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Ask Derek Deville About High-Altitude Amateur Rocketry

timothy posted about 3 years ago | from the next-week-shatner's-answers dept.

Toys 148

A few days ago, we posted about Derek Deville's mind-blowing high-altitude rocket-launch in the Nevada desert. His 14-foot, GPS-equipped (four GPS units, actually) home-made rocket ("Qu8k") managed to hit 121,000 feet, an effort that took more than a trip to the store for more Estes "D" engines. Derek has graciously agreed to answer questions about Qu8k and other rocketry projects. Please confine your questions to one per post, but ask as many as you'd like.

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ATF? (3, Interesting)

dtmos (447842) | about 3 years ago | (#37680472)

How has the relationship with the ATF and other government agencies affected amateur rocketry since 9/11?

Re:ATF? (1)

vlm (69642) | about 3 years ago | (#37680842)

How has the relationship with the ATF and other government agencies affected amateur rocketry since 9/11?

Thats pretty well documented, with them F-ing around for about a decade until the courts told them to cut it out just a year or two ago. Much better now.

I'd be interested in his personal experiences with the BATFE.

Second Try: ATF? (1)

dtmos (447842) | about 3 years ago | (#37681094)

You're right -- the story at the national level is well-known. I was trying to give him a forum to share his personal experiences, but I didn't want to bias the question by assuming he had any, and ended up not asking the question I really wanted to ask. Self-editing never works.

Let me try again:

How have the BATF (now the BATFE) and other government agencies affected your enjoyment of amateur rocketry since 9/11?

Re:ATF? (0)

jd (1658) | about 3 years ago | (#37682142)

My guess is that relationship went south quite a bit earlier - around the time a New Zealand hobbyist was offering the schematics for a DIY cruise missile that could be built by any geek with a basic toolset and $5k spare change. That episode... ...freaked out more than a few governments, as I recall. It may not have used rockets, but that's immaterial. The guidance system is the only technically difficult part of this sort of project and is the chief reason the US and USSR were in the space race to begin with. (They had less interest in reaching the moon than they did in being able to show they could hit an incredibly small target over an incredibly long range.)

Once it became known that anyone could develop a highly accurate guidance system for pennies, hobbyists would not be seen as potential recruits (a-la Bletchley Park) but as potential adversaries.

GPS (1)

LWATCDR (28044) | about 3 years ago | (#37680516)

Civilan GPS has limits in speed and or altitude both of which you exceded. How did you measure altitude and speed? Air pressure?

Re:GPS (2)

kimvette (919543) | about 3 years ago | (#37680742)

Those limits are voluntary and vary from manufacturer to manufacturer, and many devices ignore those artificial limitations. Even if the restrictions are honored by a given device, the firmware can often be modified to remove those restrictions, and it is still perfectly legal for domestic use; it just can't be exported without an export permit since it is then regarded as munitions (much like high-grade encryption back in the day). Lastly, the export restriction applies only to devices to devices when speed AND altitude limitations are exceeded, since the export restrictions are intended to prevent use on an ICBM.

http://en.wikipedia.org/wiki/Global_Positioning_System#Restrictions_on_civilian_use [wikipedia.org]

http://www.groupsrv.com/science/about460860.html [groupsrv.com]

Re:GPS (1)

vlm (69642) | about 3 years ago | (#37680886)

Also from talking to balloon guys, the speed limit would not be applicable on the way down, and the altitude at which they "cut back in" is high enough that long distance reception is still pretty easy (its not like they cut out at 1000 feet AGL). I have not heard of any GPS engine/module that required power cycling when limits were exceeded, soft fail...

Re:GPS (0)

Anonymous Coward | about 3 years ago | (#37681612)

still perfectly legal for domestic use; it just can't be exported without an export permit

Does firing something 121,000 feet up into low-earth orbit count as "exporting"? ;)

Re:GPS (0)

Anonymous Coward | about 3 years ago | (#37680796)

What are the Limits? I thought since Clinton tuned off SA on May 1, 2000 that Civilian and Military signals were the same...

Re:GPS (0)

Anonymous Coward | about 3 years ago | (#37681142)

The GPS COCOM restrictions are 60000 ft MSL, 1000 kts groundspeed. This is programmed into the receiver's firmware and is not related to SA.

Obvious Question (0)

spacefight (577141) | about 3 years ago | (#37680540)

Will it blend?

How Are You Securing Your Rockets? (-1)

Anonymous Coward | about 3 years ago | (#37680544)

In this post 9/11 world, there are terrorists such as Al-Queda and lone wolf evildoers out there looking to do harm to our homeland.

We saw our the 9/11 attackers used civilian airliners against us in such a surprising and dastardly way. Are you concerning something similiar might happen to one of your rockets? Are you protecting them so they do not fall into the hands of our enemy?

Re:How Are You Securing Your Rockets? (1)

MichaelKristopeit343 (1967642) | about 3 years ago | (#37680726)

In the pre 9/11 world, there were terrorists such as Al-Queda and lone wolf evildoers out there looking to do harm to our homeland... and they did.

you're an idiot.

Re:How Are You Securing Your Rockets? (1)

GameboyRMH (1153867) | about 3 years ago | (#37680874)

It says "Ask Derek Deville About High-Altitude Amateur Rocketry" not "Troll Derek Deville With Incredibly Stupid Questions"

It can go 36 kilometers up or further sideways (1)

Anonymous Coward | about 3 years ago | (#37680562)

Did you take precautions in case the rocket turned sideways or were you just hoping it wouldn't? Big rockets always have remote controlled self-destruct. Yours too?

So... (1)

jellomizer (103300) | about 3 years ago | (#37680566)

When people ask what you do in your spare time. How do you answer them without their eyes glazing over? Or worse listening to you intently then asking you join their Militia or just reporting you to the FBI?

Re:So... (0)

vlm (69642) | about 3 years ago | (#37680932)

When people ask what you do in your spare time. How do you answer them without their eyes glazing over? Or worse listening to you intently then asking you join their Militia or just reporting you to the FBI?

Closely related, you must work with the BATF at these levels; I know that personally from my much smaller work decades ago back when a "G" size engine was a big deal... Anyway, the BATF is famous for trying to run an undercover op of gun smuggling that is so big that they "took over" the entire market such that all illegal gun traffic came from the BATF itself. The reason for bringing this up, is I wonder if the BATF guys ever tried to entrap you or lure you into a conspiracy WRT to storage and use of rocket propellant? At least, that you can report publicly.

Public support? (4, Interesting)

dtmos (447842) | about 3 years ago | (#37680572)

Back in the 1950s and 1960s in the US, model rocketry was promoted as a way to interest youth in science and technology and, therefore, strengthen and defend the nation. However, amateur and, to a lesser extent, model rocketry are today seen by much of the public as a dangerous technology that should be suppressed, to keep it out of the hands of dangerous terrorists. How can the rocketry community regain public support?

Re:Public support? (0)

Anonymous Coward | about 3 years ago | (#37680628)

Does that mean movies like "October Sky" are now considered terrorist training films?

Re:Public support? (1)

NotAGoodNickname (1925512) | about 3 years ago | (#37681096)

What are you on about? Frigging Walmart sells model rockets and engines.

Re:Public support? (1)

notKevinJohn (2218940) | about 3 years ago | (#37681710)

I got into high powered rocketry out at black rock in the last couple of years, and if anything I can say that regulation of these motors has decreased in recent years. You don't need any special licenses from the government (ATF) to purchase motors, you just need to be certified on those motors by your local Tripoli or NAR prefecture. You used to need a small explosives license to store motors, but that is no longer the case. The only way in which terrorism/ national security becomes an issue is that you are not allowed to built a guidance system for your rocket.

The wife equation. (0, Funny)

Anonymous Coward | about 3 years ago | (#37680582)

How on earth do you convince your wife to let you do all those cool projects?

Re:The wife equation. (0)

Anonymous Coward | about 3 years ago | (#37680982)

By being a man? Seriously, if you chose to conform to society's little unwritten rules about being married and having kids at 25, instead of doing what you want, you deserve to be henpecked.

Re:The wife equation. (0)

Toonol (1057698) | about 3 years ago | (#37681948)

By being a man? Seriously, if you chose to conform to society's little unwritten rules about being married and having kids at 25, instead of doing what you want, you deserve to be henpecked.

You are tragically confused. Marriage and having kids does not get in the way of being a man; quite often, it's part of the path to being a man. You seem to think that having a family means you're henpecked and emasculated, but that's very clearly not true. You're only focusing on the pathological cases, and ignoring the healthy relationships.

Re:The wife equation. (0)

Anonymous Coward | about 3 years ago | (#37681194)

Lets just say she'll let a man with a 14 foot rocket do whatever he wants.

Re:The wife equation. (1)

godrik (1287354) | about 3 years ago | (#37681386)

by saying: "Do you want to see my rocket? It has a lot of fuel!!"

Recovery Tracking (1)

Jarik C-Bol (894741) | about 3 years ago | (#37680624)

How did you track and recover your Rocket? I did not notice anything in the video referring to this. Was it purely visual? or was the on board GPS web linked, allowing you to see its location?

Re:Recovery Tracking (1)

Kymermosst (33885) | about 3 years ago | (#37681156)

The pictures on his web site show an APRS transmitter.

Re:Recovery Tracking (1)

vlm (69642) | about 3 years ago | (#37681264)

The pictures on his web site show an APRS transmitter.

That means somewhere out there is a findu.com link to lookat it... assuming at altitude he was within range of an igate, which even at altitude might be a challenge in the middle of nowhere. Anyone have the link at findu.com?

Re:Recovery Tracking (1)

CompMD (522020) | about 3 years ago | (#37681190)

On the balloon I helped send up a couple weeks ago, we used APRS transmitting location from a Garmin GPS18.

Oldest and newest flight technologies. (4, Interesting)

deathcloset (626704) | about 3 years ago | (#37680658)

I ( and many others [jpaerospace.com] ) have been thinking about balloon assisted launch systems [youtube.com] recently.

Balloons seem like an excellent and flexible launch element which could offer a ton of altitude and avoidance of at least some friction. Have you heard of or considered this?

Re:Oldest and newest flight technologies. (0)

Anonymous Coward | about 3 years ago | (#37680946)

Are you talking about a rockoon [wikipedia.org] ?

Re:Oldest and newest flight technologies. (1)

malakai (136531) | about 3 years ago | (#37681012)

Not to answer his question for him, but if you are interested in this, on the AR list there are a handful actively pursuing this ( including JP Aerospace which you referenced ). For the Carmack Prize, this would not have helped. It would have had to achieve 100k ft from the point in which is launched from the balloon, which is at such thin atmosphere actually hurts rather than helps in this case.

Re:Oldest and newest flight technologies. (1)

wagnerrp (1305589) | about 3 years ago | (#37681764)

On the contrary. Rocket motors become more efficient at altitude, as the reduced pressure allows for increased expansion and higher exhaust velocity.

Re:Oldest and newest flight technologies. (1)

idji (984038) | about 3 years ago | (#37681018)

Why so many balloons, why not 3 or four balloons tethered by a cable at 10,000 m. Or not even tethered at all??

Re:Oldest and newest flight technologies. (1)

nospam007 (722110) | about 3 years ago | (#37681106)

"Balloons seem like an excellent and flexible launch element..."

Have you any idea how big those balloons would need to be for that weight?
Did you check the helium prices lately? It would cost a fortune!

Re:Oldest and newest flight technologies. (1)

vlm (69642) | about 3 years ago | (#37681406)

Also if you intend to have the landing within 3 miles, like this guy did, the balloons would have to climb darn near supersonic to get up there before they drift sideways too far.

Also the gyrostabilizers or whatever to launch it when its pointed perfectly up are going to be very complicated / heavy / expensive.

Finally you have to limit the rocket design to tolerate / survive getting tangled in balloon lines.

balloon launching just kinda sucks as an engineering design, when its so much simpler to just make a larger rocket.

Re:Oldest and newest flight technologies. (1)

wagnerrp (1305589) | about 3 years ago | (#37681772)

Why not use hydrogen?

Re:Oldest and newest flight technologies. (1)

buchner.johannes (1139593) | about 3 years ago | (#37681130)

Would it be possible to use a balloon to get to 30+km, then turn it around and use it as a rocket platform, launching a rocket to, say, the moon? It wouldn't have to be a very powerful rocket (and thus steerable like in the game Asteroids).
I'm probably being naive here...

Re:Oldest and newest flight technologies. (1)

wagnerrp (1305589) | about 3 years ago | (#37681814)

You are being naive. Having a balloon get you up to 30km, with no velocity besides whatever the jetstream is at that altitude, you have all of a couple percent of the energy needed to put you into low earth orbit, much less lunar orbit. You could make a modest decrease in the size of your rocket, at the cost of an absolutely monstrous balloon needed to get that much mass up that high.

Re:Oldest and newest flight technologies. (1)

LWATCDR (28044) | about 3 years ago | (#37681208)

Rockets are actually pretty old as far as flight goes. Probably predate ballons :)

Re:Oldest and newest flight technologies. (1)

EdZ (755139) | about 3 years ago | (#37681320)

The big issue is stabilisation: You'd need active stabilisation to reliably launch 'up', which when on a rocket is a huge legal no-no. Passive stabilisation wouldn't cut it, even with an elaborate launch rig, once you reach thinner atmosphere.

Re:Oldest and newest flight technologies. (2)

wagnerrp (1305589) | about 3 years ago | (#37681610)

The problem with balloon launches is the same problem with mothership launches like the SpaceShipOne. Once you get up to altitude, and modest speed, so what? The White Knight gets you to around 15km and 200m/s. Balloons get you to around 30km and 0m/s. Meanwhile, LEO starts around 150km and 8000m/s, which at that altitude is only good for a couple days before you re-enter. They can get you a decent chunk of the altitude, but are nowhere near the velocity requirements. Remember, fuel and launch mass varies exponentially with your velocity requirement. As for getting out of the thick low atmosphere, that's only going to save you a couple hundred meters per second at the most.

Now that space donut is something completely different. While motherships and balloons can't achieve the necessary velocity to be worthwhile, guns can. The problem with guns is that you need a very long barrel to get sufficiently low acceleration to be useful for more delicate payloads. You have to launch at a high inclination, so you either need an extremely deep mine shaft, or an extremely tall structure (or one built up the side of a tall mountain). The space donut is a way to build that tall structure. Rather than having it self-supporting, you use buoyancy to do it for you. Make it lighter than air, and use guy wires to position and stabilize it. You can build it as tall as the atmosphere will support it.

Re:Oldest and newest flight technologies. (0)

Anonymous Coward | about 3 years ago | (#37681896)

People who have their eyes on space are generally not interested in balloons because balloons are slow. To get into space, speed is more important than altitude, especially if you want to reach a stable orbit. Without speed, whatever you put up there will simply fall back down. That's why most launch facilities are close to the equator: More speed for free.

Towards Orbital Rocketry (2, Interesting)

Anonymous Coward | about 3 years ago | (#37680714)

Are there plans or even a roadmap you could lay out towards orbital rocketry by serious amateur groups?

Re:Towards Orbital Rocketry (1)

wagnerrp (1305589) | about 3 years ago | (#37681880)

Get some real backing by someone with money to blow. Getting into space really isn't all that difficult. Once you get staging figured out, I doubt these guys would have all that much trouble getting a rocket up 100km. There have been commercial sounding rockets capable of that since the 50s. Getting into actual orbit is an order of magnitude more difficult, and you're looking at development costs in the tens of millions to come up with something from scratch capable of doing so, even with no payload.

what are the laws about this (2, Informative)

Anonymous Coward | about 3 years ago | (#37680716)

What rules & laws do you have to follow launching a rocket like this? With so many aircraft in the air im sure there must be

Requirements for Amateur Rocket Activities (0)

Anonymous Coward | about 3 years ago | (#37681398)

FAA regs have been recently updated, here they are [faa.gov] .

Fuel (1)

bradgoodman (964302) | about 3 years ago | (#37680750)

What kind of fuel did the rocket use?

Re:Fuel (0)

Anonymous Coward | about 3 years ago | (#37681026)

Rocket fuel. But of course.

Re:Fuel (1)

FlyingGuy (989135) | about 3 years ago | (#37681958)

There are many many formulations but mostly it comes down an oxidizer, fuel and a binder.

Lots of engine builders use a variation on the formula for the shuttle solid rocket boosters (SRB's) and some use the exact same formula.

See the Wikipedia article about Solid Fuel Rockets [wikipedia.org] for mor information.

Dear Derek (0)

Anonymous Coward | about 3 years ago | (#37680772)

People have been launching large rockets at the LDRS for decades. Nothing's changed since then. We use the same principles, the same materials, the same energy sources and go the same place, same altitude and same speed. What do you say to people who think we'll colonize the universe given what we know about physics and materials?

rocketry for fun and profit (0)

Anonymous Coward | about 3 years ago | (#37680794)

We know that shooting things into space is fun, but is it profitable? What do you do for a day job?

Re:rocketry for fun and profit (1)

FlyingGuy (989135) | about 3 years ago | (#37681854)

Most everyone I know does this just for the fun of it. You can sometimes get some funding fro universities and even high schools. Students build instrument packages and you fly the package for them. The money they give you will usually cover the cost of the motor and a bit extra but that is about it.

Attitude Control (2)

charlesherdt (816162) | about 3 years ago | (#37680816)

How did you maintain attitude on the rocket? I don't see any control mechanism on the description.

Re:Attitude Control (2)

Kymermosst (33885) | about 3 years ago | (#37681188)

The vast majority of amateur rockets are passively stabilized.

Center of gravity above center of pressure.

Qu8k Construction Materials (4, Interesting)

kgholloway (1013997) | about 3 years ago | (#37680846)

I'm wondering what materials you used to construct your rocket? The sustainer appears to be made from Aluminum with welded on Aluminum fins. However the nosecone appears to be made of two or more materials. Also what did you use for the shade over the video camera that apparently melted during the boost phase?

Re:Qu8k Construction Materials (1)

GameboyRMH (1153867) | about 3 years ago | (#37681164)

Also what did you use for the shade over the video camera that apparently melted during the boost phase?

Says in one of the videos it was made of "plastic."

Re:Qu8k Construction Materials (0)

Anonymous Coward | about 3 years ago | (#37682262)

I think it's the camera casing itself that melted, not a shade proper.

flight control (1)

rastos1 (601318) | about 3 years ago | (#37680858)

The rocket landed only 3 miles from the launch site despite the tail fins being fixed. IMHO, that's impressive. How was that achieved?

Re:flight control (4, Informative)

FlyingGuy (989135) | about 3 years ago | (#37681728)

All of the big high altitude rockets have on-board computers and most have video cameras etc. On launch they go off a rail since there are no active flight controls. The accelerate at well over 10g so they are up to speed very very quickly. Once they clear the rail they can drift but at the speeds they are going up at not so very much. Almost all the drift occurs before apogee as it is coasting or at apogee as the rocket noses over and start the trip back down. Additionally for those kind of launches you wait for the least amount wind possible.

Most of these types of rockets transmit telemetry on HAM frequencies. The operator can watch real time events from the on-board computer for altitude, speed, chute deployment, location ( from the on-board GPS ), ascent stage separation, sustain stage ignition signal, sustain stage burning and all sorts of things.

As the computer detects altitude decreasing and sufficient speed has been attained the computer deploys a drogue parachute which has just enough drag to keep the nose pointed straight down so the rocket accelerates to terminal velocity very quickly.

At a preset altitude either the main chute is deployed or another larger drogue to decelerate the rocket to a speed where the main recovery chute will then deploy without either shredding or tearing the rocket to bits.

Most model rocket engines ( like an estes ) have a small charge at the top of the motor which has a time delay fuse that is lit when the motor ignites. The charge is then ignited which has just enough pressure to cause the two halves of the rocket to separate and deploy the recovery parachute at or just passed apogee so if you have any amount of wind aloft your rocket will ride the wind as it descends at from 2000 or so feet if you have a slow descent it could drift quite a ways.

Rockets like the one in question are very expensive to build and the cost can push up to $5K to $10K depending on how exotic the materials are. Launching those can easily hit $500.00 per launch or more depending on who your motor builder is and other factors.

Hurdles (2)

Twinbee (767046) | about 3 years ago | (#37680888)

What were some of the hardest hurdles you had to overcome to get this working?

Re:Hurdles (0)

Anonymous Coward | about 3 years ago | (#37681206)

More specific to the point, what points in the design/build/launch cycles created the greatest delays for you, out side of funding let's say since that's probably universally an issue. Did the FAA require more stringent designs on the rocket/motor then you as an individual could provide? What kind of "outside" expertise did you need to get the rocket approved for launch?

Re:Hurdles (0)

Anonymous Coward | about 3 years ago | (#37681994)

Apart from, you know, the gravitational pull of AN ENTIRE PLANET!!!?!!

Phallic Shape (0)

Anonymous Coward | about 3 years ago | (#37680962)

Does the phallic shape of a rocket have anything to do with your interest in the science?

Super cool (0)

Anonymous Coward | about 3 years ago | (#37680972)

That video is insanely cool. Nice work.

FAA Paperwork? (0)

Anonymous Coward | about 3 years ago | (#37681028)

Fellow amateur rocketeer here, but I got out of it with the onerous new FAA requirements for class 3 launches. Would you mind describing how you met these requirements, and possibly posting your paperwork/simulations as others have done?

GPS.... (1)

malakai (136531) | about 3 years ago | (#37681046)

.... what's the solution? You had 4 GPS receivers and none of them tracked your rocket at altitude. Obviously rocket grade GPS exists but with military export controls on them. Is this a spot where DIY's could hack together a GPS module that handles the vibration and acceleration?

Time and Materials cost (1)

stewartjm (608296) | about 3 years ago | (#37681048)

Do you have an estimate for the time and materials cost, required to design, build, and launch Qu8k?

Machinery (3, Interesting)

vlm (69642) | about 3 years ago | (#37681052)

I looked at your website pictures; clean shop (cleaner than mine, anyway); Curious what type of equipment you used to build it... I see a bridgeport-style knee milling machine, a large unidentifiable lathe with a quick change toolpost. Chinese or classic American heavy iron? Nice smoke off the carbide (carbide, unlike HSS, can be pushed hard enough to make the cutting oil burn without wearing the cutting edge) Looks like all manual machines, no CNC? TIG welding the aluminum or ? Did you CAD it all up or build as you get parts? Is something like this rocket light enough to manhandle around the shop or are their engine cranes involved, or a custom cradle of sorts?

Re:Machinery (0)

Anonymous Coward | about 3 years ago | (#37682078)

Sounds pretty lame. Everyone knows 3D printing is the future. Why isn't there a 1300 Makerbot printing out one rocket after another?

Concerned (0)

Anonymous Coward | about 3 years ago | (#37681056)

Is your rocket safe for the environment?
Does it meet CAFE standards?
Are migratory birds injured by your rocket?
Does your rocket run on alternative fuels?

That's my first question.

Costs and resources. (1)

Vellmont (569020) | about 3 years ago | (#37681146)

I'd really like to get a sense of the resources (time, machinery, and dollars) went into the project. Obviously your biggest non-monetary cost was labor, but what did you pay out of pocket? How many resources were donated (i.e. specialized machinery)?

Plans for a multi-stage version? (2)

bkmoore (1910118) | about 3 years ago | (#37681196)

Are there any plans to build a multi-stage version to reach even greater altitudes?

What's on board? (0)

Anonymous Coward | about 3 years ago | (#37681226)

I have seen a few pictures of the boards and circuitry that goes up in your rockets. I was wondering what boards these are and what their functions are? From the looks of it there is also some radio equipment on board, is this for APRS, controls, etc?

Engine? (0)

Anonymous Coward | about 3 years ago | (#37681230)

In the initial blurb, it lists the engine as a Q motor. For those who don't know, the little engines they sell kids are "A" motors. A "B" motor is twice as big as an "A" motor, likewise a "C" motor is twice as large as a "B" motor. Moving along, a "Q" motor is 65536 times as big as an "A" motor. Question: did you use Ammonium Perchlorate as the fuel for the motor, and if so, did you make it yourself?

Re:Engine? (0)

Anonymous Coward | about 3 years ago | (#37681508)

He used Ammonium Perchlorate as oxidizer for the motor. HTPB was the fuel. Yes, the team built it their selves.

Payload and G-force (1)

Spy Handler (822350) | about 3 years ago | (#37681240)

How many G's was the rocket subjected to during the launch?

What was the weight of the payload? (i.e. the combined weight of the video cameras). Can we include a small mouse astronaut on the next flight, if we substitute the 2 video cameras with one smaller one?

Would it be possible to mount a second stage on top of the exisiting rocket, say a small Estes model, and launch that from 120,000 feet?

Those socketed PLCCs on the controller board (1)

NixieBunny (859050) | about 3 years ago | (#37681250)

I saw the two PLCCs, a big 84 pin and a little 32 pin flash chip, and thought to myself, "Those sockets don't look like they're rated for the sort of vibration your rocket experiences." Have you or your electronics guru considered learning the tricks of soldering QFPs and SSOPs? It's not hard.

121,000 ft - nice - but can you go higher? (0)

Anonymous Coward | about 3 years ago | (#37681286)

121,000 feet is incredibly impressive. I was curious however how high you think you could go? Can you go higher? What would it take to get to 250,000 feet? What is the limiting factor? Time? Money? Materials?

Tripoli or NAR (1)

vlm (69642) | about 3 years ago | (#37681308)

Tripoli or NAR for YOUR sanctioning / certfication body, and in comparison you'd recommend to a noob to start with Tripoli or NAR? Or is the experience with both groups so similar its kinda like miller lite vs bud lite (gotta look at the label to tell them apart)

In Soviet Russia (1)

Roachie (2180772) | about 3 years ago | (#37681316)

Amateurs rocket YOU!

Design software (1)

vlm (69642) | about 3 years ago | (#37681360)

Did you use integrated all in one design software, or a buncha spreadsheets, or a buncha equations in octave/matlab/mathematica, or paper -n- pencil?

In light of above answer, complete this sentence: My project would have been easier for me if the computer/technical/nerdy guys on /. "did this" ...

Inappropriate answer would be "DDOS the BATF" or "launch cowboy neal" I guess I'm expecting software development ideas.

Remarkable (0)

Anonymous Coward | about 3 years ago | (#37681394)

It's remarkable how a person able to engineer such a great rocket can't properly spell aluminium :^>

solid or liquid? (0)

Anonymous Coward | about 3 years ago | (#37681424)

How do you compare difficulties of making a solid rocket of such caliber with a liquid-propellant one? Do you make your rockets with solid fuel and not liquid because it's easier than liquid or for some other reasons?

Testing (1)

vlm (69642) | about 3 years ago | (#37681432)

How did you test this stuff? both mechanically, electrically, etc? Big homemade wind tunnel, or did you freeze the electronics in dry ice to see what happens, or ?

What got you in? (1)

Synerg1y (2169962) | about 3 years ago | (#37681490)

Those are some pretty massive rockets, ever work on stuff like model helicopters and RV cars? To get to that level where did you have to start? Did you go to wal-mart and purchase a kit and go from there, or get a blow torch and start creating rocket fins?

Re:What got you in? (0)

Anonymous Coward | about 3 years ago | (#37681640)

Adding on to that, do you know any good resources for someone to go from single-stage Estes kit rockets to something much bigger? I'm really interested in amateur rocketry, but everything I've read so far seems to assume a lot of prior knowledge.

Have you ever said to yourself (1)

RevWaldo (1186281) | about 3 years ago | (#37681564)

"Why, do you realize with a weap..er.. rocket like this, I could - dare I say it? - rule the world?"

.

Accuracy and difficulty (1)

planckscale (579258) | about 3 years ago | (#37681572)

To what accuracy is the thrust nozzle lathed? In the rocketry movie October Sky http://www.imdb.com/title/tt0132477/ [imdb.com] I recall that the nozzle/motor was the most important build. Which component required the most math/sweat/swearing?

UFO (1)

Oswald McWeany (2428506) | about 3 years ago | (#37681616)

Have you any humorous stories where people mistook your rocket for something else?

A UFO, government spyplane, terrorist weapon, etc?

Have you ever considered building something mischievious deliberately intended to make people think of one of the above?

Regarding GPS and Cameras (0)

Anonymous Coward | about 3 years ago | (#37681688)

Can you explain your GPS systems and how you tracked the rocket?
I am building a sounding rocket for a competition and have had problems with tracking and recovering the rocket.

Spinning (1)

notKevinJohn (2218940) | about 3 years ago | (#37681756)

Of all the rocket launch videos I have seen, your had by far the least amount of spin on the way up, no doubt due to precision engineering/machining on your part. Have you ever considered launching a camera with a wide angle lens that could see 360 degrees around rocket and then removing the spin from the resulting video with software?

Breaking the 100,000 foot Limit .... (1)

WatertonMan (550706) | about 3 years ago | (#37681884)

From the reports, your rocket was not launched from a designated space port, insured, or cleared by the U.S. State Department. (Which all launches above 100,00 feet are supposed to be subject to.) Were you able to get a waiver to break the 100,000 foot limit imposed by the Federal Government? If so, what loops did you have to jump through to get all the powers-that-be happy?

Passive vs active stabilizing (1)

jd (1658) | about 3 years ago | (#37681954)

For low-altitude rocketry, passive stabilizing is just fine. When you start getting to the heights your rocket is reaching, it's hard to imagine that this is still the case, yet your diagrams on your website show no active mechanism for keeping the rocket upright, the base fins for stability and that's about it. (Actually, given the wind sheer, it would be almost as bad to be blown horizontally yet remain vertical. To fix that, you'd need full-blown guidance.) To be fair, though, the diagram is hellishly crowded and you may well have kept the details to what would be the most interest/use to the most people.

So, are you using active mechanisms in your current rockets and, if not, are you planning on adopting any in future projects?

Where is (1)

WillRobinson (159226) | about 3 years ago | (#37681968)

The frickin laser beam..

Just kidding, really a great piece of work.

My question is:
Did you mix the solid fuel yourself or was that made for you.

Theory vs Practical Experience (1)

Toonol (1057698) | about 3 years ago | (#37681980)

How much of the design of your rockets come from trial and error, and how much from more formal principles of rocketry? Or, in other words, how much of the planning comes from deliberate application of physics, ballistics, etc., and how much from past experience?

Rocket Assists (1)

jd (1658) | about 3 years ago | (#37682032)

There are a lot of projects that aim to give rockets an assist at the start. NASA has experimented with ski ramps (and is back to them again) but has also played with turbine-assisted ramjets and variants thereof. ScaledX opted for a hybrid liquid/solid fuel motor, to get the controllability of liquid fuels with the oomph and reduced weight of solid. Have you considered any non-standard design or are you more in the "keep it simple" camp?

controlled airspace? (1)

element-o.p. (939033) | about 3 years ago | (#37682184)

First, let me say...very, VERY cool.

As for a question, what, if any, notifications, waivers, etc. were required to penetrate controlled airspace in the launch area? At the very least, you would have penetrated Class A airspace (between 18,000MSL and 60,000MSL over the entire contiguous 48 states), so I presume you had to have FAA approval?
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