Rakaydos

You missed Hundred-Person Two Stage to Mars And Back reusable colony ships.

I remember reading that center core RTLS has only marginal gains over a reusable F9,but that barge recovery might be reasonable if they allow for a longer entry burn.

I get the feeling it's more a stratigic shoice than a tactical one. You dont have coast-crossing IR scanners looking for aircraft 24/7, like you do radar. And those heat-sensing fighters arnt doing anything if their pilots are still having a beer. So like a submarie, a stealth aircraft can sneak in and take out air defenses before the war actually starts.

Air superiority drone, then. Same thing, minus pilot.

It's about time to start planning the NEXT next gen fighter, anyway.

Lol... Damn lawyers... "Forward-looking statements can be identified by the words "anticipates," "may," "can," "believes," "expects," "projects," "intends," "likely," "will," "to be" and other expressions that are predictions or indicate future events, trends or prospects. These forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause the actual results, performance or achievements of Iridium to differ materially from any future results, performance or achievements expressed or implied by such forward-looking statements. "

Er... I may have made the symbol go the wrong way. LESS THAN 1. Not useful for a "real" rocket, not as efficent as a "Real" space engine, but with blanced values optimized for their application.

Presumably the electric part is powered by thin film solar cells across the mile long top surface, but the chemical part is apparently Al-enriched parafin and LOX.

Their proposed drive is hybrid chemical/electric- ISP around 1000, but a Twr >1

There's a square cube law thing going on there (drag goes up with cross section, buoyancy goes up with volume) that makes bigger airships better at that, but it is a known issue. The JPA people are looking at experiments done in the 60s that used active plasma manipulation to reduce drag by 80 or 90 percent, at least in the lab. They need to get at least 40% drag reduction in the real world to get this concept to work.

I'm pretty sure you didnt actually do more than skim the airship proposal, because you dont even attempt to address their solution to that problem. Short answer? An Imperial Star Destroyer sized blimp that never goes lower than the highest altitude "normal" balloons, and is built for the lower pressure, lower turbulence operating environment. Regular balloons carry cargo as far as they go, cargo is transferred to the monster designned for NO LESS THAN extreme altitude, which handles the transitions from displacement lift, to aerodynamic lift, to hypersonic suborbit, to orbit.

What theories have been definitively ruled out, as far as the underlyng physics? I'm in the "Low Vaccuum MHD Thruster" camp, but I saw a wacky idea that called for a "Plank length" for momentum, and the EM drive is literally running on universal rounding error.

3D printing is more expensive than traditional mnufacturing for most purposes. SpaceX already uses 3D printing for the parts that are improved by the process.

International standards are bad enough, I can only imagine how difficult it would have been to come up with an interstellar standard for comunication when the negotiations take thousands of years each way. Yea, I'm calling bull.

234 civilizations using the exact same frequency of laser. What's so special about that frequency?

And that's not even getting into Foreign Actors, some of whom see themselves being shut out of the launch market at the same time as so many other economic sanctions hit home...

Personally, I'd prefer a modified SpaceX BFR, with landing legs on the core and any tank modifications needed to land the core+booster on Titan. SSTO the modified core to earth staging orbit, send up the ITS return craft (set up for Titan ISRU, uncluding refueling the booster), dock and refuel both in orbit (many flights), and send it to titan. Since it's unmanned, a saturn aerocapture may be plausable even without a proper heat shield on the BFR core- no need to worry about mission duration or saturn's radiation belts. Saturn aerocapture to titan aerocapture (over several passes) should limit the Delta V needed for capture, entry, desent and landing. Then refuel, BFR to ITS to earth return.

How do you mke sure the gasses are separated, in that case? I only know the grade school "oxygen by one lead, hydrogen by the other, the water itself forms the gas seal" version.

So... 1) mine 2) place in evaporator (heat or vacuum sublimation?) 3) pump H2O gas to condensor -dump unused surface materials 4) Condence liquid H2O 5) Electrolize O2+H2 gasses (separated) from water -Pump O2 into inflatable storage tanks to await spaceship 6) Sabatier H2 gas with CO2 gas (compressed external atmosphere- impure, possibly degrading?) into methane 7) Pump methane into inflatable storage tanks to await spaceship Is there any other steps that need to be looked into to make sure they arnt hiding a secret dealbreaker?

"operations" issue. "Buisness process issue" What DO you call it when the neibor tears up your mailbox?

You're right, nobody is listening. Certiantly not SpaceX. And probably not you. SpaceX is accepting a certian amount of risk to simplify their architecture. One ship on direct entry, refuel, and SSTE(arth) is simpler than a mothership nailing aerocapture-to-orbit through uncertian weather conditions, leaving living space and engines in orbit while people and cargo land, sending fuel up a dozen times, then repeating the process back at earth. KISS Principle. Keep It Simple Stupid.

Northstar, I am confident that SpaceX will maintain their curently reveaed architecture. It's not as efficent, but it's cheaper to debug two and a half overbuilt vehicals (tanker/ship comminality makes testing easier) than build a finely tuned, carefully optimised powerpoint rocket that doesnt even work for bad conjunctions. If your one lander has a reentry failure, your mothership is dead anyway, unable to fuel up to return to earth. It doesnt matter that SpaceX is risking the entire ship at once, because the end result is the same. If anything, SpaceX might add a cycler "mothership" later in the architecture's life, the ITS ship being the "Simple lander" you crave. An ITS body that expands into a bigelo space hotel.

Out of curiosity, how many reloads do you spend nailing the perfect aerocapture-to-orbit? And IRL, you cannot predict your capture orbit that nicely because it depends on the atmospheric conditions you pass through. You're also implying a seprate dedcated tanker as well as the dedicated crew/cargo lander, because you dont want to waste mass hauling people and cargo every time you refuel the mothership you left in orbit. That's TWO extra vehicals spaceX would need to design and test.

Industry standard is a powerful first stage and a small circularizing upperstage. SpaceX has pioneered the "low and slow" stage, with the first stage just getting the second high enough for the vac nozzles to work, then coming home.

Someone in the NSF forum omented that the "scale model" is just the right size to fill that Airforce Contract for a raptor powered upper stage for FH.