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About DerekL1963

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    Rocket Scientist

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  1. Well, no. In the beginning, it was the same trajectory that Ranger and Surveyor (and many non-lunar missions used) used - right from the pad to the moon. The name (which comes from orbital mechanics) persisted even as technology/capabilities increased to the point where a parking orbit was feasible to plan for. (You need restartable engines, more battery capacity, ullage engines and attitude control, a guidance system that will be stable enough long enough, etc... etc..)
  2. Direct Ascent means going directly from one body to another without an interim stop in parking orbit. Nothing more, nothing less.
  3. Not really, no. The political environment of the 1950's-early 1960's was radically different from today. Rockets were growing by leaps and bounds, and a huge engine with no current requirement seemed like a prudent investment in the future. The F-1 wasn't the only such speculative project... Just one of the few that eventually saw the light of day. In some ways, the Apollo CSM itself (in it's earliest incarnations) can be seen as equally speculative... A general purpose earth orbiter, when no clear requirement for such existed. Later, a lunar lander when NASA had no significant funding for such a venture and only the vaguest intention of going to the Moon sometime in the future. ("Possibly in time for the country's 200th birthday" according to some early documents.)
  4. But that's the thing - the F1 was already in development before the Apollo project. The CSM's design was well advanced (as a general purpose Earth orbiter) before Kennedy set us on the road to the Moon. Sometimes I get this feeling that folks think that NASA managers sat down with a blank sheet and got started the morning after Kennedy's speech... When nothing could be further from the truth. The only part of Apollo that was anything resembling clean sheet was the LEM. Much of the rest of the Apollo Project was largely cobbled together and adapted/developed from bits and pieces of programs and projects that were already in progress. This wasn't an accident. WWII and the Cold War... When you read the biographies of a lot of middle and senior folks at NASA and with the contractors during Apollo, they're often a litany of ever larger and more complicated aerospace projects in the 1950's. That's one of the unsung secrets of Apollo's success, the level of recent engineering and management experience with the rapid development and deployment of cutting edge aerospace systems.
  5. I suspect that had more to do with limited attach points where the SRB thrust was symmetric and jettisoned SRB's wouldn't hit the Orbiter. Not quite, the Apollo Program managers avoided new tech absolutely as much as possible. That is, they avoided research (as much as possible) and concentrated (where possible) on systems that only required development. It's a subtle, but important distinction. Ditto Gemini. Gemini was conceived after Apollo, and the design definition of the latter was largely complete and the design frozen two years before Gemini flew. Gemini contributed a great deal in terms of flight experience, but very little in the way of hardware or specific technologies. They did examine thrust termination ports... But the problem was the shocks and loads of sudden loss of thrust were sufficient to shred the ET, tossing the orbiter uncontrolled into the airstream. (This is basically what happened to Challenger, and she was destroyed by aerodynamic forces.) It was proposed to add a solid rocket to the orbiter in order to provide the necessary control, but it was too heavy.
  6. Every choice of SRB was fraught with problems. Every single one. Those big rockets? Huge problems... Starting with "nobody knew how to handle them". They have to be cast nose down , handled level, and raised nosed up for assembly - and their size and weight posed serious challenges to handling and moving them w/o potentially damaging the grain. They'd be a serious challenge even today. They're heavy enough and large enough that they can't be practically transported any distance, so they'd have to be cast at KSC. (Heck, they're large enough and heavy enough that even transporting them within the bounds of KSC posed a daunting problem.) That's a significant safety problem. Storing them would also be a significant safety problem due to the sheer mass of explosive in each booster. Speaking of casting the motors... that's another (huge) known unknown. The SRB's had to match (IIRC) within 5% - and the batch size was for a matched LH and RH segment pair was within the bounds of existing technology. Nobody knew how to cast a pair of matched monolithic boosters. Heck, they'd had problems casting even one during the testing down in South Florida. (IIRC, the final test blew the nozzle off due to rough combustion attributed to casting problems.) Etc... etc... Big monolithic SRB's, contrary to the nonsense believed by many, were not a magic solution. They would have required an expensive and extensive R&D program to a TRL where they could be considered ready for flight... and even then, as outlined above, extensive problems remained to be tackled.
  7. o.0 What part of "the resulting transient shock loads would shred the ET" was too hard for you to grasp? Millions of pounds of force simply don't disappear.
  8. Not knowing to c&p between threads or quote something someone else quotes... Sevenperforce asks why they didn't put thrust termination on the Shuttle SRB's - and there's a simple answer: It wouldn't work. Terminating SRB thrust meant the SRB's would go from "pulling" on the stack to "hanging off" the stack, the resulting transient shock loads would shred the ET and toss the orbiter uncontrolled into the air stream. There, as happened to Challenger, aerodynamic forces would turn the Orbiter into confetti. The only way around this was to put a SRB on the Orbiter itself, and use it to power the Orbiter away from the disintegrating stack. Problem was, even using this SRB for orbital insertion, it was too heavy and basically wiped out a large fraction of the cargo capacity. As to the never used "1 orbit capacity"... No, they never used the entire amount of crossrange available - but they routinely used the crossrange capability to widen abort and landing windows. (Or to create them were the window wouldn't have existed without the crossrange capacity.) Here's a handy little PDF from NASA that shows the amount of crossrange used at landing through STS-88.
  9. At the Tacoma Power dams on Lake Cushman and Lake Kokanee they built literal elevators to move the salmon past the dam...
  10. That depends on the mission... Are you talking a coastal submarine (AKA "manned mine")? Or are you talking something intended to operate at longer ranges? It also depends on your intended tactical environment... Sitting at a geographical choke point? Or hunting in the open ocean? Etc... etc... There is no such thing as "all else being equal", warships are designed with a metric buttload of parameters kept in mind - many not obvious. And honestly, the jury is still out to which AIP system(s) will win the race. The field is fairly young and the amount of operational experience limited.
  11. Indeed. It's very hard to actually have things in KSP that are well thought out and carefully engineered because either a) a lot of very important things IRL are abstracted away in KSP, or b) because of the limits of KSP's Lego block building system. (Or sometimes both.) KSP is a very useful introduction to some of the very basic concepts, but it's also actively misleading in some respects. (For example, you never have to worry about keeping your batteries warm - though oddly, you do sometimes have to worry about keeping them cool.) Contrary to the bromide beloved of many KSP players, you don't actually learn as much as you think you do simply by playing KSP.
  12. That's a bit of apples-to-oranges Rizzo... Modern armor is designed to stop penetration. War hammers and other mass weapons aren't meant to penetrate in the first place. They're shock weapons, meant to bruise and break bone. That being said, modern ceramic armor will spread the impact energy of a mass weapon over a larger area thus sharply reducing it's effectiveness. Best to swing for the limbs, joints, and head. Even if a helmet and/or face plate spreads the impact out, you're still going to cause the head to move (potentially disorienting the wearer) and apply considerable force to the neck.
  13. Among other things, they'd have to modify the fairing mountings to take the higher weight/stress. And they'd have to develop new separation mechanisms to ensure the heavier fairing separated cleanly. And they'd have to go through and recalculate how the weight changes the vibration levels. And... well, you get the picture. It's not nearly so simple as just swapping out the material the fairing is constructed from.
  14. In addition to Sturmhauke's suggestions - MechJeb can also calculate transfer trajectories. It can also correct for orbital inclination, very handy for visiting Pol and Bop.