Jonfliesgoats

Pusher SRBs are a good way to go. I think we ditch boosters at relatively low q, by being pretty high, though. I may well be wrong about this. Do you or does anyone else have insight on aerodynamic loads during SRB separation on various craft?

Noise cancellation works by broadcasting sound at the same frequency as ambient noise pi out of phase. Can a properly polarized emitter do the same thing with light or RF? RF is an artifact of my personal history. I meant to say radio.

Acoustic levitation is entirely possible with known laws of physics. EM drive isn't.

History and Politics. East-West relations are at a nadir right now and we are using Russian planes to evacuate American astronauts from the S. Pole. Beyond this the plane itself is being operated by entities on opposing side of a war. In years past this would not have been possible. AN AMC asset would have been assigned to the movement of these folks.

What the other guys said is right. Also, loud mistakes erase quiet ignorance in one, some or all of us. Keep screaming ideas!

The world is strange. A Soviet era plane evacuated an American Astronaut from the South Pole. The Company operating the airplane is a joint Ukrainian-Russian firm that manages to look past the war in Donetsk. To be fair, these same IL-76s have been operating in and out of NATO facilities in Afghanistan for the last fifteen years, which has its own poignancy. An optimist would say science, flight and humanity transcends geopolitics. A pessimist would say profit and public relations transcend geopolitics. Link to an article with photos of Aldrin by the contracted IL-76, presumably on his way south in good health: http://heavy.com/news/2016/12/buzz-aldrin-health-south-pole-why-evacuated-still-alive-sick-second-man-moon-2016-wife-family-age-old-antarctica-depression-alcoholic/

Do we have decent numbers regarding Soyuz reliability in comparison to Cygnus and other systems?

If there is anything that transcends the petty tribalism and biochemical impulses of mankind, it's spaceflight. While we may be genetically programmed to explore, we have no Sopwith Pup gene. When you stop and think, that's pretty significant. We leave earth when we decide to. That's really significant! You are right to point out Americanisms. We are jerks, and I am a loud, obnoxious example. If we go unchecked we start to dismiss the achievements of other programs and we lose-out as Americans and as human beings. It's good you call us out on our crap. You help us!

Agreed. I was actually surprised that SpaceX is only showing a 30% reduction in launch cost for their reuseable vehicle. I can't imagine a booster doing more than a few cycles now. When we get boosters that can launch thousand of times over, we may see much more significant savings. Maybe?

Cheers

At lower atmospheric densities, any surface has to interact with a volume of air in order to generate equivalent forces. This means you either need to get faster (SR-71) or have bigger surfaces (U-2 or Canberra). When we start making propellers for high altitude we get into a series challenges. 1.) The speed of sound is slower up high (due to low temperature). But the propeller has to turn faster. Exceeding the speed of sound drastically reduces propeller efficiency. 2.) making a larger diameter propeller allows us to operate with lower RPM, but the higher diameter also puts the tips close to Mach 1. 3.) Even with problems 1 and 2 worked out, an airplane flying at high altitude has a higher true airspeed for a given dynamic pressure. Keeping a high altitude propeller at sustainable RPM means the propeller pitch (the bite the blades take out of the air) is often so high that a large amount of thrust is lost and lots of force is vectored against the tongue generated by a motor. 4.) Propeller blades which don't interfere with each other at low altitude start to have significant blade to blade interference at altitude. High altitude propellers exist, and can sustain flight as high as 90000 feet!!! It took a lot of very smart people a lot of effort to get blade design just right. All of that started with some guys eyeballing wood in the early 1900s. Here's a link to a NASA publication regarding a prop design for an 85hp motor to fly at 85000 feet and .4 Mach. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980017535.pdf

Oh! Yes please! My mistake.

Nah. I am just pointing out that dropping stuff from fast planes is difficult. That's why it's in the science/spaceflight forum. The ease of spaceplanes in KSP can let folks think HOTOL and other programs are closer o fruition than they are. Same with stratolaunch, etc.

In KSP, we can drop an object from a pawn flying at Mach 3 with little difficulty. In real life, when you go fast, separating an object from an airplane is really, really difficult. Aerodynamic interference, shockwaves and paving centers of pressure frequently cause separating objects to behave unpredictably. It was only in the last decade that we really got supersonic bomb release down. If we consider releasing spaceplanes from supersonic and hypersonic motherships, the engineering challenges become really daunting. So, with current technology, we have a soft limit on the speed at which we can release a spaceplane. All foreseeable motherships have to be subsonic, not just because that are big, draggy, subsonic airplanes but because the feasibility of releasing anything massive at high air speeds is questionable right now. The link is to an unclassified announcement from 2007 when we could finally drop a Mk.82 at Mach 2. http://m.slashdot.org/story/93831

Too funny?

With future advances in manfuacturing and materials we may see reuseable spacecraft come back. Everylne makes great points about the costs involved, but reuseability seems to be the direction many smart people are moving despite the lessons from the Shuttle program. Advances in parachute design and control (ram air canopies with GPS guidance) make capsules with precision recoveries much more viable. We won't see this with Orion, sadly. We are still in the very earliest phases of spaceflght (think Montgolfier bros. with manned atmospheric flight). I am confident we will see improvements in materials, propulsion and process. We just may not see it in the US due to deteriorating popular will to fly in space.

Very true. I feel myself wanting to be dismissive of the Russians, but I also don't want to be a slave to my own bias. What do you think we can expect out of ROSCOSMOS if the price of oil stabilizes? Will they do more than send Soyuz capsules and commercial satellites into LEO?

Along the lines of what Wumpus said: The X-15 is often cited as demonstrator of the feasibility of air-launched spaceplanes getting to space. The problem is that the X-15 could only achieve sub-orbital flight. The energy required to actually orbit was way beyond what could be packed into the X-15. A craft capable of launching to orbit from the X-15s profile would have been way too heavy/big for a B-52. The X-43 went super-duper fast, as Wumpus said, but getting it up to speed was a problem. So for an air launched spaceplane to make it to orbit we have to do better in one or more of the following: 1.)Get more energy density from fuels (more energetic fuel/oxidizer/etc.) 2.)Do a better job of extracting energy from fuel (more efficient/powerful engines) 3.)Get much higher/faster before releasing our spaceplane (Supersonic/hypersonic mothership) 4.)Get a much bigger launch platform to release a bigger, more capable spaceplane (Put together two 747s)

A spool of sponges that gets mechanically scraped/wringer into a separate tank? I am sure we can find a way to over-engineer a space diaper.

To be fair to guys who refer to America as "we" we are all speaking English and KSP has a decidedly NASA slant. If we were speaking Russian or French, I would assume "we" refers to ROSCOSMOS or ESA. What offends me is that nobody ever assumes "we" are the New Zealand-based space program. Kiwis have rockets too! Also, to my friends at ROSCOSMOS, best of luck. In the West we tend to undervalue and even insult Russian pilots, aerospace and engineers. There are some brilliant minds working with far fewer resources than we have over there. Good luck figuring out what happened.

A joint lunar program would be the type of large project that could justify significant political realignment. Putin is also saying he wants to normalize relations with the West. Seems like he is setting up the next, joint space venture. In either case, more spaceflight and more ambitious manned projects excite me.

Flying aircraft carriers came back after World War 2: http://www.air-and-space.com/goblins.htm After the goblin we experimented with F-84/ B-36 combinations too. We used the trapeze system pioneered with biplanes in the 30s. In terms of doctrine, this is a vestige of "The Bomber Always Gets Through" philosophy so strategic bombing that was pioneered by an Italian just after the First World War. Strategic bombing was disastrously supported by the Air Corps despite evidence from The Spanish Civil War that fighters could and did cause significant losses to bomber forces. It took the bloody losses of 1943 to convince Arnold and Eaker of the necessity of fighter escort. One can even argue that Doolittle and his decision to release fighters from escort roles during return voyages to prowl and strafe axis countryside did more to disrupt infrastructure and logistics than the bombers themselves. Another piece of trivia related to the parasite fighter program and dogged support for faulty strategies: Claire Chennault. Claire Chennault was in charge of the Air Corps fighter tactics school and pushed the idea that fighters could and would stop bombers. He became so unpopular that his career was sidelined and he resigned in 1937. Shortly thereafter he organized the AVG for the Chinese Nationalist forces and used P-40s to significantly reduce the efficacy of Japanese bombing in China. So in the parasite fighter program you see a legacy of navy airships, a legacy of career-risk management at the expense of aircrew lives, and a relationship with tactical innovation and excellence with obsolescent planes paired with innovative pilots. In the Goblin fighter, you see just how ridiculous engineering will go to support a bad idea. The trick is identifyng the next good or bad idea before we prove their merits with blood. If mid and upper level mangement and officers find themselves whitewashing things to protect their careers, that's a good signal that we may be trying to defend a bad idea. When we apply this knowledge to, say, the CV-22 or the F-35... https://warisboring.com/arrogant-u-s-generals-made-the-p-51-mustang-a-necessity-fd6063ff4893#.f6ki9z1wt

So bad it's good: Starship Troopers (film) Good: Starship Troopers (book) Bad science in thAt movie: The young child who becomes a telepathic colonel is not charismatic. In reality, a telepath would know what everyone wants to see and hear, and would use that information to further their position. Telepaths would be affable. I suppose in science fiction, a hunter of telepaths would be paranoid of anyone who seems too kind, too accommodating or too charming. A hunter of evil telepaths would only be comfortable around people who are visibly flawed and he would automatically suppress those thoughts to prevent nearby telepaths from learning what makes him comfortable and at ease. As such a hunter of telepaths would be unable to form any sort of social or romantic relationship. He would be consumed simultaneously with killing telepaths and suppressing his own thoughts.

The Russians recently announced plans to go to the moon and establish a lasting, manned presence there. Think this is feasible? Will they do it, or is it just a PR move by the Russians?

Colonies would be small, initially. I imagine a lot of boredom, sexual frustration and odd senses of humor.