DerekL1963

Yes, it looks like a skip if you "cherry pick" - but if you read the whole exchange, Evans reads up and Armstrong repeats back "Additional comments: Use non-exit EMS pattern". The EMS is the Entry Monitor System, which the CMP used to monitor the progress of the re-entry to ensure the vehicle remains on trajectory and within G-limits. "No-exit pattern" specifically means no skip. [1] Further if you scroll down to 293:20:53 in your link, when Collins discusses the entry procedure with Evans, there's no mention of a skip. They're holding the lift vector up to stretch the range a bit (215 miles according to the PAO at 192:00:07), not skipping. The AFJ/ALSJ is indeed a good source, but it's not entirely without errors and it does often require a bit of background to understand. Doing some research on skips also leads me to the master's thesis of an individual who is studying skip re-entry, on page 13 he states that "However, the skipping capabilities of the guidance were never utilized during that particular mission, nor any other Apollo Mission." [1] Mission Planning for Apollo Entry, page 12

A presumption, not a known fact.

Thirty years of studying space exploration, etc? That's about the best I can do.

SpaceX needing something isn't the same as the existence of an external market sufficient to keep the lights on and the production lines rolling. Not to mention the Atlas 401 has ten times the payload of the Falcon 1 and twice the payload of the -5. As I said, the -1 and the -5 were aimed at markets that don't exist. And the potential for smallsats mostly exists because they can hitch a ride very cheaply on someone else's larger bird.

For all the talk about the 'skip' trajectory, it was never actually used.

Electronics aren't strictly necessary if you don't care what orbit you end up in, no. But don't think for even a moment that the gyros and analog/mechanical computers needed aren't complicated pieces of precision machinery themselves.

The problem is, there isn't much market for LEO... Which is why Falcon 1 died and 5 was stillborn.

The initial explosion is mostly radiation, particularly X-Rays. This can be absorbed by materiaks opaque to X-Rays. In Orion they're using depleted uranium in the case. This only blocks the radiation, though. And it gets vaporized. Idk how it effectively focuses the blast. Even so, only 85% of the blast is focused. The initial energy release is mostly X-rays, which 'flows' much like water at those densities. This energy is redirected by the radiation case towards the channel filler (in a thermonuclear weapon the energy is redirected to the secondary). So while it's not a "shaped charge" in the picky sense that K^2 is using the term, and the physical mechanisms are different, the effect is the same - energy released by the explosion is used to vaporize and accelerate mass in a given direction. In a high explosive charge it's used to accelerate a copper liner, in a thermonuclear weapon the pusher/tamper of the secondary, in an Orion pulse unit the propellant.

I suspect not, the additional mass of heated air is very minimal compared to the mass of the propellant charge.

There's only "very little fallout" by comparison to a fission weapon of the same yield. By any rational standard, there's still considerable fallout. Doubly so considering the huge number of weapons and significant mass available to be contaminated.

I'm not sure that massive radiological dispersal in the atmosphere is much better... at least not below the stratosphere anyhow.

Active cooling could be used as a preignition source to self-pump the peroxide into its combustion chamber. o.0 It doesn't actually work that way. On top of which, you'll need to make your nozzle and chamber cooling passages much more structurally robust to withstand the increased temperatures and pressures post disassociation. (As well as somehow rigging things so the disassociation doesn't propagate upstream.) And you'll need cat packs anyhow to start the engine and bring it up to the temperature where it auto-dissociates in the cooling passages. (Which auto-dissociation also severely limits your ability to throttle and introduced considerable startup and shutdown lag.) Easier to just not let the auto-dissociation get a foot in the door in the first place.

Bear in mind, though, that a solid fueled ramjet, such as the MDBA Meteor is just an air augmented rocket that is burning dirty and undergoing ram combustion in the air augmentor. From the description of the gas generator, that doesn't seem to be the case, as there's nothing indicating it contributes significantly to thrust.

H2O2 disassociates (very energetically) at around 300 °F (150 C°). Your cooling system will have to be very carefully designed, even if dealing with yet another thing that can cause H2O2 to disassociate to your list of woes is a good idea in the first place.

We spend months living near weapons grade materials that we're very carefully kept separate from.* The material is sealed inside weapon cases, which are sealed inside the re-entry vehicles, which are sealed inside the missile, which are sealed inside the launch tube. Plutonium spread around the environment after the crash of an Orion is an entirely different matter. That's not how it works. If even one detonator fires, the whole explosive mass is going up. By design this won't cause a full detonation (which requires all detonators to fire with very precise timing), but it will liquefy (and probably vaporize at least a portion) and disperse the core. * I'm a former SSBN crewman, and FWIW I worked with the birds.

Grinding is never on the player's own terms almost by definition. If you're doing stuff you don't want to do in order to gain the ability to do the stuff you do want to do, it really doesn't matter if the thing you don't want to do is rescuing tourists for the umpteenth time or hauling back your ten thousandth ton of mcguffinite. If you want oranges, it doesn't matter whether you're offered a choice between Grannysmiths or Jonagolds. Yes, and no... We're now penalized (as of 1.0.5) for treating the contract system as a slot machine. Even if we weren't we can only accept the contracts offered, which quite often (at least for me) include a significant number of ones I don't want to do which is why players treat the contract system as a slot machine in the first place. With mods, you can make things better, but there's still a lot of cruft and grind. AKA the "MMORPG grind trap", something KSP should steer well clear of.

The MDBA Meteor is not air augmented, it's a ramjet.

Grinding for macguffinite isn't that different from grinding for contracts... you're still doing stuff you don't necessarily want to do to pay for the stuff you do want to do.

I'd love to see a Zenith family designed for the current environment myself. Not all of us use reusables.

It wouldn't have been nearly as efficient, as the F-1 was optimized for lower altitudes while the J-2 was designed for vacuum operations. (And the F-1 wasn't designed for in flight start.)

It's not that a reheat cycle is complicated, but that adding one adds complication to the overall system. (And a not inconsiderable amount of weight, because it's going to take quite a bit of energy.) One simple thing is simple, two simple things in series is less simple, etc... etc... The engineering version of Conway's Game Of Life - where complex behaviors arise from very simple rules.

I stopped reading as soon as I saw the author - William Mook is a very well known nutjob.

Hundreds of thousands, if not millions, of home cooks in the US do this every single day. It's not really a problem.

When you have to keep making things more and more complicated in order to make your scheme work... that's generally a sign that you're haring off down the wrong path.

You can't possibly appreciate how valuable it is. I made four patrols on an SSBN (and help load and test the missile in my userpic), and 'home' stuff went a long, long ways towards reducing stress. Simple stuff like ice cold Coke from a can (rather than generic cola from the fountain in a coffee cup, we didn't have glasses), or your favorite candy bar. Some guys would buy hobby magazines (and not the kind you think), put them in manila envelopes, and ration them out to themselves - one every couple of weeks. Etc... etc... Submariners, like astronauts, are less prone to that kind of stress - but we're still human, not robots.