Parashoots on Duna

[Hiatsu2k8]

When trying to use parashoots on Duna they don't deploy until the craft is almost at the ground and they never even open.

Can someone enlighten me?

[Martonaut]

dont go to fast or they will brake? XD , the times i landed at duna, I had to reduce my speed a bit with my engienes so my chutes would not brake

[r_rolo1]

Your parachutes broke due to the excessive speed relative to the ground. It will happen the same in Kerbin , btw . Next time try to aproach the Duna atmosphere almost horizontally ( that is, with a below 13 km Pe ) and wait until the ship gets to atleast 400 m/s before deploying the chutes

[sal_vager]

Actually, this is due to the chutes being designed for Kerbin, not Duna, Duna has a much thinner atmosphere so the chutes cannot open properly, they still provide a little bit of slowdown though.

You will need landing rockets as well as the chutes, or even instead of, though the chutes do help keep you the right way up for landing.

Ideally, a chute designed for the thin atmosphere would be used instead, maybe it's something we'll get at some point, though there's nothing to stop add-on makers from making a new chute

[Markus Reese]

Oooh, good idea sal. Somebody needs to make a paraglider! The .part config, wonder if can add a wing/lift mechanic to a parachute so at high speed it decels, but rapid lift, but at lowspeed, still keeps lift. Paraglide in for that fine tuned dunar landing.

[Hiatsu2k8]

So I guess this also applies to the same reason my rocket starts flipping end over end when entering into the atmosphere.

Im having problems with longer flights, making a ship and then getting it all the way to Duna or another interstellar body only to find out my ship has a fatal error.

Any tips you can give me?

[r_rolo1]

The small parachute in Duna will slow down a capsule enough for a capsule only landing. I've already done it ( I agree that it got a pretty rough landing but it landed OK ). The trick is to get to Duna in a almost horizontal trajectory, to maximize the amount of atmosphere your parachute will get in the way . That is far different from what you can do in Kerbin , where the parachutes will work fine in almost all angles of aproach ...

[sal_vager]

Rockets will flip over in an atmosphere if the center of gravity is wrong, think of an arrow or a shuttlecock, it is weighted at the front with flights at the back for stability.

A rocket of similar design will fly down nose first, but with enough weight in the rear, it will fly down tail first for a controlled landing

[Hiatsu2k8]

Rockets will flip over in an atmosphere if the center of gravity is wrong, think of an arrow or a shuttlecock, it is weighted at the front with flights at the back for stability.

A rocket of similar design will fly down nose first, but with enough weight in the rear, it will fly down tail first for a controlled landing

More specifically Im having trouble getting a rover on the ground of Dune

[Vanamonde]

Duna has a much thinner atmosphere so the chutes cannot open properly

Fie I say! How does this pernicious and base rumor persist, maligning the entirely adequate atmosphere of poor, innocent Duna?

I use engines down to the last few thousand meters/300m/s or so, then descend entirely on chutes.

Five large chutes bring down a lander

at a nice 9m/s or so. The lander comes down with full tanks in reserve for the ascent and orbit to meet a Kerbin-return ship.

The truth will set you free!

[maltesh]

Heck, I Aerobraked from an Escape Trajectory over Duna with a much heavier spacecraft than that, waited until the atmosphere had slowed me down significantly, then popped the chutes (I had only three of the large chutes), and didn't burn the landing engines at all until I was less than a dozen meters up because I thought hitting at 10 m/s might cause damage to the lander.

Said lander included three of the 1600-unit tanks and a three-man pod, three aerospikes and an NTR built into it. Far more than enough fuel to rescue my previous Duna pilot from orbit, and return to Kerbin.

If you are solely going to count on aerobraking to slow your spacecraft from an interplanetary Trajectory to Duna, coming straight down is probably a bad idea. You'll almost certainly smack into the planet that way. You need a periapsis high enough to miss the mountains, but low enough to shed velocity. I believe I went for about 8-10 km periapsis on the aforementioned descent, but I had a Mechjeb on board for fine-tuning.

Edited October 12, 2012 by maltesh

[PakledHostage]

Here's some relevant data to compare Kerbin and Duna's atmopshere. Unfortunately, the temperature axis is plotted using different units on the two graphs. The pressure and density axes "units" are the same though.

Edited October 12, 2012 by PakledHostage

[The Destroyer]

Parachutes arent AS effective, and they only deploy at a certant altitude, where the air pressure is enough (about 9000M) and they fully deploy at 500 M as long as you are going 100 M/S or slower.

[bitbucket]

Parachutes won't deploy until you have enough atmospheric pressure. They deploy at an altitude of about 20,000 meters above sea level on Kerbin, but only get enough air pressure to work at around 3000 meters up on Duna. If you're trying to land above 3000 meters elevation on Duna, the parachutes won't work at all.

If parachutes play an important role in braking your ship, land in the equatorial lowlands.

edit: visual aid!

Trying to land in yellow or red areas on this false-color altitude map of Duna will result in lithobraking before parachute deployment.

Edited October 13, 2012 by bitbucket

[MaverickSawyer]

Actually, this is due to the chutes being designed for Kerbin, not Duna, Duna has a much thinner atmosphere so the chutes cannot open properly, they still provide a little bit of slowdown though.

You will need landing rockets as well as the chutes, or even instead of, though the chutes do help keep you the right way up for landing.

Ideally, a chute designed for the thin atmosphere would be used instead, maybe it's something we'll get at some point, though there's nothing to stop add-on makers from making a new chute

On my to-do list now... One .cfg edited set of parachutes coming right up!

[TouhouTorpedo]

Here's some relevant data to compare Kerbin and Duna's atmopshere. Unfortunately, the temperature axis is plotted using different units on the two graphs. The pressure and density axes "units" are the same though.

Interesting, where are you getting the data from just curious?

A bit of further advice for future presentations, if you want to compare two sets of data always make the axies match up. You've got two different units for temperature and missing units for pressure and density. The scale of the axies also doesn't match. The problem is you can't visually pull out the data, you've got to think. You shouldn't have to think too much when looking at a graph, just look and go "oh, so thats the pattern"

Just a bit of advice on presenting data is all

[LegitBro]

Unless its just the command pod, you will need a powered descent.

[Temstar]

The KSP wiki has a much better picture of Kerbin-Duna atmosphere comparison:

20% pressure at sea level relative to Kerbin is pretty forgiving when it comes to parachute landing. Mars for example have only 0.6% of Earth's atmosphere pressure at its "sea level".

Wiki also has a Kerbin-Eve graph

Edited October 13, 2012 by Temstar