so easy and cheap. Especially when considering a prototype vehicle, which should be kept as simple as possible. Once we have proven the feasibility of airborne launching, and established a working orbiter design, we can begin experimenting with more advanced technologies.

I keep thinking about how little is required to get to orbit from 50,000 feet. Look at the second stages of most rockets, and you will see that the thrust specifications are much smaller than the first stage. Also, the amount of time that the orbiter would spend in atmosphere dense enough to make compression practical is very short, unless the compressor is to be run during the climb to launch altitude. And, would the additional weight and complexity be sufficiently superior to simply carrying the lox at take-off?

I envision the orbiter as being as bare-bones as possible, up to using kerosene from tanks on the carrier wing for the few seconds of engine test prior to launch. The weight of the orbiter at launch is critical, if we want to keep the demands for engine performance reasonable. The more that we demand from the engines, the more likely we are to need extensive maintenance after each flight.

 

[bimmer4011]

I think NASA is best suited to spend it`s budget on solar system exploration and extrasolar exploration. If they need to geto to LOE then they should use the tried and true rocket and payload. Nothing fancy like an expensive reusable `spaceplane` that is proven not to be cost effective. Why not split the difference and have a partially reusable launch vehicle, just recycle early stage engines, and recover them in the ocean like the current shuttle.

We used to have a pretty reliable launch vehicle that was cheaper than the shuttle, lets get back to basics for our workhorse vehicles. The Russians have proven the `KISS` is an effective approach to achieve LOE. Expanding on that principal with a heavey lifter will take us further out as needed.

If a simple rocket+payload+capsule is used, you could then have a relatively easy and effective capsule separation system for the crew to use should they need to separate from the main launch vehicle.

I can`t imagine it`s cheaper,, nnor easier to hang several tons from a B52 and launch into LOE, let alone putting it on a rocket sled that goes up the side of a mountain (made by ACME?).

Notice that all new comers to space (China, Japan, Europe) all use Rockets as their launch vehicle? KISS.... the concept is not rocket science, just the technology. ;o)

- Ron

 

[scottb50]

I keep thinking about how little is required to get to orbit from 50,000 feet. Look at the second stages of most rockets, and you will see that the thrust specifications are much smaller than the first stage.

Most of the work of a first stage is getting off the ground, as it gets lighter, very quickly, it provides acceleration plus altitude. If you reach 50,000ft at say mach 6 or at mach .8 means a lot more energy is needed to continue to orbit.

What I have been proposing is a hybrid system that gives the performance of the Shuttle system with a totally re-usable first stage. Basically it would be a Delta 4, except using composite cores, with an aerodynamic shell. Turbojet engines would offset the weight of the shell, engines and fuel during lift-off and climb to about 50,000 feet and and allow the first stage to return for a powered approach and landing.

The upper stage and payload would separate and continue to orbit.

 

[halman]

I think NASA is best suited to spend it`s budget on solar system exploration and extrasolar exploration. If they need to geto to LOE then they should use the tried and true rocket and payload. Nothing fancy like an expensive reusable `spaceplane` that is proven not to be cost effective. Why not split the difference and have a partially reusable launch vehicle, just recycle early stage engines, and recover them in the ocean like the current shuttle.

We used to have a pretty reliable launch vehicle that was cheaper than the shuttle, lets get back to basics for our workhorse vehicles. The Russians have proven the `KISS` is an effective approach to achieve LOE. Expanding on that principal with a heavey lifter will take us further out as needed.

If a simple rocket+payload+capsule is used, you could then have a relatively easy and effective capsule separation system for the crew to use should they need to separate from the main launch vehicle.

I can`t imagine it`s cheaper,, nnor easier to hang several tons from a B52 and launch into LOE, let alone putting it on a rocket sled that goes up the side of a mountain (made by ACME?).

Notice that all new comers to space (China, Japan, Europe) all use Rockets as their launch vehicle? KISS.... the concept is not rocket science, just the technology. ;o)

- Ron

That kind of logic would have prevented the airplane companies from switching airliners from reciprocating engines to turbine engines, even though the turbine engine is much more simple than a reciprocating engine.

We are at the very infancy of space exploration, and the only method of reaching space used to be a capsule on top of a step rocket. We have learned enough to move beyond this primitive technique, and on to a more advanced system which ultimately will reduce the cost of transferring people to orbit and back.

Just because the space shuttle has never proven to be a cost-effective method of transportation does not mean that the concept of a reusable space craft is unworkable. The space shuttle was a huge, complicated, compromise, bearing little resemblance to what the original concept was. What is amazing is that it has worked as well as it has. The only reason that it is being retired is that Congress has been unwilling to give NASA any additional money to develop a successor.

I too, am interested in science, and I love to see the pictures that have come back from our probes. But that knowledge has yet to alter my everyday life, to have any impact on the world. If space exploration is going to continue, if we are ever to be able to capitalize upon the knowledge that we are learning from our robot probes, than space is going to have to pay for itself somehow. The National Aeronautics and Space Administration was not created to study the outer planets of the Solar System, or other star systems, it was created to help American companies to move into space, just as its predecessor had helped American aviation companies develop more advanced aircraft.

The greatest challenge we face in space exploration is simply getting into space. Once we are there, things are much easier. I am not advocating launching a spacecraft up a mountain, or on a B-52. What I believe will be the future method of transporting people to orbit is a spacecraft which is carried to altitude by a specially designed aircraft, a carrier wing, which is launched by a horizontal catapult which not only accelerates the vehicle to around 350 miles per hour, but also supports the several million pounds of carrier wing and spacecraft.

People are going to be needed to make space pay, people on the spot, people with the ability to fix things, to modify them, and to rebuild them into something that will work. Getting those people back and forth across that 5 mile per second barrier is the greatest challenge the human race has ever faced. With the space shuttle, we took a giant step forward in technology, creating a space vehicle which could land on a runway at the place where it would take off again. We discovered that it is possible to send many people back and forth at once, instead of just a few at a time. We discovered that we could do this without putting the people through extreme accelerations, which had demanded top conditioning to deal with when flying in capsules.

The flip side of this proposal is the development of a very large Heavy Lift Launch Vehicle, one capable of a minimum payload to Low Earth Orbit of 100 metric tons, scalable to 150 tons, with a payload diameter of at least 10 meters. This vehicle should be designed with a minimum number of units to be produced, preferably more than 50, so that the unit costs will not be unreasonably high. These vehicles should be built assembly line fashion, at a rate which increases over a span of 10 years, plateaus, and then declines after 25 years.

Space stations, Lunar exploration gear, Lunar base materials, earth moving equipment, capacitors, batteries, cable, ice hauling equipment, a linear motor to launch payloads without chemical propellants, components for a deep space exploration vehicle, and several Orbital Transfer Vehicles comprise an initial list of payloads. But this launch vehicle should never be threatened with being man-rated. That would jack the price way up, increase launch costs significantly, and put passengers in far more danger than they need to face. By transporting people in a vehicle designed exclusively for that, and launching cargo on a vehicle designed exclusively for that, we can keep launch costs to a minimum, while enhancing safety and versatility.

 

[halman]

I keep thinking about how little is required to get to orbit from 50,000 feet. Look at the second stages of most rockets, and you will see that the thrust specifications are much smaller than the first stage.

Most of the work of a first stage is getting off the ground, as it gets lighter, very quickly, it provides acceleration plus altitude. If you reach 50,000ft at say mach 6 or at mach .8 means a lot more energy is needed to continue to orbit.

What I have been proposing is a hybrid system that gives the performance of the Shuttle system with a totally re-usable first stage. Basically it would be a Delta 4, except using composite cores, with an aerodynamic shell. Turbojet engines would offset the weight of the shell, engines and fuel during lift-off and climb to about 50,000 feet and and allow the first stage to return for a powered approach and landing.

The upper stage and payload would separate and continue to orbit.

The shuttle was a compromise between a true Heavy Lift Launch Vehicle and a reusable space plane. Adding cargo capacity increased the structural requirements so that heavy payloads required a heavy airframe, especially down cargo. By divorcing people from cargo, we can push up the cargo capability without drastically increasing production costs, which man-rating imposes. I can remember when the shuttle was quoted as having a payload of 100 tons, which was scaled back nearly by half. By making the shuttle a small vehicle, and the HLLV a big, expendable vehicle, we can achieve our aims quickly with a minimum number of launches and at minimum cost, I believe.

We have to scale up our thinking about space exploration, move beyond the exploration part into the exploitation part, where we are doing things on an industrial scale. Because industry is going to be the key to space, not exploration. The exploration will be made possible by the advances which are brought about by the industrialization. Visiting asteroids looking for light metals will teach us how to survive for long periods in deep space, which will enable a mission to the satellites of Mars. I am not sure what will enable a mission to Mars itself, as Earth governments are going to be reluctant to finance colonization efforts, and our robotic probes are advancing so rapidly that the science can be done by machine.

 

[Booban]

Visiting asteroids looking for light metals will teach us how to survive for long periods in deep space, which will enable a mission to the satellites of Mars. I am not sure what will enable a mission to Mars itself, as Earth governments are going to be reluctant to finance colonization efforts, and our robotic probes are advancing so rapidly that the science can be done by machine.

Small steps Halman. Once we manage to exploit space however it is done, will rapidly increase technology development and national income so that traveling to Mars is easy.

 

[scottb50]

have to scale up our thinking about space exploration, move beyond the exploration part into the exploitation part, where we are doing things on an industrial scale. Because industry is going to be the key to space, not exploration. The exploration will be made possible by the advances which are brought about by the industrialization. Visiting asteroids looking for light metals will teach us how to survive for long periods in deep space, which will enable a mission to the satellites of Mars. I am not sure what will enable a mission to Mars itself, as Earth governments are going to be reluctant to finance colonization efforts, and our robotic probes are advancing so rapidly that the science can be done by machine.

Science needs scientists and the reality we see at ISS would be the same as Mars. Going to Mars uses little more propellant then going to the moon. Modular cyclers make the most sense, LEO to LMO or lunar orbit. It would be a lot safer and relatively cheaper then early Antarctic stations. More like ISS with dune buggy privileges.

 

[frodo1008]

Well wow then it should be no more difficult to go on to Mars than it would be to go to the moon, right?

Whoa, wait a minute, even though the mass propellant would be approximately the same, with the current state of technology (chemical rocket propulsion) it is at the least a month to get to Mars for every day to get to the moon. It is at best some 400 times as far away to get to Mars as it is to get to the moon.

Does this possibly cause problems? Well, when the Mars going craft is some millions of miles away from the Earth and ANYTHING goes wrong there is quite probably going to be very little chance of some kind of an Apollo 13 type of rescue, now is there?

And this is without the chances of a solar flare frying everybody that would increase by at least the same 30 times during that much longer time in space. I know, the ISS people are up there at least as long, but they are somewhat protected still by the Earth's atmosphere and magnetosphere, as they are only up at an altitude of some 200 miles above the Earth's surface, and a Mars bound ship is going to be totally out in space and unprotected.

Then all that added time may not result in more propellant, but it might just mean a bit more in life support materials, by a factor of at least 30 times (months instead of days).

We ARE going to need the almost total resources of the Earth/moon system to build the necessary infrastructure in nearby space before we have the ability to reliably go as far out as Mars, and certainly even further out.

And with the discovery of viable amounts of water at the poles of the moon, the moon even more becomes the first destination, if we are going to so industrialize space in such a manner that building the necessary elements to go further out becomes not only viable, but far less expensive than having to bring everything up out of the relatively thick atmosphere of the Earth, to say nothing of a far greater gravity well to overcome just to get to even LEO let alone anywhere else!!

In the meantime I would say that our robotic explorers are certainly doing a fair job of exploration of Mars anyway, and it is they that must take the chances initially on an entire new world. So sending very vulnerable human beings at any conceivable time in the relatively near future becomes not only very dangerous, but even somewhat superfluous!

In fact, until such a time as people like Elon Musk and Burt Rutan can really have a chance at a true Cheap Access To Space System that is both relatively safe, and far more inexpensive than it has been up to now, then even going back to the moon may very well prove to be too expensive for the US.

So THAT is the area (along with more and more sophisticated deep space robotics) that needs the most concentration on at this time!!

 

[annodomini2]

I like the idea of replacing LH2 with RP-8 as a fuel. This would reduce the complexity and cost of frequent flights. In terms of the SKYLON/Sabre engine concept, the reduced thrust might be offset by the advantages of air launch. In terms of cooling the compressed air for the Sabre engine, I wonder if an extra allowance for LOX might be made so that LOX can be uilized for cooling the helium inter-loop rather than LH2. These thoughts are, of course, considerations for the engineers to work out. I have no idea if they are practical or not.

Chris

The LH2 is used to cool the inlet, LOX is used to cool the combustion chamber, not feasable.

 

[csmyth3025]

Does this possibly cause problems? Well, when the Mars going craft is some millions of miles away from the Earth and ANYTHING goes wrong there is quite probably going to be very little chance of some kind of an Apollo 13 type of rescue, now is there?

We ARE going to need the almost total resources of the Earth/moon system to build the necessary infrastructure in nearby space before we have the ability to reliably go as far out as Mars, and certainly even further out.


In the meantime I would say that our robotic explorers are certainly doing a fair job of exploration of Mars anyway, and it is they that must take the chances initially on an entire new world. So sending very vulnerable human beings at any conceivable time in the relatively near future becomes not only very dangerous, but even somewhat superfluous!

I have to disagree with the above quoted three items. Regarding the first, think back to when the European nations as well as the China were sending ships out to explore for new trade routes and new lands. These ships and the seamen they held were completely on their own once they left sight of land. Their voyages lasted literally years. Despite the hardships and the very distinct possibility that they would be lost at sea, there were people willing to make these trips and governments willing to fund them. Going to Mars is not so different risk-wise.

On the second item, I think claiming that we would "...need the almost total resources of the Earth-Moon system to build the necessary infrastructure in nearby space..." is somewhat like a 1950's politician claiming that we would need almost the total resources of the United States to build the interstate highway system. Both statements are gross exagerations. More importantly, in both cases building the infrastructure, maintaining the infrastructure, and just having the infrastructure for entrepreneurs to utilize are - in themselves - economic drivers that can propel greater development.

On the subject of robotic exploration (of Mars, specifically), robots are ok to get preliminary data, but they're no substitute for having "boots on the ground" as our friends in the military like to say.

Chris

 

[frodo1008]

Yes, and perhaps the greatest of these voyages was probably Fernando Magellan's around the world voyage. He started out with five ships and some 250 men, want to know how many actually made it?

One ship with only 18 men made it back!

We always hear about the success of these early exploratory voyages, but what we do not here is the very high failure rate.

In getting human beings to Mars we can NOT have that kind of failure, the people, whether taxpayers or private investors will not put up with that kind of loss of life, nor even the expense.

And sending only one ship with even as many as a dozen people would be an invitation to disaster, not only for that specific mission, but for any continuation of such missions in the future! Can you even begin to imagine the media circus that would form around such a mission if anything were to go wrong?

And in such a complex and lengthy mission Murphy's law would almost guarantee that something will go wrong. They certainly did not expect that a simple procedure such as stirring the cryo tanks to blow up the service module on Apollo 13, now did they (that is NASA, and they were the experts at that time on such things)?

So, the only real way to ensure that such a mission will be a success is to send enough ships to Mars that even if a couple of them should fail, the people could use the rest to complete the mission and come home safely. We may not need a five to one margin such as Magellan had, but we are going to have to have a very good redundant safety margin or risk not only the lives of some very good people, but perhaps the very space program even setting out again before the end of this century.

And having this much material in space to get to Mars is going to be vastly expensive if all of that material is brought up from the Earth. Hence, we must first learn to reliably get to the moon, not only for further exploration, but mainly to mine the materials there, and learn to use those material to build the infrastructure necessary to ensure at least a 99.9% mission success in taking human beings further out into the solar system.

It is far easier (and therefore far less expensive in the long run) to make use of the materials that are already up and outside of the gravity well of the Earth, than is is to get those materials up from the Earth itself. If humanity is ever to form a true space faring civilization that truth is going to have to be observed!

Heck, humanity is going to have to build a true CATS type of system(s) just to even be able to begin to make use of those resources in the first place, wasting that effort on just going to Mars for the sake of adventure is not going to cut it with those that are going to have to foot the bill for this, either with their very lives, or even with their money.

That may be a more conservative and somewhat more boring approach, but it is the way to an eventual successful human space faring civilization in space.

 

[Booban]

People were pretty stupid back then. We don't do that **** anymore...

I don't really know why a crew would willingly go on such expeditions other than stupidity, fatalism and life was cheap back then, and people poor. They thought people could fall off the earth, that there were sea serpents, cannibals (somewhat true), couldn't even swim, and they should've known about scurvy and still made these long voyages. One thing about Columbus trip was that they did not expect it to take so long, otherwise they probably would not have gone.

But they actually knew a lot about seafaring and their ships worked. We don't have any reliable spaceships that have been flying back and forth to the moon flawlessly over several decades. So from the get go their tech was much more advanced than where we are now in comparison.

 

[scottb50]

People were pretty stupid back then. We don't do that ____ anymore...

I don't really know why a crew would willingly go on such expeditions other than stupidity, fatalism and life was cheap back then, and people poor. They thought people could fall off the earth, that there were sea serpents, cannibals (somewhat true), couldn't even swim, and they should've known about scurvy and still made these long voyages. One thing about Columbus trip was that they did not expect it to take so long, otherwise they probably would not have gone.

But they actually knew a lot about seafaring and their ships worked. We don't have any reliable spaceships that have been flying back and forth to the moon flawlessly over several decades. So from the get go their tech was much more advanced than where we are now in comparison.

All seems like much ado about nothing. Getting in bathtubs kills a lot of people a year. If something happens in Space your pretty much toast, same as an airliner pretty much.

Safety should be the paramount issue. Orbit takes big engines and light-weight tanks, fully re-usable their cost diminishes with use.

 

[halman]

Hi,

Become a scientist is the cheap easy for space in my point of view. You have to become a scientist to go on space.
Cheapest space craft also the main way to the space .



-------------------------


Cheers !

Welcome to Space.com discussion boards!

What this discussion is about is a way that would make it possible for large numbers of people to go into space, to work, not as tourists, because so much work will be available. Who knows what the cheapest spacecraft is? So far, none of the expendables has been mass produced, and the only reusable craft is a monster weighing 120 tons. Why is the current space shuttle so heavy? Does this mean that any lifting body-type space craft must be heavy?

Because NASA was faced with the space shuttle being the ONLY means of putting things and people in orbit, they had to make it big, because the Air Force wanted to orbit giant recon satellites, as big as a boxcar, and weighing nearly as much. All of the concepts of a small, passenger shuttle got tossed out the window, and the design was scaled up to include a payload bay. But that made it impossible to hold the fuel inside the space craft, so they had to have an external tank, which weighed so much that they had to add the solid rocket boosters to lift the E.T.

The three engines which feed from the E. T. produce hundreds of thousands of pounds of thrust each, and are securely mounted in a massive frame. The entire airframe is rugged, built to take at least 6 or 7 gees, while transporting 50 tons of payload. It has to deal with off-center loads, and the torque that they impart to the frame. So just scaling the orbiter weight down to a smaller payload is not accurate. It must have internal tanks to carry all propellant, which will be empty when landing. Thrust should be through the center of gravity, if at all possible. And wing area should be increased prior to landing, if possible. Most importantly, it should be constructed of composite carbon materials, which can reduce weight and increase strength.

Instead of 120 tons empty weight, this space craft should have about 20 to 25 tons empty weight. 100,000 pounds of thrust will be more than enough to push this craft into Low Earth Orbit in a matter of minutes. Kerosene and liquid oxygen would provide enough ISP to perform the mission, and their use would minimize structural requirements for cryogenic material. So we would have a shuttle nearly the same size as the current one, but with no external tank. It would probably weigh a little less, around 100 tons, maybe, fully fueled and loaded, but it would be completely reusable, as would be the carrier wing.

And launch would only involve a small number of people, about 20 probably, not counting the actual crew and passengers. And launches could occur in much more unstable weather than now, so there would be fewer aborts due to weather. Tracking from space would eliminate the need for ground based systems, and visibility requirements would be met virtually always, as the carrier wing would lift the shuttle above any weather prior to launch.

This system offers the potential for high flight frequency, with a minimum of turnaround maintenance. A special carrier wing might be built as a ferry, to transport empty orbiters back to the launch site, so that alternate landing sites could be used. On-orbit endurance can be minimized, so that the requirements for life support are not as extensive as on the current shuttle. Life support packages could be made modular, so that a fully loaded module is swapped out for a depleted one, rather than recharging while the vehicle is in turnaround. Motors could be made the same way, so that tested motors are installed after each flight.

Without some kind of a space liner, the conquest of space can never start. We need people in space, lots of them, and the system described here is a way to get them there, cheaply, safely, and reliably.

 

[frodo1008]

I fully believe that you are correct Halman. Also, I further believe that so does Burt Rutan and his people at Scaled Composites. He is now working towards a profitable system for sub orbital flight, but using those profits he is really headed towards point-to-point profitable flight for getting to and from any reasonably large airport on the Earth in less than two hours (less time than the average in-flight movie).

Then finally, I do think that his eventual goal is true Earth surface to LEO flight at a reasonable rate for any healthy person that can afford it.

He will be doing this with a much larger launch aircraft than even the mother ship of SpaceShipTwo, (I think it is called Eve), A mother ship in the 747 or A380 class, built almost entirely of very large composites with a twin boom kind of design.

Such a ship could relatively easily carry an orbital craft which would have combination propulsion of a hypersonic and linear type aerospike engines with perhaps a small booster rocket carrying at least some 10 passengers and a crew of two.

Such a craft would be capable of launching at least once a day from any large airport with the needed facilities, certainly in the beginning either Mojave or Palmdale airports where Scaled Composites is already located.

I see absolutely no show stoppers for this, and knowing the nature of Rutan and his people do not see why it could not now be accomplished within the next decade or so.

In the meantime, I also see no reason why that other great rocket builder in spacex with Elon Musk could not use COTS to build not only a Dragon Capsule capable of reaching the ISS (whether powered by such as the Delta IV or the Falcon 9 Heavies is irrelevant to me at least) that would not only take materials up to that platform (and why ever talk of just eventually having it crash into the atmosphere when it would be just as easy to boost it up higher to a permanent orbit, if for no other reasons than historical ones) but also be capable of both being a lifeboat for the entire ISS crew as well as bringing up entire crews with one launch!

I see no reason why spacex could not do this within three years with reasonable government funding from NASA.

I think that these are the only currently reasonable and viable choices for a true CATS type of system. And Rutan's ideas still leave plenty of room for your eventual idea of a launching type of meg lift system also.

So, there IS hope.......

 

[WannabeRocketScientist]

I have recently become a really big supporter of the space elevator idea. This would provide for the lowest price for space access obtainable, cheaper than rockets or reusable spacecraft. Bring the spacecraft or passengers up the elevator, and launch.

However, with present technology I think, since we can't seem to get it together on heavy lift rockets affordably, we can simply put a rocket on a helium- filled balloon to float it high into the atmosphere, then fire off the rocket. This would reduce the amount of necessary fuel, bring down costs, and give a somewhat reusable system for putting satelites and hardware into space cheaply and safely, as, like a weather balloon, you could at the least recover the balloon for recycling. You would also need less rocket stages, as the rocket would be travelling a smaller distance, with a significantly less amount of drag and forces working against it at the start of launch.

I say we bring back the "rockoon" concept. Its attainable now, and it has been tried and tested (http://en.wikipedia.org/wiki/Rockoon), so it would most likely require little development if we simply kept it simple and kept its primary goal in mind, to put stuff in LEO (or possibly geostationary) cheaply and to work as a stepping stone to high-lift rockets or a space elevator.

 

[scottb50]

I fully believe that you are correct Halman. Also, I further believe that so does Burt Rutan and his people at Scaled Composites. He is now working towards a profitable system for sub orbital flight, but using those profits he is really headed towards point-to-point profitable flight for getting to and from any reasonably large airport on the Earth in less than two hours (less time than the average in-flight movie).

Then finally, I do think that his eventual goal is true Earth surface to LEO flight at a reasonable rate for any healthy person that can afford it.

He will be doing this with a much larger launch aircraft than even the mother ship of SpaceShipTwo, (I think it is called Eve), A mother ship in the 747 or A380 class, built almost entirely of very large composites with a twin boom kind of design.

Such a ship could relatively easily carry an orbital craft which would have combination propulsion of a hypersonic and linear type aerospike engines with perhaps a small booster rocket carrying at least some 10 passengers and a crew of two.

Such a craft would be capable of launching at least once a day from any large airport with the needed facilities, certainly in the beginning either Mojave or Palmdale airports where Scaled Composites is already located.

I see absolutely no show stoppers for this, and knowing the nature of Rutan and his people do not see why it could not now be accomplished within the next decade or so.

In the meantime, I also see no reason why that other great rocket builder in spacex with Elon Musk could not use COTS to build not only a Dragon Capsule capable of reaching the ISS (whether powered by such as the Delta IV or the Falcon 9 Heavies is irrelevant to me at least) that would not only take materials up to that platform (and why ever talk of just eventually having it crash into the atmosphere when it would be just as easy to boost it up higher to a permanent orbit, if for no other reasons than historical ones) but also be capable of both being a lifeboat for the entire ISS crew as well as bringing up entire crews with one launch!

I see no reason why spacex could not do this within three years with reasonable government funding from NASA.

I think that these are the only currently reasonable and viable choices for a true CATS type of system. And Rutan's ideas still leave plenty of room for your eventual idea of a launching type of meg lift system also.

So, there IS hope.......

As long as we can put it together in orbit, how it gets there is a matter of demand. Asteroids or the moon would be base line, Mars would be even bigger but the same thing. A simple rocket that could take a thousand pounds of payload and a module to LEO. Rutans carrier can carry any number of payloads, I would be surprised if a thousand pounds to orbit is not within reach right now.

 

[halman]

I have recently become a really big supporter of the space elevator idea. This would provide for the lowest price for space access obtainable, cheaper than rockets or reusable spacecraft. Bring the spacecraft or passengers up the elevator, and launch.

However, with present technology I think, since we can't seem to get it together on heavy lift rockets affordably, we can simply put a rocket on a helium- filled balloon to float it high into the atmosphere, then fire off the rocket. This would reduce the amount of necessary fuel, bring down costs, and give a somewhat reusable system for putting satelites and hardware into space cheaply and safely, as, like a weather balloon, you could at the least recover the balloon for recycling. You would also need less rocket stages, as the rocket would be travelling a smaller distance, with a significantly less amount of drag and forces working against it at the start of launch.

I say we bring back the "rockoon" concept. Its attainable now, and it has been tried and tested (http://en.wikipedia.org/wiki/Rockoon), so it would most likely require little development if we simply kept it simple and kept its primary goal in mind, to put stuff in LEO (or possibly geostationary) cheaply and to work as a stepping stone to high-lift rockets or a space elevator.

There is no denying that a space elevator would be the ultimate transportation system to get people and goods into and back from space. But we are several orders of magnitude in technology away from being able to implement such a system.

The rockoon was an early attempt to overcome the difficulty in launching directly from Earth. Because aviation was still in its infancy, there was no ability to carry a payload to an extreme altitude, and balloons were the only method available. However, the size of the balloons versus the size of the rockets was dismaying, to say the least, and very large balloons require nearly perfect conditions for launch themselves.

You suggest using a helium filled balloon to carry the orbiter to a high enough altitude for launch, but you may not be aware of the critical shortage of helium the world is experiencing. Helium is produced on Earth only by the radioactive decay of uranium and thorium, I believe, or some other heavy metal, and it is so light that it tends to escape from the planet fairly quickly.

What I am advocating is a launch system that uses an aircraft to carry the orbiter to 50,000 feet, where it would be launched closer to horizontally than to vertically, so that all of its fuel can be used to accelerate, and very little, if any, to fight the force of gravity. This enables much smaller engines to be used, and lighter vehicles, because they do not have to deal with the stresses of a vertical take off.

 

[halman]

As long as we can put it together in orbit, how it gets there is a matter of demand. Asteroids or the moon would be base line, Mars would be even bigger but the same thing. A simple rocket that could take a thousand pounds of payload and a module to LEO. Rutans carrier can carry any number of payloads, I would be surprised if a thousand pounds to orbit is not within reach right now.

We don't seem to have any problem putting cargo in orbit, it is just people that we have a problem with. But, without people, there will be no Third Industrial Revolution, no Lunar mining, no nothing. Breaking out of the lockstep thinking that we HAVE to launch straight up is essential to moving to the next generation of space craft, I believe. Launching cargo straight up is no problem, because we can lose a payload now and then. But we cannot take that attitude with passengers, which means that launching people straight up is always going to be much more expensive than launching cargo straight up.

At one time, we had no choice but to launch straight up. Now, we do. We are also re-examining some of the goals of our space program, to see if they are truly what we need to achieve the most right now, or if they are merely the result of romantics insisting that we keep moving outwards, irregardless of the technology we use to do it. A few years delay in reaching the Moon may make the difference between two or three people visiting the Moon briefly, and hundreds of people going there for months at a time to live and work. We know that we can get there, so let us make sure that we get there in a way that we can use over and over again, and in a way which will allow many of us to travel there at one time.

 

[vulture4]

Fist, congrats to Halman. This thread hits the nail on the head. I'd like to try to explain why we need this new direction, and how we got into the fix we're in.

The other problem is that the other safer, cheaper technologies aren't actually here today. If they were, we'd have already seen them heading up to space to do all the stuff our Shuttle can't. That stuff is currently fiction. I'm not willing to wait around for a hypothetical when I have something that works right now.

They might be here, if O'Keefe and Griffin hadn't cancelled the Reusable Launch Vehicle program.

During the building of the Shuttle, NASA made one major technical error. Previously aviation had been incremental; test each part, build a prototype, fly a little, learn a little, build another prototype. Finally, when it works well, build an operational aircraft. But during the Apollo program there was so little time that it was decided to design the final model of the huge rocket, all on paper, by the new method of "systems engineering", then build it and test all the parts at once. It worked, but only because they were lucky and because cost was completely irrelevant. They tried the same thing with the much more complex Shuttle, building the final design with no in-flight testing of any of the major components. It was amazing that it flew. It should not have been surprising that there were unanticipated costs and unanticipated failure modes. It has taken all these years to finally straighten out the risks and begin to reduce the cost.

In the 1990's NASA understood the problem. That's why the X-33, X-34, X-37 and DC-X were funded, to develop and test the design elements for a new generation of shuttles that would be practical and safe. But Sean O'Keefe and Mike Griffin, despite being NASA administrators, had no idea why they were important, and canceled all these programs between 2000 and 2004. It was then, not in 1974, that NASA dropped the ball.

Now there is a furious battle in the press over whether SpaceX and ULA can launch people safely, or whether only NASA can do it. Both are wrong. The only NASA employees who put their hands on the Shuttle are the crew. The only workforce in the world that has person-centuries of experience actually maintaining reusable spacecraft, that has the "tribal knowledge" that can't be codified, that could avoid the problems of Shuttle in a new generation of reusable spaccraft, are the hundreds of contractor engineers and technicians, mostly with USA, who actually maintain the Space Shuttle.

After thirty years, the Space Shuttle is finally flying amazingly well. The NASA budget has actually increased. We could easily keep Shuttle safely flying until a reusable successor is available. Logically a new reusable program should be started in parallel, so personnel and knowledge can be shared between the programs. Then, when the new vehicle is operational, the old one can be gradually withdrawn with no gap in operations. Instead, while newspace entrepreneurs and NASA administrators fight over who knows how to launch safely, all the people with real experience in maintaining reusable spacecraft will be fired and dispersed forever, and the dream of spaceflight, not as spectacular for a few, but rather as routine for many, will be dead for at least a generation.

 

[frodo1008]

Your post was excellent, and very true vulture4.

The only even partial discussion that I would have is that all hope is not lost at this time, for one thing Congress seems quite rightfully upset over the plans to eliminate the shuttles without having any other method of getting Americans into space other than relying on the Russians (and who is to say that some kind of geopolitical happening may shut that off too?).

Of course, I must admit that it certainly looks like that is what is going ot happen with NASA, and I (like yourself) am totally against it!

And I do not consider spacex and its Dragon capsule to be the hope that I refer to. That is just going backwards to systems that we know work, but will be just as inefficient and eventually as expensive as such systems originally were.
But at least (if spacex is as good as spacex says it is) it is something in the meantime, even if converting the Dragon over for human beings is going to take at least three years even if it is fully funded.

No, the hope that I refer to is the pure commercial efforts of Burt Rutan and Scaled Composites along with the money behind such an effort by Virgin Galactic. There are a couple of reasons for my hope in these efforts.

One: Is that it IS a commercial effort, and therefor it is to be profitable. It is this that will keep its costs down to reasonable levels. And although it has to be designed to take relatively wealth people eventually into space, it will be incremental enough that the price will eventually come down to where thousands and even eventually far more will be able to afford to get into space.

Two: Is that Burt Rutan understands the incremental process that you stated is so important in your excellent post.

First, he is going to establish a business of taking people up for a sub orbital flight to and from the same airports and facilities.

Second, I am certain that he is already working on (and may even eventually partner with such as Boeing) on a system that not only goes upwards to sub orbital flight, but also goes point-to-point anywhere there is a suitable airport on the Earth in less than two hours. This would probably require such a whole lot more of craft in both mother ships and transport vehicles that it my very well require the expertise and manufacturing capabilities of such a large aerospace company as Boeing, but Rutan will lead the way I am also certain.

Third, I am just as certain that Rutan's eventual goal will be to go the extra mile and build a practical system (such as both myself and Halman advocate as well as I believe that you do also) for taking relatively large amounts of people all the way up to LEO.

My understanding of a generation is about 20 years, and I do not think that this process is going to take more than about 10 years. So, make that half a generation, but as we first went into space with human beings some Two generations (or about 40 years ago), this is to me at least some expression of hope.

And I would rather have seen NASA do this myself, but perhaps it is indeed better if pure private capitalistic for profit efforts is the driving factor, rather than the hit and miss proposition of pure politics!!

Anyway, your post, like Halman's posts, was indeed very perceptive and well written, so my thanks to you!

And Have A Very Excellent Day!

 

[scottb50]

We don't seem to have any problem putting cargo in orbit, it is just people that we have a problem with. But, without people, there will be no Third Industrial Revolution, no Lunar mining, no nothing.
I think it's more a cost thing and the lack of things to do that would make money. Launching cargo is no more difficult then launching people when having people in LEO to manage and maintain facilities gets to be cheaper then over-engineering and building more complex payloads. Once you make it cheaper to lease a transponder, or sensor, by installing it in a manned facility and the facility can be supplied in a timely fashion you start to build infra-structure. Next you use empty upper stages and cargo containers to build other things.
Breaking out of the lockstep thinking that we HAVE to launch straight up is essential to moving to the next generation of space craft, I believe. Launching cargo straight up is no problem, because we can lose a payload now and then. But we cannot take that attitude with passengers, which means that launching people straight up is always going to be much more expensive than launching cargo straight up.

At one time, we had no choice but to launch straight up.

Now, we do? Show me the existing facility or vehicle. Straight up is the least expensive and, if done right the safest approach. With a side mounted second stage, firing during launch anyway, escape would be pretty easy. A separate rocket motor for the crew module would allow zero-zero escape capability in a worst case.

Once enough Modules get to LEO and industry will happen. Attach them to other Modules, outfitting them internally however you want. From there you could build more infra-structure in LEO or pursue further adventures.

 

[ZiraldoAerospace]

What pisses me off is that NASA has just been sitting around wasting money while they were flying the shuttle yet they had no backup plan! As mentioned, they built the X-33, X-34, X-37, HL-20 and a couple of other viable alternatives only to cancel each one a couple years into development! If they had just gone through with one of those we wouldn't be in this situation, but they spent billions half producing several easily possible designs. Also, NASA seems to over complicate everything when it comes to manned flight. Why will it take them 4-5 years to man rate and build a capsule for a Delta IV or Atlas V? I don't understand, why the wait?