reentry with edges transverse to flow?

[Penguinista]

I'm thinking a shape like a sharp edged saucer doing reentry face first
and then turning edge on for low speed landing. I expect some
concentration of heating as slowed surface layer air accelerates over
the edge. How bad would this be? How much effect would a small angle
for lift have, presuming a subsonic surface layer is maintained?

[Gavin Mendeck]

I believe you are mistaken regarding the Viking landers. The Viking
landers did use lift-generating aeroshells but they maintained an
angle-of-attack that was nearly constant throughout the entry,
presenting most of the bottom face towards the airstream. (Thus, they
never turned edge-forward.) The Viking entry profile was designed to
use the lift only to ensure a safe supersonic parachute deployment
altitude as there was great uncertainty in the Martian atmosphere
models in the 1970s. Viking did not attempt to use its lift to
correct for any range errors -- it was not a precision lander. So
far, there have been no precision landing attempts on Mars. The 2007
Scout Phoenix and the 2009 Mars Science Laboratory missions both plan
to attempt precision landing -- landing within 10 km or less of the
target site.

Respectfully,
Gavin

"James Wentworth" > wrote in message >...
> The Viking landers (encapsulated inside their flying saucer-like aeroshells)
> did this. They entered the Martian atmosphere "face first," then later in
> their descents they turned more-or-less on edge to fly like aircraft. This
> was done before parachute deployment to correct downrange targeting errors
> and crossrange errors, as well as to correct wind-induced errors. The
> aeroshells' edge-mounted thrusters served as "ailerons," "elevators," and
> "rudders" during the flying portion of their descents. -- Jason
>