Crashing into Duna

[Synapse]

My Duna rover had a Mk1 parachute and crashed into Duna. It consisted of a Rovemate body, 4 of the medium wheels, a probe body and a solar panel. I thought this parachute would be enough?

[Skorpychan]

Well, you were wrong. The atmosphere's thinner there, so you need more chutes, and maybe retrograde burns.

[Synapse]

The atmosphere's thinner there

Well yeah, but I thought the gravity was too.

[Skorpychan]

The gravity should be about a third of kerbin's, but the atmosphere is way thinner in comparison.

[stupid_chris]

The atmosphere is far from being thick enough to slow you down to a total stop on Duna. The only planets you can really touch down safely in most of the cases by using only parachutes are Kerbin and Eve. Really, Duna and Laythe would require you to slow down your descent most of the time if you don't want to crash.

[el_coyoto]

Seems like you're going to love that wonderful KSP Chute Calculator app...

Good luck on your Duna rover!

EDIT : stupid_chris is right, Duna aerobraking requires a different approach than Kerbin because its atmosphere is so thin . You need to set a 10 or 15 km periapsis and avoid a direct re-entry to make sure you spend as much time as possible in the densest part of the atmosphere. You may need to aerobrake and bleed speed over several orbits. You can also use MechJeb aerobraking predictions to plan more extreme manoeuvres (8 km PE or so ) to aerobrake in one orbit, but these can be dangerous...

Edited July 18, 2013 by el_coyoto

[HoY]

It won't take much tho, a toroidal tank and 2 of the little orange radial engines, fire retrograde a little bit while your between 50-30m from the ground. Try to slow yourself to anywhere less than 5m/s,, I think those wheels can take more than 5 but just to be safe.

[el_coyoto]

It won't take much tho, a toroidal tank and 2 of the little orange radial engines, fire retrograde a little bit while your between 50-30m from the ground. Try to slow yourself to anywhere less than 5m/s,, I think those wheels can take more than 5 but just to be safe.

Yup, in my experience, landing with chutes only on Duna doesn't seem very efficient for heavy payloads (a light rover would be ok I guess). Heavy payloads require TONS of parachutes to make sure they touch down at less than 10 m/s. (see the chute calculator app)

I rather use them to bleed speed fast during the aerobraking and then use engines to limit the touch down speed.

[Rosco P. Coltrane]

Seems like you're going to love that wonderful KSP Chute Calculator app...

Thank you thank you thank you!

I made the same mistake as Synapse. It was landing somewhat rough on Kerbin, but I assumed that less gravity would counter act the thinner atmosphere... No it won't! Too bad because my ship was carrying 3 rovers to visit more than one anomaly with only one flight... All rovers broke one wheel at landing, they still work anyways.

[Nasakev]

As everyone else has said: if you want to land with chutes on Duna, use a lot of them. Testing on Kerbin is deceptive due to its thicker atmosphere.