[ExI] To Boldly Go Nowhere, for Now

The Avantguardian avantguardian2020 at yahoo.com
Fri Sep 20 12:54:24 UTC 2013

> From: Eugen Leitl <eugen at leitl.org>
>To: tt at postbiota.org; astro at postbiota.org; ExI chat list <extropy-chat at lists.extropy.org> 
>Sent: Friday, September 20, 2013 3:49 AM
>Subject: [ExI] To Boldly Go Nowhere, for Now
>To Boldly Go Nowhere, for Now
>Why we should hit pause on manned space exploration.
>By Srikanth Saripalli|Posted Thursday, Sept. 19, 2013, at 8:08 AM
>NASA's Mars rover Curiosity's self-portrait combines dozens of exposures
>during the 177th Martian day, or sol, of Curiosity's work on Mars, Feb. 3,
>2013. The rover is positioned at a patch of flat outcrop called "John Klein,"
>which was selected as the site for the first rock-drilling activities by
>Future space explorers should be somewhere between human astronauts and
>robots like NASA's Curiosity rover on Mars.

Unless routine missions in LEO count as "exploration", manned space exploration has already been on pause for over 30 years. But it turns out robots won't be going anywhere anytime soon either because we are running out of Pu-238. And guess who won't let us make more?
NASA’s Plutonium Problem Could End Deep-Space Exploration
By Dave Mosher 09.19.13
In 1977, the Voyager 1 spacecraft left Earth on a five-year 
mission to explore Jupiter and Saturn. Thirty-six years later, the car-size 
probe is still exploring, still sending its findings home. It has now put more 
than 19 billion kilometers between itself and the sun. Last week NASA announced 
that Voyager 1 had become the first man-made object to reach interstellar 
The distance this craft has covered is almost incomprehensible. 
It’s so far away that it takes more than 17 hours for its signals to reach 
Earth. Along the way, Voyager 1 gave scientists their first close-up looks at 
Saturn, took the first images of Jupiter’s rings, discovered many of the moons 
circling those planets and revealed that Jupiter’s moon Io has active volcanoes. 
Now the spacecraft is discovering what the edge of the solar system is like, 
piercing the heliosheath where the last vestiges of the sun’s influence are felt 
and traversing the heliopause where cosmic currents overcome the solar wind. 
Voyager 1 is expected to keep working until 2025 when it will finally run out of 
None of this would be possible without the spacecraft’s three 
batteries filled with plutonium-238. In fact, Most of what humanity knows about 
the outer planets came back to Earth on plutonium power. Cassini’s ongoing 
exploration of Saturn, Galileo’s trip to Jupiter, Curiosity’s exploration of the 
surface of Mars, and the 2015 flyby of Pluto by the New Horizons spacecraft are 
all fueled by the stuff. The characteristics of this metal’s radioactive decay 
make it a super-fuel. More importantly, there is no other viable option. Solar 
power is too weak, chemical batteries don’t last, nuclear fission systems are 
too heavy. So, we depend on plutonium-238, a fuel largely acquired as by-product 
of making nuclear weapons.
But there’s a problem: We’ve almost run out.
“We’ve got enough to last to the end of this decade. That’s 
it,” said Steve Johnson, a nuclear chemist at Idaho National Laboratory. And 
it’s not just the U.S. reserves that are in jeopardy. The entire planet’s stores 
are nearly depleted.
The country’s 
scientific stockpile has dwindled to around 36 pounds. To put that in 
perspective, the battery that powers NASA’s Curiosity rover, which is currently 
studying the surface of Mars, contains roughly 10 pounds of plutonium, and 
what’s left has already been spoken for and then some. The implications for 
space exploration are dire: No more plutonium-238 means not exploring perhaps 99 
percent of the solar system. In effect, much of NASA’s $1.5 billion-a-year (and shrinking) 
planetary science program is running out of time. The nuclear crisis is so bad 
that affected researchers know it simply as “The Problem.”
Stuart LaForge
“Beyond a critical point within a finite space, freedom diminishes as numbers increase. This is as true of humans as it is of gas molecules in a sealed flask. The human question is not how many can possibly survive within the system, but what kind of existence is possible for those who so survive.- Frank Herbert

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