AstroAbaqus
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- Joined
- Jun 14, 2021
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Okay it depends what you mean by punch it. I consider a K250 in a lightweight rocket punching it. An L1000 works well too, and certainly higher thrust is fine if the second stage can clear most of the atmosphere. Also my initial guestimate is right in line with the sims. "The rockets would likely need to be staged and the velocity low in the thicker parts of the atmosphere.", but that is not important. I agree a real-world rocket will not perform like this sim, but keep in mind a four stage (or air start) rocket is what I was thinking. If all the parts worked, such a rocket would reach extreme velocity in thin air and easily exceed 100k. I keep bringing up Gary's Hamster dance rocket because of how efficient it was. Yes no commercial motors match his thrust profile, but a collection of motors can in a relative sense.
Anyway the point John Derimiggio brought up about guidance is very valid. This rocket will turn badly as it hits the upper-air winds. A guidance system takes this to a whole new level of hard.
I should back up now and get to my original point. I think more can be done with LOC Precision style components than most think can be done. I also suspect higher speeds are possible than what I initially thought. It is a a fun space to explore.
Perhaps the takeaway from this discussion to anyone reading is optimism. You do not need a professional-grade machine shop or advanced composite shop to build some very capable rockets. Though a word of caution. Staging and air starts require lots of care to be safe, especially with big motors.
Finally I have no interests in trying this challenge myself. My challenges are much more down to earth such as convincing my wife a porta potty "isn't that bad" at a launch. All of my current projects are aimed at the fields/waivers I have access to, which are modest, but still great fun.
Sorry for jumping in, but I have read the whole post and I found really interesting.
Guidance: I am pretty sure that a lot of HPR, single-stage or multi-stage did not have implemented any guidance at all. TVC, because of this we are discussing, is something very hard to implement. When I say implement, I refer to the creation of a system and its proper actuation. Especially for the relatively "short" burn of these engines and the lifting capability, is very difficult to house any type of guidance. I saw people using fins with actuators, but this was done more for the fun of doing some particular trajectory rather than actually navigating.
Materials: I totally get your vibes, and I think if this is done safely there is nothing bad in trying and fail. I love doing things and pushing limits. Indeed is possible to increase the strength of the tube by using more conventional materials like wood dowels to increase rigidity. However, the main issues are the final weight and last but not least the actual space left between the airframe and motor tube. When you fly that high, your design constraints start to look more as a real sounding rocket rather than an amateur one. So every gram you add, if is not doing something is wasted. This is why, in my opinion, if you really want to go extremely high you have to master very well minimum diameter, but this then leaves us with the point that others mentioned, without exotic materials is very hard to do. If you go minimum diameter than you do not have space internally to provide more rigidity.
I would love to join the race but despite I do stuff like that during my daily job I am not even closer to complete my lvl 1 and 2 bird. But I will follow closely .
Ps I totally understand your point of living in a flat. I used to have a flat with an immense garage at my parent house, now I live in my own house which is nice but I have no space like that and convincing my wife to have a cnc somewhere in the living room will be hard xD, but she is an engineer she will appreciate hopefully xD