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About Hesp

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    Rocketry Enthusiast
  1. I did some calculations and experiments on another old thread, but it was meant for a fuel station in Mun orbit:
  2. Amateur rocket to orbit

    @wumpus Basically you need the know-how. To build that you need engineering time, prototypes, measuring lab and testing equipment, and failures. Lots of them. Any failure you investigate correctly gives you further knowledge of the topic. Building a system that works at the first attempt without having previous experience and know-how is pure luck. On a side note, that's why every aerospace supplier must have a AS9100 or EN9100 certification.
  3. Amateur rocket to orbit

    Got it, what you say regarding the new capabilities of the process is true and i completely agree. If SLS is the only way you can manufacture a part, it qualifies automatically for production rather than just prototypes. My remark was that we both stated the same thing, when saying that it's not an alternative to machining for things that can be machined.
  4. Amateur rocket to orbit

    We said the same thing, read again. In my current job 3d printing it is an alternative to metal CASTING or FORGING for single or very small batches of prototypes. It makes you save the cost and the design time of all the casting/forging toolings and fixtures, really prohibitive if you need only a small lot, quickly.
  5. Amateur rocket to orbit

    I have some work experience in simulations and design of turbochargers... Making a functional turbopump is something way beyond the amateur/hobbist territory.
  6. Amateur rocket to orbit

    I wasn't referring to the F1 engine, specifically. To 3d print it you'll need the technical drawing and the 3d model of every single component, good luck getting those from NASA. And yes, internal surface roughness will be different from original since they are coming from a different process. Plumbing is not a big issue today with hydroforming and a certified welder doing the job. Metal 3D printing is increasingly common in prototype manufacturing compared to other processes like casting and forging, it's not an alternative to CNC milling. No need to laser sinter a part that can be obtained only by machining.
  7. Amateur rocket to orbit

    The technology you are looking for is called DMLS (Direct Metal Laser Sintering), a branch of SLS (Selective Laser Sintering). While the cost for one of these machines ranges from 50k to 500k€, there is plenty of existing companies able to "3d print" your parts. These printed parts usually need to be finished on a CNC center to achieve the required tolerances, anyway.
  8. Amateur rocket to orbit

    Basically because a (multistage) rocket with that delta-v and a guidance system is often recognized as a ballistic missile.
  9. Amateur rocket to orbit

    Try to investigate glycerol. It's been used as a fuel for internal combustion engines even if difficult to burn. The high % of oxygen in the molecule may reduce the oxidizer needed.
  10. You did an outstanding job! First of all, thank you As others already said, the major issue / difficulty to overcome with all these engines is not modeled in KSP... radiation. I'm throwing here a crazy idea, not even sure it can be done without a specific mod. What about an auto-deactivation or performance limitation of all nuclear devices (engines, reactors, etc) when the ship is in close proximity to other vessels or planetary surfaces? Of course this can be tuned accordingly to the part characteristics / need of balance. Let's take the emancipator from KA for an example, I'd like to have the open-cycle-fuel disabled and throttle limited when approaching other ships or stations
  11. Amateur rocket to orbit

    CFD. OpenFoam is an open source software. Missing previous know-how, you will need some iterations to correlate between real object and simulation data. Anyway you will need to perform also modal and thermostructural analysis with other simulation software before even building a first engine prototype. EDIT: didn't read @Steel 's answer before replying.
  12. Amateur rocket to orbit

    Right now the highest grade peroxide I can order online is a 35% solution, at about 10€/liter. You make things too easy, hot peroxide vapours are explosive and that distillation lab setup, although feasible, is very far from the "amateur" concept. Especially for the quantities needed. TATP , quite popular these days. And it's doable with hair bleach grade peroxide. I bet you'll raise more than an eyebrow buying truckloads of H2O2 (any useful grade)
  13. Amateur rocket to orbit

    Just a quick note regarding HTP... Propellant-grade hydrogen peroxide is available to qualified buyers. In typical circumstances, this chemical is sold only to companies or government institutions that have the ability to properly handle and utilize the material. Maybe I missed in the discussion HOW you plan to retrieve, store and handle fuels and oxidizers, but anything good enough to fuel an hybrid rocket is equally good enough to make a bomb.
  14. It's exactly the opposite... I haven't got numbers at hand right now, but orbital period in LMO (50km) is higher than in LKO (150km), so cosine losses are lower (and the burn is way shorter too!). Regarding the ejection angle, just zoom out the map and focus on the ejection trajectory. If the timeframe (mun position and node position in munar orbit) is right, the trajectory will follow.
  15. Actually, it helps quite a lot in reducing the size of the transfer stage. All my interplanetary missions are leaving directly from a refuel station in Mun orbit (fuel is refined and shipped from Minmus). Of course if no refuel is planned, starting from LKO is way cheaper.