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Lockheed Martin to Build Nuclear Powered Spacecraft
LouisvilleDebugger writes "The BBC reports that Lockheed Martin have received a $6M contract to develop the nuclear powered
JIMO, or Jupiter Icy Moons Orbiter. (According to the NASA project site, the first probes would not launch before 2011 due to development lead time.) On arrival at Jupiter, the extra power allows the probe to orbit each of three of the Galilean moons (Ganymede, Callisto, and most challenging from a radiation exposure standpoint, Europa) in turn, presumably helping to establish the possibility of liquid water and hence, life within the Jovian system. JIMO is a sub-project of Project Prometheus, initiated by NASA this year for the purpose of demonstrating that nuclear powered and propelled spacecraft may be safely designed and tested."
Two things: they don't state COMPLETELY safe--nothing is that. What if your steering goes out tomorrow while your driving? What if your gas tank leaks and you blow up? What if...?
Second, the chances of it blowing up in the air a la Challenger are slim. Granted it only takes once, but hey, there's no guarantee we'll all wake up tomorrow without some idiot gassing the planet.
The fact is that there are myriad possibilities for disaster in any big project, and the only thing any one person can do is to try to prepare for eventualities. Don't shoot down a project like this simply because it's nuclear. We all hear that word and think of Cherynobl (spelling?), Hiroshima and similar incedents. But just because it is nuclear powered doesn't mean that it's going to end like K-19: Widowmaker.
Think abou this: if we can do this it will forward research about our solar system by a long shot, which is something we must have if we ever hope to explore further out.
"We don't know what we are doing, but we are doing it very carefully,..." Wherry, R.J. Personnel Psychology (1995)
In any case, building a nuclear containment vessel strong enough to withstand external fire followed by a terminal-velocity plunge in to the sea is quite possible. Also, the material in an unstarted (uranium) nuclear reactor is not all that radiotoxic. You wouldn't want to handle it for long periods without protective clothing, but it has nothing like the lethality of plutonium or nuclear waste. Once the reactor has been running a little while it becomes much more dangerous, but I guess they plan to start the main reactor from a much smaller (hot) neutron source once the thing is a safe distance from the Earth.
Why is everyone so afraid of a little bit of radioactivity? Folks, especially slashdotters with the capability to read technical stuff and work with powers of ten, should just look at the issue a bit.
Radioactive material is toxic. So is rocket exhaust. So are zillions of other things in our environment, including all sorts of natural stuff in our food and our air. There is nothing magic or mysterious about radioactivity toxicity.
Your smoke detector contains a radioactive pellet. If you don't eat the thing, you are fine. Even if you do, you are probably okay (if a bit crazy). Dust contains radioactive materials. A large number of nuclear bombs have been exploded in the atmosphere, release lots of plutonium and other radioactive elements (the things are nowhere close to 100% efficient). We are still alive. Phosphorous products often have a raised level of radioactivity. If you are a camper with a Coleman lantern, the lantern mantles are radioactive. If you fly in an airplane or go to high altitudes (Denver, anyone), you are exposed to a lot of ionizing radiation (compared to sea level). Like getting a tan? You get it from ionizing radiation( UV rays).
Unless you are a fool, you wouldn't eat a gram of cyanide. Likewise, I wouldn't recommend eating a gram of a space probe's nuclear reactor. But that isn't going to happen!
Even if all the material were released into the environment (which is highly unlikely), the chances of harm to any one person are extremely low. You would experience far more danger driving to see the launch or just plugging in your computer!
Since the reactor is not activated until it is well away from earth, at launch it contains only uranium. Uranium is all over the place. Here in the Phoenix, AZ area there are significant concentrations in the soil in many areas where people live. My geiger counter gets 26 counts per minute in my driveway, but only 16 counts if it is sitting on top of the engine block of my car in the driveway. Wow! My driveway is radioactive. I guess I am doomed!
The uranium in a never fired nuclear reactor is no more dangerous than the uranium in soil - it is just more concentrated and has a different isotopic ratio (enriched reactor uranium is not more radioactive than unenriched - it just has a more U-235 (and less U-238). If it is dispersed in an explosion, it is no more dangerous than a dust storm here in this large metropolian area!
Anti-nuclear activists, a totally innumerate and scientifically ignorant press, the irrational conflation of nuclear weapons and nuclear power, and the unwillingness of people to look seriously at the issue have created a nuclear phobia in much of the western world.
The only good weather is bad weather.