Every day counts with regards to the Juno / MSL launch conflict ... see http://www.lpi.usra.edu/pss/jan92009/prese...reenmslSlip.pdf slides 8 onwards. Interesting stuff.

Last time I checked, the reference trajectory in the Horizons system had a launch date of 18 Aug 2011. Good to see this mission get off the ground .. 2855 days and 5.7 billion km flight distance (w.r.t. Sun) to go until planned Jupiter atmospheric entry on 16 Oct 2017

... add to that the 'catastrophic bush fire alert' in 3 states today. There's a fire going about 50 kms from the Narrabri Australia Telescope but it's not under threat.

Does anybody by any chance have the current orbital details, kernels or similar for Hayabusa?

On glancing on my own website, I found that two statistical milestones are coming up soon:
100AU - distance of Pioneer 10 from the Sun
200AU - distance between Pioneer 10 and Voyager 1

Naturally, the Pioneer 10 mission is over and no contact exists with the spacecraft anymore, but still impressive!

Thanks for the reminder ... need to update the trajectory in my simulations a little!

EDIT: done

That's why I still have phoenix running on http://www.dmuller.net/realtime/mars.php

Thanks for the post infocat.

A bit of my research for Pioneer 11: according to the HORIZONS system, Pioneer 11 did not achieve solar system escape velocity during its Jupiter flyby (perihelion 3.7AU, apohelion 28.8AU, eccentricity 0.77 after Jupiter flyby) so I don't think (but I don't know it) that the P11 upper stage had a much more "effective" flyby accelerating it enough to escape the Sun.

As for Ulysses, I still recall having read somewhere about a close encounter with Jupiter in 2099 but of course now I can't find it anymore. Using orbital periods and 8-Feb-1992 (Ulysses' Jupiter flyby) as a staring point, Jupiter will have completed 9 orbits by 20-Oct-2098, and Ulysses 17 orbits by 21-Nov-2098, just 30 days later. So there may be something to it, but I dont have nice (free) toys to analyse trajectories (hint hint ...) based on publicly available orbital elements. Might be able to add Ulysses to the list of escapees as well.

Thanks Phil, this is very useful. Updated my realtime simulations with that info. Having troubles finding anything of a timeline of upcoming events, or the very latest trajectory info for that matter - the data on the Horizons system has LCROSS going through the moon and I could not find any SPICE kernels. Unfortunately I'll be on the road for most of next week and can only "tweak" my existing trajectory data to match predicted impact times, can't process SPICE kernels on the road.

I have uploaded Emily's flyby blog onto my realtime simulation at http://www.dmuller.net/messenger. Less than 4 days to go.

Does anybody have the flyby timeline in spreadsheet form? Going through the encounter sim just drives me nuts, plus it doesn't match with any other info i have :-(

I don't like Vegemite ... well maybe now I do.



Yeah ... had the window to my office open overnight. Will be cleaning for the rest of the day!

You know you're an UMSFer when ... you live in a place like Mars (Sydney, Australia on 23Sep): http://www.abc.net.au/news/stories/2009/09/23/2693643.htm and http://www.news.com.au/gallery/0,23607,506...5007150,00.html

You know you're an UMSFer when ... you live in a place like Mars (Sydney, Australia on 23Sep): http://www.abc.net.au/news/stories/2009/09/23/2693643.htm and http://www.news.com.au/gallery/0,23607,506...5007150,00.html

Hi Jay. I certainly will ... just need to find some time to read the book first

That would be the shot:


Source: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1

Mercury about dead-center in the sun on 16 Sep at 12noon UTC. The Sun's apparent size is about 15 times larger than that of Mercury.

Yes MESSENGER is cruising more or less directly behind Mercury at the moment (as seen from the Sun). See also the sim images on my site http://www.dmuller.net/messenger (apologies for the "advertisement"), in particular how close the Sun and Mercury are as seen from MESSENGER and the all-dark Mercury enlargement. That can also be seen on the solar system maps on my site: http://www.dmuller.net/realtime/map.php?mt=aboveinner and http://www.dmuller.net/realtime/map.php?mt=eclipticinner. You can also see that the relative speed between MESSENGER and Mercury is now down to less than 22,000km/h. Still too much for an orbit insertion burn, hence this is a flyby and not (yet) the orbit capture.

Mercury will move to the right of the Sun as seen from MESSENGER. View from above and over time (sorry didnt have the time to make an animated gif):
16Sep: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
19Sep: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
22Sep: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
25Sep: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
28Sep: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
Flyby: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1

Got it in the mail today ... guess that will add a few more days where no work gets done

Haven't been able to find much information yet. According to the site, closest approach is 29Sep2009 17:54:58 EDT, presumably that translates to 29Sep2009 22:54:58 UTC but it doesn't state if it's Earth received time (ERT) or spacecraft event time (SCET). Does anybody know the answer to this?

The latest SPICE kernel I could find was updated on 30 Mar 09 and implies closest approach on 29Sep09 22:53:00 SCET ET at 199.7km altitude and a relative speed of 19,094km/h. That time translates to 29Sep09 22:58:32 ERT UTC. (66 leap seconds and one-way light time of 6min38sec)


EDIT: Assumed that time given is ERT and have updated MESSENGER realtime simulation (http://www.dmuller.net/messenger) accordingly

I think the only more or less realistic (partial) aerocapture scenario at the outer planets would be using Titan to assist a Saturn orbit insertion. I read that the Titan atmosphere is "quite good" for that - dense atmospere & low gravity, and known to quite a degree. It will still require orbit trims and possibly a retro-burn to "finish up" the orbit insertion, but still use much less fuel than without the slowdown at Titan (hopefully the fuel savings vastly outstrip the weight of the heatshield+related equipment). The day-or-so it will take the spacecraft from the Titan atmosphere encounter to periapse should give enough time to calculate the additional burn needed.

No such option exists at Uranus or Neptune AFAIK.

Even if you have a strong rocket, budget constraints will still force missions to go as low-weight and low-cost launch as possible.

Isn't St. Paul a city? You might want to make the first flying 4WD the trigger for going to the basement


typical umsf suggestion:

Patience ... the timeline scrolls through the events, and only shows the next 15 events. Titan closest approach (not close at all actually) happened on the way out. Full, static timeline at
http://www.dmuller.net/realtime/mission.ph...mp;appear=black

Mmm I love this stuff.

I have written a very quick page that uses the solar system simulator to show what Voyager 2 was seeing exactly 20 years ago:
http://www.dmuller.net/realtime/imagesv2nep.php

and don't forget, the 30th anniversary of the Pioneer 11 flyby at Saturn is coming up soon as well:
http://www.dmuller.net/realtime/p11saturn....sion=pioneer11h

Mixer: if memory serves me right then I think they managed to attribute some percentage of the anomaly to heat pressure from the power source.

PhilCo126: when you say "other spacecraft" I think you may be referring to the "anomaly" that some spacecraft get a bit too much acceleration out of planetary flybys. If you refer to P10/P11 style slowdown then I'd love to know which other spacecraft were affected

I dont recall for sure but if memory serves me right they published their flyby timeline very close to C/A, maybe 2 or 3 weeks in advance.

The press-kit seems to have been published on 13 Sep 08 for the 06 oct 08 flyby