NASA Selects Contractor for First Prometheus Mission to Jupiter

[alexblackwell]

NASA Selects Contractor for First Prometheus Mission to Jupiter<br />September 20, 2004

 

[rocketwatcher2001]

That's AWESOME!<br /><br />For years I've wanted us to do something like this. <div class="Discussion_UserSignature"> </div>

 

[starfhury]

Alright! JIMO is a go! It's about time we made a real nuclear powered probe. This is going to be the way of the future. Nuclear power will help open up space more than any other technology we have available today. Twenty years after to JIMO, who knows? We might be launching Discovery to Jupiter. Hopefully with out HAL.<br /> <div class="Discussion_UserSignature"> </div>

 

[wvbraun]

Great! I love JIMO.<br /><br />What about Boeing? Didn't they get anything? After all, they had prepared such a nice website...

 

[wvbraun]

Boeing Project Prometheus website

 

[bobw]

From your link:<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Under the contract, Northrop Grumman will work with a government team to complete the preliminary design for the spacecraft. <p><hr /></p></p></blockquote><br /><br />Is Northrop Grumman going to start with a blank sheet of paper for the design or are they going to engineer a structure that looks like the artist's conception? I can't find an artist's conception drawing of Promethius on the Grumman site. Do you expect it to look like the one at the NASA site, the Boeing site, or something else?<br /><br />wvbraun (or anyone) please feel free to express your opinion, too <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

 

[bobvanx]

The SNAP10A video on the Boeing site is very... thought provoking.

 

[CalliArcale]

Northrup got it? WOOHOO!!! That's great news! I know they've been frustrated at playing second fiddle to Boeing and Lockheed (to the point where they weren't even invited to compete for the JSF contract). It's about time a big contract went somewhere other than Boeing or Lockheed.<br /><br />Hmmm.... One of my coworkers recently got a tremendously good offer from them and jumped ship to Northrup in Redondo Beach. She said she was being put onto an R&D program that the company hoped would become a really big program in the very near future. That was last summer. I wonder if it was JIMO? <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[thermionic]

I'm thrilled JIMO is gaining some momentum. Personally, I'm much more excited about this project than manned mission to Mars.

 

[alexblackwell]

Jupiter's Newest Satellite<br />Gabriel Spera<br />Crosslink: The Back Page

 

[rybanis]

Now if they had something to launch a probe that size into orbit on...that'd make it sweeter. <div class="Discussion_UserSignature"> </div>

 

[bobvanx]

>more excited about this project<br /><br />Absolutely. Nuclear power in space is so obvious from just about any perspective you care to view it.<br /><br />And actually, a space-rated high power source would support a manned mission. But first things first.

 

[mikejz]

<font color="yellow">Now if they had something to launch a probe that size into orbit on...that'd make it sweeter. </font><br /><br />They do, the problem is that currently it is a museum piece.

 

[scottb50]

Rah! Rah! Rah! Nuclears a waste of time until we get beyond Uranus. <div class="Discussion_UserSignature"> </div>

 

[bobvanx]

>beyond Uranus.<br /><br />ouch.

 

[bobvanx]

> beyond Uranus.<br /><br />If you could perhaps, further illuminate your opinion, I'd happily let a little sun shine.

 

[scottb50]

Solar power is a lot lighter to launch and requires a lot less infrastructure to operate and maintain. Would you send a manned mission anywhere with only one reactor?<br /><br />How much does a reactor mass, and how would you use it? If you expect to have massive amounts of power to reach outer worlds as quick as possible you have to consider the cost of coolant and/or propellant.<br /><br />Nuclear can be used three ways: use a coolant, run a reactor at high power and expell the coolant to produce thrust, the problem becoming how much coolant you can carry, it runs out pretty fast. The second method is to use a sealed coolant to heat a propellant, say Hydrogen to provide the needed thrust, less potential but less propellant needed. Third, ion/electric, which produces minimal thrust over a long time, like two years to get to the moon.<br /><br />1 and 2 require a huge mass to either transfer the reactors heat to a coolant or directly cool the reactor and be expelled. The third can be done much easier using solar power. <br /><br />I'm all for solar/electric engines, they are well proven and chemical means are available to slow-down to enter an orbit, the problem being we can't put a vehicle into an inter-planitary trajectory with a solar/ion engine, let alone a nuclear reactor. We don't have a lauch vehicle that could come close to putting anything in LEO. <br /><br />The faster you get there the more energy it takes to slow down and enter an orbit, the more propellant you need and the higher the launch weight.<br /><br />Solar power can provide more than enough energy well past Saturn, which is well beyond the point we could reasonably think of sending a manned mission in the near future, remember we can't even get to LEO reasonably. I doubt a manned mission to the moons of Jupiter, let alone Saturns would be worthwhile anyway, looking at the time frame, even with Nuclear or solar powered engines. Remember we have to get back, how much propellant/coolant would that take?<br></br> <div class="Discussion_UserSignature"> </div>

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>1 and 2 require a huge mass to either transfer the reactors heat to a coolant or directly cool the reactor and be expelled. The third can be done much easier using solar power.<p><hr /></p></p></blockquote><br /><br />There are limits, however, to solar power generating capabilities, and the performance of ion propulsion is closely tied to how many watts are available. Some in this thread have said that solar power is not useless until you get past Uranus, but in reality, to move a manned vehicle fast enough to get to Mars, even solar power at this distance will not suffice. There's a limit to how much bigger the solar arrays can be than the vehicle, and not just because of mass.<br /><br />As it stands today, solar power is not sufficient for even the power generation needs of an outer-solar-system vehicle with conventional chemical propulsion. The Stardust mission took solar power the furthest it has ever been from the Sun, and its power needs were relatively modest. For a spacecraft such as Cassini, solar power is impractical. How much more impractical, then, for a spacecraft many times larger which has an ion drive to consume most of its electrical output? <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[SteveMick]

Calli wrote: "There are limits, however, to solar power generating capabilities, and the performance of ion propulsion is closely tied to how many watts are available. Some in this thread have said that solar power is not useless until you get past Uranus, but in reality, to move a manned vehicle fast enough to get to Mars, even solar power at this distance will not suffice. There's a limit to how much bigger the solar arrays can be than the vehicle, and not just because of mass"<br /><br /> As an advocate of solar thermal rockets for many years, I find these remarks to be somewhat misleading.<br />STR's can acheive thrust levels enabling 1/100 to as much as 1/10 of a gee acceleration of a manned or unmanned vehicle. By using a series of perigee thrusts, an STR can reach escape velocity and by using a lower Isp thrust by increasing mass flow rate, can escape to interplanetary trajectory. In marked contrast to JIMO as it now stands, the STR will take less than a month to escape as opposed to TWO YEARS for JIMO! Once on an interplanetary trajectory, the STR can use its concentrator mirror to generate considerably more energy than JIMO for electric propulsion by using triple junction solar cells able to use concentrated sunlight at nearly 30% efficiency. An STR system capable of 100KW elec. at Jupiter will have about 25 times this much thermal energy at earth's distance for a solar thermal rocket and with the cells potential of 1KW/kg., it is feasible to generate more than 100KW near Earth without a large mass penalty.<br /> As for relative mass, the situation would be laughable if only real money weren't involved. At last word, JIMO will require a new booster since nothing we have can even launch it to LEO!<br /> If you really want to get off the JIMO bandwagon, compare costs between the two systems: the differential is around a factor of 100 in favor of solar.<br /> In development time, solar would take a small fraction of the time and have dozens of probes in orbit at Jup

 

[bobvanx]

>JIMO will require a new booster<br /><br />Yay! We need one, anyway, to build the Solar Power Satellite system for Earth's future energy needs.<br /><br /> />it's about politics and whose friends make money<br /><br />We've got to stop worrying about this. Look, there are always going to be people who have money and resources, and we can't be jealous of them. What we can do is task them to be accountable to the needs of the larger community. Space Nuclear Power is an enabling technology for colonization. So if you want to see humans living in space, let the people who have the money and power have their fun and make sure you use it to further your own goals.<br /><br /> />advocate of solar thermal rockets for many years<br /><br />I've got a buddy at l'Garde, and they would love to build an STR, and it's a wonderful tech. And it's cheap. Which means it doesn't generate many jobs. Which means that it won't get built and enter service until the economies of transportation demand it. So if you really want to see STR, then stay focussed on getting people into space.<br /><br />Which requires Space Nuclear Power.

 

[yurkin]

Scott<br />An even better example of the inadequacies of solar power in the outer solar system is looking at Rosetta. Its 64 square meter panels can only get 395 watts at Jupiter. Jimo might be able generate as much as 200kw, so to do that using solar arrays would be 32,400 meters squared. Rosetta’s array operates at 25% efficiency, so even if you could build a 100% efficient solar array it would still need to be huge.<br />http://www.esa.int/SPECIALS/Rosetta/ESAHVF7708D_0.html<br /><br />Project Prometheus encompasses NEP, NTP and next generation RTG’s like the one on Mars Science Rover. If solar power is insufficient for an advanced rover how do you expect it to be sufficient for a human Martian exploration?<br /><br />I was going to recommend you view the Prometheus Presentation on Boeing’s Prometheus website. Unfortunately that websites been taken down. I guess Boeings a little sore about losing another contract.<br /><br />Steve<br />Didn’t you already lose this argument? I seem to recall you had a total lack of both facts and reason.<br /><br /><font color="yellow">Is it just coincidence that a recent Star Wars contract was for a 100KW LEO based target discrimination radar?</font><br /><br />No it’s not coincidence its nonsense. <br />For one thing the space based radar is a black project, so you have no idea how much energy it requires and therefore the 100kw figure is a lie.<br />Oh and I’ve seen a picture of the SBR’s satellite in AWST. It’s got big folded up solar panels.<br />And finally if solar power is as powerful as you believe it is, then why would the DOD not want to use it in their satellites?<br /><br /><font color="yellow">In marked contrast to JIMO as it now stands, the STR will take less than a month to escape</font><br />That figure is unsubstantial by reality. The STR ground tested at Glenn had a max thrust of 20N, that’s not exactly warp speed.

 

[SteveMick]

Beleive me I am not trying to be sarcastic - I really don't understand your logic. In what way is space nuclear power related to getting more people into space? As currently construed, JIMO does absolutely nothing to get anyone into space and indeed diverts huge amounts of money for more than a decade to something which seems irrelevant. <br /> I think your insight about why STR's have not been funded (don't cost enough)is completely accurate, but economies of scale bring down the cost of costly things so that they become cheaper and therefore more useful. Solar already is cheap and so is better to use to transport beyond LEO now. Later the tech behind JIMO may benefit from increased op in space, but it has a long way to go to become competitive in terms of cost and specific power. It isn't about jealosy its about using available funds to actually do something that is truly useful. Any program that lasts more than a decade, history shows, is very unlikely to survive politically long enough to do anything.<br /> By the way, we need something better than a booster if we are to change the paradigm - something that is air breathing IMHO.<br />Steve Mickler

 

[dan_casale]

SteveMick wrote:<br /> />> As an advocate of solar thermal rockets for many years, I find these remarks to be somewhat misleading. <br /> />>Once on an interplanetary trajectory, the STR can use its concentrator mirror to generate considerably more energy than JIMO for electric propulsion by using triple junction solar cells able to use concentrated sunlight at nearly 30% efficiency. An STR system capable of 100KW elec. at Jupiter will have about 25 times this much thermal energy at earth's distance for a solar thermal rocket and with the cells potential of 1KW/kg...<<<br /><br />Now I'm confused. Are you talking about solar thermal or concentrated solar photovoltatic? Anyway here is a link to a table that gives sunlight values for the different planets.<br /><br />http://www.hq.nasa.gov/office/pao/History/conghand/environ.htm<br /><br />From the table <br />Intensity of sun-light at mean distance (intensity at Earth= 1.0)<br />Mars .43<br />Jupiter .037<br />Saturn .011<br /><br />The collector will need to be this many times larger:<br />Mars 2.33<br />Jupiter 27.03<br />Saturn 90.91<br /><br /><br /><br />Are you talking about this kind of a thermal rocket? (Note: the link covers both NTR and STR)<br />http://www.neofuel.com/moonice1000/<br /><br />Here is the information (party line) I have on Prometheus:<br />http://spacescience.nasa.gov/missions/prometheus.htm<br />

 

[backspace]

Dangit. Can't find that snap video... do you have a link?

 

[backspace]

quickly, before someone else starts throwing it around... didn't the US have a failed reactor attempt in the 60's?