posted on Jun, 2 2008 @ 12:27 PM
Originally posted by blimpseeker
Well....until someone coughs up a video of this phoenix thing doing a test run on good 'ol earth, i think i will be in Big Head's camp.
and you can't show that armadillo video, look at the size of those tanks!...how many tests and they still haven't won the lunar challenge????
Several tests. As for the size of the tanks, you do realize that the Lunar Challenge requires a LOT more engine burn time than the Phoenix Lander's
descent profile? The lander's braking engines only need to fire for a few seconds...the Lunar Challenge vehicles have to do a vertical takeoff, a
translation, and a powered descent, all in a gravity field that's 3x or so as strong as the one Phoenix was designed for...of course the tanks are
larger. The point of showing that video was as a counter to the OP's repeated insistence that you can't land a rocket backward...obviously, you can,
and under more demanding conditions of gravity, atmosphere, and thrust duration than Phoenix faced.
another thing that doesn't sit well with me with the Phoenix is the heat shield, the way that it just falls off, doesn't seem possible with the wind
pressure pushing it up into the lander. it would have to be "shot" off as an ejection seat on a plane would be.
Not really. Check the landing sequence again...if you don't like or trust the animations that NASA, JPL, and UA had made to explain things, I believe
Space.com had a time-line of events. The heat shield doesn't separate from the lander until after parachute deployment. Once the parachute is out and
has a good canopy, all you have to do is release the locks holding it in place. Since the lander is being decelerated by aerodynamic drag from the
parachute, as well as air resistance, it's going to fall more slowly than the heat shield...and the heat shield pulls away from the lander, no
Big Head brings up another good point.
why not better quality pictures? why not video of the lander...uh...landing like the armadillo has from underneath?
I'm with Big Head...SHOW ME THE VIDEO!
[edit on 2-6-2008 by blimpseeker]
Perhaps because the Phoenix Lander kept all of its cameras in stowed, protected positions to avoid getting dirt or dust on a lens, or to avoid
scratching a lens in the event that the deceleration engine burn kicked up dust. For the folks at the Lunar Challenge, that would be an inconvenience
that could be fixed by replacing a scratched lens, cleaning a dirty one, or ignoring the problem completely since a little dust or a scratch wouldn't
impact their mission. For Phoenix, the fix would be a little more complex.
If you want video of the landing, the Mars Reconnaissance Orbiter got images of the Phoenix Lander under its parachute during the non-powered portion
of its descent.
[edit on 2-6-2008 by Brother Stormhammer]