The proposed 2003 budget for NASA would scale back spending on the international space station and space shuttle but promote the development of nuclear technology in space.

Unveiled Monday, the Bush administration proposal offers $15 billion to the space agency, $500 million more than 2002. Most NASA missions would receive slightly larger budgets in the new fiscal year, with two major exceptions.

Space station Alpha, the subject of intense criticism for billions in cost overruns, would lose roughly $230 million over its 2002 allotment of $1.7 billion.

The space shuttle program, which Bush administration budget documents scold for inefficient safety upgrades, would receive about $65 million less than its $3.3 billion last year.

In fact, the White House plan would consider outsourcing many shuttle jobs to private contractors, and even sell off some of the shuttle hardware.

"Competitive sourcing will enable the full transfer of shuttle operations and possibly some portion of infrastructure ownership to a private entity," read the proposal for fiscal year 2003, which begins October 1.

Sean O'Keefe, the new NASA chief, declined to speculate on the number of federal jobs that might be lost due to competitive outsourcing.

"We're just starting down that road," he told reporters Monday.

The Bush administration issued a report card grading the effectiveness of various NASA groups. Predictably, those involving human flight fared poorly.

So-called Outer Planet programs were given failing marks as well. Citing swelling budgets and launch delays, the Bush budget would scrap all future funds for proposed Outer Planet missions to Europa, a large Jupiter moon that some speculate harbors life, and to Pluto, the only planet that remains unvisited by a probe.

The Bush report did praise the Discovery and Explorer missions, comparatively inexpensive classes of unmanned expeditions that have roamed Mars, landed on a nearby asteroid, collected interstellar dust and orbited Earth to observe the planet, the sun and the heavens.

O'Keefe said the immediate task at hand for NASA was to set priorities for missions based on scientific value, expected costs and technological constraints.

'There are really a large number of interesting things to do. We need to think about what current limitations exist," he said.

Taking a politically risky position, the Bush plan would push the development of nuclear power and propulsion for future missions into space.

The move could give a boost to troubled deep space projects that have yet to find technologically feasible propulsion systems or enough juice to conduct long-term studies on the surface of other planets like Mars.

But it could also set of storms of protests from activists who called into question the safety of past nuclear probes, citing the risks of accidental crashes should something go wrong at launch.

www.cnn.com

....And as the scraps of metal and radioactive material rain down, the scientists realize that it was not as good as it sounded. :rolleyes:

There are merits to nuclear powered probes...I just am not sure if the benefit is outweighed by the potential costs...

This is bull****. It figures Bushler would push this crap to enrich his nuclear cronies. The risks behind this are far too high to push forward with this crap. That nazi has no right to endanger the whole planet to further his agenda, that dumb pos doesn't know what will happen if one of these Cassini type probes explodes on launch or re-enters the atmosphere like the sattelite did last week.

A launch explosion high over Florida could contaminate the entire state, re-entry into the atmosphere would spread nuclear particles around the globe.

There are many other ways to fuel these things, I really don't think turning Florida into a nuclear waste dump is worth taking better pictures of some far away star. I can just see them launching these things on Titan rockets, kaboom!

I really have no particular like of Bush or his policies on many issues, but nuclear powered spacecraft are one of the issues that I tend to agree with him. The problems that CA claims are indicative of the intense public dislike about anything nuclear. This is really unwarranted. Nuclear power for spacecrafts is not very dangerous at all.

First of all, the nuclear power is not at all like nuclear fission or fusion. I think that people in general understand this difference, but some do not and claim that something like Chernobyl could happen if there was an accident on a Cassini type craft. This is impossible. The materials on a spacecraft are not weapons-grade or even explosive.

Most opponents claim that the danger is radioactive materials. It is true that these pose some danger, that is indeniable. However, the fuel is contained in protective casings designed to withstand enormous impacts and explosions. Further, these capsules are positioned on the craft so that they will not all experience the same forces during an accident. The result is that if one experiences enough stress to destroy it, most of the others would not experience this same stress and thus would not be destroyed.

Further, the amount of radiation that would be released in a catastrophe is not too great. The estimate is about 1 millirem per year across the world. A person living in Denver is exposed to 30 millirem more per year than someone living at sea level purely as a result of being at a higher altitide.

Nuclear power has been used over twenty times on spacecraft. 3 of these flights had malfunctions during the mission. In NONE of the 20 something missions did a nuclear unit malfunction in any way. Thats as good of a record as NASA could hope for, though of course a single failure would have probably doomed nuclear power in space for a few generations.

CA claims that "there are many ways to fuel these things." Well, unfortunately, that is not really true. Since NASA stopped using nuclear power on their missions, there is not a single feasible plan for an exploration satellite that can explore the outer solar system. Solar power cannot work, the solar flux at that distance is too small.

My point is that alot of people jump on the bandwagon when it comes to nuclear issues. People think of Hiroshima, Chernobyl, and Three Mile Island, and associate the terrible events with the word nuclear. Just because a technology can be used poorly does not mean it has to be used poorly. Unfotunately I am forced to put my trust in other people to ensure that things are done correctly, and therefore I understand where opponents are coming from when they criticize nuclear technology.

Nate

Nate,

How is heat converted to electricity by these space vehicle nuclear reactors? It must be something more powerfull than a thermal couple.

The power production systems on Cassini and previous nuclear spacecrafts use RTG's, which are Radioisotope Thermoelectric Generators. These are not nuclear reactors in the normal sense of that term.

Each of these 3 RTGs has a few kilograms of plutonium pellets encased in the RTG. The plutonium decays naturally by releasing radiation, usually alpha particles. These collide with surrounding atoms and produce heat. Silicon Germanium thermocouples are used to generate electricity from the heat. Excess heat is used to warm the spacecraft's vital components. These RtGs provide something like 700 Watts of power, and degrade at a few percent per year. Thus after the 11 year life of Cassini, they should still be producing plenty of power for NASA's common extension of the life of spacecraft. There should probably be power to beam back data even when the craft has no power for propulsion left.

I hope that helps, it is about all I know on Cassini.

Nate

Thermal couples are really just PN junctions, so I buy the Silicon Germanium junctions. It's all solid state, but I am a little surprised they would generate enough current. Interesting...

RTGs have been used and refined for 30 years, so NASA has put alot of research into them. I am sure their thermocouples are about as state-of-the-art as they get.

Originally posted by Thutmose
really have no particular like of Bush or his policies on many issues, but nuclear powered spacecraft are one of the issues that I tend to agree with him. The problems that CA claims are indicative of the intense public dislike about anything nuclear. This is really unwarranted. Nuclear power for spacecrafts is not very dangerous at all.


How is it not dangerous? Would you live near near the launch site when one of these was being launched? Cassini had 72.3lbs. of Plutonium on board. If that was dispersed over Florida.. well um sucks for the Floridians.

First of all, the nuclear power is not at all like nuclear fission or fusion. I think that people in general understand this difference, but some do not and claim that something like Chernobyl could happen if there was an accident on a Cassini type craft. This is impossible. The materials on a spacecraft are not weapons-grade or even explosive.

That's not the issue though, it's the radioactive particles that would rain down on people below that I'm concerned about.

"This is by far the most Pu ever attempted to be launched in a space mission. Inhaling less then 27 millionths of a gram of Pu will give you lung cancer and also causes long term genetic damage."

Most opponents claim that the danger is radioactive materials. It is true that these pose some danger, that is indeniable. However, the fuel is contained in protective casings designed to withstand enormous impacts and explosions. Further, these capsules are positioned on the craft so that they will not all experience the same forces during an accident. The result is that if one experiences enough stress to destroy it, most of the others would not experience this same stress and thus would not be destroyed.

So claims NASA, I don't think we can trust these capsules when so much is at risk. Did you see the video of the Titan rocket explosion a few seconds after launch? It was absolutely amazing! It was like a small atomic bomb going off. I think it was one of the biggest non atomic explosions ever. I can't see how one of these capsules could survive and explosion of that magnitude??

Further, the amount of radiation that would be released in a catastrophe is not too great. The estimate is about 1 millirem per year across the world. A person living in Denver is exposed to 30 millirem more per year than someone living at sea level purely as a result of being at a higher altitide.


Correct me if I'm wrong, but background radiation is completely different than vaporized Plutonium.


Nuclear power has been used over twenty times on spacecraft. 3 of these flights had malfunctions during the mission. In NONE of the 20 something missions did a nuclear unit malfunction in any way. Thats as good of a record as NASA could hope for, though of course a single failure would have probably doomed nuclear power in space for a few generations.

What type of failure did these 3 have?


CA claims that "there are many ways to fuel these things." Well, unfortunately, that is not really true. Since NASA stopped using nuclear power on their missions, there is not a single feasible plan for an exploration satellite that can explore the outer solar system. Solar power cannot work, the solar flux at that distance is too small.

I believe that is a result of the Nuclear industry/government pushing their agenda on NASA. I have heard several different alternatives to get these probes into deep space, one of them being this...

"This modest generation of 745 watts of electricity, can now be done in deep space conditions, by using a combination of advanced photovoltaics (solar power) and long lived fuel cells. The National Aeronautics and Space Administration (NASA) has been using both solar and fuel cell technologies since the days of the Gemini missions back in the mid 1960's. NASA, however has denied that the Cassini mission can use the solar fuel cell process, stating that Saturn's solar insolation is only about 1% (it's 1.087%) compared to the Earth's. Well thanks to the European Space Agency (ESA) announcing back on 4/29/94, "a technology milestone, the development of new, low-intensity, low-temperature (LILT) solar cells that are capable of 25% efficiency, the highest efficiency ever reached, and could be used in deep space missions. If given the contract to do the work, within 5 years ESA could have solar cells ready to power a space mission to Saturn," said Dr. Carla Signorini, a ESA physicist in Noorwijk, Holland.

Some background info to show where NASA is coming from: For the 1989 Galileo mission to Jupiter, a NASA witness swore in court that it could only be completed by getting its electricity from the 49.25 lbs. of Pu in its RTG's. Yet, two weeks after the launch, in response to a Freedom Of Information Act requested by Professor Karl Grossman of the State University of N.Y. at Old Westbury and the narrator of the award winning film Nukes In Space (A request that was filed two years earlier with NASA and the Department of Energy (DoE) ) The Jet Propulsion Laboratory (JPL) acknowledged that solar energy could substitute for nuclear power. "Based on the current study, it appears that the Galileo Jupiter orbiting mission could be performed with a concentrated photovoltaic solar array power source without changing the mission sequence or impacting science objectives" so stated one of the reports. A year later when the Ulysses mission was launched, NASA actually admitted in its pre-launch Final Impact Statement "that solar could substitute for nuclear power but would require a redesign." When are we going to find out from NASA that the Cassini mission could have had a solar fuel cell redesign, just before the launch, or just after?

A JPL study showed it would take 5,380 sq. ft. of solar power, or 2, 30' x 105' solar arrays (but that = 6,300 sq. ft. ?) (it should be 2, 30' x 90' = 5,400 sq. ft.) to produce the 745 watts of electricity in deep space. This, they said would make Cassini too massive for launching. (But not with a booster rocket with a little more thrust) I have cautiously calculated the solar #'s out myself, and found it's more like 3,900 sq. ft. or 2, 30' x 65' solar arrays to produce the 745 watts. ESA has evaluated (strong armed) this JPL study and concluded that "our LILT solar cells aren't a viable power source alternative for the presently defined Cassini mission of NASA." The key words here are, "Presently Defined", NASA and the ESA are playing Orwellian word games, knowing all to well that the Cassini mission can be redesigned to use solar fuel cells, but that's not what is "Presently Defined" by NASA. Cutting edge technology in clean renewable solar hydrogen fuel cell energy is what is needed to be funded, not nuclear. If funded, Cassini could be redesigned to use solar fuel cell technology and launched within 3 years.

NASA, JPL, the DoE's national nuclear laboratories, and the corporations that have been involved in the producing of nuclear hardware for the space missions insist on sticking with nuclear on Cassini. NASA has been in bed with the DoE and its laboratories, the Department of Defense (DoD), the National Security Agency (NSA), The Pentagon, and all the military industrial complex corporations from the start. Then, near the end of the Apollo days, NASA sold their souls to the military for new contracts. Just take a look at the Space Shuttle missions, many of them are top secret military missions. "


My point is that alot of people jump on the bandwagon when it comes to nuclear issues. People think of Hiroshima, Chernobyl, and Three Mile Island, and associate the terrible events with the word nuclear. Just because a technology can be used poorly does not mean it has to be used poorly. Unfotunately I am forced to put my trust in other people to ensure that things are done correctly, and therefore I understand where opponents are coming from when they criticize nuclear technology.

See, I think sending Plutonium up on a rocket loaded with rocket fuel is irresponsible and idiotic. Do we really need up and close pictures of Uranus:p?? It just isn't worth it to me. Are they going to ask everybody on this planet for permission before they play with our health? And what about future generations? The radiation from a bad accident could last for melliniums. And another issue not talked about is what about the effet on other planets. What if one of these probes eventually crashes into another far off planet that has life and we contaminate their planet?

Jeff-

Another issue to think of is that radioactive materials are 'graded' This is not weapons grade material...

I'm aware of that, I'm not concerned with it causing a nuclear blast, just the nuclear dust that would result from being exploded by a rocket fuel explosion.

Gimme Solar...http://www.sublimespot.com/sublime/image_feb_2000/40oz_sun_11.gif

:cool:

Jeff-

The issue is that grade matters, that coudl very well be a factor in the stregnth of the nuclear material...

For example, octane rating...

87 is LESS combustive than 104...

If you take that to a larger scale its easy to see that a 'fuel' grade radioactive material may not be NEARLY as harmful (even in an explosion) than a weapons grade material.

Perhaps I sounded a little too enthusiastic in my previous message. I am not a gung-ho supporter of launching all sorts of nuclear material into space. I just happen to think that the frontiers of space will be closed to us as long as we restrict ourselves to solar power. Maybe we can squeeze out a solar mission to saturn, but even then we could not really provide power out there or beyond to any reasonable sized craft.

Some more clarifications...
The unit of rem does take into account the type of radiation. Thus, 1 rem from plutonium is equivalent to 1 rem of background radiation. Also, the fact that it is not weapons grade would have been taken ino account in an estimate of the radiation. Weapons grade plutonium would be able to undergo fission.

Also, 2 of the three nuclear failures were pieces that fell into the ocean after a weather satellite failed to launch correctly. They were retrieved, refurbished, and reused. The 3rd was the plutonium unit from Apollo 13s lunar lander that sunk in the Pacific Ocean. It is still there.