Career Mode Start Impossible as of 1.0.3 drag

[Sharpy]

BTW, 2 modular griders = three chutes for the capsule?

[Nich]

So you are saying blunt objects go faster that aerodynamic ones?

Nope you got it wrong. As the speed of an object increases, the drag force acting on the object, resultant of the substance it is passing through, increases. At some speed, the drag or force of resistance will equal the gravitational pull on the object At this point the object ceases to accelerate and continues falling at a constant speed called terminal velocity (also called settling velocity). An object moving downward with greater than terminal velocity (for example because it was thrown downwards or it fell from a thinner part of the atmosphere or it changed shape) will slow down until it reaches terminal velocity. Drag depends on the projected area, and this is why objects with a large projected area relative to mass, such as parachutes, have a lower terminal velocity than objects with a small projected area relative to mass, such as bullets.

No I am saying it is blunted for thermal reasons

Drag has 3 regimes subsonic (<.85) transonic (.85-.99) supersonic (1-7ish) and hypersonic (7ish +) and the Cd (Fd = p*A*r*Cd*V^2 i believe it has been a while) value can change wildly at different speeds in the same regions but also changes as the object changes regions.

in the subsonic regimes aka terminal velocities the flow is happy to go from the high pressure blunted area to the low pressure area on the sides of the craft. However going from lowpressure area at the sides to the high pressure area behind the craft needs to be done gradually (tapered) so the flow does not separate. Once separated you get a very large pressure drag on the order of 5x and the object would become unstable and flip randomly due to eddy currents.

Transonic you would need a PhD to understand fully but basically has to do with the fact that some of the air is supersonic and some is subsonic and depends largely on the specifics of the object.

Supersonic is the same as subsonic behind the shockway but at the shock wave you have an instant pressure and velocity change (speed and direction) not to mention shockwave interaction if everything is not behind the initial shockwave

Edited June 24, 2015 by Nich

[rofltehcat]

I just tested it and went with two fleas that are radially mounted to the main stack with two extra parachutes on top. Creates a lot of drag but at the beginning it doesn't really matter, I guess. I think two parachutes would have been fine as well. For new players it probably sucks if they don't know.

Small rose cones are 23 science away and radial chutes are 20 science away, both can be used to mount more parachutes on the rocket. My first launch gave me 16.9 science (didn't really try maximizing science).

[nobodyhasthis]

No I am saying it is blunted for thermal reasons

Blunt for thermal reasons was what wanted to say. You said originally...

UM I hate to break it too you but capsule is more aerodynamic (i.e. should fall faster) with the blunt end down. Think of a rain drop.

Never compared it to anything. Just showing a way to stabilize and aerobrake a Mk 1 Pod in game.

Drag has 3 regimes subsonic (<.85) transonic (.85-.99) supersonic (1-7ish) and hypersonic (7ish +) and the Cd (Fd = p*A*r*Cd*V^2 i believe it has been a while) value can change wildly at different speeds in the same regions but also changes as the object changes regions.

The final subsonic terminal velocity is all we need to worry about when talking safe parachute speed. The point where Fd = Fg. However lets talk thermal effects for a second. The part of aerodynamics your talking about is true. It is not high pressure edge that is problem but the low pressure wake left behind. It does indeed get even more complicated when we get into vortex bubbles and creeping flows. However we will be getting off topic. The real question is ...What is the final terminal velocity of the first built ship in game and how do we lower it enough to open a chute safely early in career play?

The pictures I posted show in game physics at work and possible solutions. Nothing more.

Edited June 24, 2015 by nobodyhasthis

[TheSoundOfTrees]

Half -rant begins :

I did a few very basic low tech "up to low space, drop everything, science and back" today ( design : third booster, second fuel engine with second tank). 90% of the time the capsule + science crash on landing. I spent the day trying different orientations of the capsule (no fuel left) on reentry to try and slow it enough for having a chance to deploy the chutes before the crash... Any mistake in orientation and bye bye...

I am patient. I love to experiment. But if I had wanted to deal with deadly re-entries, especially with basic rockets, I would have installed the mod...

I am a beginner. In 1.0.2, launching a rocket and getting it back was not difficult : the difficulty was in having it do exactly what you wanted it to do. Now, the main difficulty seems to be the last minutes of the flight.

I tested 1.0.2 for a few weeks before buying the game last week - I should have waited until I could test 1.0.4.

I would suggest to make the parachutes more solid and resist up to 350 m/s. For beginners' sake.

End of rant. Back to trying to land in one piece.

[selfish_meme]

I started a new career in 1.04 to help a friend. The SRB's are so powerful now I advised him to set 50% thrust. The parachutes seem fine and I had no explosions. Some landing legs at career start would be awesome for maximising retrieval. I know you can use the girders but its not intuitive.

[nobodyhasthis]

I started a new career in 1.04 to help a friend. The SRB's are so powerful now I advised him to set 50% thrust.

Good beginner advice. Nice one. Back in earlier versions. It was quite a surprise when the FAR mod was installed and the first SRB was used. The thrust is so high that it put the rocket into lethal supersonic speeds a few seconds after launch. Usually with fatal craft shredding results. Now in 1.0.4 stock we are seeing something almost the same. Turning down the SRB thrust at the start is a good idea. At lot of it is wasted anyway once the ship hits the max speed. A slower but longer burn gets better results at the start.

I did a few very basic low tech "up to low space, drop everything, science and back" today ( design : third booster, second fuel engine with second tank). 90% of the time the capsule + science crash on landing. I spent the day trying different orientations of the capsule (no fuel left) on reentry to try and slow it enough for having a chance to deploy the chutes before the crash... Any mistake in orientation and bye bye...

I am patient. I love to experiment. But if I had wanted to deal with deadly re-entries, especially with basic rockets, I would have installed the mod...

I am a beginner. In 1.0.2, launching a rocket and getting it back was not difficult : the difficulty was in having it do exactly what you wanted it to do. Now, the main difficulty seems to be the last minutes of the flight. I tested 1.0.2 for a few weeks before buying the game last week - I should have waited until I could test 1.0.4.

I would suggest to make the parachutes more solid and resist up to 350 m/s. For beginners' sake.

End of rant. Back to trying to land in one piece.

Oh, I feel your pain. After the last update I had to do a gut wrenching pull up to save the crew. Done by a counter intuitive use of stabilization fins. As a suggestion keep your eye out for an update to the Real Chutes mod. Where you will find more robust Kevlar material and drogue chutes.

However all that said it does not help a brand new player that is seeing the game physics for the first time. You are right about the initial first experience. The learning curve is unfortunately steeper in 1.0.4

Edited June 25, 2015 by nobodyhasthis

[tater]

It's not really hard at all.

[ImaSpaceJunk]

Kerbal training at the start of hard career mode.