CEV for Mars Direct-Entry?

[mikejz]

Given that the the velocity of Direct-Entry to Mars is around 5.4km/s (Modest compared to a return lunar entry). And several proposed variants of the CEV include a airbag system for ground landing; Is it conceivable that with the addition of a significant retro rocket system and changes in the parachute system that a CEV could actually be used for entry and landing on Mars in a flat terrain area?

 

[mattblack]

I doubt it. Even with airbags under the CM, there probably isn't a parachute big enough for Mars' thin air: You'd need a descent stage of some sort. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[henryhallam]

You can lose a lot of velocity during descent and landing at Mars with parachutes but there tends to be about 100 m/s left over, IIRC. Once you have slowed down to that sort of speed, drag is next to nothing so further deceleration is difficult. So a descent rocket is needed for that last little bit (even with airbags unless you want a hell of a bounce!)

 

[mikejz]

By "retro rocket" I am talking directly about a descent rocket (something that fires after the parachutes have done all the can. <br /><br />I was wondering if something along those lines could actually be added while maintaining the core CEV design.

 

[tap_sa]

<font color="yellow">"I was wondering if something along those lines could actually be added while maintaining the core CEV design."</font><br /><br />It might work but it's a one-way ticket then. Or did you have any plans to lift the CEV back up to orbit, possibly return to Earth with it?

 

[henryhallam]

I remember hearing about some early ideas for lunar missions where the CEV would be taken all the way to the surface and back. So potentially you might be able to do the same thing for Mars missions, if you had sufficient heat shielding to protect the ascent stage as well as the CEV. I have the feeling that a specialised Mars ascent/descent vehicle would end up lighter and more reliable though.

 

[najab]

><i> I have the feeling that a specialised Mars ascent/descent vehicle would end up lighter and more reliable though.</i><p>Yup. The reason it works for Lunar missions is because no heat shielding is required to land on the Moon (due to its atmosphere being so thin).</p>