• Content count

  • Joined

  • Last visited

Community Reputation

521 Excellent

About Steel

  1. SpaceX Discussion Thread

    I mean... It might be 'possible', but considering the X-37 is unmanned the only internal space you have available is the payload bay with no life support systems (or windows for that matter). You'd basically ride to the moon in a large space coffin
  2. I said weather patterns more from the point of view that, if there are regular formations, there is probably some specific weather pattern that happens regularly in the area that causes it.
  3. Short answer: I'm sure there is, but I'm also sure it would be incredibly complicated. We're probably talking a PhD's worth of work to do it, since you're looking at weather patterns, fluid dynamics, hill geometry e.t.c
  4. Amateur rocket to orbit

    Welcome to the forums! That's a really nice summary, echoing what some of us have been saying earlier in the thread. Your project sounds really interesting (I wish there had been something like this at mine when I was there) do you mind if I ask what university you are a part of?
  5. SpaceX Discussion Thread

    Yeah sorry, one of your quotes snuck it's way in some how!
  6. My question, how do you persuade so many people to go? Obviously the whole pioneer thing appeals to some, but for that many people to go there has to be a tangible benefit
  7. Yeah fair point. So assuming the engine was designed by a sane person in the first place such that it is sonic in the throat region, reducing the throat area will decrease mass flow rate.
  8. Why does Hydrogen peroxide is so toxic?

    It is not that toxic, but it is potentially highly explosive when concentrated. It decomposes exothermically (releases a lot of heat), so if it's not treated with care it can suddenly explode without much of a warning
  9. My point was that, keeping all the rest of it the same (i.e exit area, chamber size e.t.c) reducing the size of the throat of an engine would decrease mass flow rate.
  10. You could try, but as you say, you start running into material problems because increasing chamber pressure usually necessitates an increase in temperature too. My guess would be that any mass savings in the nozzle would be at the very least cancelled out by the increase in mass of the chamber, if not exceeded by it.
  11. Reducing the throat area reduces mass flow rate and thus thrust.
  12. Roughly, but there are a lot of other factors that go into it, so a linear scale will not always be true. For example, the Merlin 1D vacuum nozzle is the same size as the entire standard Merlin 1D engine and nozzle put together, but the M1D and M1DVac have almost identical mass flow rates. Thickness is down to aerodynamics and cooling requirements. So an ablatively cooled vacuum nozzle will be very thin, while a regeneratively cooled sea level nozzle will be much appreciated thicker
  13. So, basically for any engine you will have a target area ratio (area of the throat Vs area of the nozzle exit) which will be decided based on how much ISP you require and how heavy can allow the nozzle to be. The area ratio then determines the length and radius of the nozzle, since the exit radius is related to the length.
  14. Are we talking about the nozzle specifically or about the general dimensions of the rocket as a whole (one chamber size, throat area, e.t.c)
  15. Thanks! Rocket nozzles aren't quite that simple unfortunately. Generally you can get most of the potential thrust from a short nozzle with a well designed bell contour, however increasing the length can also improve your thrust slightly. The size of this increase is dependent on how good the nozzle is, so generally you'll see a larger effect for simple nozzle (i.e conical) than for more complex ones. However, the biggest thing that changes with nozzle length is ISP, since a longer nozzle has a larger exit area, thus a larger throat-to-exit area ratio and thus a faster exhaust velocity. Mass flow rate is fixed for any given combination of chamber pressure, throat area and outside pressure, so the nozzle has no effect. Basically, it scales with exhaust velocity, which is related to thrust and ISP. It also differs depending on the design of the nozzle, but that's another story.