|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Plutonium on Next Atlas V - Bad Idea?
The next Atlas V will carry plutonium in RTGs on
the Pluto New Horizons probe. "http://www.spaceflightnow.com/atlas/av007/050814pluto.html" This will be the seventh Atlas V, but it will also be the *very first* Atlas V flown in the "551" configuration, with five solid boosters and a five meter fairing. According to the report above, a recent environmental impact summary stated that the "mean probability of a plutonium release during the flight is about 1 in 300". Atlas V has had six successful launches, but only three have flown with solid motors, and there have been problems with the Atlas V solid motor development effort. One of the early solid motors failed during a ground test. I think I recall reading that Aerojet has had to certify a new "B" solid motor model to reduce acousitic loads. No Atlas V has flown with more than three solids to date. This launch will have to be approved by President Bush. I suspect we will be hearing a *tiny* bit more about this in the coming months. - Ed Kyle |
#2
|
|||
|
|||
Launch the thing. Quit being a woosy about nuclear power and let's get
real reactors into space. More and purer plutonium (100kg), has been spilled in the United States from making atomic bombs than would be theoretically lost in the worst case of one of these birds. Full steam ahead! |
#3
|
|||
|
|||
On 14 Aug 2005 20:00:08 -0700, "Ed Kyle" wrote:
The next Atlas V will carry plutonium in RTGs on the Pluto New Horizons probe. Should you care to calculate how large your solar panels have to be, out at Pluto's distance, then you will see that RTGs are the only real choice. Hopefully, they stuck in an extra RTG or two, when out past Pluto it would be going out a long way. "http://www.spaceflightnow.com/atlas/av007/050814pluto.html" This will be the seventh Atlas V, but it will also be the *very first* Atlas V flown in the "551" configuration, with five solid boosters and a five meter fairing. Well that is not uncommon, when they can swap the parts around as needed. According to the report above, a recent environmental impact summary stated that the "mean probability of a plutonium release during the flight is about 1 in 300". Atlas V has had six successful launches, but only three have flown with solid motors, and there have been problems with the Atlas V solid motor development effort. One of the early solid motors failed during a ground test. I think I recall reading that Aerojet has had to certify a new "B" solid motor model to reduce acousitic loads. So they had an early design problem and have since fixed it. No Atlas V has flown with more than three solids to date. Well this one is going to Pluto. This launch will have to be approved by President Bush. I suspect we will be hearing a *tiny* bit more about this in the coming months. Yes, but not that much. Due to past launches the public now sees that there is little risk here. And should this rocket like explode during launch, then they can go and pick up all the pieces. Also, since this is the one probe that NASA did not want to build, but due to public (and scientific) protest, congress forced them to build it anyway, then it would be an odd notion for the public to now protest over the very hardware that they forced NASA to build. You got it. You live with it. Cardman. |
#4
|
|||
|
|||
Cardman wrote:
On 14 Aug 2005 20:00:08 -0700, "Ed Kyle" wrote: The next Atlas V will carry plutonium in RTGs on the Pluto New Horizons probe. Should you care to calculate how large your solar panels have to be, out at Pluto's distance, then you will see that RTGs are the only real choice. Hopefully, they stuck in an extra RTG or two, when out past Pluto it would be going out a long way. "http://www.spaceflightnow.com/atlas/av007/050814pluto.html" This will be the seventh Atlas V, but it will also be the *very first* Atlas V flown in the "551" configuration, with five solid boosters and a five meter fairing. Well that is not uncommon, when they can swap the parts around as needed. According to the report above, a recent environmental impact summary stated that the "mean probability of a plutonium release during the flight is about 1 in 300". Atlas V has had six successful launches, but only three have flown with solid motors, and there have been problems with the Atlas V solid motor development effort. One of the early solid motors failed during a ground test. I think I recall reading that Aerojet has had to certify a new "B" solid motor model to reduce acousitic loads. So they had an early design problem and have since fixed it. No Atlas V has flown with more than three solids to date. I agree that RTGs are needed for this mission. What I am wondering is if it is a good idea to launch them on an unproven launch vehicle configuration. An Atlas 551 is a much different animal than the 401 that launched last week. At 568 tonnes, it weighs 235 tonnes more (70% more) than 401 at liftoff. Its SRBs provide 635 tonnes (1.4 million pounds) more thrust than the 401's 428 tonnes. Only seven of these, the world's largest single-grain solid rocket motors, have flown to date - and never more than three have flown at a time. - Ed Kyle |
#5
|
|||
|
|||
Cardman wrote:
On 14 Aug 2005 20:00:08 -0700, "Ed Kyle" wrote: This launch will have to be approved by President Bush. I suspect we will be hearing a *tiny* bit more about this in the coming months. Yes, but not that much. Due to past launches the public now sees that there is little risk here. I suspect the "public" who live near the Cape wouldn't agree with the "little risk" bit. They remember quite clearly Titan 4A-20, Delta 241, and Delta 259, all of which blew up within eye and ear shot of the Cape during the past eight years. - Ed Kyle |
#6
|
|||
|
|||
On Sun, 14 Aug 2005, stork wrote:
Launch the thing. Quit being a woosy about nuclear power and let's get real reactors into space. More and purer plutonium (100kg), has been spilled in the United States from making atomic bombs than would be theoretically lost in the worst case of one of these birds. Full steam ahead! Go to work cleaning up Hanford and don't be woosy about protective gear, etc. |
#7
|
|||
|
|||
On 15 Aug 2005 06:51:17 -0700, "Ed Kyle" wrote:
Cardman wrote: Yes, but not that much. Due to past launches the public now sees that there is little risk here. I suspect the "public" who live near the Cape wouldn't agree with the "little risk" bit. They remember quite clearly Titan 4A-20, Delta 241, and Delta 259, all of which blew up within eye and ear shot of the Cape during the past eight years. So what are they going to do? Watch this launch, while licking their lips, eagerly wanting this rocket to explode. And should it really do so, they will all rush out of their houses, race to be the first to get to these RTGs, crack them open, and then to quickly feast themselves on the plutonium contents? The officials can then try beating them back with sticks. :-] My point is that paranoia always works wonders to turn a small problem into a seemingly much large one. And if someone did find an RTG by accident, and to carry it all the way to their local police station, then I doubt that their radiation exposure would be very much anyway. Not the best idea to hide it under their bed though. The point is that they should just keep away from these RTGs, when longer term exposure would be unhealthy. And you can be certain enough that if this launch did go bang, then the first thing that these official would do would be to secure these RTGs. Cardman. |
#8
|
|||
|
|||
Any launch can fail.
If they have to launch plutonium, and they do, then it should be encased that it can survive a launch pad explosion. Same as man rating - you have provisions that the crew can survive if the rocket explodes. It's a bit easier, since a lump of plutonium dioxide is less fragile than an astronaut, and can be encased in titanium or what ever is needed. |
#9
|
|||
|
|||
I used to work in nuclear litigation from the plaintiff side. My job
was to build databases to help aggregate and let the attorneys search all of the documents discovered in cases. People have no idea of the amount of plutonium that was spilled into the environment and how many people, workers, residents, etc, sacrificed unknowingly their health and their lives so that we could maintain an effective strategic deterrent. You could probably make the argument that the entire Columbia River system has been contaminated with plutonium and other radioactive and poisonous systems from Hanford. There were experimental, controlled releases, there were numerous accidents, and bad stuff got into the environment. Same as for Rocky Flats, Fernald, and others. At Rocky Flats, they actually had very serious fires, and, they had some really goofy cleanup procedures. They put a bunch of nasty stuff into the ground and put a big concrete "pad" on top of it, but then you had earthworms and insects eating radioactive stuff and spreading it around to the surrounding community. All in all, even though Chernobyl has gotten a lot more publicity, even unclassified documents show that the total amount of radioactivity released by our nuclear weapons program was -MORE- on a nationwide basis. Hanford alone released the same amount, just over 50 years, but when you are talking about stuff whose halflife measures in decades at a minimum, a few decades doesn't matter. Those of us over 30 have strontium 90 in our teeth and the only metal they can use to make certain geiger counters with comes from salvage from pre-1945 - all other metal is now mildly contaminated and I think they harvest scrap from the German High Seas Fleet that scuttled itself after World War I. With all of that, life in the United States goes on. And for that reason, I think that given that we can absorb a certain amount of radioactive punishment, that we are living in a "worst case" already, and the potential gain from nuclear powered space craft, we may as well explore other planets. Unless you can invent a nonnuclear technology with a specific impulse of 3000, nuclear powered spacecraft are the only feasible way that we can truly get to Mars or to other planets - by making the travel time measured in weeks, or months, and not years. I support not only the use of RTGs in space, I also think it was a mistake to cancel Prometheus and the plan to build a nuclear plant in space, and I hope free enterprise will someday pick up the slack or that NASA will come to its senses. Yes, we risk maybe a 1000 people dying from an accident, but, the gain is the ability to spread humanity, over time, to other planets, and manage the risk of human extinction because of a catastrophic natural disaster on earth. It's worth it. |
#10
|
|||
|
|||
On 15 Aug 2005 06:22:36 -0700, "Ed Kyle" wrote:
I agree that RTGs are needed for this mission. Well, then going to Pluto does not allow much choice in your launch vehicle. Considering velocity and launch cost that is. What I am wondering is if it is a good idea to launch them on an unproven launch vehicle configuration. The hardware used seems quite good. The well proven and reliable Russian RD-180 engine. Both the 4 and 5 meter nose cone fairings have both been flown. And so that only leaves the 5 SRBs, which is the maximum number of their between 0 to 5 options. An Atlas 551 is a much different animal than the 401 that launched last week. Yes, both these are different ends on this same scale, where this 551 launch is the most powerful Atlas V launch to date. Here is what they have launched so far... Atlas V(401), Hot Bird 6, August 21, 2002 Atlas V(401), HellasSat 2, May 13 2003 Atlas V(521), Rainbow 1, July 17, 2003 Atlas V(521), AMC 16, December 17, 2004 Atlas V(431), Inmarsat 4-F1, March 11, 2005 Atlas V(401), Mars Reconnaissance Orbiter, August 12, 2005 All successful launches. Two used the 5 meter nose cone. Three made use of SRBs. And all used the single RD-180 engine, when there is also a two engine option. So the only real extra risk is from using 2 more SRBs than with any previous launch. And well lets just say that this rocket would be designed for this very option, where lesser requirements just scale back on this. At 568 tonnes, it weighs 235 tonnes more (70% more) than 401 at liftoff. Maybe that is because apart the usual two stages of the Atlas V design, then the New Horizons launch will also make use of a Star 48B third stage. This additional stage is what gives it that higher escape velocity. Its SRBs provide 635 tonnes (1.4 million pounds) more thrust than the 401's 428 tonnes. Why bother to compare it to their smallest 401 configuration, when the proven 431 and 521 options compare better? Only seven of these, the world's largest single-grain solid rocket motors, have flown to date - and never more than three have flown at a time. Yes. And all with a successful launch. So in January 2007 this successful New Horizon's launch will increase this number to twelve. Cardman. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Index charts to the 50 plates of Barnard's dark cloud atlas | canopus56 | Amateur Astronomy | 2 | August 10th 05 12:00 AM |
Index charts to the 50 plates of Barnard's dark cloud atlas | canopus56 | Amateur Astronomy | 7 | August 9th 05 11:56 PM |
Atlas of Light Pollution vs. Experience | [email protected] | Amateur Astronomy | 14 | March 31st 05 10:20 PM |
Heritage Atlas/Titan Update | ed kyle | History | 2 | December 7th 03 06:44 AM |
Atlas V Vandenberg Pad | ed kyle | History | 0 | December 1st 03 03:34 PM |