NEAR Shoemaker Touchdown Coming Up

iso9k writes "As reported from Space.com: The first asteroid touchdown in history is slated for Feb. 12 as NEAR Shoemaker attempts to gently drop itself onto the battered and boulder-strewn surface of Asteroid 433 Eros. The NEAR team itself is out of money for operations. They are out of Deep Space Network tracking time. And the probe itself almost out of fuel. This will be the first time that the United States has been to another body where we are the first ones to land. The race's to the Moon, Venus and Mars were won by by the former Soviet Union. The chances of the probe making a successful touchdown: less than 1%. On the eve of Feb 11 and 12 look up to the heavens and wish our little probe good luck and thank it for its dedication and service."

Comments

A few comments on the thread...

[HerringFlavoredFowl]

Thought I'd point out a few corrections to the thread...

1. The US has landed probes on venus. But the russians still have the best record.
2. Considering Jupiter is a Gas Giant, as you go deeper into it's atmosphere the pressure and temperature get higher and higher. Any probe you send burns up. The "solid" part of the planet is under such extreme pressure/temperature conditions that it is not yet possible to build a probe that will survive to this point.
3. The offical Near Page is http://near.jhuapl.edu/
4. The point of the landing is to get as near as possible to the Eros while still taking usefull data. They have mentioned before it's not an attempt to land, just a practice in which they are hoping to gain useful data. How many of us remember pioneer-venus's and magellan's end of life atmosphere probing? Led the way to our areo-braking efforts on Mars. Or the Lunar Prospector end of life experiment with the moon. Interesting gamble to find water...
5. Someone mentioned valentines day, I remember they had targeted Feb. 14 as the touch down date. Why it changed, I don't know. Also, for the last V day they snapped a wonderful valentines day photo of Eros, http://near.jhuapl.edu/iod/20000213b/index.html

The NEAR Picture of the Day

[Royster]

I've been checking out the picture of the day since this time last year. There is some awfully interesting geology going on up there.

Eros is covered in regolith. As it slides down the walls of the craters, it exposes new surface which hasn't been darkened by the solar wind. Old craters melt into the background. Fine regolith pools in the bottom of craters.

I imagine that some impacts jolt the asteroid enough to shake everything up a little. I the microgravity near Eros, it shouldn't take much of a jolt to make something "airborne". Much of the same physics that describes shaking containers of different sized objects must describe what's going on here.

1 percent?

[ruck]

Two things:

1. It's pretty clever that the probe is landing (crashing, whatever) on Eros so close to Valentine's Day.

2. On the other hand, it's unfortunate that the NASA has put the chance of the thing surviving at 1%. Now it's a lose-lose situation. If it doesn't make it, it's unfortunate. If it does, it's even worse... "See, those NASA morons said it only had a 1% chance. I bet the bozo who did that calculation was the same guy who used inches instead of centimeters on the Mars probe," etc.

Eros tumbles ...

[JoeGee]

end over end. Basically it wobbles on at least two, if not three, axes -- look at NEAR's movies.

Even if NEAR manages to "land" at a relatively stable point on Eros NASA will be very lucky to have the probe's antenna pointing towards Earth for a fraction of Eros' short day. I suspect that constant contact with the probe will not be possible even under the best of circumstances.

Someone please correct me if I am wrong, but with Eros' low mass/gravity wouldn't anything attempting to land on the points farthest from Eros' pivot points risk being lobbed out into space like a wiffle ball unless some seriously delicate maneuvers managed to come very close to nullifying the relative velocity of the probe to the asteroid?