What will be the maximum data transmission rate at Jupiter?

315 days to first launch opportunity

New Horizons does have much more storage capacity than Cassini. So it could perhaps store a lot of stuff onboard for more boring parts of the cruise.

New Horizons will be able to transmit at 37 Kbps from Jupter, and a little over 1 Kbps from Pluto. The s/c has redundent 64 Gbit solid state recorders.

As to Jupiter imaging resolution, color images made near closest approach (C/A) will be
of a resolution comparable to the Cassini image posted above. Panchromatic images will be about 3X better. However in both cases the imagers are very senstivie, having
been designed for optimal perfomance at 32 AU. As such, there is likely to be
overexposure in regions away from the terminator near C/A.

You mentioned a distant Centaur flyby. Assuming the launch date doesn't change, what do you mean by distant? 1 million km? 50 million km?

Ted,

2002 GO will be 2.7 AU awa-- good OpNav practice and a chance to get a solid phase
curve. We will search along the path for better (closer) candidates after launch, but
Monte Carlo sims tell us not to expect anything close enough to generate real maps
unless we get incredibly lucky.

Has any thought been given to what Kupier Belt objects might be encountered after launch? How close might those flybys be? Or does that also depend on the launch date?

A lot of work has gone into KBO flyby planning. NH1 can probably only get
to 1 or maybe 2 KBOs, and those will be small, i.e., Eros-sized or a bit
smaller. This is because after we leave Pluto-Charon, we can only
maneuver 100 m/s or so off this course, which means turning only ~0.1 deg.

(NH2 can hit a large KBO because we can target it from Jupiter or Uranus
as the "substitute" first target for Pluto.)

We will not choose the first NH1 target KBO until about 2012, because
we will have much better knowledge of KBOs by then in general, and
the possible targets along our trajectory in particular.

-Alan

Now leave the man alone so he can go and finish it before Jan '06

Doug

Doug- Thanks, I do have a day job-- in fact, three of them by last count. Maybe I should assign someone to do Q&A with this site. The questions are good ones.

-Alan

I think I speak for everyone here in saying that we greatly appreciate your taking the time to answer our questions.

I second that.

Let me also chime in that your presence on this board is most awesome!

I think Pluto holds a special place in the public consciousness, being the "last" planet out there and the only one not directly visited by a mission yet. I have been waiting for a Pluto mission since I was a kid - and finally watching it happen, hearing the details in real time by no one less than the PI is wonderful. Tomorrow I am taking my 5th grade class to Send Your Name To Pluto and having them sign up... Let the Inner - Outer Solar System rivalry begin!

Perhaps we should start a thread and just submit questions to it - then if you can find someone appropriate Alan - I can string them together into a coherent set of questions that 'tell the story' fire them off in an email and then report back here?

Doug

I think it's great to have you onboard Alan. It's so cool to be able to ask questions to the people actually working on the mission and get a response within a day. Compared to these days, Voyager happened in the dark ages. You had to wait a month for a magazine to see the first results, and ofcourse that wouldn't anwser all the question you had. Internet is a great tool to make people enthousiastic about a mission and give them something back for the tax money they pay to fund the missions. I really like the MER and Cassini rawimages website as you can use them to create your own mosaics. I hope New Horizons will do the same. If you do so I think it would be great to include some target pointing and distance information in the filename as this would really help us amateurs to find matching images to create mosaics from. MER includes a lot of info in the filename which is great, Cassini does not which makes them harder to use.

A lot of visitors on this forum also hang out on IRC in #space at irc.freenode.net. Perhaps you would like to join some time for an interactive question and anwser session ?

Alan,

I also most appreciate your interest in our forum. Its fantastic to see the progress in building NH as a real spacecraft, after this long series of troubles.

Therefore I have my own special question - sometimes in the late 80s there was a mission called TAU on the drawboards of NASA I believe. It would have a ion engine to reach 1000 A.U. and this far away point should enabled the TAU-craft to obtain extremely precise astrometric measurements (parallaxes out to the Magellanic clouds!). Could NH accomplish some astrometric measures out to 50 A.U. ? Is the original TAU-craft still a secret project at NASA ?

Sometimes in about 10 years from now, ESA would fly the GAIA mission, also a precise astrometric mission, but near Earth.

regards
Robert

yes, it now seems to be the 400 AU Interstellar Probe concept ... lots of details here

Alan has written a new piece updating the status of NH and his feelings towards the project click here

I hope we'll see more photos before the thermal blankets cover the innards.

312 days left before launch window opens

Hi- this is John Spencer, frequent lurker (and occasional contributor) on this forum. I'm also a New Horizons science team member, and rashly volunteered to help Alan Stern get back to running the mission by helping him answer New Horizons questions here. So fire away...

We just had a meeting of the science team here in Boulder, and we are all starting to get psyched about the fast-approaching launch. Along with several other current team members I've been working on some version of this mission since the early 1990s, and we are so used to it being a distant and hypothetical idea that it's a shock as well as a thrill to have everything becoming so real so quickly.

Welcome john_s !

I must say it is refreshing to have real project people willing to subject themselves to this type of free for all discussion. It's not only an opportunity for those of us on the outside to interact and learn but also a way for us to feel a part of the adventure. Stand by for the first shot ....



NET 307 days to launch

Welcome John - let the interrogation begin!

Thank you, john_s, for taking the time to answer our questions.

According to the New Horizons website, NH will be 11,095 km from Pluto at closest approach. Isn't that inside the orbit of Charon since the pair is 19,600 km apart (according to here)?
I seem to remember that at one time, it was thought that Pluto's atmosphere may envelop Charon. Is that no longer considered likely or is the Pluto CA distance preliminary and can be changed via TCMs?

That's funny, we were just talking in the hallway yesterday about how we might get close enough to Pluto to detect some deceleration of the spacecraft due to Pluto's atmosphere- not sure yet if that's possible though I suspect the effect will be negligible. The atmosphere is indeed pretty extended, due to the low gravity, and one of the spacecraft's tasks is to estimate its escape rate via Pluto's perturbation to the solar wind. At 11,000 km altitude the atmosphere will pose no risk to the spacecraft.

You're right that we can easily change the flyby altitude, and the current value is just a working number. Coming closer gives better measurements of Pluto's gravity and solar wind perturbations, but makes imaging more difficult due increased smear rates and slew times.

Sports fans-- Updated NH mission and payload Powerpoints presentations have been posted at www.boulder.swri.edu/pkb

Enjoy.

Onward to 2006,
-Alan

Yummy, thanks!

According to the Mission Overview (24MB) the observatory phase begins C/A - 4 weeks and the post encounter studies last 2 weeks, why are these periods so different?

Outbound is less interesting. as Pluto is a crescent, and already explored at high-resolution on approach. About 2 weeks post-encounter we do the KBO targeting maneuver, and then begin the less hectic, final observation phase for pluto-Charon.

Thanks for the fast reply, too fast for this edit

Also there is no capability for the "search for magnetic fields" in the science tracability matrix of the Payload Overview (14MB) yet there is a solar wind particle detector, won't this instrument be able to indirectly detect the plasma sheet of Pluto's field if it exists?

Yes, very perceptive. Back in 2001, we carefully considerd but rejected flying a MAG on NH because it greatly complicates the s/c (booms, magnetic cleanliness, etc.).
However, SWAP (our solar wind particle detector) can potentially infer a mag field at
Pluto-Charon based on the particle flux trace through the system and the kinds of
solar wind disturbances/magnetospheric boundaries the instrument discovers.

There are several new NH downloads including an EPO poster at
www.boulder.swri.edu/pkb for those interested.

Thanks, Alan.

Time to buy more printer cartridges! Thanks, Alan.

Public Hearings Set for Pluto Mission




Good luck, Alan.

Thanks for the best wishes, enjoy the download candy.

Onward to 2006!
-Alan

Ahh - good 'ol Shake and Bake.

I saw the flight structure for a comm sat undergo a launch simulation shake about 7 years ago. Astonishing noise - the sort of noise that you can feel in oyur stomach. How such precise delicate machines can be designed to withstand extremes of acceleration, heat and pressue is one of the miracles of modern science.

Doug

Press Briefing To Be Held March 29 for Pluto New Horizons Environmental Impact Statement

These things always baffle me. Is it as if the launch will destroy the environment or something like that?

Not if the launch goes as planned, no. But any time you launch a spacecraft with plutonium on board, a launch failure has the potential (however remote) of introducing said plutonium to the environment. The E.I.S. is just a safeguard to make sure NASA has taken reasonable precautions against any negative environmental impact from plutonium handling before, during and after the launch.

I'm not one of the anti-nuke whackos, believe me -- I believe NASA does, indeed, take all reasonable precautions. But I also think it's a good idea to hold *anyone* using or handling such dangerously toxic materials as plutonium to a very high safety standard.

-the other Doug

I wonder what would happen if the public knew of all the military payloads that carry such things that never make the news in any way what soever

Doug

Honestly, I think a majority of Americans wouldn't care all that much. It's only a relatively small lunatic fringe here that is swayed by the anti-nuke Chicken Littles.

I may be a little overly optimistic, here, but I think a large majority of the general public understands that the risks of disaster are relatively tiny.

-the other Doug

Personally -- and speaking as someone who (to my continuing amazement) apparently did play a major role in getting NASA to reverse its original rejection of this probe, through my series of SpaceDaily articles (details on request) -- I remain very uneasy about launching something as toxic as Pu-238 unless it's absolutely necessary, and I would hope they can hold it to an absolute minimum in future missions. For instance, not a single one of the four proposed highest-priority New Frontiers concepts after New Horizons -- including the Jupiter polar orbiter -- requires it. I'm not wildly happy about their putting it on MSL; I think there might very well be ways to make a solar power system work effectively(including dust-cleaning mechanisms and concentrator mirrors).

Actually, I'm a lot less uneasy about orbiting nuclear reactors, since those use U-235 -- which is normally extremely non-radioactive -- as their fuel, and so don't start producing dangerous radioisotopes until they've actually been turned on and allowed to run a while. Put them into a high Earth orbit before you do that and they are no danger whatsoever.

Can you say "RORSAT"?

Redux an earlier post. While browsing through the summaries of the recent Lunar and Planetary Science XXXVI (2005) Conference this paper about maximizing mission science return caught my attention. It outlines a successful flight experiment onboard the EO-1 spacecraft called the Autonomous Sciencecraft Experiment (ASE).

This type of software based intelligence demonstrated the capability to make decisions on instrument targeting and to optimize the data stored and transmitted. For the critical close encounter phases of the mission this may be extremely valuable.

no less than 287 days before launch

During the jupiter flyby will we be doing Moon science?

I would love to see any surface changes on Europa since the Galileo Mission.

Yes, we'll be doing plenty of Jupiter moon science, though there are a few constraints that will limit what we can do. Primary constraint at the moment is limited onboard storage capacity, and the fact that we want to keep data management as simple as possible- we won't be able to do multiple write/download/erase/rewrite cycles on our solid-state-recorders, for instance. There's also the unusual problem that when your cameras are optimized to work at 30 AU, everything at 5 AU looks very bright, and we'll be saturating at minimum exposure on many of our targets. Our best views of Io are likely to be taken in Jupiter-shine rather than sunshine, for instance.

Despite these constraints, we'll be taking images and near-infrared spectra of all the satellites. Surface changes on Europa won't be a high priority, because the lack of changes between Voyager and Galileo epochs, in images at much higher resolution than we'll be able to get with New Horizons, make changes between Galileo and New Horizons unlikely. But we'll be cataloging surface changes, plumes, and hotspots on Io, and making near-infrared spectral composition maps of the satellites at higher spectral resolution than Galileo. We'll also be watching Jupiter eclipses of the satellites to study their atmospheres.

We can't make final plans till after launch, when we'll know the precise trajectory, the Jupiter flyby date, and the satellite viewing geometrys. Then we'll have a few months of hard work to come up with a detailed plan that makes the most of this unique opportunity.

Thanks for the quick answer!


As long as global imaging of Europa will be done, I'll be VERY happy!



I'm so excited about this mission.

Sorry, but it's unlikely that we'll get complete global imaging of Europa, because due to the overexposure problem we will only have a narrow strip of unsaturated terrain near the terminator in each image, so it would take too many images to build up complete coverage. Even on Io, where global imaging is higher priority, we probably won't achieve that goal. But we'll do our best...

Glad you're excited about the mission- so are we!

I want to see Io......

....I miss Galileo

I do too. I would like to see a Galileo-2 type mission. It could probably be developed more quickly than a Europa orbiter. With a high data rate and a very large data recorder, it could really send back some incredible shots. My bias against the Europa orbiter is basically my hands down rejection of the case that Europa is more interesting than the other moons. I think it is one member of a four part set that all need to be understood (in addition to the planet and inner moons) in order to understand the Jovian system (and outer moons, if they are not all captured asteroids).

I'm curious if there is a trajectory map is available threw the Jupiter system?


Also will any close encounters with asteroid's on the way out?



Sorry for all the questions, the main horizon page does not cover these questions in detail.

As John said - not until after launch. The exact launch date will define where the jovian moons will be at the flyby - and launch windows and elv's being what they are - the only time you can guarentee when you're going to leave the ground is when you've done it :0

Doug

With its 20cm scope NH will be able to perform a population survey of the Kuiper belt by direct imaging and by measuring dust debris, what search strategy will be used?

282 more days and nights before launch