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Amateur Rocket Heads Into Space
scubacuda writes "Space.com has an article on a group of amateur rocketeers (the Civilian Space Xploration Team) hoping to send the first amateur rocket, Primera Spaceshot 2002, into space by the end of June from the Black Rock Desert in Nevada. If all goes well with the Federal Aviation Administration (FAA), the team will send a rocket stands about 17 feet tall (5.18 meters) and weighs 550 pounds (249 kilograms) 62 nautical miles (114 kilometers) in the atmosphere (12 miles higher than the 50-mile altitude largely regarded as the boundary of space). (MSN version here)"
They're going to beat the Oregon Rocketguy. That's sad.
Mmmmmmm
I think it's interesting that this rocket uses solid propellant rather than the liquid fuel that most high-altitude rockets use. Might this be the first completely solid fueled rocket to reach space?
Hasn't anyone been to a drag car race at the local drag strip? Bunch of d-i-y hot rods made from strewn together junk racin away trying to mimic the pros .... inevitably, at least blows up every night ... or horribly malfunctions .... but hey ... at least they aren't rockets! This cannot be a good thing,
Nope, in the writeup we have a mixing of land miles, nautical miles, and metric kilometers.
This screams failure.
I have been pwned because my
Balancing a pile of shivering metal on a pillar of flame is not all that easy.
After all, they don't call it rocket science for nothing.
"It is a greater offense to steal men's labor, than their clothes"
Sorry....but obligatory... So now we have networks in space.... So isnt it only a matter of time before we have an orbital beowulf cluster? ;)
When in doubt, parenthesize. At the very least it will let some poor schmuck bounce on the % key in vi. (Larry Wall)
This reminds me of the late 70s (or was it early 80s) TV movie that became a series, S.A.L.V.A.G.E. in which amateur rocketeers built a rocket in a junkyard and went to the moon. I was a little kid then, but the show was cool! IF CSXT can pull this off, they should start a satellite launching business. They would probably do a better job than NASA, considering it's new cost cutting plan.
http://www.uncoveror.com/nasa.htm
The Uncoveror: It's the real news.
I got dibs on their computers! Who wants their TVs?
Oh come on, you just know they aren't going to need them anymore.
qslack.com
The FAA won't clear them to fly. Why? To protect them from the The Terrible Secret of Space!
"Oh no, 3 horny women and only 2 condoms...Thank god I read slashdot"
Will we be able to buy them in a twelve pack like flying cars in the year 2000?
Oh well, guess not. We should get both by <?php echo year+25;?>.
You can't judge a book by the way it wears its hair.
Americans use nautical miles becuse we don't understand the metric system. The right wing kooks used to think it was a communist plot, and rednecks still do. Most of us, in fact, don't know if a nautical mile is the same as a regular mile, a "country mile," or "a mile as the crow flies." It's mostly ignorance, not arrogance.
The Uncoveror: It's the real news.
From that article ...
AlsoKarma? Karma? I don't need no stinkin' karma.
> We use ISO A4 here.
;-)
Yes, leave it to the Europeans to have to have an ISO standard to tell them what to write letters on...
Chasing Amy
(We all chase Amy...)
"The more corrupt the state, the more numerous the laws"-Tacitus
On a side note, the article says:
Michaelson said his team, made up of people from around the country, had an original launch date of Sept. 26, 2001, but pushed it back to June following the terrorists attacks of Sept. 11.
How much are you willing to bet that Tom Ridge's folks are keeping a keen eye on their team? Whatever they learn about rocketry must give the feds the willies.
Linux at home
I went to a ham radio fest recently for the first time, and I noticed that most of the guys there were older men. I guess ham radio must have seemed a lot more exciting to young people several decades ago. And I know that is true with Rocketry because of the hype back in the fifties and sixties over the russian ICBMs and getting to the moon first. So what do you guys think, are rocketeers a dying breed or is it an interest which is becoming more popular lately? On the one hand, many of the fifties-era, crew-cut, slide-rule carrying rocket scientists are gone. But OTOH, you don't have to be a superpower to get in the game now and space may be on the verge of commercialization. So is Aerospace Engineering a "cool" profession for the next generation?
When I lived In Las Vegas I used to shoot off my rockets in that desert, its amazing that something this historic is being held in the same place I flew off my PBC pipe rocks we made in tech class! Very very very cool! oh well Hopefully they wont hit a plane or something...:-)
keanmarine.com
IANARS(I am not a rocket scientist), but looking at the picture of the first rocket, it looks like an American flag was tied on to the side of it. I don't know anything about rockets, but wouldn't this flag cause problems as far as aerodynamics and wind, etc?
The first try was brought down by wind shear, but the article didn't go into explicit detail about the crash. Just based on watching NASA shuttle launches, I never saw anything like that hanging off the side of the rocket. Maybe this would have caused a problem? Or is the flag so insignificant compared to the propulsion of the rocket?
Not trying to go offtopic but I agree. The Challenger explosion back in 1986 (or was it 85) was caused by the decision to launch in extremely cold weather by the contractor, Morton-Thiokol (not sure on the exact name, but that's close).
There was a documentary recently about the explosion and they interviewed the head engineer of the project, who fought to abort the launch but was overridden by management, but they wouldn't listen to him.
If a project like this was to plant a LEO payload then another MIR style amateur radio BBS would be kind of cool.
Maybe the (project like this') co-ordinators could take people's submissions for payload ideas, then they and/or we could vote on the best and send it/them along also.
Me lost me cookie at the disco.
Happy Birthday!
-Bucky
I've met the guy once or twice an heard about losin a fin couple years back. guy has a screw or two loose but the math seems proper. From wha i undertand the guy had to put up a fight to the faa/military to launch the thing. they gave em a fair amount of flack on the whole rocket launch shit.
that our fellow Slashdotter/Linux nut/3D guru John Carmack isn't launching his XPrize contender. For those who are not following his adventures in amateur rocketry, a few years back he started a company called Armadillo Aerospace which is a hobby project of sorts. They have created prototypes for hydrogen peroxide powered landers and are working on a suborbital launch in a near future.
Honestly, with the amount of money that Kuroshin has generated over the past few days, $100,000 from Slashdot users to make a /.rocket should be easy. Who cares what we stick up there. Let's just do it because we can.
While we're up there, someone could drop a huge EMP pulse down to the planet surface for the ultimate slashdotting...
Heh, but somehow I don't imagine it being the first time you've said 'Yes, I'm 18' on the web.
Nautical miles are slightly longer than "plain" miles. They are 6076 feet, which is the length of a one minute arc on the earth's surface. I have no idea how the 5280' mile got its length.
I think the main reason that we haven't picked up the metric system is that American's have learned about how big a foot, yard, gallon, and the like are, but don't have any good estimates for how big kilograms, liters, and centimeters are. Also the average american hasn't done dynamics under the english system, messing up lbf and lbm more times than I could count in college was enough for me to see the logic in the metric system.
Degaussing scares the bad magnetism out of the monitor and fills it with good karma.
Comment removed based on user account deletion
How much are you willing to bet that Tom Ridge's folks are keeping a keen eye on their team? Whatever they learn about rocketry must give the feds the willies
I doubt it; first, the Homeland Security office is too busy figuring out their turf in the administration to actually do their job, and second, rockets are about the last thing they have to worry about terrorists using against the U.S.
I don't know how often it is used, but the U.S. does have a four-stage solid-fuled rocket capable of launching small payloads to orbit.
While Ky's launch will probably be pretty private (if only for safety reasons) - AeroPac is having our first launch of the year at the same spot (BlackRock ) - Northern Nevada this weekend.
.... and camping
Sat and Sun mornings are the best time for launching (low winds) - the playa is BIG lots of room for recovery
The Reaction Research Society pretty much did just this back in 1996. They launched a solid-fueled rocket carrying an amateur television transmitter to a height of approximately 280,000 ft., which is about 46 nm.; just three miles short of the official "boundary". They weren't going for an official record, although I believe it was and remains the highest amateur launch to date.
The rocket reached a maximum acceleration of 35 Gs, and attained mach 4.5 in 5 seconds. Their site has some good photos and video of the launch, both from the ground and from the rocket.
-Jeff
-Vercingetorix
"Necessitas non habet legem." -St. Augustine
Space Propulsion Engine for Flying Saucer - New Physics
Inventor of 3D volume holographic optical storage
shopping his concept for Space Propulsion Engine
using Propellantless Mass to US and other countries.
for further look at biography background goto
http://colossalstorage.net/colossal.htm
He says he has looked at and researched the world's space agencies, aerospace
companies, universities research, and corp. research and feels very confident
knowing others technology while no one knows his.
He is working in top secret and he says no physicist or scientist he has ever studied or researched had this approach and knows his concept will work to give near light speed travel thru Galaxy with 500K/Miles per Hour to start or 138 miles/sec. Nasa fastest time are 25,000 mile/hr or 3.9 miles/sec
he says it is a mankind first concept !!
I'm a rocketry hobbyist. I fly up to H power models. Not very ambitious, but I'm part of the rocket nerd community.
Ky is a real guy. A competent fellow who, while sometimes a bit of a self-promoter, is very competent and not a nut-job dreamer. Ky and his wife are regulars at HP and experimental rocketry launches. They sell a line of heavy-duty parachutes and other recovery gear.
I have full confidence in Ky and his team.
As for those other guys:
The Oregon RocketGuy strikes me as an earnest, overconfident not-quite-a-nut. I think he's backed off from his "first flight will have me in it, tests cost too much!", which is a good thing for all involved. I hope he can pull it off.
The British X-prize hopeful, Bennet -- I forget his first name -- is a pretentious con-artist. The rockets he launches are nothing special. You can see dozens like it at a typical LDRS event. He claims that these are test flights, to test recovery gear etc., but they're really just large model rocket launches. Watching the videos of him at work is embarassing.
Example: A year or two back, one of the cable channels had a segment on one of his test launches. After setting up the rocket on the beach, he and a helper walked to their launch bunker (a hole in the sand), spooling out the launch leads as they went. It turned out that the leads were too short. They couldn't reach the foxhole. Duh?
When the time for launch came, we see Bennet instruct his helper on how to press the launch button on the second launch controller, and to be sure to do so at exactly the same time he pressed the button on his controller.
SECOND launch controller? Because the model had multiple motors, right? But model rocketeers with any experience know how to hook up multiple igniters in parallel, eliminating the nasty problem of buttons pushed out of synch.
Scientific balloons have attained heights of 52 kilometers (32.3 miles) and carried payloads of up to 3,600 kilograms
E C: www.sciam.com/1999/1199issue/1199smith.html+balloo n+OR+balloons+altitude+space+miles+OR+kilometers&h l=en&ie=UTF-8
http://216.239.37.100/search?q=cache:34Avny4awz
thanks for your rocketry story! i remember building model rockets when i was younger, and dealing with all sorts of details that went into the launch. my younger brother was into it, too, and i think some of these details were a little too much to bother with.
see, we were super competitive. i remember building a C power rocket one afternoon. my siblings and i were very competitive. the aforementioned brother HAD to build a rocket, too.
of course, he, being the youngest brother, ended up getting shafted in the dough-for-fun-fund. he wound up scrounging enough money to buy the Mosquito, a rocket that used A (AA? AAA? what's the smallest rocket?), and was no taller than a pencil.
launch time was nearing for me, so he set to work at a feverish pace. he soon came out with this hideously spray-painted, still-wet and dripping with paint yellow and black rocket that looked uber pizacrap.
we launched it in front of our house in the suburbs. neighborhood kids came out to watch. he threaded the rocket onto the launching pad, connected the fuse up, and started the countdown.
3...
2...
1...
FWOOOOOOOSH!
sucker flew straight! straight up REAL FAST! all these kids were ooohing and ahhing. even the folks across the street were impressed! the rocket didn't get too high-- it was still very visible when it began to slow down and arc downward.
there's something terribly graceful about a rocket gliding in the air-- it was beautiful. not a peep was heard in the crowd.
so heavenly, so peaceful! we knew that any moment now, the tiny secondary charge would gently pop the nosecone off and unfurl the streamer which would let it fall gently to the ground...
so graceful!
then BOOM! the rocket BLASTED toward the earth at something akin to warp 10. kids were screaming and tried to run away, but it was just too fast! it impaled itself into the ground, several inches deep, still smoking, and then caught fire.
kids were crying. parents were yelling. we began to try to figure out what happened. he glued the nosecone, which is supposed to pop off, into place.
that secondary charge had nowhere to go but out the back of the rocket. and when the back of the rocket is facing up, the rocket's gonna go down. fast.
THE MORAL OF THE STORY:
NEVER GLUE THE NOSECONE IN PLACE.
also, WET SPRAYPAINT IS A FIRE HAZARD.
Let the government run the space program? These are the same people that tell us how our lives should be morally, and do the exact opposite. Granted, something should be done to control contractors besides ISO and NADCAP standards, but the government shouldn't be it.
I hope these chaps are successful in getting their rocket up there. We'll be one baby step closer to opening the space market to the private sector.
http://www.forum-addicts.com
their Nintendos. The instant satisfaction factor of playing Max Payne has not yet lost it's gloss; but it will. Once you've shot every imaginable bad guy, with every imaginable weapon while falling through fluidic space backwards and tumbling... it will get old and the rewards of the longer term pursuits will again seem worthy of the efforts. Computers have been an adventure for a couple decades now, but soon, for most, they'll just be tools again, about as exciting as screwdriver design.
Thankfully some will retain their interest after the glam is gone, Blessed be the inventers of Torx.
Nobody really thought that outer space started at fifty miles of altitude -- sixty or seventy five miles up was the start of real space. Then the US developed spy satellites that could dip down to about 60 miles to get a better look and refused to agree to any treaties that wouldn't allow that. So, space is not what it used to be.
So I multiply by 4, add 9, divide by 11 .... 8=)
Consider my ass out there this weekend! I'll see if I can get our fledgling Planetary Society chapter to haul their lazy, sluglike posteriors out there.
Why is it when I hit ^R that ZSH calls me a cocksucker?
62 nautical miles (114 kilometers)
Um, no. Actually 62 miles is just a shade under 100 km. 100 km would be about 62.14 miles. And this significance of this is... (wait for it)
(12 miles higher than the 50-mile altitude largely regarded as the boundary of space)
Um, no. The 50 mile altitude is what the USAF awarded astronaut wings for to X-15 pilots who exceeded it, and may even be the US legal definition of where space begins, but it's 100 km (ah!) that is the boundary of space as far as the International Aeronautical Federation is concerned.
-- Alastair
Ky Michaelson and his team are for real, and it will be interesting to see if they make it work: our group will be out at Black Rock cheering them on.
That said, as far as I know, this rocket lacks what is known in the trade as "active guidance": i.e., it cannot steer itself. This leads to two big problems. First, it is very hard to build a rocket that will go up very straight to 100km. Large fins are required for the upper atmosphere, but they cause tremendous drag near the ground. (Also, BTW, the potential landing radius of the debris in the event of failure of the airframe or parachutes is huge: part of why the FAA is so nervous about the whole thing.)
Second, even if the rocket does make it "into space", it is essentially impossible to make it into orbit. To orbit something, you need to go up and then sideways: this requires steering.
Imagine putting a car out on a salt flat, tying the wheels down, aiming it north, and letting it travel for 50 miles. It would probably end up somewhere north of where it started. More than that, it would be difficult to say. This rocket is aimed 50 miles up. With luck, it will end up falling from above us somewhere. More than that...
you mean like these guys who fly from (roughly) the same spot?
Erasing screwed up moderation selection.
They are most certainly NOT a dying breed :)
Have a look at our group : http://www.mars.org.uk , we are a group of young professionals who have launched at Black Rock before, using a rocket motor ordered from the VERY cool and capable Ky Michaelson - he's a dude...
Regards.
It appears that there is a mistake in this article. The mile (mi) nautical mile (nmi) seem to be treated as the same distance. However, one mile is 5280 feet, and one nautical mile is 6076.1 feet by this definition, or 6080.27 feet in the definition given in GDict. This means that the estimated altitude of the rocket will be approximately 71.35 standard miles (mi) or 71.40 standard miles (mi) (respectively).
It also appears according to this NASA page that 50 miles is the altitude one has to achieve to be called an astronaut in the USA. However, the atmosphere's friction boundary is 75.76 miles, according to the same page. So the rocket will be approximately 4.41 to 4.36 miles short of the friction boundary, but any lifeforms (bacteria, etc.) that survive the journey will be astronauts in the USA.
All data is speech. All speech is Free.
Yes, I'm an idiot :P ... D'oh!
:)
The motor we bought was from Kosdon - and he's a dude, too.
Good luck to Ky's group anyway
62 nautical miles (114 kilometers) in the atmosphere (12 miles higher than the 50-mile altitude largely regarded as the boundary of space). (MSN version here)"
62 miles high is not space it does not even achieve a stable orbit never mind escape velocity. In my book this is not space.
I certainly hope they succeed. I was wondering what constitutes space junk? If the rocket does cross the boundry, how long until it comes down?
"Only one thing, is impossible for god: to find any sense in any copyright law on the planet." Mark Twain
I have no idea how the 5280' mile got its length.
Blame the Romans. Lacking the technology to measure minutes of arc like us modern-types, they had to make do with low-tech measurements like "one thousand paces."
--G
Scared of losing your billions in funding?
Government of the people, by corporate executives, for corporate profits.
I'm not suggesting the people in the article are terrorists, but neither was the husband and wife team that invented the airplane.
Who was the wife, Wilbur or Orville?
Hey kids, there's only 5 days left 'til Yak Shaving Day!
err.... I think you're supposed to glue the nosecone on the mosquito. If I remember correctly, it was light enough to just tumble down. I think you are supposed to put a hole in the tube to vent the ejection charge gasses (or maybe use a motor that doesn't have an ejection charge?)
get nemulator
Yeah, you're right, you were supposed to glue the nose cone of the Mosquito on. No hole in the tube, though, and no special motor: the ejection charge was supposed to blast the remains of the motor out of the rocket so the rocket would tumble down (the real trick was finding the damn thing).
Motors without ejection charges are mostly meant for use as the non-final stages of multi-stage rockets, IIRC.
When I first read your post, I was confused as to why somebody would shoot a rocket 46 nano-meters. Then I noticed that 280,000 ft. is not 46 nm, so I thought maybe you meant km, but that would be 85 km. Then I figured it out: nautical miles. I did a google search, and found that n.m. is the correct abbreviation for nautical miles. I hate the english system.
Only the english system of units would have so many different measurements of length. Stupid footlongs, chains, fathoms, feet, inches, miles, and nautical miles. I hate it that we still use those units in this country.
To repeat, I hate the english system of measurement.
I'm off my soapbox for now.
I'm taking the don'ts.
Maybe in 20 years we'll all be flying to space with our own rockets...
...I can remember getting into small rockets like those from Estes, particularly one called the Mean Machine. Towering six feet into the air - far above my jr. high head at the time - painted all black with a shiny nose cone. It was too big for the starter launch rod we had, so one of us had to hold the thing up til a split second before launch.
I volunteered to watch 100 yards away by the tennis courts at the park.
The damn thing tipped over on ignition and screamed past my head -- distace to my skull a mere 5 feet. It hit the fences south of me and compacted.
We rebuilt by cutting off the 4.5 feet of crushed toilet paper roll that made up our little rocket. The remainder was a much safer, though less satisfying, version we called the Mini-Mean Machine.
A toast to solid-state engines and all the money invested in childhood spaceman dreams...
I have a similar story
I won an essay contest in 5th grade and got to go to Space Camp. One of the days there we built estes rockets - I think we used the Payloader, because there was a clear tube below the nosecone. We found some lucky insects and shot them off.
One girl's rocket wouldn't start. After several failed launches, the instructor unhooked it and tried to take the engine out. She couldn't. These rockets had a hook assembly in the bottom and had been hastily put together. This one had the hook glued in place and unable to move, keeping the engine from sliding out. The instructor had no problem pushing it farther in though. So she just shoved in a new engine.
It launched successfully on that windless day, everybody clapped, and a few seconds elapsed. These engines were single stage engines - some engines are made without a delay so they can ignite another stage while a lower stage separates. In this case, the delay allowed the rocket to point downward before the "second stage" was ignited. The old engine that had had problems was now sending the rocket straight at us. We yelled and ran, and the rocket made touchdown right where we had been standing, the slender nose cone burying itself about 6 inches into the soft dirt and the engine still burning, the body tube twisted and blackened, unraveling about its sprial seam.
A few of us ran back toward the rocket to get a look at it. And right as somebody was pulling it out of the ground, that's when the _second_ ejection charge went off...
:-)
Vidi, Vici, Veni
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
Two Words: Lifting capacity
Most balloons do not have much of a payload and I have a suspicion that getting a decent sized payload up high requires a really really big balloon.
Any physicists/aeronauticists out there to confirm this?
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
The Mosquito was actually my favorite because it was light, the engines were cheap, and you didn't have to worry about getting stuck in a tree (empty field with lone tree == gravitational vortex?). It did become mildly dangerous when the engine failed to eject. It's too bad the newer ones have a hollow plastic nose cone instead of the balsa on the originals.
I am becoming gerund, destroyer of verbs.
I also made a very bad rocket when I was young. The nosecone was glued in place, but I was smart enough to provide a side door for the parachute...
But, I only had a C power thing to put into that big (2 feets) rocket.
At the moment the rocket began to lift off, I knew there was something wrong, rockets are not supposed to accelerate this slow...
The rocket went slowly about 50 feet in the air, then it began to arc and was now heading for the earth, toward my neighbour's house.
Then the thrust endend (thankfully!), and the rocket dropped like a stone. The second charge blew up a part of it, and it catched fire.
I think that's why I don't work at NASA now...
But it was fun!!!
Try it! Library of Babel
We used to take the "C" or "D" engines and strap them to homemade lego dragsters. From much experimentation and many demolished legos, we were finally able to make it go straight. Man, did those things go fast! Phase II (live gerbil driver) was scrapped due to maternal intervention
I remember a few horrible rocket designs. One was the "Enterprise", which I'd gotten as a gift. It was flimsy just sitting on my desk, I knew there was no way it was going to fly. But I tried anyway, I was young and felt that Estes wouldn't build something that wouldn't fly. The thing completely disintegrated on launch. I never found the main body (where the rocket engine and chute were located), but the saucer section and engine nacelles (those two things hanging off the back) were scattered about the launch site.
Another was the Pershing Missile. Huge rocket, like three feet tall, six inches in diamter. The nose cone must have weighted at least two pounds. I think it used a single C engine, which made no sense but I figured if that's how they designed it, I'd give it a try. Yeah, it launched, about 15 feet in the air and came plummeting back down. The nose cone never separated; not that it would have helped since it was too low for a parachute, but the weight of the nose cone crushed the body. Oh well, I guess some rockets were designed simply to build and display. I had to build a special launch pad too, since the flimsy 3-legged one kept tipping over.
Speaking of tipping over, we forgot to tighten the wingnut later (I think it got partially stripped when I put the Pershing on it), and just as my friend was launching his Mosquito, the rod slipped. The Mosquito fired about 10 degrees above vertical. Now, that was a sight! The mosquito screaming across the field an slamming into a woodshed about 150 yards away.
Another carzy model was the "Drifter". It came with a huge parachute, like 36" for a small rocket; I was too young to figure out what was going to happen. That thing drifted at least a mile and a half as we chased it down on our bikes. We lost sight of it, and didn't find it until a week later, hung up in a tree.
I doubt anyone back in my hometown does it anymore; the burbs have grown more crowded, the people are more paranoid, and kids more apt to stay inside. It's a shame, because I have some great memories from my rocketeering days.
-- If god wanted me to have a sig, he'd have given me a sense of humor.
I don't have a warm a fuzzy feeling about having armatures trying to lob heavy objects into space. If you think about it, it is really crazy.
If the guidance goes awry they could kill someone.
"Let's pack a big cylinder with rocket fuel and light it."
"OK, but first pass me another beer."
The race isn't always to the swift... but that's the way to bet!
Yes, NASA wanted to launch, but so did the Thiokol management. It was the Thiokol engineers that didn't want them to launch. (or so i thought...)
that is stuff that matters
Hey. Do not knock the little guys. Amature radio proved it mettle (no relation) by providing the very first TV reception in space while in orbit. You think not? Just ask NASA. Sure, they send down the clips. But, the first time they "received" video via TV, it was on the amateur bands. Of course, anyone who knows anything about the astronauts knows that most of them are into amateur radio with some of the top permissions available. Just for the record.
NexuSys - Linux support by the best
The problem is that, as a balloon rises, the force pushing it up decreases. As the density of the gas inside the balloon approaches the density of the air outside of the balloon, the forces of gravity and reach equilibrium.
Any balloon is going to have an absolute limit as to how high it can go.
The reason [liquid fuel is used in most well-developed space launch systems] is simple: solid fuel allows no control over the burn. You can't change thrust except in predetermined ways, you can't shut it down, you can't restart it. That's why liquid fuel is necessary for all but the simplest applications.
There's an alternative: Solid/liquid hybrids, such as AMROC (AMerican ROcket Corporation) tried to commercialize.
Basic idea is you use one part (typically the fuel) as a solid, the other part (typically the oxidizer) as a liquid.
You only need to throttle ONE of the two parts to get the throttling advantage if you chose to throttle the oxidizer (which results in a lowered flame) rather than the fuel (which results in a lean and unstable flame). Meanwhile, a fuel-only solid fuel is literally safe as houses.
With only one part liquid you have only one tank, one set of valves, one pump-or-tank-pressurizer, and no problems with balancing the fuel flows of the two parts.
LOX is reasonably easy to make and handle, only moderately dangerous, while LH2 is extremely difficult and dangerous to make and handle. LOX is dense while LH2 is very light - much less dense than an equivalent amount of hydrogen bound into a compound (such as a hydrocarbon). So you're way ahead to use a LOX/solid hydrocarbon hybrid.
AMROC used LOX and synthetic rubber. The fuel part was 'way stable - they handed out paperweights made of it for fund-raising trinkets and bounced them off the desks of bureaucrats who wanted them to get explosives licences for their fuel facility. (I've still got one around here somewhere.) One of the advantages of this combo was that it was flat-out impossible to get it to explode. (The worst you could do is make it burn extra hot.)
AMROC got pretty far along before they folded. The end came after their primary evangalest/fundraiser died in an auto accident. (I forget his name just now. But he was the same guy who talked the city of Chicago to let the people making the move The Blues Brothers to air-drop an automobile over the city.)
They had already done their engine tests and had their first suborbital launch ready to go at a rented pad at Vandenberg. They went ahead with the test and had what was probably the worst possible engine failure: After lighting the LOX valve stuck at 10% open - too low to get off the pad, too high to put out the fire. So the rocket sat there burning up, and eventually flame-damaged part of the launch tower. They didn't have enough funding for a second try, and without their primary fundraiser they folded.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Not being too bright (still), I once launched an Erector Set. Seriously. It was actually supposed to be a rocket motor test stand (forget why I needed *that*), but it had one design flaw. Though the stand was held down by one of those big 6v lantern batteries, the motor thrust was directed skyward, instead of towards the ground.
And yes, this thing was built from a 70's vintage erector set: potmetal, bolts and nuts.
When the day came, I set this thing up in the back woods. I was 14 or so, so mom was in attendance. Slipped in a nice C-motor, wired it up, stood back, and flipped the switch.
The battery flew a good six feet. The stand -- did I mention it was an erector set? -- shot straight up about 5 feet, tipped over 90 degrees or so and began swirling like a dervish through the woods, bouncing off tree trunks, hurtling sidewards at myself and then my mom (both of us running for our lives at this point), spewing smoke and exhaust every which way, before the motor finally burned out and the thing crashed down in a heap in the grass, about 15 feet from where it started.
We approached it gingerly, coming up to it just in time for one last convulsive, metallic lurch as the ejection charge fired.
Mom, she just looked at me grimly and said "You're not trying that again." Me, I did not become an engineer of any description.
I'm wondering why they've gone back to the old technology of Solid Fuel rocketry when 58 years ago Liquid Fuel rocketry was getting quite successful with the 'A-4'?
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(David Bowman, EVA near HUGE Monolithic Win-PC in orbit around Jupiter) "My God - its full of Malware!"
AMROC was bought by SpaceDev and they are continuing the work.
Paradox:
Does this mean that if you have a vacuum in a balloon it will have no problem going really high?
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
If you could build a balloon that was strong enough to contain a vacuum without collapsing, yet having a large enough volume to reduce the total density to less than air, vacuum would be the ideal contents of a baloon.
But what you're doing is exchanging additional structural elements for the the weight of the gas, so you're really getting nothing. In addition, it would be impractical to build a vaccuum chamber that would resist crushing close to the ground. Your balloon would have to be made out of steel.
The U.S. awards astronaut status to anyone who flies above 50 miles. At 50 miles, atmospheric density is one-thousandth that at sea level. You'd die instantly if you stepped outside at that altitude.
At 100km, the atmospheric density is near-vacuum, and rudders and wings on an aircraft will not work - no aerodynamic control is possible. If you step outside your vehicle, you will explosively decompress.
This quote is an old cliche, which dates back at least to Baudelaire's 1864 short story, The Generous Gambler. The line (translated from the French) goes something like "the Devil's finest trick is to persuade you that he does not exist".