Mercury Flyby 1 Options

[ugordan]

Looking at JPL's Solar System Simulator - That dot is very close to where Earth should be as seen from MESSENGER.

*sigh* Again?

This is SSS view at the time of the last frame in question, using MESSENGER NAC field-of-view in that it preserves pixel sizes.

This is the view at the time Earth was at that relative position, again NAC FOV. This is the same view, zoomed out to twice the WAC FOV.

It cannot possibly be Earth.

[ollopa]

Looks like Ulysses could be troubleshooting for several days. This from the Operations Summary:



15 January EPC 1/TWTA 1 Switch off/on Test 1 - 015.01:18 ERT.
Operational test to validate future mode of operations.
Failure to re-acquire X-band downlink at the expected time.
Commands to switch EPC/TWTA 1 repeated without success.
S/C now configured to S-band downlink.


16 January TBD



17 January TBD



18 January PPSP configuration change - GRU ON - 018.hh:mm SCET.



It's at http://ulysses-ops.jpl.esa.int/ulsfct/opssumm.html

[ugordan]

Things always seem to work themselves out, don't they? Oh well, at least MESSENGER didn't have a cosmic ray trip 30 minutes or so after C/A.

Do they really need the 70m dish to receive from basically our neighborhood?

[tedstryk]

I hate to sound mean, but if they were testing some new operations mode that involved turning the transmitter off and on in the middle of the Messenger flyby, they ought to have to wait until the Messenger data is downloaded. This is probably my impatience speaking

[robspace54]

At noon today, the highgain download from MESSENGER was to start, but... my spy in the APL Kremlin reports (I got the email at 12:31 PM) that Ulysses (which is north of the sun on it's polar pass) declared an emergency, AND the 70 meter DSN dish that was to be used has a transmitter problem. So NO high gain down load today from Mercury space.

But the housekeeping data from MESSENGER says that the observations were completed and the data is stored. :-)


Rob

Need more DSN...

[jasedm]

Need more DSN...

The state of the Deep Space Network seems to be the hot issue of the moment - competing priorities, dwindling resources.
It's like doing a very good weekly shop, and then getting home to find your fridge ain't big enough...

[jsheff]

But such small objects would be inherently unstable as light pressure and various effects related to it would destabilize the orbits quickly, no?

I wouldn't be so quick to rule it out just on orbital stability grounds. Nature has a way of surprising us with all kinds of orbital resonance tricks up its sleeve. It was within my lifetime that everyone was convinced that one side of Mercury always faced the Sun. More to the point, wasn't it at one of the M10 flybys that the UV instrument folks thought (and maybe even announced!) that they had seen a satellite around Mercury? I mention this just to show that the Mercury satellite idea, while unlikely, is not totally out of the question.

- John Sheff
Cambridge, MA

[scalbers]

Here's a quick (and preliminary) Mercury map update. This utilizes Ted Stryk's color Mariner 10 mosaic and part of his recent colorized Messenger approach image.



Nice to witness such a planetary encounter in the internet age.

Steve

(image revised 1/15 2020 UTC)

[jabe]

seems that no pics to be released today..
check here for blog entry at planetary society.

[elakdawalla]

Quick change to that -- just got a call from Louise saying they may release that one image late this evening after all, i.e. in the wee hours for those of you in Europe.

I've been told that on top of the Ulysses anomaly, both Mars Express and Dawn have gone in to safe mode

--Emily

[ugordan]

Great, now I have to stay up! It's Iapetus all over again!

BTW, what is it with these statistical chances of timing safe modes at the most inconvenient time? One safing event is a fluke, but three is just obnoxious. It's a conspiracy on spacecrafts' part, I tell ya.

[jabe]

both Mars Express and Dawn have gone in to safe mode
--Emily

Yikes!! mars express is one thing but to have DAWN go into SAFE mode is another..ok..I'm more partial to the dawn mission Lets hope all gets worked out ok..maybe this will get more funding for a few more 70 m dishes

[ngunn]

I've been told that on top of the Ulysses anomaly, both Mars Express and Dawn have gone in to safe mode

Are these events related? Have we had a pulse of something nasty passing through the Solar System?

[deglr6328]

Well its not the sun, that's for sure. http://sohowww.nascom.nasa.gov/sunspots/ three probes going into safe mode at the same time seems highly improbable. My money is on a very large GRB.

[gcecil]

But such small objects would be inherently unstable as light pressure and various effects related to it would destabilize the orbits quickly, no?

Nope Phil et al, there ARE stable satellite orbits, over 5 Myr timescales. Here's the poster that I saw at the Orlando DPS. Johan Warell gave me a quick rundown just before my talk on our non-Mariner hemisphere imaging.

An Optical Imaging Survey for Faint Mecurian Satellites
Johan Warell1, O. Karlsson1
1Uppsala Univ., Sweden.
Presentation Number: 25.03
Facility Keywords: NOT
We present the results of an imaging survey of Mercury's Hill sphere in search for objects dynamically bound to the planet, motivated by the existence of hermeocentric orbits that have been shown to be stable over 5 Myr or more. A six-day survey of Mercury's apparent vicinity from 6 to 140 Mercury radii, with full coverage between 19 and 73 Mercury radii, was performed with the Nordic Optical Telescope on La Palma using ALFOSC in the R-band. The deepest limiting magnitude of 18.6 at a signal-to-noise-level of 3 corresponds to a hermeocentric object size of 0.5 km, while the brightest limiting magnitude corresponds to a size of 1.6 km. While two suspected sources were found, no hermeocentric objects could be confidently identified.
Our survey significantly improves on the results obtained from Mariner 10 data both in terms of aerial coverage and smallest detectable object size, but still no hermeocentric satellite has been identified. This result is however not unexpected for two reasons. Firstly, the survey size limit is 1.6 km, and as any objects likely to be in orbit are of impact debris or captured Inner Earth Object origin, existing natural satellites are probably significantly smaller. Secondly, though the dynamical lifetime of close hermeocentric objects (mean semimajor axes smaller than 30 Mercury radii) are of the order of at least 5 Myr, major impacts capable of ejecting substantial debris fragments are not very likely to have occurred during the past several Myr. This survey is not able to make predictions on the probability of existence of small hermeocentric objects (in the size range less than decameters), which remain undetected. These have to await possible discovery in close-range searches from the MESSENGER and BepiColombo spacecraft