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Ask Derek Deville About High-Altitude Amateur Rocketry 148

Posted by timothy
from the next-week-shatner's-answers dept.
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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Ask Derek Deville About High-Altitude Amateur Rocketry

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  • ATF? (Score:4, Interesting)

    by dtmos (447842) * on Tuesday October 11, 2011 @12:31PM (#37680472)

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

    • by vlm (69642)

      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.

      • 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?

    • by jd (1658)

      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 w

  • by LWATCDR (28044)

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

    • by kimvette (919543)

      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 spe

      • by vlm (69642)

        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...

    • by maroberts (15852)

      I worked for a GPS company in the early 1990's. Due to the first Gulf War, some of our civilian marine GPS systems were strapped into fast jets and worked perfectly well within the performance envelope of a Tornado fighter/bomber....

      Today, even if limits have been put into the sets, its probably not a difficult matter to look in the code for the appropriate constants and change the firmware.

      Ours ran on an 8MHz 68000, I'm sure your average GPS phone nowadays has a much more capable CPU.

  • Will it blend?
  • 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?

  • 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?

    • by vlm (69642)

      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 rock

    • "I build rockets go out to the desert and fire them into space." that's about 50 times more interesting than any other hobby i can think of off the top of my head.
  • Public support? (Score:5, Interesting)

    by dtmos (447842) * on Tuesday October 11, 2011 @12:39PM (#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?

    • What are you on about? Frigging Walmart sells model rockets and engines.
      • by Chris Burke (6130)

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

        Yeah well I wouldn't use what Willing ALlah's MARTyrs sells as an example of something safe!

      • by dtmos (447842) *

        What are you on about?

        Just one example [space-rockets.com] of the FUD the industry has had to deal with.

    • 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 a
    • 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.

      Mostly by the model rocketry industry as a way to bandwagon on the public's brief infatuation with space travel.

      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.

      That's what the tinfoil

  • 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?
    • by Kymermosst (33885)

      The pictures on his web site show an APRS transmitter.

      • by vlm (69642)

        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?

    • by CompMD (522020)

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

  • by deathcloset (626704) on Tuesday October 11, 2011 @12:46PM (#37680658) Journal
    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?
    • by malakai (136531)

      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.

      • by wagnerrp (1305589)
        On the contrary. Rocket motors become more efficient at altitude, as the reduced pressure allows for increased expansion and higher exhaust velocity.
        • by edremy (36408)
          Power would be better, but for control you'd be in a world of hurt. I doubt there's enough air up there to make the fins anything more than extra weight, and he doesn't have a steerable nozzle on this rocket. I didn't see any kind of gyro stability on it either.
    • by idji (984038)
      Why so many balloons, why not 3 or four balloons tethered by a cable at 10,000 m. Or not even tethered at all??
    • by nospam007 (722110) *

      "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!

      • by vlm (69642)

        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

      • by wagnerrp (1305589)
        Why not use hydrogen?
    • 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...

      • by wagnerrp (1305589)
        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.
    • by LWATCDR (28044)

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

    • by EdZ (755139)
      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.
    • by wagnerrp (1305589)

      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 va

      • Balloons aren't very useful if you're aiming for orbit, but for amateur rocketry where we're just trying to get something crazy-high and take a few pictures before a ballistic/chute reentry, it's likely a viable technique. This rocket achieved 37km from the ground. How high would it have gone if they'd launched from 30km and boosted the whole way with much lower air resistance? The balloon might limit you to a smaller rocket, but I'm certainly interested to find out what's possible!

      • by khallow (566160)
        High altitude balloons do three things for you. The altitude of 30 km is actually not that significant (perhaps 30 m/s of delta v), but it's there. Second, they're above virtually all of the atmosphere so your rocket can be optimized for vacuum (that generally improves ISP considerably). And third, because of the before mentioned thing, atmospheric losses are very small. You also launch above the weather, though balloons are notoriously sensitive at launch to windy conditions.

        White Knight gets you most
        • by wagnerrp (1305589)

          Launch flexibility is the only thing air-launch systems have going for them. Systems like Pegasus can launch from anywhere in the world, at any time, in nearly any conditions. Their low cost per-launch means a lot of smaller projects can afford to be the primary payload on a launch, and get priority orbit selection, rather than get stuck on whatever orbit inclination someone else wants to use. That said, it is one of the most costly launches per unit mass in existence, and as you stated, balloons lose ma

  • by Anonymous Coward

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

    • by wagnerrp (1305589)
      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.
  • by Anonymous Coward

    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

  • What kind of fuel did the rocket use?
    • by FlyingGuy (989135)

      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.

  • How did you maintain attitude on the rocket? I don't see any control mechanism on the description.
    • by Kymermosst (33885)

      The vast majority of amateur rockets are passively stabilized.

      Center of gravity above center of pressure.

      • Center of gravity above center of pressure.

        This works perfectly in theory, but maintaining this is hard. Most amateur rockets have a 'good enough' approach to stabilisation. The bigger the rocket gets, the more variation in CoM inline with thrust and the harder the problem gets. See the Scandinavian amateur rocket a few months ago that ended up pitching by something like 70 from vertical.

  • by kgholloway (1013997) on Tuesday October 11, 2011 @01:02PM (#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?
    • 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."

  • 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 (Score:5, Informative)

      by FlyingGuy (989135) <flyingguy AT gmail DOT com> on Tuesday October 11, 2011 @02:19PM (#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.

  • by Twinbee (767046) on Tuesday October 11, 2011 @01:05PM (#37680888) Homepage

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

  • .... 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?

  • Do you have an estimate for the time and materials cost, required to design, build, and launch Qu8k?
  • Machinery (Score:4, Interesting)

    by vlm (69642) on Tuesday October 11, 2011 @01:19PM (#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?

  • 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)?

  • by bkmoore (1910118) on Tuesday October 11, 2011 @01:33PM (#37681196)
    Are there any plans to build a multi-stage version to reach even greater altitudes?
  • 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?
  • 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.
  • 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)

  • Amateurs rocket YOU!

  • 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.

  • by vlm (69642)

    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 ?

  • 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?

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

    .
  • 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?
  • 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?

  • 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?
  • 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?
  • 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 cr

  • 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.

  • 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?
  • 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?

  • 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?
  • Three questions regarding next launch: Where? When? May I come?

    (Well in fact it's too far away for me, but I'd love to ;-) )

  • How do you get around the restrictions on civilian GPS. Whilst I'm sure this was taken into account, civilian GPS receivers are limited to speeds quite a bit below the speed achieved, and altitudes of around half of the achieved altitude:

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

    "The U.S. Government controls the export of some civilian receivers. All GPS receivers capable of functioning above 18 kilometres (11 mi) altitude and 515 metres per second (1,001 kn) are cla

  • As an old - school rocket hobbyist - one of the good outcomes was furthering an interest in science and engineering. Personally, model rocketry influenced my decision on which university to attend (one of the professors there was heavily invalid with the NAR) and design to study Aeronautical and Astronautical Engineering. My question is this - how can we foster the same interest today, given the attacks on rocketry by various well meaning, but misguided, agencies?
  • http://en.wikipedia.org/wiki/N-prize [wikipedia.org] I'm very impressed. Great job. Question? Do you have any comments on an N-Prize sort of launch? Do you feel it is achievable at even one orbit? If so are you part of a team?
  • ...you could aim a few of those at Wall Street and Liberty Street in NYC??? Be a pretty cool project, big guy...
  • I was impressed and somewhat humbled by all the different activities you had featured on your website. Do you ever sleep?

    In all seriousness, how do you (appropriately) balance work, family, and play time? In looking at your website, you seem to do at least two of those (family + play time) very well.

  • 23 miles is a great feat, congratulations!

    I'm a layman but having read about the stroke victim in Antarctica I got curious about the application of aerospace technology to emergency transport, rescue, communications, observations, and whether focus on these issues could help attract funding to civilian engineering teams.

    For example, it is apparently 5430km from Wellington, NZ to the Amundsen-Scott South Pole Station, and more like 6000km from Australia.
    What would it take (team, cost, time, technology) to bu

  • Where/how did you learn the information needed in order to pull off a feat like this? Related: How long have you been working on these types of projects?
  • I noticed you said the temperature at its lowest was -32C, and the pressure was only 93 Pascals. Did you need special electronics/cameras in order to operate under these conditions?

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