shadowfax

So meanwhile as you\'re flying around with the jet, you\'re burning fuel. If you burn enough fuel so that you no longer have enough fuel to use up all your oxidizer, then you\'ve just magically added an oxidizer weight penalty to your ship that doesn\'t need to be there. I should, however, have been more clear - the more efficient design is to have a jet take the ship up to altitude, then separate and go back to the runway while the ship continues on rocket power. We\'re also assuming that we have a fuel which will play nice both with air as an oxidizer and with the oxidizer you bring with you. There\'s a reason rocket fuel isn\'t gasoline and an oxygen bottle.

The main conceptual difference between an air breathing engine and a rocket engine is that the rocket engine carries its oxidizer with it along with the fuel, while the jet engine picks up its oxidizer in flight by sucking air into itself. So an engine that could switch from a rocket engine to an air breathing engine would be pointless, because you\'re already carrying your oxidizer around with you for it to be a rocket, and you\'re carrying it in the proper amount for the fuel to be burned with it. So if you start using air as your oxidizer, now you have all this stored oxidizer that you\'re carrying around and which you can\'t use because you\'ve already burned the fuel you were supposed to use it with, which is a weight penalty for 0 gain. The smarter design would be air breathing engines for atmospheric flight and a rocket engine for non-atmospheric flight. And you can already make a ship with that in KSP.

This brings up something that HarvesteR and the gang are probably going to want to think about before the first commercial release - educational licenses for computer labs. It\'s been awhile since I was in high school, and I was there during an era when computers, space, etc were decidedly uncool, but I can think of a lot of kids who would have been all over a KSP club. That should be even moreso the case today, now that kids no longer get stuffed in lockers for using computers.

Are you referring only to the orbit projection, or did your ship actually go through the planet? Because if not, then you create through-planet orbit paths every time you launch before you reach orbital velocity.

Yup. There are whole warehouses in the East full of people who sit at computers all day and either bust through captchas or, if they\'re lucky, spend 12-16 hours a day playing MMOs farming in-game currency to sell for real money. You\'ll never auto-filter out all the spam. The keys are to have your ip ban list up to date, enough mods to have a continual staff presence, hopefully 24/7 in most cases, so that staff can kill the spam before anyone sees it, and to have forum software that allows you to delete every post by a given member from an admin console, without actually having to see any of the posts. This is a lesson I learned the hard way on my small car club\'s forum when some jerk posted horse porn in every sub-forum. All our mods are in the same time zone (because it\'s a regional club) and so we were all at work and unable to delete it without the pictures popping up on our work machines. I upgraded the software that night to one that had much better deletion controls

Hopefully in the future you will be able to put radar on your ship so that you can more easily locate object that are outside of visual range.

If we were only talking about this game, then why were we debating Apollo reentry procedures?

Again, the more you slow down, the steeper your reentry angle is. If you slow down enough to deorbit from a high orbit in a reasonable amount of time, your reentry angle will be too steep. You need to make the angle shallower or you will not survive. Also again, when they came back from the moon, they set their trajectory so that they would reenter at a shallow angle, which is possible when you\'re intercepting the planet, but not possible with a single burn when you\'re already closely orbiting it unless you want to spiral down for an unreasonably long time. If they just bombed straight for the earth, which is what would happen if you slowed down too much in a high orbit, they\'d have come in too steep. Instead, they set their course so that they would intercept earth just to the side, rather than head on.

Because in order to de-orbit in a reasonable amount of time from a high orbit, you have to come in at a steep angle, which is exactly what happens with lunar return. You then do a burn to change your orbit so that you enter the atmosphere at a shallow angle, whether that burn is at the end of a lunar-earth transit or a high earth orbit. You COULD do a shallow de-orbit burn from a high orbit, but you\'d be up there for a very long time slowly spiraling down toward the atmosphere. That\'s fine if you have a boatload of oxygen, water, and food available, and you\'re willing to spend all that time doing nothing but falling very slowly, but otherwise, you need to descend a bit faster initially.

Totally misread that. I was thinking he said the apokee was increasing.

First, I should clarify that I\'m not pointing straight at the planet when I do this - I dip my nose a little below the horizon. You\'re assuming an acceleration determined only by gravity. If you use the gravity to help accelerate you to a given velocity, and then use engines to maintain that velocity, you can (in KSP anyway, from my experimenting) get to your end velocity faster because the really hard work of accelerating was helped along by the planet. This won\'t make you faster than if you launched and went straight to an escape velocity, but it does work if you\'re simulating a launch to normal orbit, and then an escape burn (for instance, you launch to a normal orbit, then take on fuel from an orbiting supply, and then head out). With most of the rockets that I build (other than the ones that are intentionally stupid) I have boatloads of fuel once I reach orbit, and so I tend to measure 'cheaply' as a function of time rather than fuel.

I wonder if it\'s a timing issue. If you disengage SAS when it\'s applying a force, then it can\'t apply an opposing force to compensate for the fact that the force it was applying when you disengaged it was too high. Put in terrestrial terms, if you swerve your car violently to the left, and then take your hands off the wheel, you won\'t end up going the direction you wanted to go because you stopped applying inputs before the necessary counter-steer.

You\'ll have to adjust the instructions in that video a bit. Now that we have atmosphere above 30-something-k, if you try to make a stable orbit at 50 you\'ll deorbit quickly due to atmospheric drag. A good way to get a cheap and dirty 'I don\'t care what kind of orbit it is as long as it\'s an orbit and not an escape or a crash' orbit is to go straight up until around 10-12k, then slowly pitch the nose over so that you\'re pointed at the horizon at about 25k. Keep accelerating to around 2300k at which point you should be somewhere between 60 and 70k up, depending on your rocket configuration. At this point you should (if you built it right) have plenty of fuel left in your ascent stage to tweak your orbit (it will be highly elliptical, but not obnoxiously so).

Because stopping all spin means that you will spin relative to the planet, whereas SAS tries (I think) to keep your orientation constant relative to the planet. Say you\'re in a polar orbit, and you start at the equator at an exact tangent to the planet. As your orbit carries you over the pole, if your rocket isn\'t spinning, you\'ll still be oriented the same direction you were when you were at the equatorial tangent, but because you\'re over the pole, your rocket is now facing either directly toward or directly away from the planet. You appear to have spun 90 degrees, but you really didn\'t.

It seems to me (an admitted amateur enthusiast) that if you enter the atmosphere at the right (or wrong, depending on perspective) angle and velocity, gravitational acceleration will override aerobraking. The first post never mentioned speeds, but if the apokee is increased after the first atmosphere intercept, then it seems likely the net deceleration from aerobraking was less than the net acceleration from gravity. By the time the capsule was again going against rather than with gravity, it was already out of the atmosphere and not being slowed by air anymore. Remember that the Voyager probes aren\'t using any propulsion - they used planetary gravity wells to slingshot themselves to higher speeds.

A way to really help understand how orbital maneuvering works is to fire up orbiter and go through the Delta Glider - ISS / Mir scenarios. It\'s a good way to crystallize the idea that pointing at something and hitting the gas isn\'t the way to get to that something. Actually, the maneuver you described in your first post is the one I use to cheaply achieve a fast escape velocity. You slingshot around the planet, using its gravity to help accelerate you instead of having to use fuel to do all the work.

Just an update - still no confirmation email from the $15 USD donation on Aug 15th. Paypal shows it going through.

http://news.bbc.co.uk/2/hi/programmes/from_our_own_correspondent/9573163.stm

Nope, toasters have microchips. http://express.howstuffworks.com/toaster-autopsy.htm

It's been over 24 hours and I've not gotten the email. I'm not particularly concerned, so I'm just reporting it as an FYI.

That's somewhat true of the Shuttle's computers, but Apollo's stuff was pretty state of the art. Remember Apollo happened when most computers filled a large room. Apollo used one of the first integrated circuit computers made.

I am using that. A Lot.

Nyan in Space?

Keep in mind that I haven't installed this particular pack (yet) and so I don't know if the author preserved directory structure when zipped. If he did, all you should have to do is unzip it directly to the parts folder of your ksp install. If that doesn't work, check for the part name in the cfg file, and make sure it matches the folder that was created when you unzipped it to the parts folder (I bet it does, or someone would have complained by now). If that does not work, I would suggest that you open an explorer window, navigate to the /ksp/parts/(thispackname) folder, open that, and then post a screen shot so we can see what's going on.

I had this happen on Skunk's mod pack when I screwed up and had the texture files in the wrong folder.