whoa, this is a BIG scratch-built QP project… and a very fun time in Dick’s magic workshop…. Tom used the SGI workstation for CFD modeling of the flights breaking Mach3… more photos to come…
The upper stage, seen here, can take a P motor (imagine solid propellant filling the bottom 6 ft., to the silver band by my right hand)
Casts a long shadow over our pile of L2 birds… 😉
It looks like a huge sharpened grey wax crayon, just for adults. So much propellant. I wonder if there is a size that crosses the limit of a hobby rocket. Maybe as big and long as a man can hold it with his hands.
I like that new buddy icon! Good idea, you and the rocket since we always see you with rockets. A much better photo of you too.
Amazing! Awesome!
Have "hobbyists" like yourself already exceeded Mach 3 with rockets like these, or is that the current target you guys are shooting for? Why is that upper section so much work? What are the special physical requirements for it?
What are the rules and laws regarding any limits on how big and "bad" you can build rockets as hobbyists?
I have always been amazed and fascinated by your photos and stories about your rocket-related activities.
**Seen in the Physics group.**
I will try to address some of the questions posted to help provide answers….
How heavy/light is it?
>>> This airframe upper stage will weigh a little under 200 lbs with full fuel. Fuel weight is roughly 120 lbs. The airframe is roughly 80 lbs empty. Very very light for an object of this size and strength. Traditional non-composite equivalent sounding rockets are closer to 370 – 800 lbs fully fueled. It has a second 8" diamtere booster stage not shown in the photo that is about 8 ft high, and contains an additional 200 lbs of fuel. Both stages bring the airframe in a lilttle over 20 feet. We are working on other airframes like a full size 45 ft long Nike Hercules you can read more about here: http://www.nikeproject.com/Hercules/index.htm
Combined, this sounding rocket can reliably delilver over 25-50 lbs of payload over 100,000 ft, or about 22 miles straight up. The highest we have flown is just over 390,000 ft, or about 73 miles stright up. Again, not exactly what a typical hobbyist can do. Still makes the hair stand on the back of your neck, though, when it roars off the pad!
Why is that upper section so much work?
>>> Composite materials have to be carefully assembled to insure proper alignment of fiber orientation with anticipated flight shear loading and contact with the resin matrix. Resins transfer loading distributed to the material to each individual fiber. You also have to make sure that resin matix contact and density between fibers is proper to insure loading distribution within the composite material. If properly constructed you end up with a material structurally stronger than steel, at about 5-10% of the weight. Composites save fuel, which you have to burn fuel to take with you. Glass and carbon are the predominant fibers used, carbon having the advantage of lighter weight and higher compressize and tensile strengths, but at the cost of radio RF transparency and high thermal conductivity. We used e- glass for this design which is better that traditional glass, but better RF transparent than carbon fiber. There is also application for Kevlar in some composites we build.
What are the special physical requirements for it?
>>> Solid propellant rockets are a race between converting all the fuel chemical energy to potential energy, stored as momentum in the velocity of the airframe, and the thermal heat flux of the propellant combustion driving up operating temperatures exceeding the failure limit of the motor casing and materials. A typical solid propellant motor has an operating internal pressure in excess of 2500 PSI at a temperature exceeding 5500 F. To endure this hostile environment, you have massive thrust ratios associated with this energy transfer, imparting extremely high G loading on the airframe. This rocket will produce a little under a million newtons or total force during its full flight performance, with a burn time of just under 15-20 seconds. That is a lot of energy transfer expended in a short period of time to impart upon an object. Anticipated G loading will exceed 50-100G’s. This requires special materials, components, and design to handling these extremes. Typical liquid motors are throttlable, meaning you can controll the thrust, and they have regenerative cooling of the combustion chamber because they use cryogenic fuels. You can operate these motors at much lower thrust rates, which also allows you to put organisms on-board. Most organic life forms would not be able to handle the flight environment extremes of most solid rockets, which is why they are used primarily for munitions and ordinance delivery. We hope to change that with some new technology we will be developing that will allow the first throttleable solid motors.
What are the rules and laws regarding any limits on how big and "bad" you can build rockets as hobbyists?
>>> This answer is complicated because there are many national and international regulatory compliance restrictions that are dependent on lots of different parts of what makes up the rocket, as well as where and how it flies. I am not sure I would exactly classify us has hobbyists. This rocket is as state of the art as any defense contractor might produce for the DOD or NASA. We don;t use the exotic materials that they do, because they are more dangerous. We are focused on making rocket technology safe, and cheap, which is usually not in most aerospace organizations dialect. Anyone remember the DOD $25,000 toilet seats? Military technology is focused primarily on killing people. We try to avoid this at all costs. Different priorities, I guess.
That said, we certainly are civilians, which is what Mavericks is all about. There is a lot more technology involved in producing a rocket of this class, than your typical hobbyist builds. Like the birth of the personal computer industry in the late 70’s, we are technologically on the edge of civilian space exploration capacities for humans as a species. The tools and technologies are now at all our finger tips cheap, if we choose to learn to use them. In a nut shell, there are restrictions on air space, thrust, vertical and horizontal velocity on telemetry communications and on-board GPS capabilities, radio telemetry power ratings, propellents and explosives, and many others. A rocket is a complex assembly of a variety of technologies that all have regulatory restrictions. Then again, you can always get a waiver under the right conditions…..and if youa re clever, you can find other ways to accomplish things that governments have not considered in their assumptions about the laws they write. Not sure that answered your question, but hopefully gives you some perspective.
Have "hobbyists" like yourself already exceeded Mach 3 with rockets like these, or is that the current target you guys are shooting for? –
Yes. We really do not shoot for speed in suborbital operations. Speed becomes more critical in orbital flights. Depending upon altitude, you need to attain critical velocities to maintain the orbit. At the minimal altitude you can attain orbit, this typically represents about Mach 22-23. This is typical of the shuttle orbital velocity. Thermal heating becomes an issue with sustained supersonic or hypersonic flight above Mach 1.3. Surface temperatures will exceed 2000F and higher which has the danger of exceeding the glass transition temperature for the composite if sustained flight velocities at this speed endure within the atmosphere. Composites can fail. Not a good thing at Mach 3 or Mach 22, as a recent shuttle crew experienced during re-entry over Texas. Early ICBM’s used inconel steel to handle these flilght environments. That adds lots of weight., significantly increasing the size of your rocket. Supersonic jet aircraft have a bigger problem here than rockets, because they have to fly in the atmosphere. Thankfully we will have left the atmosphere for the most part of this flight regime, so we do not anticipate this level of heating. Atmosperic denisty decreases dramatically about 65K feet, because most moisture does not extend above the tropopause, which ends here. We do get to revisit upon re-entry, but that is another discussion.
Wow, rocketmavericks, thanks.
A very interesting read… I just thought this would make a good long article, or even a book. I’m not a rocketry hobbyist and I have no idea how many there are, but is there a market for this kind of condensed knowledge? I can imagine it would be a nice way to mingle scientific and technological knowledge with stories and photos of rocket launches and crashes etcetera… I’m always fascinated by Steve’s photostream because I’m techno-inclined and I like things that have tremendous power and can go boom. I know there are lots of people like me around – potential article-readers and book-buyers 🙂
thanks rocketmavericks!!!!!! nice to read,
So the thing i learned is, that your rockets can not stay in orbit, cause of the little velocity compared to a shuttle.
but would it be possible to build a smaller upper stage which ejects at the highest point, that could reach this speed to stay in orbit…. or asked the other way around, would it be possible for you as "hobbyist" to put a satelite (a real small one) into orbit?
Another question on the return, would it be possible to use a parachute from the highest point? Or asked the other way around, how can you produce good film from the descent, without spinning around like steve’s rocket at the last time.
When i was a child i vistied "Peenemünde" the place where werner von braun build the V2 (A4), and i was fascinated by the gyroscope he build to stabalize and guide the missile…. you every thought of using such thing to stear your rocket?
questions questions questions 😉
So YOU have been hiding those WMD that someone has been looking for! Better be careful we may have to open up a big can of WAR on you!
Sorry, I couldn’t resist.
A lot more questions…..
Market for this information…..I dunno. Maybe?
Would it be possible for you as "hobbyist" to put a satelite (a real small one) into orbit?
>>> Yes. We are working towards this. My question is: What should it do? There are rules we have to obey. With so much crap flying around up there, you have to be very careful. Think about it. Mach 22 is faster than the muzzle velocity of a bullet exiting an M-16. There are thousands of objects, some the size of a greyhound bus, flying around the earth up there at this speed. Even a grain of sand that hits one of these up there is a real problem. If two object collide, then you create lots of objects going mach 22 (M-16 bullets) flying around.
Another question on the return, would it be possible to use a parachute from the highest point?
>>> A parachute is an inflatable wing. A wing produces lift and drag, both of which are used to control the descent. The problem at apogee (highest point) is there is no fluid (air) as space is a vacuum to inflate the parachute( wing), so the object just free-falls and accelerates under the gravitational pull of the earth. From 100,000 feet, your will reach close to the speed of sound, when you will come upon the atmosphere, and at that speed we will begin to generate a massive amount of heat. Terminal velocity only applies within the atmosphere, where you have fluid (gases) to push back on you. That means you better be packing a kevlar chute, as its BBQ time.
Decelerator technology is yet another interesting challenge. The moon for instance has no atmosphere, so how do you slow down enough to land on it? There is no place to shed off the energy you attain in flight reaching it, because the only way to shed the energy is as heat, and you have no atmosphere to transfer the heat to.
If you are interested in learning more, go to the Rocket Mavericks website and contact us. We love to share, and we would love to create more evangalists like Steve, who we have given the bug to. It addictive as hell. Once you go Mach, theres no going back!
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