ijuin

If it's gyroscopic, then it should precess when disturbed by the launch forces or by a player trying to turn the rocket. However, the current SAS module simply produces oscillation instead of precession.

Using solar panels of a similar power/mass ratio as those on the International Space Station would imply that any solar power system masses on the order of a hundred tons per megawatt. For your ten megawatt beam below, you would need to deploy over a thousand tons of solar panels--a daunting task if you have to use chemical rockets to lift that stuff up from Earth. Until we find a cheaper way of getting stuff into orbit (or start building them out of raw materials from the Moon or asteroids), economic considerations favor fission power over solar when you are at the multi-megawatt scale. You might do better using said fission reactor to power your laser instead of the VASIMR engine though . . . The 1 kg sailprobe is comparing apples to oranges--I thought we were speaking of manned spacecraft, which by definition would require dozens of tons of payload as a minimum? Sure, if your payload is small enough that the one ton of engine mass and dozen tons of reactor/structural mass dwarf it, the VASIMR looks like dead weight, but not so much when 50% of your non-propellant mass is payload. I think I specified a manned mission to an outer planet as an example of where VASIMR is optimal for a near-future (i.e. within our lifetimes) mission. Missions where the delta-v exceed three times VASIMR's plausible exhaust velocity will run into the same 'can't carry enough fuel' limitation as any other carry-your-reaction-mass craft.

The biggest technical issue with the N-1 was that it could not tolerate the failure of any one of its thirty first-stage engines--and with thirty of them, it was six times as likely to experience an engine failure (for any given per-engine reliability factor) as the Saturn V. Lose one engine and the whole stage goes bad--notice that every launch attempt resulted in a loss of vehicle while the first stage was still firing--and two of them were for issues that should have shut down only one engine but resulted in the loss of all or nearly all thrust for the entire stage. http://en.wikipedia.org/wiki/N1_rocket#Launch_history However, I do think that if the Soviets had succeeded in a manned moon landing, US/USSR space competition would have continued and we would have seen a push for moon bases and a Mars mission.

Maybe, but lasers-in-space for a photon-driven sail of a given acceleration will require orders of magnitude more electricity than a VASIMR system. Lasers require on the order of one hundred megawatts per newton of thrust, while VASIMR has been demonstrated at a power consumption of 50-80 kilowatts per newton of thrust for an exhaust velocity of 50 km/s, with power requirements increasing with the square of exhaust velocity (hypothetically 2,000 to 3,000 km/s if the power density could be raised to match the laser example above). As such, laser propulsion for interplanetary manned flight will have to wait until gigawatt-class solar power satellites become available, while VASIMR can run on an array not much larger than that of the International Space Station (for within Jupiter's orbit at least). We could build a VASIMR manned mission to Jupiter by 2030 that could get there in less than a year if we cared to spend the kind of money that we spent on Apollo.

Alternatively, electron-positron annihilation gives ISP/c above 0.9, but then you have to figure out how to confine teracoulombs worth of them without protons and antiprotons to balance them. Anyway, the rocket equation tells us that a mission propulsive delta-v exceeding four times the effective exhaust velocity (assuming no refueling) is outright implausible even with staging, and without staging the limit is around 2.5 times the effective exhaust velocity. By 'viable', I meant 'does not require anything that we believe to be outright impossible according to our current concepts of physics and engineering'. For anything that we could build 'right now' (with current technology and a budget the size of the entire US Department of Defense), a few megawatt-class VASIMR engines powered by a fission reactor is the upper limit. http://en.wikipedia.org/wiki/VASIMR One of these could get us to Neptune in a single year, but interstellar travel within a human lifespan is still out of the question.

Required delta-v depends pretty much on how soon you want to get there. Alpha Centauri is 4.36 light years from Sol, so at a cruising speed of 10% of the speed of light you will get there in 44-45 years. For a one-way mission, total delta-v is just over twice your cruising speed. For a round-trip mission, total delta-v is just over four times your cruising speed. As for where to launch from, the delta-v involved in the flight is so much more than the velocity needed to orbit/escape from Earth that it pretty much doesn't matter where you launch from--though if your engines can not lift your entire starship from the ground into orbit, then you might want to assemble the whole thing in low Earth orbit. Propulsion-wise, unless new discoveries in physics give us additional options, we have three viable choices for our engines: 1: Antimatter rocket. Antimatter is the most energy-dense fuel that can be carried, and with the use of drop-off fuel tanks, your starship can reasonably travel at 90% of the speed of light both ways on its voyage (especially if you refuel the 'matter' half of the reactant at Alpha Centauri instead of carrying all of your return fuel). Such speed can let you take advantage of relativistic time dilation to make the voyage shorter from the astronauts' frame of reference (only about two years each way instead of five). 2: Lightsails. Have about a terawatt of solar-powered lasers in our solar system focusing their beams onto the sail to drive it, and you can get up to 40-80% of the speed of light. By separating part of your sail at the opposite end to act as a mirror to reflect the laser back onto your spacecraft, you can slow down at the other end, and then you can do the same again (assuming that the people back on Earth keep the laser turned on) to accelerate back towards Sol. 3: Fusion. Being a hundred and fifty times less energetic than antimatter, you probably won't be going faster than 20% of the speed of light with this--unless you can build a workable Bussard Ram-Rocket, that uses a huge magnetic field to scoop up hydrogen from the interstellar medium, thus giving you an inexhaustible fuel supply. On the other hand, fusion reactors are much less likely to go kaboom if their fuel leaks, unlike antimatter.

Not bad at all--you made her look ladylike and attractive while keeping the 'bulging-eyed green people' aspect.

Perhaps you should have the ion engine engaged constantly starting as soon as you are out of the atmosphere? (Or as soon as the stage below it runs out of fuel, if that happens above the atmosphere already) Then you would have the maximum amount of ion engine thrust time, building your horizontal momentum all the way up as well as back down.

Of what the fuel tank looks like, I presume, assuming that it is not visually identical to the standard ones.

True, however the current RD-170 engine has a specific impulse of 338 vacuum / 308 sea level as compared to 285 vacuum / 263 sea level for the F-1 engine. Five RD-180 engines would have approximately the same combined mass and thrust as the five F-1 engines on the first stage of the Saturn V, and would get eighteen percent more impulse ( = increased payload capacity). The Saturn V was great, but we can do even better now, if we bothered to spend the same amount of effort and money that we spent to develop the Saturn.

Just watch out for all of the 'Over ninety thousand' gag posts that will probably show up.

He's making a reference to the anime Tengen Toppa Guren Lagan (TTGL).

Just FYI for you guys--the escape velocity from any given altitude is equal to the square root of two times the circular orbital velocity.

Nice! Now we have a real service module!

Ok, then I'll purchase the Orbital Satellite and Basic Rocket.

To scroll up/down as you seem to be asking, you need to use your middle mouse button/scroll wheel. Can anybody here tell me what the alternative is for those who do not have scroll wheel mice?

Cool! It makes me want to salute those brave Astroneers!

Oh, I thought we were doing the 'roll call' of signups before beginning the first turn, sorry. In that case, do I have enough funds to buy the Basic Rocket and Orbital Satellite, or does the Kapitalist penalty make that too expensive? If I can't afford both, then I want to buy the Basic Rocket. If I can also hire Engineering teams immediately, then I would like to hire 2 to research on the Basic Rocket. In sum: If possible: Purchase Basic Rocket program Purchase Orbital Satellite program Else: Purchase Basic Rocket program Hire 2 Engineers for Basic Rocket program Else: Purchase Basic Rocket program Endif

So, I am assuming from the picture that the ion engine can draw fuel from a tank stacked above it within the same stage? Handy! And a '65 Chevy? Nah, what Jeb needs is a '69 Dodge Charger--his very own General Lee!

I am a fan of BARIS, and would like to join the game. My nation: The Kerbalia Confederacy ('The KC' for short) Kapitalist, Militarist, Science Focus (science is the way to find new methods of blowing up our enemies!) The KC was founded 150 years ago by an alliance of colonies on the New Kerbalia continent who rebelled against their king's attempt to tax their beer. That pretty much sums up their core values--liberty, low taxes, beer, and kicking butts.

When you get to 5 tanks you are better off separating it into multiple stages (e.g. a 2 tank stage on top of a 3 tank stage). This is because the empty fuel tanks still have mass, so the 4 empty tanks will be hauled along while the 5th one is being used. At the point of 5 tanks, the dead weight of the tanks exceeds the weight of just having a separate engine for the upper 2 tanks and throwing away the lower 3.

Sounds handy. I'm going to try it out.

The fact that you are willing to do multiple releases per day instead of making us wait till you're finished for the day shows how much you care for the game and for your testers and fans.

Them Duke boys is gonna land themselves in a whole heap o' trouble!

Maybe Jeb modified an automotive cruise control to serve as an autopilot?