Slashdot Mirror
NASA's Mars Polar Lander May Have Landed Safely
JabberBoi writes "On January 3, 1999, NASA lost contact with the Mars Polar Lander after it was supposed to land on Mars. An assessment report by NASA suggested that the lander's legs may have sent an incorrect signal to the craft's computer, which in turn caused a premature shutdown of its landing engines -- resulting in the craft crashing on Mars. However, according to this article from Space.com, analysis of images of the Polar Lander's assumed landing site area obtained by the Mars Global Explorer were sent to a U.S. 'spy' agency called the National Imagery and Mapping Agency (NIMA) to determine if any signs of wreckage or the spacecraft could be discerned through pixel analysis. The article describes NIMA as an 'acclaimed leader in describing, assessing, and visually depicting physical features on Earth' from imagery taken by spy satellites. NIMA's report states that the images they analyzed suggest a successful landing based on identification of three separate parts of the Mars Polar Lander: an upright Polar Lander, and two 'pixel return' signatures that suggest the lander's parachute and heat shield. These findings suggest that something else may have caused the Polar Lander mission to fail. Conspiracy theories about why the Polar Lander never called home abound."
The "conspiracy theories" link has an interesting picture at the very bottom, of a site near the martian polar ice cap. It does look a lot like plant life, but I suppose it could also be some sort of striated rock formation. Does anyone know if that site or something nearby is going to be investigated by any of the landers approaching Mars this month?
"The slave who knows his master's will and does not get ready...will be be beaten with many blows."Luke 12:47-48
If NIMA can discern wreckage (or lack thereof) on a small space craft on Mars based on those photos, I wonder what they can see here on earth.
Look carefully at the data presented. At site 3 they have one bright pixel. This they have extrapolated to be a high speed impact, complete with ground scarring. Sounds like a pretty powerful computer model they are using if it can deduce all of that from a single data point of one bright pixel. It sure seems to be able to fill in a lot of blanks from absolutely zero supporting data.
Site 2 has 2 bright pixels. From this they have deduced that the lander is sitting intact on it's 3 little legs. That's quite an astounding conclusion for such a minimal amount of data. Again, it begs the question, just how much 'filling in the gaps' is that computer model doing ?
This really makes me wonder, after all, these are the folks doing image analysis for intelligence purposes. 3 pixels on a 1.5 meter resolution is enough to conclude there is a lander sitting upright, and a high speed impact 3 miles away, yet they cannot seem to locate the 6 meter diameter parachute that should still be attached to the much smaller unit they have 'identified'. Gotta wonder, if they can find a lander that's 2 meters, based on 1.5 meter pixel data, why cant they locate a 6 meter object that's not possibly any farther away than the length of the cords attaching it? this should be childs play, because it's going to occupy no less than 8 pixels, and likely it should occupy 12 of them. The location of the parachute should provide more supporting data than all the rest of the data they have combined, yet they cant find it.
This is a very interesting insight to the methodology in use by this agency, begs a few questions about the rest of thier work. Are these folks normally in the habit of drawing conclusions based on extrapolated data obtained from uncalibrated visual systems ? Do they normally draw conclusions from incomplete data, even tho there is strong evidence to suggest the conclusion is not correct, based on the missing correlation data that should be present (missing parachute).
These are interesting academic questions, until you put the final perspective on it. The conclusions this intelligence agency draws, become part of the basis for starting wars.
Just an FYI to all the /.'ers, the group formerly known as NIMA has changed its name to the National Geospacial Agency, or NGA.
-1: flamebait should really be -1: inciteful
This is why we need a comprehensive satellite array around Mars before we start firing probes down. What we should do, IMHO, is create a ring of support satellites around Mars with everything imaginable, cameras of every kind, return to Earth containers, etc. That way, when we crash probes onto Mars, we can intensively photograph and document everything. What have we learned from this failure? Absolutely nothing. If the probe really is intact, why aren't we receiving anything? We haven't learned anything because we can't go back, look at the actual probe, and do tests, etc. At least if we had a satellite ring, we could do more documentation.
And when the probes land successfully, we can save space and power on the probes by just having enough power to send signals to the satellites, which then boost the signal and fire back to Earth.