US/NASA make first batch of Plutonium-238 in 30 years.

_Tombstone_

50g, size of a Golfball. They currently have 77lbs of the stuff, enough to meet demand for missions they've planned but half is going off and will have to be mixed in with new more powerful blends coming down the line.

They're planning on making an awful lot of it:eek:

With continued coordination, both agencies plan to increase production after this important demonstration milestone and will start with 300 to 400 grams (about 12 ounces) of plutonium dioxide per year. After implementing greater automation and scaling up the process, ORNL will produce an average of 1.5 kilograms (3.3 pounds) in subsequent years.

Next mission to use the stuff will be Mars Rover 2020 to seek signs of past life on the Red Planet, test technology for human exploration, and gather samples of rocks and soil that could be returned to Earth in the future.

http://energy.gov/articles/us-demonstrates-production-fuel-missions-solar-system-and-beyond

I wonder what 238 tastes like...

gizmo555

_Tombstone_ wrote: »

I wonder what 238 tastes like...

Don't eat too much, the lethal dose is 227 micrograms.

Capt'n Midnight

_Tombstone_ wrote: »

50g, size of a Golfball.

Plutonium is between 16 and 19.8g/cm3 so 50g is more like a level teaspoon.

Plutonium oxide is 11.5g /cm3 so less than a level tablespoon if they do it that way.

Juno is to use solar out at Jupiter. So nuclear is really only for power in outer solar system. Or Mars with the clouds and stuff. The main use is to keep instruments warms.

_Tombstone_

gizmo555 wrote: »

Don't eat too much, the lethal dose is 227 micrograms.

I was wondering how they knew this, assumed they'd given it to mice and then up the dose by weight but nooooo

feeding radioactive material to mentally disabled children[4]

exposing U.S. soldiers and prisoners to high levels of radiation[4]

irradiating the testicles of prisoners, which caused severe birth defects[4]

exhuming bodies from graveyards to test them for radiation (without the consent of the families of the deceased)

Sigh

_Tombstone_

On the other end of the scale, NASA Juno Jupiter Mission has set a solar powered record beating Rosetta.

NASA's Juno mission to Jupiter has broken the record to become humanity's most distant solar-powered emissary. The milestone occurred at 11 a.m. PST (2 p.m. EST, 19:00 UTC) on Wednesday, Jan. 13, when Juno was about 493 million miles (793 million kilometers) from the sun.

The previous record-holder was the European Space Agency's Rosetta spacecraft, whose orbit peaked out at the 492-million-mile (792-million-kilometer) mark in October 2012, during its approach to comet 67P/Churyumov-Gerasimenko.

Capt'n Midnight

_Tombstone_ wrote: »

On the other end of the scale, NASA Juno Jupiter Mission has set a solar powered record beating Rosetta.

NASA scraping the PR barrel again.

Juno was launched in 2011 with 49.7 m2 of panels.
Rosetta was launched back in 2004 with 64m2 so ESA got out there first ,
and with bigger panels


But I love the Lego on Juno and can't wait for the pictures and science. I just wish NASA would stop spamming us with trivial stuff because they've way better things.

SNAKEDOC

I would imagine some of the new stock will go toward testing for an ipdated nerva engine. A nars mission would probably be the first application for such an engine. Exciting to see if they do launch one given the preformance of they had in the 60's before it was cancelled.

Capt'n Midnight

SNAKEDOC wrote: »

I would imagine some of the new stock will go toward testing for an ipdated nerva engine. A nars mission would probably be the first application for such an engine. Exciting to see if they do launch one given the preformance of the midels they had in the 60's before it was cancelled.

Pu 238 is used for heat / generators because it decays by itself. It's rare as it has to be made.

It's not fissile like Pu239 so you can't split it on demand which is kinda needed in a controlled reactor

And reactors are heavy so while you save a lot of weight on fuel and tankerage you loose on engines and shielding. So you aren't going to get off the ground with it. Maybe stage two, but it won't replace stage one. It certainly can't compete with the cost of stage one's using cheap propellants like HTP/liquid oxygen/hydrocarbons/Solid boosters.

Nerva only had twice the specific impulse of existing rocket engines. Way, way less than existing ion thrusters so it's only of use for manoeuvring in a gravity well or for time critical apps. Even then caching fuel in GEO or Lagrange points by using ion drive from LEO would take away most of that advantage so no need for humans to ride the nuke.

NASA have spent $18Bn on SLS and will spend a lot more before the first launch test and most of the hardware was flight proven on the Shuttle program. Saturn V program cost €4Bn per completed rocket including development costs. So if you just built them from the plans cost might possibly be as low as $3Bn each. No nuclear program is going to be remotely close to that , never mind what public opinion says.

Then again if they could get Project Orion going using Laser fusion ...