Agate

Musk's business plan has an extra step that makes all the difference: 1) Start with ridiculous amounts of money.

They've been selling these since I was a kid: http://www.abundantearth.com/store/ecosphere.html

There's not all *that* many cosmic rays, the Sun's and Earth's magnetic fields offer quite a bit of protection, and many of them go right through you.

Service bays cause spontaneous explosions of spaceships. If any part of the spacecraft is anywhere near the doors when they open, kaboom. Goes double for parts that also move. If a part is attached to the outside of a service bay, or really anywhere near the bay, the game may treat it as being *inside*, rendering it unusable at best, kaboom at worst. And objects attached inside the bay but in the wrong place may rattle continuously, causing control difficulties at best, kaboom at worst.

To my mind, it looks like they've got a bare concept that they've thrown some 3-d graphics at, but there's no engineering design yet. This concept is based on Ariane 5: the distinguishing feature of Ariane 5 is that it's got an oversized "main stage" that provides propulsion from liftoff almost all the way to orbit. (SpaceX drops its first stage at about V = 1.8 km/s; Ariane 5 keeps the main stage running until about 7 km/s). That makes the main stage engine big, expensive and worth recovering, BUT it means that the mass of your recovery hardware (wings, landing gear, propellers) has a much bigger impact on payload, since it must be carried almost all the way to space. In addition, re-entry is a lot harsher at this speed. That means there are a bunch of possible showstoppers: 1) Turboprop and turbofan engines are very heavy compared to rocket engines with similar thrust. Often, that doesn't matter because the savings in fuel and tank mass makes the engine mass negligible, but the plan here is to ditch the tanks, so engine mass matters. (Especially given the flight profile of Ariane 5, see above.) 2) The turboprop engines are going into space, so you're going to need to design them to be vacuum tolerant. A space-rated jet turbine is not exactly off-the-shelf technology. 3) The wings on this thing are very short and stubby, and the payload (a ginormous rocket engine) is pretty heavy. Also, the wings have to be flat boards rather than a classic asymmetric airfoil shape, or they'll throw off the rocket during launch. Odds are good it's going to fly like a brick, with a high stall speed that will make landing an exciting challenge. 4) The video shows folding propellers that deploy in flight. Designing props that fold when you want them to and not when you don't is a challenge. There are a few aircraft (motor gliders) that do this, but they operate under much less stressful flight conditions. 5) The nose of the return vehicle needs a heat shield to protect it during re-entry. But the nose also needs to have ginormous pipes and clamps running through it to mate the engine unit to the fuel tank during launch. This is doable: the Space Shuttle has a bunch of doors in its heat shield to solve this problem. But I think we can all agree that the ideal number of holes you want in your heat shield is zero. And none of this is shown in the video. The upshot: this may be doable, and hell, it might work better than SpaceX's plan. But the final design would involve a lot more careful design than the "strap some wings onto the side of an Ariane 5 engine" concept shown in the video. Which makes me suspect they haven't even started doing their homework yet. SpaceX will either succeed or prove its design impossible long before this concept ever flies. SpaceX and Ariane 5 launch videos, to compare staging design:

This one goes out to the amazing service bay. Convenient storage system for small parts, destroyer of space ships. Post your service bay fails here!

I spent some time this week doing this. Well, not intentionally using asteroids for heat shielding, but aerobraking asteroids in Kerbin's atmosphere. Rthsom's right: while asteroids look like space rocks, they're actually made of styrofoam, and no amount of torque could keep my space tug from flipping around engine-first as soon as it hit atmo. Your spacecraft will act as a heat shield for your asteroid, unfortunately.

The rules should definitely be: on Kerbin, no torque wheels, no thrusters, nothing but wheel power.

The fact that "seconds" is the only unit metric and American units have in common is not a good reason to use Isp. I mean, I could tell you that my own mass is 2 seconds, if by that I mean the period I would bob up and down at if tied to a certain bungee cord. But that would be ridiculous, and Isp is exactly that same ridiculous. But we're stuck with it, so sigh.

Found a pretty impressive Half Dome northeast of KSC. Cliff's about two and a half miles tall. I never liked the Mun's polar mountain. It was obviously a mapping glitch rather than a real mountain.

Ladies and gentlemen, the heavier-than-air zeppelin. The bad news is, it's just as slow. The good news is, it's still full of explosive hydrogen, but for a completely different reason.

I'm a physics professor, and when I teach this stuff, I teach the exhaust velocity form Rune listed. I figure if I don't tell students about "specific impulse", maybe eventually it'll go away.

Best part about that suit is the crotch-window, so you can see where you're stepping. Genius.

Hacked my save to get rid of the Pol exploration, so no new Pol missions, but I do have a Pol milestone that I can't cancel. Is it safe to edit the save to remove this milestone contract, or will that mess everything up?

Yeah, now that I've solved the Pol problem, I've picked up that one. It so happens that I've got a spare segment of my near-Kerbin-orbit station I'm not using... (it was intended to be the central hub, but I didn't realize that a Radial Attachment Point is nothing like a Clamp-O-Tron Docking Port until I tried to dock with one.)

So I'm pretty deep into career mode: I've got a good orbital station, small 9-kerbal Mun and Minmus bases, and a couple of pet asteroids, and my unmanned Duna mission is en route; waiting for Eve to come into alignment next. Labs are spitting out science at a pretty good clip, I've got about 1000 banked up now. But I can't spend it until I can scrape together 2.4 million Kerbucks to upgrade my research facilities to access the next science tier. Holy damn that's a lot of money. I can fill a lot of contracts pretty easily: science contracts for the Mun and Minmus consist of poking my head out of the base airlock for a second, but that's tens of thousands here and there, and I need millions. My only high-value contract is "build a Mun base", for about a million Kerbucks. I've got that started, but it demands that my station have ungodly amounts of fuel and oxidizer in it. Rather than carting all that stuff up from Kerbin, my plan was to mine it on-site. But I can't get the mining technologies until I upgrade the research facilities. Catch-22. I'm not sure this is a gameplay question: I think the solution is to just keep plugging away one contract at a time. But I am curious: is this a common problem? - - - Updated - - - On a possibly related note: my contractees are *obsessed* with Pol. Just did a forum search that found this thread about a Pol bug. I wonder if fixing that will solve my cash problem.

cicatrix wins the thread. Real world rockets have a computer that's a lot better at keeping the rocket pointed in the direction of the airstream than you can manage piloting by hand.

With a thick stubby rocket and center-of-mass targeting, you can push as hard as you'd like without spinning out of control. In any case, you don't need big engines, you need specific impulse and fuel. Of course, you don't need either when you let gravity and aerodynamics to do your work for you! (Class B asteroid on high polar collision course, redirected to equatorial orbit using Munar slingshot, retrograde orbit changed to prograde with a high-apoapse burn, then aerobraked into prograde low Kerbin orbit. I think I only used about 150 m/s delta-V all told. Physics!)

Contract: build a Minmus surface station, plant a flag on Minmus. Okay! Designed a single gigantic lander with lab, science bay, rover docks, etc, but since it's never coming home again, no need for a re-entry stage. Did a test launch to see if it would get into orbit, intending to revert and fine-tune the design. Got into orbit on the first try, so hey let's shoot for Minmus. Docked with Kerbal Station One to refuel, then fired for Minmus. While outbound, took the time to double-check the contract. "Build an outpost on Minmus with power (check), 9 person capacity (check), and a communications antenna. A ... communications... antenna. Oops. Revert! Can't revert. Okay, let's go back home. Wait, no re-entry shield. Okay, let's bring it back into low orbit and dock it as a new Kerbal Station One module. With landing legs, sure, but at least I can recover the astronauts later. So I modify the orbit to a free-return trajectory, and then I decide to get clever: I'll aerobrake in Kerbin's atmosphere to save on delta-V. Did you know that a 9-kerbal habitat is very big and very lightweight? It's got a lot more drag than you'd think.

Environmental Visual Enhancements, or some other mod that provides volumetric clouds. Skip the city lights, imo. The only problem with the mod is it makes periapsis/apoapsis markers hard to see against the clouds: if it were a stock part of the game Squad could adjust the colors to improve contrast.

This is *exactly* what I'm working on building right now. Standard fighter bomber, with two science bombs mounted on under-wing rails. Each science bomb contains science gear, a Mk 25 parachute on the back, and an EAS-1 Command Seat on the front containing one regulation kerbal scientist. Parachutes auto-deploy when released, and the bombs drop helmet first to protect the delicate science gear. It's hilarious and fun. I'm working on a video.

My suspicion, which I haven't risked a Mun landing to confirm, is that this happens when you have your focus centered on the planet rather than your spacecraft.

I used to do this too, but eventually decided that since the specific impulse (fuel efficiency) of RCS is low, if I find myself relying on RCS to get home, I'd be better off carrying a small fuel tank instead. RCS is still handy for shedding sideways velocity on approach to landing, though...

Haven't played the game for about a year; I'm back for 1.0 career mode. Currently I'm farming the Mun and Minmus for science, so I can start building bigger things. Sat down last night for a quick Munshot. Highlight of the evening: after screwing up a Mun insertion burn, scientist Tormund lands without enough fuel to get back home again. But maybe it's enough to get into orbit where he can be rescued? Let's go for it. Nope! Suborbital death now guaranteed. But maybe not! Tormund grabs the Mun rocks, bails out of the capsule, and starts firing his suit thrusters to slow down. Eventually crashes into a crater wall going probably 40 m/s ... and lives to tell the tale! What now? Well, first order of business, Tormund's gotta plant a flag and grab some Mun rocks, because that's what they pay him for. Now for rescue. Throw a probe body inside the service bay of a new lander, clear the Kerbal sandwich crumbs off the driver's seat, and fire that puppy into space. Land next to Tormund. Well, 1 km away but who's counting? Get walking, buddy! Tormund climbs aboard, time to go home! Rescue lander definitely has enough fuel to get into Munar orbit... but not enough to leave it. Time to send a rescue vehicle to rescue the rescue vehicle. In the end, Tormund went through three space ships, two landing sites (one of them a faceplant) and an orbital docking, but he made it home alive, and he brought some Mun rocks with him. - - - Updated - - - And day before yesterday, I built a launch vehicle with no rockets: it's just stacked decouplers with a probe body on top. By firing them off rapidly in sequence, I was able to get up to 400 m altitude. I tried building ridiculous staging with decouplers firing in parallel for more thrust, but it didn't help much. This seems like an obvious thing to do: has anybody else tried it? KSP fans being KSP fans, I'm sure somebody will reply with a decoupler-powered Mun rocket.