I worked the Horizons system a bit more and get the following c/a times and distances. Most are pretty close to the timeline Liss provided, with the exception of Phoebe (arguably not a close approach in either scenario!). According to these numbers, the undiscovered near-miss moon would have been Epimetheus at a distance of 6676km ... or about 6 minutes 45 seconds, given their relative speed of 59,271km/h!
Disclaimer: Horizon states that the trajectory data are reconstructed to fit the observations and is thus probably not as accurate as trajectory data available for current missions. Nevertheless:

After consulting JPL's NSSDC and Horizons websites, it seems that Saturn closest approach was at
01 Sep 1979 16:29:34 UTC at an altitude of 20,591 km (using a Saturn radius of 60,268 km).

I will update my website in due course.

Pioneer 11 30 years ago ... now showing on my website at http://tinyurl.com/c6vopp

Aaaa nice one. Never heard of it. They dont do much advertising :-)

i remembered going to an exhibition like that when I was a child.

I was actually toying with the idea to propose to our dear politicians here in Australia to use one of the long Australian highways and their rest-stops to make a scale model of the solar system distances. On the 1600km Eyre Highway from Norseman WA to Port Augusta SA Earth would be 53kms from the starting point (if we go 30AU to Neptune). But probably it's a waste of time so I havent done anything about it.

congrats from me as well ... have fun!

I sent a Twitter message (tweet) to AMES with that question. They have just answered: don't know myself, but can ask around. ...

EDIT 29/04: another tweet came back: "I asked our news chief here at Ames about the Pioneer but he is not aware of any celebrations.".
Anyway, I will try to create a historic simulation for the flyby.

Thanks Liss & all other for these beautiful timelines. I have taken the liberty to include them in the timelines on my website for Pioneer 10 and Pioneer 11 ... please let me know if you object to that.

Selected trajectory information about some missions (including EPOXI) are now tweeting automatically to my Twitter account about once every day

Thanks for asking, Rich! Have updated the EPOXI Realtime Simulation accordingly.

Incidentally I figured out how to make my website tweet to my Twitter. In due course I hope to get it to periodically tweet mission updates onto my Twitter. Standby.

IIRC from reading elsewhere, observations will be made if a Trojan happens to be in the right place. But yes all Neptune Trojans discovered so far are at L4. But then again, New Horizons won the lottery once already with Asteroid 2002_JF567, so why not again

Is there an estimate as to when New Horizon enters and exits the region around Neptune's L5 where there could be Trojans hiding? I made a rough guesstimation as to the L5 flyby (lacking precise info about L5 other than it being 60 degrees behind Neptune) which resulted in closest approach on 06 Nov 2014 at a distance of 3.79AU.

Dear Rich,


Thanks so much for the clarification. I will incorporate the file into the next data update.



Yes the SPICE kernels are public and for most missions they can be found at http://naif.jpl.nasa.gov/naif/
EPOXI, still under the Deep Impact name, is listed under the Comet and Asteroid missions at http://naif.jpl.nasa.gov/naif/data_comet.html
The Horizons system at http://ssd.jpl.nasa.gov/?horizons also runs on SPICE kernels but occasionally it is not updated. At the moment it seems to use



Thanks.

If you wish to include timeline events, feel free to send them to me and I'll upload them in due course. Anything to create a grain of outreach for your mission :-)

Whilst extracting data for the "notional DSN coverage" of my realtime simulations, I stumbled over (the probably widely known) fact that from around April 2010, only the Canberra DSN station will be able to communicate with Voyager 2 as it is that far south of the ecliptic by then. At least they will get 24 hours coverage of Voyager 2! Might be a selling point to maintain and upgrade the antennas there ...

21 Mar 2009
30 Sep 2011

Hello Rich, welcome to UMSF. I am running realtime simulations for current interplanetary spacemissions, including EPOXI, so I am greatly interested in up-to-date SPICE kernels to extract trajectory data (spk_od224_NoBurn-full.bsp is the current file, right?) and/or in up-to-date Horizons data (which seems to be there). I also include a mission timeline, so I am very keen on any mission events (TCM's, particular observations, etc) that I can include in the timeline, preferably in advance of them happening.

I have noted that EPOXI is not on the Solar System Simulator (http://space.jpl.nasa.gov/) ... Deep Impact is but gives an error if you enter today's date ... which I think would be a good tool to have (both for the general public and to incorporate images into my simulations). So maybe you could suggest to the team at the Solar System Simulator to have EPOXI enabled :-)

Good luck with your mission!

Spacecraft signal received and separation confirmed. Well done, GOCE

I have incorporated a simple model of the Pioneer Anomaly into my realtime simulations of Pioneer 10 and Pioneer 11.

Modelled as a straight-line differential based on information in the Astronomy Magazine, March 2009, p. 24-26:
Pioneer 10: 1998 58,000km -> 1 Jan 2050 2,548,000km
Pioneer 11: 1998 6,000km -> 13 Jan 2050 1,912,000km

Always glad to receive a more precise model (of the effect, NOT the cause) from anyone out there …

I was watching the webcast and heard them talking about "all green" and that the doors will open now and the tower move away. That was 10 minutes prior to launch. I thought something was fishy when nothing moved ... either the camera froze or the door / tower didnt move. Let's hope it will work next time!

Early release version of the Kepler realtime simulation is now online at http://www.dmuller.net/kepler

Looking at the Horizons numbers (inspired by the Triton sighting) I found the following coincidence: NH will cross the Uranus orbit on 18 Mar 2011, just one day after its "closest" approach to Neptune (at a cool 22.988AU) ... thanks NH for such a nice birthday present!

Does anybody know where I can find the spice kernels for Kepler? Since it's orbiting the Sun, I would want to include it on my site.



It will slowly fall behind Earth as it goes around the Sun ... Kepler orbits the Sun and not Earth. To keep it at a constant distance from Earth would involve at least two major trajectory correction maneuvers, so it is much more efficient to launch it into an orbit which is similar to that of Earth

Have a look at http://www.mpi-hd.mpg.de/cassini/xxm/SM-7/SM-7_all.txt
That seems to be what's in the running, but I have no further insights other what's been said on this forum and that website

I found a website which lists 4 different scenarioes for the XXM at http://www.mpi-hd.mpg.de/dustgroup/cassini/xxm/xxm.html
Anybody has any idea as to which one is most likely to be chosen?

I am currently using "dawn_ref_081031-090601_090209_mga_c2_v1.bsp" for my realtime simulation which gives the correct C/A time. Prior to that file being available I used "dawn_ref_081031-090601_090129_dc023p2_v1.bsp" which was also yielding the correct flyby time.

I have corrected the event times (from ET to UTC) and added whatever I could extract from the Dawn journal to come up with the following timeline for the realtime simulation: