100km LKO in only 2800m/s dV -- Ongoing Experiments

[Mipe]

Seems they've decided 2800 m/s launch profile is a bit much and raised drag in 1.0.1.

[Temeter]

My launch profiles were still at 3400 d/v.^^'

[Radam]

33% more drag afaik.

[RocketPilot573]

Anyone know how much delta-v is needed in 1.0.1/2?

[cybersol]

Anyone know how much delta-v is needed in 1.0.1/2?

The best way to orbit in a rocket in 1.0 seemed to be to punch through the lower atmosphere with high TWR (2-4) on a ridiculously shallow trajectory (30% above horizon at 13km) until you almost burned yourself up (almost being key). With a near perfect trajectory I had a rocket that only too 2900 dV to get to a 70km circular orbit in 1.0. The same rocket needs about 3200 dV to get to orbit in 1.02, so about 10% more. Plus I suspect that rockets with lower TWR will be more similar between the two versions.

[SanderB]

I've launched a 1-stage 100t rocket to orbit with 3km/s vacuum dV in 1.0.2. Horizontal at 20km isn't dead.

Edited May 2, 2015 by SanderB

[Renegrade]

That's because they do stay below terminal velocity, contrary to what we do in KSP.

We are below terminal velocity. Rather far below it. Unless you have a pad TWR of three+ or you're flying at right angles to the airflow. I'd like to see your rocket in the latter case.

If you're using old terminal velocity indicators from like KER or something, it's likely wrong as it would be using soup-o-sphere math. Ditto for old charts (the old charts are extra BONUS wrong as terminal velocity depends on the aerodynamic shape of the rocket and isn't something that can be done with a one-axis chart).

And how is that exactly what one should expect?

Air losses in real rockets are the next best thing to zero (0.4% to 1.4%). Here it's something like... 10-20%. So vacuum (0%) is closer to what one would expect (1%) than here (15%). Well, unless one is a layperson -- the same type that thinks space is 'up' rather than 'to the side' or that air is at sea-level pressure until you're in orbit where it abruptly cuts off to zero etc.

It's the "this has poor atmospheric Isp so I can't use it until I'm actually in orbit" thing all over again >.>

(the underlying assumption here being that Squad is aiming for a "look and feel" of an Earth launch, with similar ratios of concerns and such, which is why Kerbin has 9.81m/s² surface gravity for example. They could have gone for fully realistic densities which would have resulted in a 0.094g surface gravity)

TL;DR: The bulk of the atmosphere's volume can be more accurately described as a vacuum than as sea level pressure.