NASA space ship

The idea of a spacegoing 747 is essentially a reprise of arguments for a SSTO, which has been studied on and off since the 1960's.

If you look at sites like Encyclopedia Astronautica you will find descriptions of literally dozens of projects, and they all have one thing in common: they never got built.

Why not?

Probably for the simple reason that any SSTO will have a fuel fraction of 90%, leaving only 10% of the lift off mass for structure and payload. Any issues at all will pretty effectively eat the entire payload mass (extra bracing, more robust engines etc.), meaning any SSTO of any configuration is going to be pretty marginal, at best. The closest anyone has gotten to even a reasonable pre prototype is the "DC-X" program, and it would be a very long shot to develop it into an actual flyable to space piece of hardware.

The short answer is rocket technology as currently practiced is not the answer for lifting payloads to orbit in an economical manner, but virtually any non rocket system either has massive ground infrastructure, small payloads or both. Launching a laser powered "lightship" like the ones Liek Myrabo proposed has light and reusable spacecraft, but instead of needing 35GW generated through massive rocket engines for a Saturn sized payload, you need 35 GW of laser energy delivered to the receiver during flight. A "Lofstrom Loop" is megaengineering on a massive scale (and only launches 5 tons at a time), and "skyhooks" require material science technology that hasn't been invented yet. You can do the calculations for mass driver or railgun systems.

And as for air breathing systems, look up LACE (Liquid Air Cycle Engine). This has been worked on off and on since the 1960's, and Skylon is only the latest example, which should suggest that this is not an easy trick to pull off.

So for the moment, my money is on Elon Musk and SpaceX, which is massively lowering the costs of travel to orbit through the simple expedient of streamlined management structures (no one could suggest the Falcon9 is qualitatively different from the Atlas, yet UA charges $400 million/launch while SpaceX charges @ $50 million).

Rather than continue to flog the SSTO idea, I would like to direct your attention to an idea for a "covered wagon" spaceship proposal:

http://www.centauri-dreams.org/?p=32311

Now while this hand waves the issue of getting to LEO, once we are there then economics will push spacecraft design towards a solution of this sort if only because larger and more elaborate ships will simply be unaffordable.

I also believe this sort of thinking will also inform a lot of other design choices. NTR rockets won't be elegant devices powered by LH2 and offering ISP's of 1200 seconds, but brute force "steam rockets" pumping liquid water through the core and ejecting steam at a fraction of the ISP, in order to eliminate cryogenic tankage, devices to split water into H2 and O, liquification plants, refrigeration units etc. "Cargo ships" simply won't exist because shippers will want to use minimum energy orbits which take decades to complete; far better to simply shoot an ISO container from a mass driver to some sort of orbital "catcher's mitt" device at the target. Solar sails or some equivalent (magsails or electrostatic sails) will probably dominate space commerce outside of bulk freight because they are economical.

For most space going hardware and software, these economic drivers will push things to simple, inexpensive and relatively rugged solutions, much like most consumer goods on Earth are today (planned obsolescence aside, even so, most items require virtually no operator or owner maintenance at all during the item's life, which suggests that designing things to last "forever" is indeed possible, should an incentive exist to do so).

Rather than continue to flog the SSTO idea, I would like to direct your attention to an idea for a "covered wagon" spaceship proposal:

http://www.centauri-dreams.org/?p=32311

Now while this hand waves the issue of getting to LEO, once we are there then economics will push spacecraft design towards a solution of this sort if only because larger and more elaborate ships will simply be unaffordable.

Maybe, possibly... Issue tend to be that all the complex stuff that is needed for each ship, is also the expensive and troublesome part, so, building big means that the expensive parts become a much smaller part of the total cost, and thus means more payload compared to total weight and cost.

Personally being a longtime Elite, Space Rouge and Privateer 2 player, i definitely like the idea of being able to achieve a "Volkswagen in space", it all depends on what techs that can be realised.

My focus has long been on a constant thrust for minimal fuel use engine, but cheating physics isn´t easy.
It´s one of the techs that could let small&cheap spacecrafts prevail.
Another very desirable component would be an EM shield capable of drastically reducing cosmic radiation, while not relying on size nor scaling up.

For most space going hardware and software, these economic drivers will push things to simple, inexpensive and relatively rugged solutions, much like most consumer goods on Earth are today (planned obsolescence aside, even so, most items require virtually no operator or owner maintenance at all during the item's life, which suggests that designing things to last "forever" is indeed possible, should an incentive exist to do so).

Space is trickier. "simple, inexpensive and relatively rugged" is rather difficult to combine with space unfortunately.

And in regards to item lifetime, try finding the article about the east German lightbulb.
They designed one with a basic lifetime around 80 years of constant on, and rightfully thought "damn we´re good!", but when they offered the design to some west German company, they pretty much panicked, as it would totally remove their massproduction need. The lightbulb wasn´t even very expensive, maybe 5 times more than a regular one, for 50 times longer lifespan.

Point being that yeah, lots of things really can be built to last "forever". If someone really wants it.
Space does mess up the equation though, radiation and extreme cold with the occasional extreme heat, or worse, the rapid hot/cold of a standard planetary orbit, really not nice for the materials science engineers.

Still, materials science is going places so maybe we can get some neat stuff sometime soon?

Tenshinai wrote:

Rather than continue to flog the SSTO idea, I would like to direct your attention to an idea for a "covered wagon" spaceship proposal:

http://www.centauri-dreams.org/?p=32311

Now while this hand waves the issue of getting to LEO, once we are there then economics will push spacecraft design towards a solution of this sort if only because larger and more elaborate ships will simply be unaffordable.

Maybe, possibly... Issue tend to be that all the complex stuff that is needed for each ship, is also the expensive and troublesome part, so, building big means that the expensive parts become a much smaller part of the total cost, and thus means more payload compared to total weight and cost.

Personally being a longtime Elite, Space Rouge and Privateer 2 player, i definitely like the idea of being able to achieve a "Volkswagen in space", it all depends on what techs that can be realised.

My focus has long been on a constant thrust for minimal fuel use engine, but cheating physics isn´t easy.
It´s one of the techs that could let small&cheap spacecrafts prevail.
Another very desirable component would be an EM shield capable of drastically reducing cosmic radiation, while not relying on size nor scaling up.

For most space going hardware and software, these economic drivers will push things to simple, inexpensive and relatively rugged solutions, much like most consumer goods on Earth are today (planned obsolescence aside, even so, most items require virtually no operator or owner maintenance at all during the item's life, which suggests that designing things to last "forever" is indeed possible, should an incentive exist to do so).

Space is trickier. "simple, inexpensive and relatively rugged" is rather difficult to combine with space unfortunately.

And in regards to item lifetime, try finding the article about the east German lightbulb.
They designed one with a basic lifetime around 80 years of constant on, and rightfully thought "damn we´re good!", but when they offered the design to some west German company, they pretty much panicked, as it would totally remove their massproduction need. The lightbulb wasn´t even very expensive, maybe 5 times more than a regular one, for 50 times longer lifespan.

Point being that yeah, lots of things really can be built to last "forever". If someone really wants it.
Space does mess up the equation though, radiation and extreme cold with the occasional extreme heat, or worse, the rapid hot/cold of a standard planetary orbit, really not nice for the materials science engineers.

Still, materials science is going places so maybe we can get some neat stuff sometime soon?

"simple, inexpensive and relatively rugged" also implies occasional failure, in an environment where a failure can easily cause death. Not the way I want to go.

Simple inexpensive and relatively rugged covers things like using a massive water shield and microwave heated water plasma for thrust rather than various nuclear or ion engines for thrust and magnetic or electrostatic radiation shields; simple, cheap and far fewer failure modes.

To think that there are "no" failure modes is ridiculous, what we need to think about is how to build things where there are fewer places where failure can take place, or are relatively easy to fix.

While Volkswagon sized spacecraft would be useful, I rather doubt that any manned spacecraft could be built at that size. A possible exception would be a "work suit" or pod like the ones in 2001 with very limited time on station, deltaV etc. Even a "space fighter" like an X wing or Starfury would be rather implausible in real life (just to drive the point home, look at the apparent size of these spacecraft by comparing the size of the pilots to the ships, then look at a real fighter like an F-15 compared to the size of the pilot).

Once you factor in life support, radiation shielding and the fuel or remass needed to move around in space (not to mention the power plant to run the drive system) and I think your smallest space ship would be rather large compared to vehicles on Earth. I would guess that a small jet like a 737 might be the starting point for comparison (think of the wings as the radiators). Add booms and shadow shields if we have nuclear reactors and things get even larger....

While Volkswagon sized spacecraft would be useful, I rather doubt that any manned spacecraft could be built at that size.

Not SIZED... That would be utterly useless.

I was referring to that kind of niche.
Something cheap enough that just about anyone who really wants one probably also CAN get one.

Even a "space fighter" like an X wing or Starfury would be rather implausible in real life (just to drive the point home, look at the apparent size of these spacecraft by comparing the size of the pilots to the ships, then look at a real fighter like an F-15 compared to the size of the pilot).

OTOH, an F-15 is a HUGE fighterplane. You have to cut 5m length and wingspan to get down to the Gripen for example.
And Gripen is only slightly longer than the "official" length of an X-W. And the latter doesn´t need to bother with lateral stability stuff in atmosphere.

So, definitely not directly comparable, and also not outrageous, just a bit on the too extreme side.

Thucydides wrote:Simple inexpensive and relatively rugged covers things like using a massive water shield and microwave heated water plasma for thrust rather than various nuclear or ion engines for thrust and magnetic or electrostatic radiation shields; simple, cheap and far fewer failure modes.

Unfortunately those solutions are often heavy and have a limited performance. As a consequence, both key parts of the rocket equation tend to be affected rather negatively.

aairfccha wrote:

Thucydides wrote:Simple inexpensive and relatively rugged covers things like using a massive water shield and microwave heated water plasma for thrust rather than various nuclear or ion engines for thrust and magnetic or electrostatic radiation shields; simple, cheap and far fewer failure modes.

Unfortunately those solutions are often heavy and have a limited performance. As a consequence, both key parts of the rocket equation tend to be affected rather negatively.

Too true, but if we want relatively inexpensive spacecraft then we need to economize somewhere. Rick Robinson in his Rocketpunk Manifesto website has mentioned that aerospace hardware seems to come in at a price of $10,000/ton, so spacecraft will probably cost somewhere in the same order of magnitude (Elon Musk notwithstanding).

Now Elon Musk and SpaceX demonstrate how advanced "management" practices can cut costs dramatically, but the actual hardware of the Falcon and Dragon are not much different from the ULA Atlas 5 heavy or the "Orion" space capsule, so once you factor out the overhead, then pound for pound, I suspect that the Falcon 9 and the Atlas 5 cost about the same.

Once you are in free space, then out of the box solutions might help; ultra light solar sails which do not have to be folded to deploy will have far superior performance to today's sails (I need to look up the reference, but the K. Eric Drexler design from the 1970's had the theoretical ability to send a payload to flypast Pluto in 3 years from launch). Using a sail like that would provide almost unlimited mobility without the use of remass. You can probably think of other ways to cut down on weight and/or cost.

The other great advantage of developing low cost spacecraft is the demand will increase considerably, allowing the builder to start using assembly line production, driving down costs even more in a virtuous circle.

747 sized space ship is a covered wagon. What we need is an Aircraft Carrier sized small space ship. Big enough to have the CNC machine needed to make what ever needs to be fixed and the spares and raw materials to make extra spares. New designs and unlike a Wagon in space a command system and structure that doesn't have a reliance on others.

The wagons can exist sure but we need the ship that they dock with for help when they need it.

We need this eventually to base our space operations in a given area, say Jupiter station : https://s-media-cache-ak0.pinimg.com/or ... 36d23e.jpg

Or for travel anywhere outside of the near planets and moons that can support life. Unless this is what you mean by a covered wagon, then I'm all for it.

The problem with small space ships is the need for artificial gravity. Without gravity more than a year or two in space and your body will not work once it experiences gravity again. Even reduced gravity like Mars is suggested to have some effect but be survivable for Humanity and future Marslings. Mars has about 1/3 Earth Gravity.

With a small space wagon you can't spin it slow enough to make artificial gravity without causing disorientation for those aboard. A wagon train wagon is great with gravity and an open plain full of food and water and supplies and the ability to get off the wagon.

In space you are stuck on the wagon. Your small wagon has no gravity and your bone mass will wilt away taking you with it. That is why you need a big enough space ship, the bigger the better to make artificial gravity.

The problem with spin induced gravity is that the spin has to affect everything and everyone for them to have gravity. The 2001 space odyssey ship was pretty small, maybe too small if the runner ran the other way they could get close to weightless turn around and double the gravity affect. Plus space sick with the constant whizzing about. Give yourself Mars gravity or half Mars Gravity and you might just have trouble doing basic things. Pee the wrong way and it is worse than peeing into the wind. A champaign cork becomes a missile that beans a girl sunbathing on the other side of the ship (straight up). Golf baseball tennis.... Nope.

Jump off a tall building and despondent Joe ends up floating around the ship until a tree whacks into him. Any thing that flies, bugs, birds, bats, and planes well they become very different things. Spin based gravity only works on the ground. Buildings are fine but Guns bows and rocks become very odd things indeed. Leading a target takes on a whole new meaning and what goes up doesn't necessarily come back down.

Fluids and lakes could have nasty currents and rain wouldn't fall. Boats might be in for a surprise and air cars and planes will use wings to turn fast but not stay aloft. Landing is different, you land with the rotation, vertically from the ground's POV and in a spiral from the planes. Take off is opposite.

It is such a cool thing to consider. A James Bond Bourne Chase scene would be really cool. Scampering from roof top to opposite side of the habitat landing soft in a roll or slammed into a wall.