Tuesday, May 27, 2008

Phoenix Lander on Mars

This image of the Phoenix Lander on the surface of Mars was taken with the HiRISE camera aboard the Mars Reconnaissance Orbiter about 22 hours after Phoenix landed on the surface. The insets are closeups that are labeled and show not only the lander, but also the affects the landers rockets had on the surface surrounding the lander and also the heatshield and the backshell and parachute nearby on the Martian surface! You can even see some details in the parachute! Click on the image to see the full resolution version or visit the HiRISE website for this image for more details..

I'm not sure which direction the lander came in from, but it was probably the bottom right, though I also suspect that it might be the bottom left since the heatshield appears to have bounced towards the upper right. It looks like the wind may be blowing towards the bottom or bottom right since the parachute appears to have pulled the backshell towards the bottom and the chute itself is laying in that direction. Also, there appears to be a little wispy dark trail to the bottom right from the heatshield impact site. And my friend Joe who works on HiRISE says they should get some better images soon taken from closer range.

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Phoenix lander on chutes with crater backdrop

It gets even better! Yesterday, I posted about the HiRISE image of Phoenix on its parachute descending to the surface. Well, today, we get to see the bigger picture which shows the lander against a backdrop of the crater Heimdall which is about 20 km away with the spacecraft about 8-10 km above the surface. It looks as if the lander is heading straight for the crater, but that is due to the way the MRO spacecraft and HiRISE are looking obliquely across Mars to see the lander. Click on the image above to show the full resolution version. The inset at the lower left corner of the image shows a high resolution closeup of the lander which shows details in the parachute as well as the shroud lines and backshell enclosed lander.

Great work by the folks on MRO & HiRISE to plan for and actually succeed in taking this spectacular image! Coming soon: More pictures of the Phoenix Lander, this time on the surface of Mars!

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Monday, May 26, 2008

Phoenix on its chutes

Now how cool is this! The Phoenix Lander made a successful landing on Mars yesterday and while it was descending on its parachutes, the HiRISE camera on the Mars Reconnaissance Orbiter snapped this image of Phoenix. This is the first time that an orbiter has gotten an image of a lander in flight around another planet. Like I said, now isn't this COOL! You can see the parachutes, and the lander that is still in its backshell as well as the lines connecting the parachute to the backshell, all against the backdrop of the Martian surface below. I'm sure the HiRise camera will also be returning images of the lander on the Martian surface and I think the first attempt at that should already have been made and is just awaiting analysis.

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Tuesday, May 13, 2008

APOLLO - Apache Point Observatory Lunar Laser-ranging Operation

Now this is cool. As you may know, 3 of the Apollo missions and one of the Soviet Lunokhod rovers left laser retroreflector experiments with arrays of corner reflectors that would bounce a laser beam straight back from where it came, allowing Earthbased telescopes to measure the distance to the retroreflectors. Up until now, only the McDonald Observatory in Texas and a couple other experiments in other countries have been used to make such measurements and with a precision of something like a few centimeters.

This relatively new program that went into operation in 2005 uses the 3.5 meter telescope at Apache Point in New Mexico is called, somewhat appropriately, APOLLO. Incredibly, they've made big improvements over previous experiments such that they are achieving accuracies of about a millimeter in their distance measurements to the Moon! They are measuring times of photon returns to a few picoseconds! Their equipment receives photon returns substantially more efficiently than previous experiments.

With this kind of capability they will be able to test Einsteins theory of General Relativity as well as the precision of the inverse square law of gravity itself. It can measure the constancy of the Gravitational constant G, not to mention measuring the exact motion of the Moon as well as of their own observatory over time which includes the affects of continental drift, all to higher precision than has ever been done before.

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Thursday, May 08, 2008

Jim Oberg's article on the recent Soyuz re-entry anomalies

Spaceflight is dangerous. It won't be anything routine and safe like air travel for a long time to come. The forces involved in launch and landing of a spacecraft are enormous and the vehicles us feeble humans have ingeniously designed and built are just barely in control of those forces.

The recent Soyuz re-entry that brought the Expedition 16 crew back to Earth is a prime example and reminder of that. One failure can spell doom for a ship and her crew as we are from time to time reminded so horribly by accidents like that of Columbia most recently and of Challenger, Soyuz 1 and Apollo 1. Happily, in this case, the failure appears to have been overcome by a design improvement after a similar re-entry glitch in early 1969 that nearly claimed the life of a Soviet Cosmonaut. It appears likely that the service module that supports the Soyuz spacecraft in orbit with rocket engines, supply tanks, and solar panels failed to separate from the re-entry module. And like a paper airplane, the combined vehicle began re-entry nose forward with the heat shield still nuzzled between the entry module and the service module. The front of the entry module is not designed to withstand the temperatures the heatshield is there for and not only contains a fragile hatch, but the parachutes that are needed to safely land the crew on the ground at the end of the flight. The new design which Oberg believes had been untested to this point allows the service module to break free during re-entry as the temperatures and atmospheric stresses build up on the vehicle even if the separation bolts fail to fire.

For more details, read Oberg's article here.

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