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Posted by: Redstone Sep 26 2005, 09:56 PM

http://www.nasa.gov/home/hqnews/2005/sep/HQ_05283_New_Horizons.html
http://www.jhuapl.edu/newscenter/pressreleases/2005/050926.htm
http://www.space.com/missionlaunches/050926_newhorizons_update.html

Coming up...
October: communications checks
November: hydrazine loading and Atlas V countdown rehearsal
December: integration with Atlas V
January: LAUNCH!

No pictures on the http://science.ksc.nasa.gov/shuttle/countdown/video/video90lh.html yet.

But still pictures http://mediaarchive.ksc.nasa.gov/search.cfm?cat=4.


Is that the flight RTG attached to the spacecraft? Or just a dummy?

Posted by: odave Sep 27 2005, 12:43 AM

I just showed this picture to my 8 year old, and told her that when that spaceship finally gets to Pluto, she will have graduated from high school and be getting ready to go to college. Her reply:

"Whoa!"

Indeed...

Posted by: hendric Sep 27 2005, 02:07 AM

She sure is pretty with all that gold foil.

Alan et al, any last minute emergencies or "Holy sh__!" like they had on MER?

Posted by: spfrss Sep 27 2005, 09:30 AM

[quote]
Is that the flight RTG attached to the spacecraft? Or just a dummy?
[endquote]

IMHO it is just a dummy with the proper mass/dimensions to be used for spin/balance testing.

live long and prsper

mauro

Posted by: BruceMoomaw Sep 27 2005, 09:31 AM

As I understand it, the only possible show-stopper now is that they still need official permission from Bush to launch that much plutonium. I'm sure he'll agree, once they've explained to him what Pluto is.

Posted by: paxdan Sep 27 2005, 10:26 AM

trouble is nobody is quite sure at the moment what pluto is

Posted by: remcook Sep 27 2005, 02:06 PM

"I'm sure he'll agree, once they've explained to him what Pluto is. "

just say this is the only chance he'll get to launch something nuclear and get away with it. He'll love it

Posted by: odave Sep 27 2005, 05:56 PM

I thought it was "nucular"

Posted by: um3k Sep 27 2005, 06:00 PM

At least it isn't "nuklarr!"

Posted by: Bob Shaw Sep 27 2005, 08:46 PM

"Ma fellow amphibians, we have today launched Mickey Mouse and his faithful dawg to their home planet. World. Thing..."

Posted by: BruceMoomaw Sep 27 2005, 09:20 PM

Actually, the blood-chilling thing about "nucular" is how many non-Bushians pronounce it the same way -- including Tony Blair, Walter Mondale, and (as the supreme insult) Clinton's first Defense Secretary, Les Aspin. A DEFENSE SECRETARY who can't say "nuclear" is a bit much. And what the hell was Tony learning in those pricey private schools, besides a plummy accent?

Posted by: Bob Shaw Sep 27 2005, 10:10 PM

Bruce:

If we tell you what Tony Blair was *really* taught, then we'll have to kill you. Aha.

Bob Shaw

Posted by: Jeff7 Sep 27 2005, 10:38 PM

Sadly enough, look at http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=nuclear&x=0&y=0. Pronunciations:
'nü-klE-&r, 'nyü-, ÷-ky&-l&r


I don't know when it happened (post-2000 perhaps?) but nucular is apparently an approved pronunciation now. Who wants to be the first to storm Merriam Webster's HQ?

Posted by: SigurRosFan Sep 27 2005, 10:43 PM

How many RTG pellets are now on board??

Posted by: hendric Sep 28 2005, 12:30 AM

"Mr. President, we're sending the plutonium back to Pluto, where it came from." Now we just need to get some Neptunium onto a spacecraft...

Posted by: edstrick Sep 28 2005, 06:59 AM

BruceMoomaw: "..Actually, the blood-chilling thing about "nucular" is how many non-Bushians pronounce it the same way ..."

The word is a pronunciation booby-trap. Much the same way I think poor Neil Armstrong got booby-trapped as he stepped onto the moon.

"That's one small step for <a> man...One giant (etc)

The first phrase builds up a cadance with the article "a" brutally interrupts. I've always thought that was an accidental built in booby-trap that nailed Neil with a vengence.

Posted by: BruceMoomaw Sep 28 2005, 07:31 AM

Well, I certainly never had trouble with it -- unlike, say, "February" or "arboretum" (which my mother fouls up every time -- fortunately, it's not an everyday word). Far as I'm concerned, the ability to pronounce "nuclear" correctly is a sort of IQ test for politicians: no one who can't get it right should be allowed near a position of major national leadership.

Posted by: BruceMoomaw Sep 28 2005, 07:33 AM

I forgot to mention that Eisenhower also fouled it up routinely, but this is hardly a shock. The immortal statement "Things are more like they are today than they have ever been before" has been attributed both to Ike and to Gerald Ford, either of whom was fully capable of it.

Posted by: spfrss Sep 28 2005, 08:36 AM

The problem I think is not the presidential approvation to launch NH, but the so-called
'ecologists' à la Bruce Gagnon.
I still remember the protesters who tried to stop the launch of Cassini, Galileo and Ulysses even by judicial means, fearing a launch accident or something.

live long and prosper

Mauro

Posted by: Richard Trigaux Sep 28 2005, 09:22 AM

Ooops

Posted by: Richard Trigaux Sep 28 2005, 09:24 AM

Step 1: learn to pronounce it correctly

Step 2: learn that it is dangerous

Posted by: Richard Trigaux Sep 28 2005, 09:46 AM

I fully support far exploration, including to far planets. And anyway 30kgs of plutonium in a space probe, it is still that in less on Earth. Good bye and thanks goodness.

But what I fear is not ecologists blocking the launch of Cassini; it is rather the following scenario:

the launch fails, the rocket explodes... Worse, it let the probe on a long elliptic orbit, letting some days of suspens before the RTG re-enters the atmosphere at 10km/s, dispersing worldwide a deadly dust of plutonium... Still worse, the RTG was hardened to sustain such events, and it falls on the ground... in one of "certain countries".

Remember that 7 microgram of plutonium 239 dust is enough to kill somebody (by lung cancer from breathing dust) and Pu 238 is still more active.

We cannot say it will never happen. It is simply a matter of statistics: the number of nuclear probes, multiplied by the fail rate of rockets...

If such a thing would happen, Mr Bush may definitively forbid the use of RTGs in space probes. And he would not be alone to think so.

Bye bye Pluto.


OK, this forum is not about ecology. But it is certainly not about burying our head in the sand: space exploration implies some dangers. And thus some responsabilities. Even at our level of simple supporters.

Should we abandon the exploration of far planets for this reason? The choice may be not ours.

Perhaps there are other less dangerous solutions. Not at hand, but searchable.

Posted by: djellison Sep 28 2005, 09:59 AM

Please go and read the safety reports for the launch. To say that a launch failure would unleash a worlwide distribution of a deadly dust is highly missleading and far from the truth.

Doug

Posted by: Sunspot Sep 28 2005, 10:33 AM

I remember the fuss over the launch of Cassini and how envirnomental campaigners "emabarked on a campaign of misinformation" to get NASA's attention. ...... and even Martin Sheen showed up lol

Posted by: djellison Sep 28 2005, 10:41 AM

If the public were made as aware of the military payloads that contain radioactive material as they are of the civilian ones - all hell would break loose.

Doug

Posted by: RNeuhaus Sep 28 2005, 03:33 PM

I will put anything nuclear information from NH spacecraft here to clear any doubts and any missleading about the nuclear worries:

Designed for Safety
More than 40 years have been invested in the engineering, analysis and testing of RTGs. As described below, safety features of an RTG include the use of a specific type of fuel material, a modular design and construction and the use of multiple physical barriers.

The plutonium dioxide fuel contained in RTGs is a specially formulated fire-resistant
ceramic that is manufactured as pellets to reduce the possibility of fuel dispersion in a
launch or reentry accident. This ceramic form resists dissolution in water and reacts little
with other chemicals. If fractured, the ceramic tends to break into relatively large
particles and chunks that pose fewer hazards than small, microscopic particles.

Multiple layers of protective materials, including iridium capsules and high-strength
graphite blocks, protect and contain the fuel and reduce the chance of release of the
plutonium dioxide. Iridium, a strong, ductile, corrosion-resistant metal with a very high
melting temperature, encases each fuel pellet. Impact shells made of lightweight and highly heat-resistant graphite provide additional protection.

Each RTG contains 18 heat source modules with four plutonium dioxide pellets in each
module. There are two plutonium dioxide pellets in each graphite impact shell, and two
graphite impact shells go into each heat source module. The figure below shows part
of a heat source stack within the RTG.

Risk Assessment and Launch Approval
Any mission that plans to use an RTG as a power source undergoes a safety analysis
carried out by the Department of Energy (DoE). The safety analysis report provides a
comprehensive assessment of the potential consequences of a broad range of possible
launch accidents. In addition to the DOE review, an ad hoc Interagency Nuclear Safety Review Panel (INSRP), which is supported by experts from government, industry and
academia, is established as part of a Presidential nuclear safety launch approval
process to evaluate the safety analysis report prepared by DOE. Based upon the INSRP
evaluation and recommendations by DOE and other Federal agencies, NASA may then
submit a request for nuclear safety launch approval to the White House Office of
Science and Technology Policy (OSTP). The OSTP Director (i.e., the President’s science
adviser) may make the nuclear safety launch decision or refer the matter to the President.
In either case, the launch cannot proceed until nuclear safety launch approval has been
granted.

RTGs can provide continuous power in regions of space where the use of solar power
is not feasible. Over the past 40 years, RTGs have been used safely and reliably on 25
missions, including six Apollo flights to the moon, two Pioneer spacecraft to Jupiter and
Saturn, two Mars Viking landers, two Voyager missions to the outer planets, the
Galileo mission to Jupiter, the Ulysses mission to the Sun’s poles, and the Cassini-
Huygens mission to Saturn.

Long reliability.

Rodolfo

Posted by: SigurRosFan Sep 28 2005, 04:06 PM

But how many RTGs are actually on board?

Earlier ...

--- Half of the plutonium for New Horizons was on hand when DoE stopped work at the nuclear weapons plant in July 2004. A total of 36 of the 72 fuel units ordered had been left over from a spare RTG built earlier for NASA's Galileo and Cassini missions. When the lab shut down, it had 18 more units in the works. The 2006 launch will go ahead with as few as 61 fuel units.

Los Alamos scientists could convert plutonium bought from Russia into pellets packaged in hockey-puck-sized containers. Then the Argonne National Laboratory at Idaho Falls would put those RTG containers into the RTG.

An RTG with a full load of 72 fuel units can deliver 200 watts of electricity. With only half of its fuel, 36 fuel units, it could deliver about 100 watts. With a minimum of 61 fuel units, the RTG could provide 170 watts of electrical power. The electricity would be used to power seven science instruments and spacecraft systems aboard New Horizons. ---

Posted by: Richard Trigaux Sep 28 2005, 05:38 PM

Thanks RNeuhaus for your informations.

So it seems that the maximum possible precautions were taken:
-plutonium ceramics cannot disperse in dust., even when broken or exposed to fire
-iridium-graphite casing can withstand the heat of any rocket explosion. (Irridium 2454°C graphite more than 3000°C)
-iridium casing will not rust if fallen in a ocean or place difficult to reach such as a rain-foret.

The policy being, of course, in such a case where a very large risk is involved, to envision the worse case as BEING TO HAPPEN and avoid any nasty effect even in this case. So I suppose that the worse possible accident was envisioned.
The worse case here is a re-entry at more than 11km/s, from a trajectory error in a gravitationnal assistance manoeuver using Earth. In this case the atmospheric braking flame is theoretically hot enough to melt irridium and the ceramics, which would form droplets and eventually dust. But I hope the guies are not dumb and they envisioned this case, where anyway the flame is only during a given time, so that it has other things to grind before reaching the plutonium.

Anyway if a RTG was to fall on the ground, it would be a maximum alert for the local police to avoid ignorant or malevolent people to take away the parts.

Posted by: helvick Sep 28 2005, 05:50 PM

Not sure but Alan Stern's message http://www.unmannedspaceflight.com/index.php?showtopic=675# on Feb 19th says:


These RTG's degrade at around 0.79% per annum so 190W at Pluto (mid 2015) works back to around 205W now and should still be >165Watts in 2031.

Alan commented later:


So basically, no worries, loadsa juice. Let's just all do our bit to make sure that we don't let woowoo panic merchants hamper the launch.

Actually I've just been re-reading the whole thred - it's well worth it.

Posted by: SigurRosFan Sep 28 2005, 06:22 PM

Thanks a lot, Helvick!

Posted by: mike Sep 28 2005, 07:18 PM

Chernobyl exploded rather spectacularly and yet people still build nuclear reactors.

Posted by: SigurRosFan Sep 28 2005, 07:29 PM

0.79%? I thought the spacecrafts RTG generally loses 3 to 5 watts of power-generating capacity a year.

What is correct?

Posted by: helvick Sep 28 2005, 08:24 PM

The loss is exponential not linear - it follows the half life of Pu-238 (more or less) which is around 87.7 years. So after 87.7 years you would have 50% of the power you have right now.

Posted by: deglr6328 Sep 28 2005, 09:21 PM

Isn't Martin Sheen a chain smoker? hilarious.

Posted by: SigurRosFan Sep 28 2005, 10:41 PM

Okay. I calculate 200.8 Watts for launch power.

Posted by: BruceMoomaw Sep 29 2005, 03:46 AM

Yep, there is no doubt that environmentalism attracts zany fanatics. So, however, does space exploration. And NASA's previous straight-faced official estimates of accident probabilities (one in 100,000 of a Shuttle exploding during launch) are not the sort of thing calculated to bolster public confidence in the agency's competence -- or its honesty.

I myself strongly doubt that there's any danger whatsoever -- even in the event of a high-speed reentry. (The Pu pellets are encased in iridium shells, after all. And when the rocket carrying the Nimbus 3 weather satellite blew up in 1968, the Pu cores in its two RTGs not only didn't powderize, but fell into the sea off the coast of Vandenberg virtually intact, were recovered by a robot submersible months later, and were simply refurbished and flown again on Nimbus' successor the following year.) But there's always a first time; and I myself will breathe a little easier after this thing is successfully launched.

Posted by: Richard Trigaux Sep 29 2005, 10:03 AM

[quote=BruceMoomaw,Sep 29 2005, 03:46 AM]
when the rocket carrying the Nimbus 3 weather satellite blew up in 1968, the Pu cores in its two RTGs not only didn't powderize, but fell into the sea off the coast of Vandenberg virtually intact, were recovered by a robot submersible months later, and were simply refurbished and flown again on Nimbus' successor the following year.)

[/quote]

Good info. Good test. Not the worse case, but the most probable.


[quote=Sunspot @ Sep 28 2005, 10:33 AM)
I remember the fuss over the launch of Cassini and how envirnomental campaigners "emabarked on a campaign of misinformation" to get NASA's attention. ...... and even Martin Sheen showed up lol[/quote]


I think you all should not laugh so easily about environmentalists: they have their concerns too, and if we had paid a little bit more attention to what they say, we would not have ozone depletion, nuclear wastes, climate change, etc. (only scientists gave earlier warnings). And it is not because we are interested in space exploration that we must just get egoistically blind to the related environment concerns. Please do not become zany scientists!

It happens that I am among the pioneers of the french environmentalist movement, in the 1970'. I still back up the idea, but I must admit that since there was much taking over by leftists shemanigancers and "zany" dogmatists, so I prefered to take some distance from the main stream. As everybody know environmentalists generaly reject all what is nuclear (electricity plants, and of course weapons), but they have no general agreement about "scientific nuclear" such as synchrotrons and space probes.

And for people like me who feel environmentalist AND scientific, I have no ready made reply about such a question than "should we use RTGs?". The only thing I would state is that we should urge smart fusion research (not the cumbersome tokamaks) which does not arise such heartbreaking environment issues. Imagine a ion engine powered by a 1Mw lithium hydride cell: it will be the key for real freedom of move in the whole solar system and beyond. And I am in the process of writing a novel in where all rely on fusion interstellar spaceships and terraforming machines (with real physics).

Posted by: djellison Sep 29 2005, 10:08 AM

But in this case - totally unfounded concerns - and they embark on a mission to spread missinformation. I dont laugh at those who object to the launch of RTG's into Space - they make me angry.

Doug

Posted by: Richard Trigaux Sep 29 2005, 10:16 AM

Add to this the degradation of the thermocouple junctions by the neutron flux. Semiconductors are used to build thermocouples to convert the heat into electricity, and these semiconductors crystals must be perfect and very pure, and thus they are very sensitive to impurities and crystal defects. The neutrons emanating from the RTG heat sources are not very numerous, but they can transmute some of the semiconductor atoms, forming impurities. Or most probably the atom recoil and secondary beta/alpha emissions will disrupt the crystal lattice. I am sure of what I say, having worked in the domain. But I cannot give figures about the degradation rate. It is slow enough to allow Cassini (and Pioneer and Voyager) to work, but Cassini will be very probably out of power before being out of nuclear fuel.

Add to this that the thermodynamic efficiency of the convertion of heat into electricity may decrease with the temperature of the heat sources.

Posted by: tty Sep 29 2005, 11:39 AM

It was actually a steam explosion but OK. However I think that reactors (and RTG's too) built and operated now conform with the main safety lessons from Chernobyl:

Don't build reactors of materials that will burn (graphite)

Don't build reactors where power goes up when the coolant goes down

Don't monkey around with reactors unless you know what You're doing

Don't build reactor enclosures from wood and tarpaper

tty

Posted by: djellison Sep 29 2005, 02:04 PM

A little bird tells me, NH is...

72 pellets, 190+ Watts in 2015

Doug

Posted by: SigurRosFan Sep 29 2005, 02:20 PM

What is the birds name?

Posted by: djellison Sep 29 2005, 03:38 PM

It was from Alan via email to me - I think he just clicked reply to a private-message email



From Alan:
"You know we're getting closer to launch when this happens: You too can spend, spend, spend on cool NH gear at:

http://www.pcxhost.com/store/st7/tp8/products/browse.jsp?category=1916&unique=1128007511703&sid=D0691216FDAE032CDF43ECD368B53D04D5CC0A8A "

Doug

Posted by: Richard Trigaux Sep 29 2005, 04:11 PM

I understand your anger, Doug. But usually it is polluters and authors of catastrophes who spread misinformation, to justify their shemes or to escape punishment.

Posted by: Richard Trigaux Sep 29 2005, 04:15 PM

Hey but this is not a science site, it is a shop. Do they sell T-shirts to fund the new Horizon project?

Posted by: Sunspot Sep 29 2005, 04:25 PM

... I distinctly remember seeing and hearing a women in a news report leading upto the launch saying they "had embarked on a campaign on misinformation" to get NASA's attention. How can you expect people to make a decision on an issue when they're being lied to? As much as I support environmental concerns and issues, enviromental groups are notoriously loose with scientific facts - thanks in part to the publics disinterest and ignorance of science.

Posted by: helvick Sep 29 2005, 05:15 PM

You're quite right - even though these are solid state devices there is some level lof degradation over time which is why I said that it follows the half of Pu-238 more or less.

Its a long time since I did any nuclear physics but I don't recall that there are any Neutrons emitted as part of the Pu-238 decay cycle. (Pu238->U235+Alpha and all subsequent decays are "Nasty Radioactive Isotope"+Alpha|Beta|Gamma ... Lead). It's still a stressful environment for the thermocouple but the dominant component of the loss of power should be the fuel's half life.

Posted by: Richard Trigaux Sep 29 2005, 05:37 PM

Alas this is often true.

I think science should be learned into primary school, there is no need to be a graduate to understand most basic facts. People understanding the world in which they are living are, I think, less prone to violence or fanaticism.

About environment, it is often scientists who first ring the alarm. Only after environmentalist develop these concerns in a more pro-social perspective. So ecology owes nearby everything to science. But despites this I knew environmentalist who were really anti-science. And really uninformed about it.

Posted by: Richard Trigaux Sep 29 2005, 05:47 PM

Pu238 undergo a very small percentage of spontaneous fission, see http://environmentalchemistry.com/yogi/periodic/Pu-pg2.html even more than Pu239. So we can expect that there are neutrons. I also remembered when I worked about this I saw a Cassini radiation map, indicating a neutron flux centered on the RTGs. Weak, but enough to damage certain electronic parts in the long run. This is the reason why the RTGs are often mounted at the end of long booms. For NH it is much closer, I am astonished. Perhaps electronic components are better today.

Posted by: BruceMoomaw Sep 30 2005, 12:18 AM

"... I distinctly remember seeing and hearing a women in a news report leading upto the launch saying they 'had embarked on a campaign on misinformation' to get NASA's attention. How can you expect people to make a decision on an issue when they're being lied to? As much as I support environmental concerns and issues, enviromental groups are notoriously loose with scientific facts - thanks in part to the public's disinterest and ignorance of science."

Unfortunately, they are hardly alone in that regard. It was Dean Acheson -- remembered as being one of the more enlightened Secretaries of State -- who said that the government frequently has the obligation to make things "clearer than the truth" to the voters in order to get their support for its Enlightened Policies.

Posted by: ljk4-1 Sep 30 2005, 02:18 AM

In the same vein - Jeff Foust once relayed to me that he attended an anti-Cassini rally in Cambridge, MA in 1997, just before it was launched. He was the only pro-space person in attendance. One woman actually told him that she did not want to know the facts, as she had already made up her mind about Cassini and because it was nuclear-powered, it was therefore bad and had to be stopped.

And we wonder why truly intelligent beings from other worlds will not contact us.

Posted by: Mark6 Sep 30 2005, 02:32 AM

Carter pronounced it the same way, and he is an actual nuclear engineer!

Posted by: spfrss Sep 30 2005, 07:06 AM

If you go to

http://www.pluto.jhuapl.edu/overview/deis/intro.html

you can read the Draft Environmental Impact Statement about NH

Live long and prosper

Mauro

Posted by: Richard Trigaux Sep 30 2005, 07:15 AM

There is not only Pu238 in the RTGs. Pu238 is not produced from isotopic separation from other Pu isotopes. This process would be very difficult and anyway not complete, lefting an amount of Pu239 and even Pu240. It fact it seems that they start from Neptunium. There are only two "stable" isotopes of Np: 236 and 237, and they are much easier to extract from ordinary nuclear wastes of electricity reactors. Then they irradiate this neptunium into a special nuclear reactor, where it absorbs neutrons until it forms Np238 which quickly beta decays into Pu 238. But the time this pu238 remains in the reactor, it can in turn transmute into Pu239 and even Pu240. So whatever the method, there is a percentage of Pu239 in the Pu238. They certainly try to minimize it, as it does not produce heat, but it cannot be completelly avoided. It is like that, in nuclear physics even a theoretically "clean" reaction often has parasitic minority paths which can be very harmful.

So the presence of Pu239 is enough to explain that the RTGs emit neutrons. The other rays (alpha or beta) are damped by the casing before reaching the thermocouples.

Another consequence of this is that the RTGs are not just recycled nuclear wastes, they require the production of other nuclear wastes to be manufactured, so they arise the same issues than the nuclear reactors. The only white point is that the RTGs fuel cannot be used to make bombs, in case it falls into bad hands.

Posted by: ljk4-1 Sep 30 2005, 02:33 PM

When Blair was interviewed about the Huygens landing on Titan, he readily confessed he wasn't into science in school and learned very little on the subject as a whole as a result.

It's sad how when it comes to science, people almost brag about their ignorance on the subject. May explain the current state of the world.

Posted by: Richard Trigaux Sep 30 2005, 07:07 PM

It is still worse than that: Huygens is not just about science, it is our first landing on a completelly unknown world, ant it has many enthraling philosophical implications and is a mater of strong poetical/existential emotion. And these concerns are for everybody, not just for scientists or amateur astronomers like on this forum. I wonder if people who feel nothing about space exploration are really incarnated on our planet, or if they are hovering somewhere above (or under). "Ooooh, Huygens, it is about Saturn, so it is about science, very complicated, headache and all, oooh" (This post is not specially aimed at Mr Blair and other politicians, there are many street populists who are much worse)

Posted by: mchan Oct 4 2005, 03:35 AM

In the latest PI update, Alan Stern describes NH's journey to KSC including a close encounter with a reckless driver.

http://pluto.jhuapl.edu/overview/piPerspective_current.html

Mike

Posted by: Richard Trigaux Oct 4 2005, 08:58 AM

Frightening to think that the Pluto mission could have finished in a traffic crash. A meteorite in space w<ould be more romantic.


The classification of reckless drivers encounters:
First kind close encounter: just fear
Second type close encouter: bolts and nuts smashed.
Third type close encounter: humanoids injuried.

Posted by: Rob Pinnegar Oct 4 2005, 05:12 PM

Heh, heh. Funny how this dovetails nicely with the sub-thread Mike started a while back. Buddy was probably rushing home to avoid missing this week's WWE Smackdown. He'll probably never know how close he came to actually doing something significant (although in a negative way).

It's a pity that the cops weren't able to pull him over. It can't be often that they get the opportunity to ticket someone for endangering a United States spacecraft.

Switching topics: Does anyone happen to know how reliable the launch vehicle for New Horizons (Atlas-Centaur-STAR) is thought to be? How many previous missions have used this configuration?

Posted by: mchan Oct 5 2005, 04:01 AM

No previous mission has used the exact configuration that NH is using (Atlas-V with 5 SRB's, Centaur, Star-48). The NH FEIS gives a estimate of 93.8% of a "successful launch leading to Pluto trajectory". That number was calculated before the successful launch of MRO, so a revised calculation with the other factors unchanged will yield a higher estimate of success.

There have been 6 launches of Atlas-V to date, but the first time for a new configuration always has the potential for something that was not thought of beforehand. This launch will likely have more than the usual reviews to reduce the potential of missing something.

-Mike

Posted by: Richard Trigaux Oct 5 2005, 01:22 PM

Posted by: djellison Oct 5 2005, 10:17 PM

Lots of posts deleted - it had all got far too political and personal.....consider lots of wrists slapped!!


Doug

Posted by: hal_9000 Oct 12 2005, 07:47 PM

Exploring NASA Links, I found a link for New Horizons' clean room....
Feed is here:




Good Watching...

Posted by: ljk4-1 Oct 14 2005, 06:06 PM

MISSION: New Horizons
LAUNCH VEHICLE: Lockheed Martin Atlas V 551 (AV-010)
LAUNCH PAD: Complex 41
LAUNCH SITE: Cape Canaveral Air Force Station, Florida
LAUNCH DATE: Jan. 11, 2006
LAUNCH WINDOW: 2:07 to 4:07 p.m. EST

The Centaur stage was hoisted onto the Atlas booster on Tuesday, and
mating should be completed by this weekend. New Horizons spacecraft
testing and processing activities in the clean room are on schedule.
The instrument to measure the solar wind around Pluto was installed
in the spacecraft and tested Oct. 6. Spacecraft communications
testing with Deep Space Network tracking stations is scheduled for
tomorrow and Saturday.

Previous status reports are available on the Web at:

http://www.nasa.gov/centers/kennedy/launchingrockets/status/2005

For information about NASA and agency programs on the Web, visit:

http://www.nasa.gov

Posted by: RNeuhaus Oct 19 2005, 10:36 PM

New update about NH. Good detail about 7 science instruments.

# Alice - an ultraviolet imaging spectrometer that will probe the atmospheric composition and structure of Pluto.

# Ralph — a visible and infrared camera that will obtain high-resolution color maps and surface composition maps of the surfaces of Pluto and Charon.

# LORRI, or Long Range Reconnaissance Imager — will image Pluto's surface at football-field sized resolution, resolving features as small approximately 50 yards
across.

# SWAP, or Solar Wind Around Pluto — will measure charged particles from the solar wind near Pluto to determine whether it has a magnetosphere and how fast its atmosphere is escaping.

# PEPSSI, or Pluto Energetic Particle Spectrometer Science Investigation — will search for neutral atoms that escape the planet's atmosphere and subsequently become charged by their interaction with the solar wind.

# SDC, or Student Dust Counter — will count and measure the masses of dust particles along the spacecraft's entire trajectory, covering regions of interplanetary space never before sampled.

# REX, or Radio Science Experiment — a circuit board containing sophisticated electronics that has been integrated with the spacecraft's radio telecommunications system, will study Pluto's atmospheric structure, surface thermal peperties, and make measurements of the mass of Pluto and Charon and KBOs.

http://www.spacedaily.com/news/outerplanets-05o.html

Rodolfo

Posted by: Richard Trigaux Oct 20 2005, 05:28 AM

What will New Horizons do near Pluto?

Just a fly-by or satellize?

And, eventually, after, will it try to reach other objects, or will it just escape on an interstellar trajectory?

I know that satellizing around Pluto is more difficult than around Saturn, but if we accept the price it can be done.

Posted by: mchan Oct 20 2005, 05:56 AM

The New Horizons website has a good summary and more --

http://pluto.jhuapl.edu/mission/mission_timeline.html

Getting into orbit around Pluto is _much_ more difficult than it is for Saturn. For a short time of flight, the flyby speed will be high. And Pluto has very little gravity to help compared to Saturn. You would need an incredible amount of fuel or exotic propulsion.

Posted by: Richard Trigaux Oct 20 2005, 01:24 PM

OK, a fast fly-by, and perhaps an attempt to rendez-vous another small Kuyper belt object in the following years.

Posted by: RNeuhaus Oct 20 2005, 01:25 PM

The mission of NH is not only focused on the binary Pluton and Charion but also of the remants of Kiups Belt. Up to now, it is still unknown which them the NH will visit. Hence, now, 15 years away, it is still to early to identify them. Hence, its fly-by trip will last up to 2-3 hours to cover all 6 of 7 (Alice, Raplh, LORRI, PEPSSI, SWAP, and REX) science instruments on them.

Rodolfo

Posted by: BruceMoomaw Oct 20 2005, 09:03 PM

Alan Stern says its RTG fuel -- although less than originally planned -- can keep it working for about 10 years after the 2015 Pluto flyby. Hopefully that's enough to get at least one flyby of a small additional KBO (as yet unidentified) -- or two of them, if we're really lucky.

(That's still almost a decade less than the two Voyagers have already worked! I wonder how long NH could be kept working and sending back data from just its three instruments that are relevant to deep-space observations.)

Posted by: Comga Oct 25 2005, 04:53 AM

They (and all of us) would have to be extremely lucky to get two KBO targets. The limitation is not RTG power, but fuel. The odds on being able to divert to one KBO target are supposed to be good, but not so the odds on discovering two KBOs pretty much in line. The spacecraft can only turn its path something like a degree or two. That's a pretty narrow cone in which to discover targets.

Posted by: punkboi Oct 26 2005, 06:05 AM

HAHAHA! So true

Posted by: imran Oct 29 2005, 12:42 AM

http://today.reuters.com/news/newsArticle.aspx?type=scienceNews&storyID=2005-10-28T183101Z_01_SCH865244_RTRUKOC_0_US-SPACE-PLUTO-WILMA.xml

Posted by: BPCooper Oct 29 2005, 04:50 PM

The rocket itself was not damaged, don't trust Klotz. Just some ground equipment.

Posted by: Redstone Oct 29 2005, 05:16 PM

As we get closer to launch, I thought post this chart of New Horizon's Launch window. It's taken from the http://www.lpi.usra.edu/opag/oct_05_meeting/new_horizons.pdf



The prime window is only 17 days long. After that, NH's arrival at Pluto gets later fast. Amazingly, the later part of the window sents NH on a Pluto-direct trajectory. No gravity assists. Even considering the longer flight time, and the fact that the mission involves a lot of rocket for a little spacecraft, a direct throw out of the solar system is pretty impressive. Hopefully, it won't be needed!

If the window is missed completely, then NH will launch in 2007, and we'll have to wait to 2019-2021 to see Pluto.

Fingers crossed!

Posted by: BPCooper Oct 29 2005, 05:59 PM

Thank's for posting that. I assume that the day-by-day vs arrival year is based on how close to Jupiter it winds up coming; and then later, Pluto's distance? The impression given on the NH website is that immediately after Feb 2nd it jumps to 2019 (and that before and after there are no variances).

Posted by: Alan Stern Oct 29 2005, 07:26 PM

The plot shown is an old version of the launch window depiction. It should
not have been shown at OPAG, but little things like this happen.

Back in 2004, I realized that 28 Jan was very close to being able to make
2015, energetically. Our mission design team was thus able to make
28 Jan an Aug 2015 arrival. Just one month later than all the other 2015
arrivals, which are in July. We could even have moved some of the other 2016
days to 2015, but at the expense of our radio science, which requires a near
opposition geometry to minimize IPM scintillation; to preserve the
radio science, we stuck with 2016 July.

The bottom line is that about a year ago we moved the arrival for a 28 Jan '06
launch from July 2016 to Aug 2015, giving us 18 days total for 2015 arrivals.

-Alan

Posted by: BruceMoomaw Oct 30 2005, 06:53 AM

You got any word on how serious the possible storm damage to the booster was, Alan?

Posted by: Alan Stern Oct 30 2005, 10:34 AM

Bruce- It's only superficial. The threat to launch is the possible Boeing strike.

-Alan

Posted by: BPCooper Oct 30 2005, 04:55 PM

The Boeing strike should have no effect on NH processing (and certainly not Atlas processing). Like I said, there was no damage to the booster itself, only some ground equipment.

Posted by: Alan Stern Oct 30 2005, 05:10 PM

To the contrary, the Boeing strike could effect processing of our Boeing third stage.
We are actively working with KSC, Atlas, and Boeing, to mitigate possible effects,
but there is no guarantee.

-Alan

Posted by: BPCooper Oct 30 2005, 05:33 PM

That's right, I forgot about that. Thanks. I shouldn't doubt you of course :-)

The stage itself is Thiokol, by the way, but I know it has a Boeing spin table and adapter attached.

Posted by: ljk4-1 Oct 31 2005, 05:31 PM

At an interview regarding the Huygens landing on Titan, Blair admitted he learned very little science in school and did not care for the subject.

Par for the course for most political leaders. Which goes a long way towards explaining the state of things in the world, along with a certain US leader who thinks kids having to learn ID along with evolution is a "fair and balanced" idear.

Posted by: BPCooper Nov 2 2005, 10:49 PM

http://spaceflightnow.com/atlas/av010/051102srbreplace.html

Article noting the SRB replacement. This differs from what I was told, in fact it differs from what KSC PAO said (that there was no noticible anything, even a scuff, on the rocket and that the SRB replacement was purely for precaution). Apparently there was a tiny ding.

Regardless, they said today there will be no impact to the launch date.

Posted by: BPCooper Nov 5 2005, 02:24 AM

I had the privelege to go inside the clean room at the PHSF today to photograph New Horizons, and I thought I would share my photos:

http://www.launchphotography.com/NewHorizonsProcessing.html

It was a pleasure meeting Alan and the other members of the NH/APL team.

Posted by: mike Nov 5 2005, 02:39 AM

It's amazing to me that such humble-looking machines are the first man-made objects to travel so far. The king of Spain couldn't send out a little probe to determine whether there was a quick route to India. And yet, these humble-looking machines will show us things we could never have imagined (until we see them, and then it will all be perfectly obvious, but I digress), and New Horizons will likely outlive me (and you, and that other guy).

Thanks for the pictures.

Posted by: ljk4-1 Nov 5 2005, 04:27 AM

Will anything of note other than a microchip full of names be placed on NH before it is launched?

Posted by: dvandorn Nov 5 2005, 09:21 AM

I'm impressed by NH's relatively small physical size. As someone who remembers the early Mariners and such, it's an interesting comparison. There's a huge amount of sensing capability packed into that thing, which is no larger than the Voyagers.

In fact, it looks to me to be perhaps smaller than the Voyagers, overall.

NH looks like a 21st-century space probe, all right!

-the other Doug

Posted by: mchan Nov 6 2005, 04:30 AM

Great photos. Thanks for sharing.

For seeing the launch in person, is the view better from Jetty Park or from along the Indian River due west of complex 41?

What is the launch azimuth for the NH launch?

Thanks,
Mike

Posted by: mchan Nov 6 2005, 04:39 AM

Voyager's HGA dish appeared to be larger than the main spacecraft bus structure, while NH's main structure appears slightly larger than the HGA. Voyager also had the boom mounted scan platform and RTGs vs all body mounted for NH. Oh, and Voyager had a mag boom which was cut from NH.

It would be interesting to see a side by side to scale graphic showing all the spacecraft that are or will be on solar system escape trajectories.

Mike

Posted by: mcaplinger Nov 6 2005, 04:39 AM

I don't know for sure, but I think the view from Jetty Park of LC41 would be pretty bad. LC41 is way north, very close to LC39. I would think any good site for a Shuttle launch would be better for LC41. It's not like a Delta launch, where the view from Jetty Park is probably as good as from the VIP site.

We watched the MRO launch from the causeway site and it was OK.

Posted by: BPCooper Nov 6 2005, 04:13 PM

No, not Jetty Park, you cannot see the pad from there.

Your best bet is Port Canaveral/cruise ship terminals, outside of CCAFS Gate 1. That is the closest spot at about 12 miles away.

Alternatively you could watch from Titusville along the river, but that is nearly 14 miles away. Unfortunately 41 is the furthest pad for watching a launch from if you are viewing outside the gates.

Playalinda Beach/MINWR had been open for every Atlas 5 launch through Inmarsat earlier this year...it's just 4.5 miles from the pad out there (almost as close as the press site is). But at MRO, NASA had it closed. So presumably, if it's a NASA payload NASA will order all of KSC property closed including Playalinda.

Posted by: ljk4-1 Nov 7 2005, 03:06 PM

It is sad that there are so few poets on this site.

Only the fifth probe ever being sent out of our solar system - 28 years after the Voyagers - and nothing more than a US flag and a microchip full of names on it to serve as any kind of "greeting" to either our distant descendants or starfaring ETI who may find it one day.

Anyone going to do something about this? The Voyager Records were "rush" jobs, but they made it. And they did it without the Web or even cell phones to facilitate things.

Why hasn't The Planetary Society said word one about doing something?

And speaking of lack of poets and poetry, what is with the lame names given to US space probes these days? New Horizons? Deep Impact? Mars Observer? My, how obvious and uninspired. Why don't we just name them Big Metal Shiny Things Sent Into Space on a Rocket. There are plenty of relevant explorers and astronomers who deserve some kind honor by having their names on our robot adventurers.

Posted by: djellison Nov 7 2005, 03:09 PM

We disagree on the pros and cons of bolting messages onto spacecraft - but that's an opinion issue.

However it is outside the realm of opinion and simply a matter of what is or is not possible. It is TOO LATE to put something on NH.

Doug

Posted by: ljk4-1 Nov 7 2005, 03:14 PM

I guess that's my question then - why didn't SOMEBODY think of doing it when there was time? Does anyone honestly think that a US flag or a bunch of microscopic names are going to mean anything to anyone way out there in space and time?

There should be some kind of committee/organization that has definite plans for important information to be placed on all missions beyond our Sol system. I will be glad to help with such a concept when and where needed.

What a waste of an opportunity.

Posted by: ugordan Nov 7 2005, 03:26 PM

And what happens when such a probe blows up on the launch pad? No honor there, but you waste a good name.
I suppose I can totally understand the Japanese and their habit of renaming their spacecraft once they're up and about.

Posted by: ljk4-1 Nov 7 2005, 03:30 PM

So let us adopt the Japanese tactic and change it on the way. That is fine with me.

Or you can add a 2 to the next probe. Works for me too. Shows we don't give up from a few setbacks. And the person gets to be on TWO spacecraft.

Posted by: mike Nov 7 2005, 06:19 PM

Who's to say what some alien species will think of our microchip when they find it? Maybe they'll think it's the Magical Word of God, or maybe they'll think it's recipes, or lists of star names, or the people who built the probe, or a table of some obscure scientific data that they'll someday be able to decipher, if they just keep trying, and trying, and trying some more..

A microchip with names on it could very arguably be more interesting than a simple gold phonograph and line etchings of naked people.

Poetic enough?

Posted by: ljk4-1 Nov 7 2005, 07:12 PM

No, it isn't.

Posted by: mike Nov 7 2005, 08:08 PM

Ah. It's easy to complain and never actually do anything yourself.

Posted by: ljk4-1 Nov 7 2005, 08:16 PM

I already offered to do what I could in the endeavor of placing relevant and detailed messages onbiard deep space probes, but apparently the so-called powers that be have no interest in such things.

Do you have any means of making such things happen? If all I am able to do is make some noise to make things happen, then so be it.

Posted by: mike Nov 7 2005, 10:41 PM

I probably have no more means than you. However, I'm not sure how any alien species will be able to decode any written language at all, and images might just be confusing. Ultimately I think putting anything on the probe is useful, whether it be names, a diagram of our solar system, sound clips of Eminem, sensors, engines, transmitters, software, DNA (inevitably)...

Posted by: Comga Nov 8 2005, 04:29 AM

Alan Stern talked about putting a few objects in New Horizons. One of them was to honor Clyde Tombaugh, who discovered it. Don't know if any item actually made it.

Posted by: Comga Nov 8 2005, 04:31 AM

Oops. I meant to say that Clyde Tombaugh discovered Pluto, of course.

Posted by: mchan Nov 8 2005, 05:46 AM

Latest PI update --

http://pluto.jhuapl.edu/overview/piPerspectives/piPerspective_current.html

The RTG is coming in at about 200 W, a bit higher than the 190-192 W stated earlier. It's all good according to the link above.

Posted by: ljk4-1 Nov 8 2005, 02:12 PM

I wrote to John S directly about the message issue on NH. He kindly responded after talking to Alan Stern. He said they did consider putting some kind of message/information package on NH but felt that the politics and other legal wranglings were not worth it, plus budgetary issues were involved. John said it is too late to put anything new on NH now.

At least they did seriously consider it. I think this is also why an independent committee should be formed working with NASA and any other space agency that plans to launch probes into interstellar space to create messages/info carriers for those future vessels. This may help to avoid giving the mission team any extra issues beyond the usual ones in making space probes.

John did not mention anything about a Clyde Tombaugh momento, but I will ask him. I certainly think it should happen with CT of all people. If they could put Gene Shoemaker's ashes on Lunar Prospector....

Posted by: edstrick Nov 9 2005, 08:02 AM

Looking at the icon of the Pioneer message, I'm amused and frustrated by the memory of a wonderful T-Shirt I saw about 15 or 20 years ago at a WorldCon (World Science Fiction Convention).

Some fan was wearing a T with a almost replica of the Pioneer image, but the graphic had been modified to change the male and female humans to male and female Pink Panthers!

I *wanted* a copy of that shirt and gave him my name/addr so he could tell me where he found it, but I never heard from him and never got one.

Posted by: Comga Nov 10 2005, 04:36 AM

That's great news about the RTG. On that link, Alan talks about how it will directly contribute to higher reliability at Pluto and the KBO fly-by.

Also a report of steady progress on the rocket from:

NASA EXPENDABLE LAUNCH VEHICLE STATUS REPORT: E05-017

Mission: New Horizons
Launch Vehicle: Lockheed Martin Atlas V 551 (AV-010) Launch Pad: Complex
41, Cape Canaveral Air Force Station, Fla.
Launch Date: Jan. 11, 2006
Launch Window: 2:07 to 4:07 p.m. EST

The fit check of the Radioisotope Thermo-electric Generator power system
with the spacecraft was performed this week. The generator will be
installed at the launch pad. The spacecraft was weighed this week, and
it will undergo a "dry" spin balance test Nov. 13-15.
Hydrazine fuel for attitude control and course correction maneuvers will
be loaded Nov. 17-19. A "wet" spin balance test with fuel aboard is set
for Nov. 22-24. Two solid rocket boosters were attached to the Atlas V
this week. Four of the five are mated. The last booster will be erected
in December. For prior status reports, visit:

http://www.nasa.gov/centers/kennedy/launchingrockets/status/2005

Posted by: mchan Nov 10 2005, 05:12 AM

And here's hoping they get additional margin on the fuel load as well. More gas for more flexibility in the encounter maneuvers.

Posted by: Redstone Dec 1 2005, 06:43 PM

The STAR-48 third stage has arrived at KSC. If you look at the http://pluto.jhuapl.edu/gallery/webcam.php, you can see technicians working on it right now.

News article http://www.floridatoday.com/apps/pbcs.dll/article?AID=/20051201/BREAKINGNEWS/51201010

Edit: Looks like the techs are done for the day. You can see views of the kickstage on the NH webcam and at the http://science.ksc.nasa.gov/shuttle/countdown/video/.

Posted by: hal_9000 Dec 1 2005, 10:12 PM

Do anybody have the schedule of this week?

Posted by: BruceMoomaw Dec 1 2005, 10:35 PM

The one thing they still seem seriously afraid of is the possibility that a problem will emerge with the third stage requiring intervention by Boeing technicians (who are still on strike).

Posted by: Redstone Dec 2 2005, 02:59 AM

http://www.nasa.gov/centers/kennedy/launchingrockets/status/2005/elvstatus-20051129.html is:

Dec 4 Hydrazine Loading
Dec 5 Atlas V tanking test
Dec 6-7 "Wet" spin balance testing
Dec 9 Mating of NH and 3rd Stage
Dec 12 Encapsulation of NH stack inside fairing
Dec 16 Transport of stack to pad.

Launch still scheduled for Jan 11.

Alan may drop by with more detail if we're lucky. I'd like to know whether they have decided how much hydrazine to load, and what that means for the extended mission.

Posted by: Alan Stern Dec 2 2005, 11:14 AM

I guess you got lucky-- I checked in on the discussion this a.m.!

Have you seen the KSC pix of the Atlas and third stage? There
are some very nice ones.

I am at APL this week for various meetings. Today is the formal flight ops
review.

Yesterday afternoon we decided on the hydrazine load. The max we could
possibly load is 80 kg of fuel+pressurant. This is set by a limit on the third
stage+NH mass relating to spin stability during third stage. The minimum
for the mission requirements is about 60 kg. Every kg of hydrazine
corresponds to about 4.5 m/s of onboard DeltaV. We came in a little light
on the s/c, allowing us to go to 77 kg, so I'm very happy.

As to Bruce's comment about the project being concerned about third stage
problems, I'd like to know where he heard that. I am at the Cape
half my life it seems, and at APL the other half, with HQ squeezed in
in the third half, and I'll tell you the concern Bruce expressed has never
been mentioned to me or in my presence.

-Alan

ps. Your schedule looks pretty close to reality.

Posted by: BruceMoomaw Dec 2 2005, 12:27 PM

I got it directly from Andy Dantzler at the COMPLEX meeting, after asking him a question about what effects the Boeing strike might have on the launch. He did say, though, that it was unlikely.

Posted by: Alan Stern Dec 2 2005, 12:32 PM

Andy knows better.

Posted by: Redstone Dec 2 2005, 02:28 PM

Good news! I hope this gives you a big search volume in which to look for target KBOs beyond Pluto.

The KSC site now has some hi res pictures of the 3rd stage. Not a very pretty piece of hardware, but built for speed.

Posted by: yaohua2000 Dec 10 2005, 09:39 PM

Farthest ever distance from Pluto on December 17

New Horizons is scheduled to be transported from Payload Hazardous Servicing Facility at Kennedy Space Center [28 30' 36" N 80 38' 51" W] to Launch Complex 41 at Cape Canaveral Air Force Station [28 35' 00" N 80 35' 00" W] on December 16, 2005. The first launch window should be open between 19:11 UTC to 21:07 UTC on January 11, 2006.

So if the transportation to be on time, the spacecraft will be 4790263643 kilometers away, the most distant ever, from Pluto at 2005 Dec 17 05:58:47 UTC.

However, if the spacecraft at Payload Hazardous Servicing Facility without transportation to the launch complex, the farthest distance should be 4790263646 kilometers and occurs at 2005 Dec 17 05:58:58 UTC.

(Data from JPL Horizons, instantaneous distance without light-time correction)

Posted by: PhilCo126 Dec 11 2005, 04:56 PM

Still some questions on the New Horizons spacecraft ...

1. What will be the overall weight of the spacecraft ( how much of that is propellant ) ?

2. The JPL webpage states that the spacecraft is both 3-axis stabilized AND spin-stabilized ???


3. Any message(s) or special logo(s) on the outside of the spacecraft ?

Thx in advance,
Philip

Posted by: Alan Stern Dec 11 2005, 05:08 PM

1. What will be the overall weight of the spacecraft ( how much of that is propellant ) ?

478.325 kg, 76.84 of which is fuel, and 0.16 kg of which is He pressurant.


2. The JPL webpage states that the spacecraft is both 3-axis stabilized AND spin-stabilized ???

This means it is versatile and designed to fly in either mode. 3-axis for most pointed
science observations, and spin stabilized to save prop during most of cruise.


3. Any message(s) or special logo(s) on the outside of the spacecraft ?

Just two small American flags; big logos and flags on the Atlas, however.

-Alan

Posted by: PhilCo126 Dec 11 2005, 06:21 PM

Thank You for the fast reply Alan ... Many webpages state that the spacecraft is limited to 465 kilograms, the payload capacity of the Atlas V

O.K. I thought it would be able to fly the probe in both modes, I guess it's the first spacecraft to do so ?

Do You know anything of the computing hardware onboard ?
( memory size, RAD750 microprocessors, etc ... )

Philip

Posted by: punkboi Dec 11 2005, 06:27 PM

I heard the spacecraft uses an Ultra DMA hard drive and a 2.20GHz AMD Athlon processor. Just joking.

Posted by: Alan Stern Dec 11 2005, 06:30 PM

Phil--

Thank You for the fast reply Alan ... Many webpages state that the spacecraft is limited to 465 kilograms, the payload capacity of the Atlas V

> That was originally the case but the 3rd stage came in 13 kg light, so about a
year ago we used that windfall to let NH grow a little and thereby carry more fuel
that nit might have.

O.K. I thought it would be able to fly the probe in both modes, I guess it's the first spacecraft to do so ?

> No, it's not uncommon on outer planet missions.

Do You know anything of the computing hardware onboard ?
( memory size, RAD750 microprocessors, etc ... )

> I'll post some information or a link once I make sure it's not an ITAR
> issue.

Philip

[/quote]

Posted by: Jeff7 Dec 11 2005, 06:35 PM

That's it? Seems kind of small. About 70% of the mass of each of the Voyager probes (fuel included), and puny compared to Cassini. Just so long as it gets the job done.

Posted by: Alan Stern Dec 11 2005, 06:47 PM

We made it as light as possible so the launcher could give it the maximum speed
possible.

Posted by: PhilCo126 Dec 11 2005, 07:44 PM

Thanks again for Your reply Alan, I fully understand the Int Traff Arms Reg issue certainly nowadays ...
Could You point out the different bands of telecommunications and the approx diameter of the large antenna ?
How long would telecom be underway from Pluto to Earth ?
Philip

Posted by: Alan Stern Dec 11 2005, 08:57 PM

Phil,

2.1 meter HGA diameter.

X band.

10 Gb of data back to Earth at 768 bps. You can do the math! The lossless
compression is near 1.8:1.

-Alan

Posted by: ugordan Dec 11 2005, 09:29 PM

Ouch! Talk about putting the long cruise time afterwards to good use!
Why such a large reduction in the bitrate? Cassini IIRC has a 20 watt transmitter and a somewhat higher diameter HGA, but even when the larger distance is taken into account NH bitrate still seems abysmally small?
Is the 768 bps science telemetry or total rate?

Btw, sorry for this barrage of questions here, we're just very curious

Posted by: Alan Stern Dec 11 2005, 09:46 PM

That's 2.5x what PKE would have delivered from Pluto: 300 bps. All I can say is it does the job, and it's all we could afford for power and HGA mass.

-Alan

p.s 768 bps is the total bit rate, spec'ed at 32 AU geocentric distance. We might get
50% better once we cal in flight and see how we're doing. It's slow, but it'll get us
the goods. I put my discretionary mass into instruments long ago.

Posted by: Vaughn Dec 12 2005, 02:07 AM

Hi Alan-
I've been doing some research for a paper model of New Horizons and saw in an old paper that it may be able to use the second half of the redundant radio system to double the data rate. Any truth to this?

See you in Fl,
Vaughn

Posted by: Alan Stern Dec 12 2005, 02:18 AM

Vaughn,

Yes, that is the plan, to get the radio occ in both two separate polarizations using the
two separate receiver-USO chains.

-Alan

Posted by: edstrick Dec 12 2005, 09:24 AM

Compared with 8 1/2 bits per second for Mariner 4 after Mars flyby... it took quite a while to send back 21 1/10th 200 by 200 pixel 6 bit images.

Dense data storage is so nice. Flyby missions have the luxury of taking 2 and a half forevers to send back their data. You do want some sample data at the last opportunity before flyby to see if things like exposures need tweeking or if there's a particularly distinct marking you want a maximum resolution image sequence retargeted to, but that doesn't require a dataflood.

Posted by: PhilCo126 Dec 12 2005, 11:36 AM

Looking forward to see some details on the Computing bits & pieces of NH

By the way, was New Horizons built in-house at NASA-JPL or by some contractor ?


( Design was by John Hopkins Applied Physics Laboratory ... was it built at that University ? )

Posted by: punkboi Dec 12 2005, 07:57 PM

I do believe it was built at APL...much like the NEAR spacecraft

Posted by: ljk4-1 Dec 12 2005, 08:06 PM

What is the farthest distance (and currently planned date) New Horizons will be from Pluto before it can start returning useful images of that planet/comet and its moons/minicomets?

And by useful I mean better than what we can currently see from Earth.

Thank you.

Posted by: djellison Dec 12 2005, 08:24 PM

NH will be able to see Pluto at a resolution better than that of the HST from 12 weeks before fly-by



Doug

Posted by: djellison Dec 12 2005, 08:29 PM

I am reminded of an episode of Father Ted....

The idiotic Father Dougal can not understand why the little model cow on the window ledge looks to be the same size as a real cow a few hundred meters away on a hill, and the long suffering Father Ted tries to explain it...

Ted : Now concentrate this time, Dougal. These (pointing to plastic cows on table) are very small; those (pointing out of the window) are far away...
http://www.geocities.com/TelevisionCity/Studio/1728/sounds/small.wav


Now concentrate....Alan's head is small, and NH is FAAAR away...


Lovely photo - kudos to which ever KSC/JHU/Press person took it, it's the sort of thing you'd put on your wall, and in 20, 30 years time show to young relatives "this is what we did in 2005"

Doug

Posted by: punkboi Dec 12 2005, 08:46 PM

I read somewhere that within 12 weeks prior to close encounter New Horizons will be able to take images that far exceed the resolution of Hubble's photos.

And New Horizons will begin observations 4 months to closest encounter.

EDIT: Thanks djellison, I got my info from that chart

Posted by: Steffen Jan 10 2006, 06:14 AM

Just noticed Alan on this website:

http://www.spaceflightnowplus.com/index.php

Posted by: abalone Jan 10 2006, 10:11 AM

Alan, just dont forget to let go when they light the fuse.