With the right sort of magic chemicals this might work. But the total mass of chemicals would need to be a huge percentage of the total mass of the shell - perhaps 95+%. No known 19th century chemicals and shell materials would have allowed this to succeed.
The problem with a gas-powered railgun is that the maximum speed of the projectile can never be more than the expansion speed of the gas (in practice, it is always significantly less); once it is moving faster than the gas expansion speed, the gas can never impart additional momentum on it, just as a guy pushing a car will stop applying effort once the car is moving faster than he can run. The most energetic explosives expand at about 8600 meters per second, which is still significantly less than what would be needed to achieve orbit. As Chronos notes, you also can’t circularize your orbit, although a very, very careful calculation of trajectory that includes drag might allow you to maintain a low and unstable orbit for a few passes around.
A plywood motor would be hopelessly overweight, and you’d need far more than a couple of plys. The layup you describe would have the motor popping open like one of those Pillsbury muffin cans when placed in a fire. Modern fiber-wound composite rocket motors have several layers with different wind angles to keep the stresses equalized, and then require a very robust and careful transition between the cylindrical body and the end domes, not only to be able to resist the stresses but also to prevent the dome from expanding unevenly, putting the nozzle out of alignment and making the vehicle unstable.
The RL-10 is an upper stage motor which obtains high performance but relatively low chamber pressures. The comparison to solid rocket motors, especially first stage space launch or long range ballistic vehicles is apples and oranges.
Not true. This is what happens when you don’t steer a vehicle properly. You’ll find that without at least some kind of rudimentary stabilization and steering a vehicle that is sufficiently large enough to make a space orbit will begin tumbling pretty quickly. Heck, the Germans had huge problems with the A4 (V-2) rocket before they built a control system to keep it stable. The problem isn’t just wind shear (although that is a problem not just for control but also structure) but that even a modest irregularity in combustion–say, caused from slag accumulation, uneven propellant combustion, or nozzle liner ejection–will also cause small errors that will rapidly cumulate into unstable vehicle dynamics. In many vehicles this is partially compensated for by rolling the vehicle about its thrust axis stability requiring a separate roll control system (or multiple gimbaling nozzles), but for the most part this control is imparted by some kind of thrust vectoring system (jet vanes, vernier nozzles, liquid injection TVC, pivoting or gimbaling nozzles, et cetera) which is controlled by a sophisticated analog or real time digitial avionics system that is well beyond mechanical computation systems of the 19th century.
Tsiolkovski did a lot of ground-breaking work in applied orbital mechanics, staged rocket conceptual design, and so forth, but his work with avionics controls systems was rudimentary, and much development was would be required to get to practical control systems.
This is not to say that a timeframe more accelerated than that of history could not have been achieved; certainly, rocket development lay fallow for many years of the early to mid 20th century (even, for the United States, after WWII up to the successful Soviet launch of Sputnik I), but in 1880s the materials science, understanding of the theory and application of controls, combustion dynamics, structural and vibration & shock analysis, et cetera were vastly underdeveloped. And throwing more money at this in the 19th century while possibly stimulating the development of some of these technologies would still require several revolutionary breakthroughs. Calling it “just an engineering problem” belies the complexity of the problem in the same way as referring to neurosurgery as “just a medical problem.” The technology of building space vehicle class rockets is fairly well established today, and given a modern understanding of what direction developments needed to take might have been achievable by a knowledgeable time traveler in the 19th century, but from back then looking forward all of the prerequisite technologies are not at all obvious.
The problem with ceramics is that the ones that are good at withstanding thermal loads tend to be brittle, and the ones that are structurally robust tend to break with high thermal impulse. Ceramic materials capable of being both tough and withstanding thermal stresses weren’t developed until the mid-20th century.
Something akin to this (rocket sled launcher) has been considered many times, as in theory it gives you no restriction to the mass or energy carried by the “first stage”. In practice, however, the idea appears unworkable for a number of reasons, including protecting the vehicle during initial impulse, aerodynamic losses, building and maintaining this launcher, et cetera. Burying a cannon in the ground will provide relatively little structural support at the chamber pressures required, and again, you wouldn’t be able to achieve more than a small fraction of the velocity of the expanding combustion gases. Staged rockets are far more efficient despite the parasitic weight of the case and nozzle (and for liquids, the tanks, pumps, et cetera). But rocket staging is a very delicate, very complex operation, hence why many early ballistic rockets, including the orbital-class Atlas, tried to avoid or minimize staging.
Stranger
Wow… take a day away from the boards, and this may be my most successful thread ever!
I want to thank you all (especially the engineers and other learned folks) for participating. Keep it coming.
The good thing with ANY fiction is you can use magical handwaving. I’m hoping to avoid that, as I want this to be… believable, I suppose.
We’ll have to see. I’ll be reading on that paraffin based engine quite carefully… I love the idea, and yes, it is chock full of old tyme goodness!
I don’t think paraffin is going to be energetic enough in a large motor for a space launch vehicle, although if you embedded alumina particles you might get enough resultant thrust. I think, however, you are going to have to compromise somewhat on believability in order to use 19th Century technology to get to orbit; if they could have done it then, someone probably would.
The problem of a sealed chamber is really a nonissue itself; this isn’t really that difficult. What is far more difficult in the days before efficient batteries or catalytic fuel cells would be generating enough energy to scrub breathing air and keep one or more crew alive, and more significantly, being able to re-entry and land safely. Figuring out how to make a reliable thermal protection system took a lot of brain sweat, the best analysis tools of the day, and no small part of guesswork and trial and error, and this was using bleeding edge materials of the 'Fifties and early 'Sixties. It turns out to be not so hard (unless you insist on flying down a winged vehicle rather than a blunt arsed capsule), and the Apollo and Gemini re-entry heat shields were massively overdesigned, but developing the technology and the means for a reliable, controlled re-entry were far from trivial even given the available knowledge and test abilities of that day.
Stranger
Considering this is intended to be (plausible) fiction, I think rudimentary wireless communication is acceptable. Hertz was studying radio waves in the 1880s, and the theory was there since the 1860s.
I could see transmitting simple on/off signals to the rocket to stabilize or change its trajectory. Perhaps even occasional ‘alive-or-not’ communications with a hypothetical crew. Without an FCC, the fictional engineers would have free reign to use the best possible frequencies for transmitting through clouds, the ionosphere, etc.
The receiver would be the hand-waviest part of this setup, as I believe Hertz detected his radio waves by observing a tiny spark cross a gap in a circuit on the other side of his laboratory. There were no tubes or cat’s-whisker diodes, so I have no idea how one would rectify or amplify the signal. But with a Victorian world that includes vastly improved mechanical computers, I think a creative writer could come up with some way to make communicating with the rocket or its occupants plausible.
Neil Armstrong said shortly after returning from the Moon that he felt we had the technology to send humans to Mars. Given Neil’s modest nature, and that he’s an engineer, I’m going to say this wasn’t an exaggeration. We probably would have done it, if it hadn’t been for Nixon.
The bandwidth and throughput of such telemetry would be problematic at best, even given the entire radio spectrum to play with. Without electronic controls only the most simple corrective control systems could be implemented, nothing better than the simple mechanical systems used in the early Aggregat rockets. A guide beam would require at least fairly developed thermionic valve technology, and would only work for the portion of the trajectory that isn’t over the horizon; sufficient for short-intermediate range ballistic missiles like the V-2, but inadequate for an orbital launch vehicle.
With all due respect to Mr. Armstrong, if this is what he said in 1969 or 1970, he was wrong, or more likely, quoted out of context. The United States didn’t even land unmanned probes onto the surface of Mars until 1975. We did not then and do not now have either the life systems or propulsion technology to send people to Mars and return them with a reasonable expectation of success. This is not to say that we could not have developed it in the interim period–with nuclear propulsion technology like NERVA or ORION, and reasonable advances in environmental technology, it is entirely plausible that we could have developed it by the 'Eighties or early 'Nineties–but such a mission with Apollo-era hardware or a linear expansion therefrom would have been a near-suicidal stunt. The Apollo Plus studies included conceptual proposals for a manned Mars mission which never got beyond high level pictureboards because the technology and experience was entirely inadequate.
Stranger
He felt that any technological challenges to overcome would be relatively “minor.” Its discussed in depth in First Man. (IIRC, he said it in September of '69.) He didn’t put us sending a man to Mars with the next Apollo rocket going up, but he felt that we could build what we needed for the mission in less time than it took NASA from JFK’s announcement at Rice, till Neil set foot on the Moon. Given that Neil’s a man known for understatement, one has to conclude that he either failed to understand the challenges (unlikely, but possible) or that he’s right.
The chamber pressure of the RL10 is about 600 psi. That peak pressure occurs in a portion of the chamber that is completely jacketed. The pressure drops gradually through a part of the chamber that is not continuously jacketed. That is the part I was referring to. Whether the RL10 is like or unlike other engines in other respects is irrelevant.
Somewhat surprisingly, I found a reference from 1956 giving the grain-direction strength of pine plywood as almost 20 ksi. That gives it a specific strength on a par with the D6AC used in the shuttle SRBs, which have an MEOP of about 1000 psi and a very large radius, to which the membrance stresses are proportional.
I said a suborbital vehicle would require less sophisticated controls than an orbital vehicle, not that it would need no controls whatsoever. Modern launch vehicles have to be guided through winds aloft in order to preserve structural margins. This requirement could be relaxed considerably at the cost of being able to launch only on very calm days.
I’m not saying it would have been easy, only that it would have required no science beyond that known in 1880. Developing neurosurgery in 1880 would have been much more difficult than building a rocket, for the simple reason that clinical medicine was almost totally unscientific at that time in history.
I’d have to go with the former. We have no experience in keeping people alive and healthy in the low gravity/microgravity and radation environment for the total mission duration of a Hohmann orbit trajectory to Mars and return. We do not have the propulsion technology for a faster trajectory (though in the timeframe of that statement the NERVA/Rover nuclear thermal rocket program was still in progress and grandiose visions of manned space exploration were still in vogue) and the problems of boosting and sustaining sufficient provisions for a 29 month mission without resupply, including landing on a world with some atmosphere and then taking off again with an ascent system which has to remain functional for over a year without servicing, are daunting even today.
This is not to demean Mr. Armstrong, who is not only technically astute but noted for his coolness during crisis (both Gemini VIII Agena docking spin and the Apollo XIII landing), and has consistently refused to profit from his stature; no man more deserved to be the first to walk on another celestial body. But the conclusion that it would take less than eight years to go from a (barely) manned flight to the Moon to a landing on Mars is not realistic. With a dedicated effort, fifteen or twenty years might have been possible (assuming success in the development of necessary technologies) but doing it before 1980 was hopelessly optimistic. Unfortunately, thanks to Nixon, Reagan, and (H.W.) Bush, we’ll never know, and much of the legacy knowledge and experience in developing the technologies for spaceflight has been lost, requiring people to make many of the old mistakes (as well as some new ones) again.
Not if we’re comparing the RL-10 to a solid motor, which is a very different system, mechanically much less complex but operationally more difficult to fly owing to the lack of throttling capability and inherent variability in performance.
The primary failure mode of an undamaged fiber composite pressure vessel is typically interlaminar shear due to variation in strains in transitional zones. You might be able to make the body of the case from plywood sufficient to resist the hoop strains (wood is a very strong material for its weight) albeit the variability in local strength of wood will require substantial overdesign, but when you transition to a terminating forward or aft dome–which is where pressure vessel failures typically occur–you’re going to have very serious problems. You can’t just throw out material strength numbers and call it good; you have to consider the weakest part of the structure where the failure is going to occur. There is just no way you are going to be able to wrap plywood into a continuous dome shape and retain the inherent strength of the wood, and the failure of the adhesive layer in between layups from differential strains is going to cause your plywood pressure vessel to pop like a Chinese New Year favor.
The problem is more than just wind shear and vehicle bending modes through such, though; sure, at low altitudes and significant angles of attack you can use aerodynamic forces to stabilize the rocket, but at a zero-normal angle or in exoatmospheric conditions the vehicle is reliant on thrust vector or attitude system control to maintain direction. This is non-trivial and has been the bane of many efforts to extend workable short range ballistic missiles into longer range or suborbital vehicles.
I have to disagree; it would require both advancements in materials science and avionics controls systems, both theory and application. In addition, an orbital class vehicle would require advances in combustion science for either solid or liquid propellants, and of course the requisite advances in manufacturing technology. Could you have orbital or suborbital vehicles in the 1920s or 1930s, given a directed program with a blank check? Possibly. In 1880? Not a chance.
Stranger
It would certainly demand vast creativity. Even the most basic radio communication would be a serious stretch for that era. To plausibly explain communicating with an orbiting device (whose receiver needs power, a usable antenna, and must survive a violent launch) would strain the pens of the best writers in history. Living occupants are another gigantic hurdle to plausibility.
I don’t see this passing the laugh test.
Neil wanted to use a manual backup pump for the LEM, but was overruled by NASA because it wasn’t “high tech enough.” I’m thinking that someone who was willing to have the “Hail Mary” device be hand operated on something that’s going to be a quarter million miles from the nearest service station is probably not going to want to go with the uberhigh tech solutions which work great so long as you can keep them in pristine condition, but something which will work no matter what. Sort of like the M-16 vs the AK-47 debate. One works well for a modern military, but doesn’t do so well for guerilla forces spending much of their time in rather inhospitible places like swamps and deserts.
"Apollo XIII landing"? (I assume you mean the Apollo XI one, and Neil was also cool during combat and testing of the X-15.)
IIRC, Buzz Aldrin has pretty much agreed with Neil on the matter (and I would suggest not disagreeing with him ;)), and both of those guys were there, not only in the sense that they were “rocket jockeys” but in the nuts and bolts of both the designing and construction phases of the Apollo program. No doubt the engineers put in a great deal of “Scotty factor” into the designs, and it might well have been that Neil was willing to ride on that margin all the way to Mars.
No doubt, being fighter and test pilots.
I recall Werner Von Braun telling an interviewer that he would send five or six ships to Mars, so that they could rescue each other as required.
I’m neither, but I’d be willing to do it all the same. “Boldly going” and all that.
This is not just a matter of low tech versus high tech; it is a matter of reliability and sustaining a livable, enclosed habitat in vacuum and a hostile radiation environment for over two years. This is well beyond the then and now current state of the art in manned spaceflight, and in a Mars mission there would be no means of rescue or aid for any physical defect or breakdown of components.
I stand corrected; it was indeed Apollo XI. Neil Armstrong and Buzz Aldrin may have opined the plausibility of a near-term Mars mission, but there are reams of data and trade studies that show that a credible effort–even the crude ones proposed based upon expanding the Apollo system and using purely chemical propulsion–is easily beyond a decade in development. Nuclear propulsion would help, as would the inexpensive ground-to-orbit capability that the Space Transportation System (Space Shuttle) was supposed to provide (according to advocates), but both are far from reality. The astronauts are, of course, supposed to speak positively about the future of the program, both to the benefit of the space program and themselves, but realistically a manned mission to Mars is an endeavor for which the technology still does not exist in mature form, and a high risk mission is not only unacceptable from a safety perspective but also the overall risk to the program; failure of a one-off, desperate stunt mission could sink such a program.
And this is really the only intelligent way to go this. Although there is additional expense, and a higher risk of failure for any individual ship (more vessels means more inspection effort and quality control issues), the overall mission risk is reduced substantially by redundancy. There are other benefits to multiple vessels as well, including being able to cover more ground once on-orbit, the economy of scale of building several units, a greater payload capacity and the ability to bring non-mission-critical science assistance, et cetera. However, the fundamental problems of long-term exposure to hazardous radiation environs, reliability of non-flight-serviceable systems, et cetera still renders this questionable given the current state of the art. A willingness to invest in research into nuclear thermal or nuclear electric propulsion, cheap heavy lift access to space, serious medical research into alleviating the problems of low gravity and microgravity, et cetera could advance this from speculation to plausibility, but this is still beyond current means.
Stranger
Radiation. They say its bad for you, pernicious nonsense. (I’d quote the article, but the salient points are too deeply buried in other matters to excise out and remain coherent.)
There were scientific pronouncements up until Neil got his footie prints all over the Moon that it wouldn’t work, either. You’ll note that neither Neil, nor I, stated, “Yeah, just strap a bigger booster on the capsule and we’re good.” Neil and Buzz both thought that there’d have to be lots of R&D on the matter, but that the leap would be within our grasp and not something we’d have to spend years researching technology A, just so we could get to technology B, in order for us to have technology C that would actually take us there. Remember, when Kennedy made his announcement, we’d only just begun puttting humans into space (can’t remember if we’d even made a complete orbit at this point or not). When Neil was talking, we’d at least proven it was possible to send humans to another world and bring them safely home again.
NASA and other highly educated types tossed out a number of ideas of how we might get to the Moon before settling on the method that we used. While I’d not turn my nose up at using nuclear powered rockets, I wouldn’t complain if we used some other method.
I don’t know Neil Armstrong, I’ve never met Neil Armstrong, but from everything I’ve been able to gather, he’s not the kind of guy to say something just to “score points.” It seems to me that if the brass at NASA told Neil to go out and say that we’ve got the ability to figure out how to go to Mars in the same amount of time it took us to go to the Moon and he didn’t believe it, he’d have kept his mouth shut/quit NASA long before he did.
We’ve had two catastrophic failures of the shuttle program, and despite the calls for the abandonment of the manned space program, we’ve yet to do that (Obama seems to have shifted his position and is now willing put more money into the space program for manned missions).
Agreed.
Only because we choose not to invest in their development.
I’m surprised that no one has mentioned the Mythbusters “Confederate Rocket”. They built and flew a way cool unit. Used a chunk of graphite for the rocket nozzle, fueled it with nitrous oxide and paraffin. Made mostly of pipe and plumbing fittings. Took two days to build, flew over a mile …
Now, the only way you could ever get one of these to space would be to take it up high with a hydrogen balloon. Perhaps one of the resident rocket scientists could say whether this would all be possible, if you could get up to say 50,000 feet before you fire off the rocket.
w.
that’s sort of been my idea… imagine a large, stable platform anchored at 4 sides by large balloons, or tethered to dirigibles. If it’s at around 20,000 feet, and my protagonist launched from there…
(large balloons or dirigibles are practically required, from what I understand…)
They will be big balloons. 
You don’t feel the Space Shuttle represents investment in developing heavy lift capability?