Postcards from the Bleeding Edge
Tuesday, November 15, 2005
Went to sleep with the image of Minerva helplessly drifting away from Hayabusa. Had a dream with alarms going off like 1201! 1202! Watched Columbia cover the skies of texas in fire. Saw Beagle burn up and the Mars Polar Lander fall its last few hundred meters. Watched Ranger 4 hit the other side of moon silently, where no one else but my dream self could see it. Eventually I woke up, still hearing 1201! 1201! in my head, even now, as I write...
... knowing that ultimately - the Eagle, landed.
I'd like to write at the end of this week - the Falcon has landed. Something like that would make nightmares like tonight's worth it.
Bonus link - the Apollo 11 crew addresses congress ¶ 12:40 AM 0 comments
Sunday, November 13, 2005
One of the reasons I'm big on asteroids in Aten orbits is that they have a surface temperature range that passes through what is required for life. 2062 Aten, the lead asteroid in the class, has a mean surface temp of 275 degrees kelvin, which translates out to 35 degrees fahrenheit - chilly, but survivable. I don't have any data on the temperature range (min and max) such asteroids go through, but it stands to reason that some have a range of surface or interior temps within the known earth-life-and hardware survivable range. Still looking for data... I think there is an ideal temp range for spacecraft and habitable structures, but I don't know what it is. (hardened COTS computer hardware has a comfort zone of -40c to +80c - some might say -40 to +100c is feasible - but what of the other components?)
And what kind of raw materials would be available on a typical aten? Too hot, and you have no volatiles. Too cold, and cellular metabolisms can't function. Construction of shelter is easy, use an instant shelter, and just add water.... Or adapt a spacehab... you might want to burrow down a dozen meters both for insulation and extra radiation shielding.
The main problem is getting rid of heat in a near vacuum, there would have to be a heat exchanger mounted in the crust. You need one anyway, to boil out various volatiles.
Transport back from an Aten is straightforward - if you use a restartable engine like the Vulcain or the RS-72. Same fuel (NTO/MMH) that took you out takes you in, but this time you end up in Earth orbit with plenty of extra fuel. How much extra fuel typically? Take a wild guess (and comment). (take a look at an Ariane upper stage dry and wet, that should help...)
Wouldn't it be cool if something like a hydrogen-sulfide metabolism could survive on an asteroid?
I've been worrying a bit about the newly discovered class of Aphohele asteroids, which orbit just inside Earth's orbit. While only 2 have been definitively discovered, at least 50 are projected to exist. As they spend most of their time in the Sun's glare, they are very hard for Spaceguard in its present form to spot.
Mean surface temp on 2003 CP20 is a blistering 323K (122F).
And what kind of raw materials would be available on a typical aten? Too hot, and you have no volatiles. Too cold, and cellular metabolisms can't function. Construction of shelter is easy, use an instant shelter, and just add water.... Or adapt a spacehab... you might want to burrow down a dozen meters both for insulation and extra radiation shielding.
The main problem is getting rid of heat in a near vacuum, there would have to be a heat exchanger mounted in the crust. You need one anyway, to boil out various volatiles.
Transport back from an Aten is straightforward - if you use a restartable engine like the Vulcain or the RS-72. Same fuel (NTO/MMH) that took you out takes you in, but this time you end up in Earth orbit with plenty of extra fuel. How much extra fuel typically? Take a wild guess (and comment). (take a look at an Ariane upper stage dry and wet, that should help...)
Wouldn't it be cool if something like a hydrogen-sulfide metabolism could survive on an asteroid?
I've been worrying a bit about the newly discovered class of Aphohele asteroids, which orbit just inside Earth's orbit. While only 2 have been definitively discovered, at least 50 are projected to exist. As they spend most of their time in the Sun's glare, they are very hard for Spaceguard in its present form to spot.
Mean surface temp on 2003 CP20 is a blistering 323K (122F).
Labels: apohele, asteroid, asteroids, aten, space, space05
¶ 11:01 AM 0 comments
I so wanted to wake up this morning to some stereo closeup photographs from the Hayabusa probe -- but it appears that a sign got flipped and Minerva was launched away from Itokowa rather than towards it.
From MSNBC:
Here's to hoping next week's landing goes ok. ¶ 8:03 AM 0 comments
From MSNBC:
- The hopper robot was deployed at 3:24 p.m. Japan time, from a distance of about 180 feet (55 meters). Hayabusa “was able to establish radio contact with the free-flying MINERVA,” according to the JAXA report. But at the later update, officials said the small probe was now expected to drift away from Itokawa and not fall to the surface as planned. Its batteries are expected to be exhausted in a day or two.
Here's to hoping next week's landing goes ok. ¶ 8:03 AM 0 comments
