up-to-date parachute calculation? - new Eve atmosphere etc.

[Sharpy]

So, my miniprobes (less than 0.5t each) arrived at Eve yesterday. According to http://ksp.freeiz.com/ one drogue chute should have slowed down each probe to around 7.65m/s at 10,000m and under 4m/s at sea level. And instead my probes sustained serious damages on impact at around 10m/s at altitudes of <1000m. It seems Eve is no longer as soupy as it was.

Any more up-to-date parachuting requirements resource out there?

[FancyMouse]

It's not going to be as simple as it used to be - now it depends on your vessel shape (same mass could behave differently) and even entry profile (same ship could behave differently).

Better do testing yourself and develop some rules of thumb that fit the type of vessel you build. It's going to be different for everyone.

[Sharpy]

Not nearly as much as you think, at least for safe speeds of 7m/s and less. In that case the drag of the payload compared to drag of the required number of parachutes is of order of 3%, and such is the error in calculated speed. The calculation could easily assume the payload is dragless and come up with a worst-case scenario which would be likely within 5% of the real thing - at these speeds drag of the craft itself is really minimal.

Yes, it would be much harder if you were to calculate e.g. with spaceplane abort sequence: can an MK3 cockpit be slowed down under 70m/s (of its impact durability) by a single drogue chute? In this case the cockpit's drag is comparable to the drag of the chute and can't be neglected. But if you want that cockpit land at neat 6m/s, you must attach four radial parachutes, and once again, whether the cockpit drag is 0.1 or 10, it's nothing compared to the chutes.

Edited July 6, 2015 by Sharpy