GoSlash27

And also excessively tragic and depressing Best, -Slashy

http://www.spacesafetymagazine.com/space-disasters/challenger-disaster/nixon-administration-shuttle-safety/ ^ Just to show that my definition of safety is neither "idiosyncratic" nor "unreasonable". I'm not the first person to point all this out. Nope. Best, -Slashy

All of this, and more. Abort modes are just part of the vehicle and mission design parameters when designing a launcher that is as safe as possible. Ideally, the vehicle should be designed so that nothing can fail. That's usually not possible, so then you look at ways that vehicles can be prevented from killing people in the event of a failure, or redundancy, or simplicity, or (in the worst case) abort modes that can save the crew even while the vehicle is lost. There are going to be some parts of the mission that are extremely risky (no workarounds or aborts possible), but you try to minimize having to do that. There are some risks that cannot be foreseen until they happen, but when they do you redesign as necessary to eliminate them. The problem with the STS orbiter/ stack layout is that none of these considerations were accounted for in the original design. If anything went wrong with the SRBs at any point, the crew would die. If a single SSME malfunctioned at any point during much of the flight, the crew would die. If the vehicle caught fire on the pad, the crew would die. If anything substantial came loose and fell off... well, the crew might not die, but they were certainly at grave risk of dying. If something got bent or structurally weakened, the crew would die. An so on, and so on. NASA did their best to keep the shuttle fleet running perfectly as best they could and tried to dial in as much safety as was feasible in the aftermath of fatalities, but there was only so much that could be done because the STS was not *designed* with safety in mind from the outset. Best, -Slashy

Stuck in the way- back machine and liking it -Slashy

Jhorriga, True, but (taking the carrier analogy) tactical spacecraft have no business cowering in the hangar during the battle. Their job is to be out patrolling, protecting, taking the fight to the enemy. The tactical craft are the weapons and they protect the carrier. Expecting the carrier to protect the tactical craft is a recipe for disaster. Best, -Slashy

DDE, I didn't mean *literally* shirt-sleeve, I meant "not in a space suit" shirt sleeve. I'm assuming that in his universe things break down and wear out under heavy use, and that maintenance and repairs are difficult to perform in the dark in a space suit. Best, -Slashy

Physics Student, The specific impulse is actually a pretty handy figure. If you take a mass of fuel and set the thrust so that it exerts the same force as that mass at sea level, your engine will take Isp many seconds to exhaust the fuel. Aside from being easily convertible to exhaust velocity, it is also easily convertible to fuel flow rate. This allows you to calculate time to fuel exhaustion for a stage, the fuel mass consumed during a fixed time burn, or figuring the Isp of multiple engine types running in parallel. In the same sense that DV takes 2 forms (the DV required to execute a maneuver or the DV a stage will produce), Isp also takes 2 forms (exhaust velocity or fuel flow rate). It makes it easy to chuck numbers over the wall from one realm to another. Best, -Slashy

Physics Student, Using Isp makes it easier to calculate stuff like parallel stages and figuring burn times. Other than that... not much point to it. I don't know if it's easier to think of efficiency in terms of Isp or if I've just gotten accustomed to it. Best, -Slashy

Jeb's destiny, We can help you with that, but we need more info. Can you explain what you're trying to do in more detail? Best, -Slashy

The scene that @razark mentioned above. It was also what twigged me to Yuri Kondratyuk's influence on Apollo. It was only after that I learned about his other radical contributions like inertial guidance, space suits, hydrolox, etc. That dude was a *serious* visionary although nobody knew it at the time. If you've never seen it, it's worth your time to acquire a copy of this miniseries and give it a watch. Best, -Slashy

Yup. I think he only originally printed about 2,000 copies in Russian and he had to destroy all manuscripts and notes because being a spaceflight guy in his day and place was so dangerous (politics). I understand that there was a later reprint, complete with English translation... but I've never been able to find one. Best, -Slashy

Starman4308, If you find a source for a reprint, please let me know. I'd love to have a copy for my nerd- shrine. Best, -Slashy

Starman4308, Well, I'm sure you know most of the errata surrounding Apollo, but Kondratyuk was an unsung father of it. Perhaps *the* father of it, because he provided the outline of how it all had to go down in order to be successful and NASA got the plan from him... Kondratyuk was a very obscure mathematician/ physicist even in his own day. He concurrently and independently (and less famously) developed the Tsiolkovsky rocket equation at the same time as his legendary colleague, but it was just a footnote in his overall design to explore interplanetary space, which was exceedingly pragmatic for his day. He put together a manuscript with treatises, doodles, and equations and nobody wanted to print it because it seemed so fanciful. He wound up getting it printed in a limited run to pretty much no reception except in very small academic circles. That was pretty much it for his aerospace ambitions and he went on to civil engineering. That would be the end of his involvement, except... Fast forward to the Apollo program, and the big question was whether we would be going with the "Direct Ascent" approach or the "Earth Orbit Rendezvous" approach. And then along comes John Houboldt, who suggests a radically different approach; the lunar orbit rendezvous. He is credited with the success of the program because he wouldn't let it die, but it wasn't originally his idea. Houboldt read the report from the Space Task Group which mentioned an oddball proposal from a junior engineer at Vought named Tom Dolan and was convinced that this was the way it had to be in order to be successful. But it wasn't actually Dolan's idea either, because he got it from this crazy book he found written by some obscure Ukrainian guy named... Yuri Kondratyuk. So the entire concept of detaching a small lunar lander from a mothership in lunar orbit, landing, returning to orbit, and docking in order to save weight (because weight is always the overriding concern)... That was all Kondratyuk's idea. Additionally, the free- return trajectory and the gravity assist were originally his ideas as well. And as I said earlier, he also invented the rocket equation completely on his own although Tsiolkovsky gets the credit. Pretty much the entire Apollo design and mission plan was initially laid out in Kondratyuk's book, and that's where NASA got it from... though through convoluted channels. Kondratyuk's life was a great deal more mundane and tragic. He went into civil engineering, was convicted of sabotage and sent to the gulag, was placed in exile, volunteered for the army in WWII, and died in battle in 1941. It would be nice to be able to tell him that it wasn't all for naught, that his 'silly book' was critically important in future years and that he was right all along. Apologies for the text- wall Best, -Slashy

foamyesque, Haha yeah, I'm aware. I don't remember who it is, but one of the members likes to place the cargo in a nosecone in the CoM. That seems to work pretty well also. Still... I prefer not to do it that way. Better to leave the airplanes with a uniform mass and shape IMO. Best, -Slashy

I would love to have a conversation with Yuri Kondratyuk aka Aleksandr Shargei (though I would need a translator). I would explain the entire Apollo program, how 'lunar orbit rendezvous' came to be the mission mode, and how much credit he deserves for making all of it possible. Best, -Slashy

foamyesque, I know your question was directed at @Brikoleur, but I'd like to weigh in on this too. I'm kind of an oddball in that I never use spaceplanes to transfer cargo, only crew and supplies. I find the cargo bays restrictive, and don't like to design my missions to fit inside them. Thus, for me "payload" is strictly the mass of supplies that get transferred in orbit. For crewed missions, I consider the "mass" to be the mass of the passenger compartment(s) divided by the number of Kerbals contained. My passenger ferry spaceplanes are always small; 4 crew members (not counting flight crew) each way per flight. I rarely find a need to move more crew than that in a single go. My supply tankers, OTOH, tend to be as large as I can make them while keeping them reliable and easy to fly. Best, -Slashy

PakledHostage, I think that's what most of us are doing tho'. It is perfectly reasonable for someone to love the Shuttle, yet objectively look at it's strengths *and* weaknesses. You don't have to "hate" the STS to see the serious safety hazards and exorbitant costs that came with it. As I pointed out in my OP, I am thankful for the contributions the STS has made to the space program and I consider it to be one of the greatest feats of engineering in human history. I also loved watching it launch and loved following it during reentry and landing. Despite all that, I can set my feelings about the STS aside and dispassionately analyze it and come to the conclusion that it had some serious problems. I *think* that's where most of us are. Best, -Slashy

PB666, Sorry dude, I know you posted something, but I don't know what. You have rightly earned the honor of being the first person on this forum I've ever put on ignore. May as well find someone else to inflict your rude behavior on. Best, -Slashy

You assume too much. I have read it many times and understood it's implications when it came out, as did NASA when they rushed to shut it down before it got more people killed. I am also fed up with your snotty attitude. I asked you repeatedly to keep it civil, and you don't seem to be willing to do that. I'm not interested in anything else you have to say.

http://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceNavy As long as you're going with a "space carrier" analogue, tho'... You have a large internal hangar, well- lit. It is primarily intended as a shirt-sleeve working environment for the repair and routine maintenance of tactical/ support daughter craft. It can be subdivided in an emergency (or during GQ) by internal airtight and fireproof doors to compartmentalize it. Each compartment has it's own reserve bottled air and can be vented to extinguish a fire. 2 large airlocks at each end to transfer tactical/support craft in and out of the hangar. Tactical/ support craft are attached on the outside, and most routine evolutions are conducted there. Refueling, rearming, etc. There is no need for catapults or runways, but there *is* a need for tight traffic control in the approach to and departure from the carrier itself. It's crowded airspace. Best, -Slashy

This is the report that shut the Shuttle down early: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110008208.pdf Obama had originally planned to fly it until 2013, but then this came out and they realized how much of a gamble it was to continue any further. They managed to squeeze out 3 more flights to get their affairs in order (each one personally authorized by the President) and then that was it. Best, -Slashy

PB666, "Here in the real world", the shuttle program was retired because NASA deemed it too unsafe to fly. Period, full- stop. Furthermore, I've grown tired of your unwillingness to maintain a respectful tone when everyone else here is doing their best to be civil and polite despite their disagreements. Do me a favor and please refrain from addressing me anymore until you decide to do so in a civilized manner. Please and thank you, -Slashy

Brikoleur, In my experience, 10km is really too high. I've gotten my best fuel efficiency at 3-6km for low thrust spaceplanes. You might want to try various altitudes if you're inclined to experiment. But yeah, it really does depend on the design of the spaceplane. Best, -Slashy

I understand that this isn't your point, but it is far less likely for that to happen than having the booster impact the orbiter right next to it. A capsule is also a lot more resilient than an orbiter. SRBs can be equipped with thrust termination ports like they use on ICBMs. It is possible to shut them down instantly in the event of an abort, so I wouldn't say they should never be used on a manned launch. Liquid fuel boosters are safer overall, tho'. Best, -Slashy

KerikBalm, It does make some theories seem less likely, such as payloads that were intended to reenter. Best, -Slashy