After more than 17 years relentlessly exploring the effects of solar activity on the space that surrounds us, the Ulysses mission is now approaching its end.

From the "programmes in progress" section of the latest ESA bulletin

The third northern solar polar pass was completed on 15 March. In spite of the reduced data rates following the X-band anomaly in mid-January and the transition to an S-band mission, key arameters
characterising the solar wind, magnetic field and energetic particles continued to be measured. The picture that emerges shows great similarity to that observed in 1995, during the first northern polar pass, with the spacecraft immersed in the fast solar wind flowing from the Sun’s northern polar coronal hole.
Efforts to delay hydrazine freezing will continue in the coming months. It is very difficult to estimate exactly when the hydrazine will freeze since predictions are based on thermal modelling rather than actual temperature measurements in telemetry. However, a projected mission operations end date of 1 July 2008 has been agreed. It is possible that operations could continue beyond that date but it is also possible that the mission will end earlier. Once freezing occurs, it may be possible to thaw the fuel again for a while by switching off instruments but the science mission will essentially be over. When thawing is no longer possible, the loss of manoeuvrability will result in an increasing Earth off-pointing angle and the loss of telemetry after about a week.

Today at ESA Headquarters, the Ulysses Legacy press conference
http://www.esa.int/esaSC/SEMPEQUG3HF_index_0_ov.html

Today is June 30th, so folks, say goodbye to old Ulysses, he's heading home at last... End-of-Mission July 1st, 2008.

Rob

A sad nominal date, although tracking is still scheduled through the middle of the month (basically, this is as long as they figured fuel-bleeding might keep the hydrazine lines from freezing). A major science blow occurred at the end of May, when it reached a point at which it could only send data to the 70 meter antennae at 512bps. This is significant because the tape recorder plays at 1024bps at its slowest, meaning that Ulysses can only send data in real time now. Back during the 2003-2004 Jupiter Distant Encounter, the tape recorder was turned off for about three months so that it could operate all instruments at the same time (as opposed to power sharing, which it needed to do when far from the sun, since during the recent perihelion it could shut its heaters off and get the same effect). However, this required 24/7 DSN coverage, which, given the Jovian Science (a highlight was the additional data about dust streams from Io) that was being done, was worth it. However, at 512 bps (and soon to drop below that), it would be hard to justify constant coverage.

A sad day to be sure, but also a happy one. Could you ask for a more successful and long-lived mission? What a wonderful tribute Ulysses' longevity is to the scientists and engineers who designed and built it.

"A man of genius makes no mistakes. His errors are volitional and are the portals of discovery."

-Joyce

Yes, a hugely successful mission... many congrats to all involved. There's still a huge amount of science hidden in all those squiggly plots that it's produced - I'm sure it'll be a few decades until we fully appreciate its legacy.

<---- image at left shows Ulysses's 1996 comet Hyakutake encounter, in case it isn't obvious!

Ulysses hanging on valiantly
http://www.esa.int/esaCP/SEMKWKSHKHF_index_0.html

Humm...changes in the solar system?...any idea of what kind of changes we might be talking about here?...
Guess we'll have more details tomorrow...

That should indeed be interesting. I assume the phrase "50-year low" means that prior to the IGY and the orbiting of the first satellites, there were no good measurements of the solar wind, so it could easily be much longer than 50 years since the present levels were reached. I guess if that trend continues for a couple decades it will be a good time for people to go to Mars, as long as no solar sails are involved.

I'm starting to get the chills...Can it be related to this?...

Don't fret, a new sunspot just appeared today.

Ulysses finds that the solar wind pressure and magnetic field strength is 20% lower than the previous solar cycle, and the lowest since such measurements began.

Implications are that Voyager 1 and 2 could reach the heliopause sooner than predicted, if this trend continues.

Even though most of the questions at the audio conference had to do with the earth's climate.

sigh....

I wonder what it does mean for the climate...... clearly something unusual is going on.

Climatology's been ruled off-topic for UMSF I'm afraid. For alternative forums, you may find this search of interest (or not )

There are status updates on Ulysses at http://ulysses-ops.jpl.esa.int/ulsfct/the_..._continues.html
This is the latest, dated 11 December:

Dear Ulysses colleagues,

It has been a couple of months since my last status report. That's
because nothing much has changed. We are continuing with our S-band
science mission and typically we are now tracking once a day for
about 2 to 4 hours. We don't want to increase pass durations much
more than that because the temperature of the TWTA radiator panel
(close to the cold hydrazine pipework) now falls rapidly when we
switch the S-band transmitter on. But we are looking to increase our
tracking time by taking two short passes per day separated by enough
time for the radiator panel temperature to rise again.

The data we have been getting recently has been of very good quality.
The spacecraft-Earth distance has been decreasing and the link margin
has increased to a point where we don't need to drop to 256 bps very
often. In fact, we are close to being able to support 1024 bps which
would enable us to get data from the tape recorder again. We're
keeping a very close eye on the downlink SNR and we'll try 1k data
again if we think the data quality won't be degraded. No promises though.

There's another benefit from the low Earth range when coupled with
the fairly low Earth drift rate that we're experiencing this month.
If the hydrazine froze or ran out tomorrow, we could continue to
acquire telemetry for around 20 days before the High Gain Antenna
offpointing was too great to support even 128 bps. That's compared to
about 5 days if the fuel had frozen back in May or June this year.
However, this is a short-lived effect and by February next year,
we'll only have 8 days of data before the end.

The latest mission status. Ulysses is still alive!



Status report: 20-Feb-2009

Date: Thu, 20 Feb 2009 11:45:38 -0800
From: Nigel Angold
Subject: Ulysses Status Update 5

Dear Ulysses colleagues,

Yesterday was mission day 6712 and we surpassed 400 days of S-band
mission operations. Given that we thought the spacecraft would only
survive a few months after the X-band transmitter failure on 15
January 2008, that's pretty good going!

The last month or so has seen a dramatic increase in data return.
This is due in part to a request by NASA HQ for additional DSN
coverage and also due to the fact that we can record and play back
data again on board the spacecraft. That's possible because the
spacecraft-Earth distance is low enough to support a 1024 bps
telemetry data rate at the moment (this situation will last until
sometime in mid-March). I've attached a plot of our weekly data
return percentages which clearly shows the recent improvements.

As far as the hydrazine is concerned, it's obviously not frozen yet,
but there can't be very much left. Our estimate is that we have
almost no fuel left even using our best-case estimates. However, it's
very difficult to get an exact figure of fuel usage over the mission
given that we have had about 3 years of closed-loop conscan
operations to control nutation when the spacecraft fired the thruster
autonomously. During those periods, we had to estimate the number of
pulses fired by monitoring the increase in catalyst bed temperature
after each period of thruster activity which is not the easiest thing
to do. So the bad news is that we don't have an exact estimate of how
much fuel is left but the good news is that it's still above zero!

We hope that the data returned is continuing to excite you as the
solar activity slowly begins to increase.

Best regards,
Nigel

I was in JPL's Space Flight Operations Facility (SFOF) yesterday afternoon and saw a scrolling display indicating that, at that moment, the DSN was receiving data from Ulysses. So it was still alive as of about 00:00 March 17 UTC...

I would love it if it picked up one last comet tail!

The day has finally come! The last day for mission operations on Ulysses will be 30th June 2009 (see newsflash item on http://ulysses-ops.jpl.esa.int/). The LAST ground station pass of the mission is currently scheduled for 30th June 2009 over the Madrid DSN 70m station (DSS-63) from around 15:25 to 20:20 UTC (08:25 to 13:20 PDT). This will be a full year after the originally announced mission end date of 1-Jul-2008!

An open-loop slew manoeuvre will be executed before the start of the pass to set up the spacecraft to point directly at the Earth for the middle of the pass in order to maximise the downlink margin. Due to the short notice and low priority for DSN allocation, a full decommissioning of the spacecraft (including some end-of-mission engineering tests that a number of former and present Ulyssess engineers have been waiting to try out) will not be carried out.

It is expected that the events in the Ulysses mission support area at JPL leading up to the ceremonial last command to the spacecraft will be carried live on real-time streaming video and/or with mission ops blog update in real-time. Check http://ulysses-ops.jpl.esa.int/ often for announcements and the timeline for the final day of operations. The mission ops team members can now all be counted on the fingers of one hand, so plans can change ...

... so long and thanks for all the fish ...

The little spacecraft that could... and DID from Oct. 6, 1990 to June 20, 2009. STS-41 got you started, but the rest was on your own!

Fare the well, good friend.

-Rob

Man I saw the launch live at Cape Canaveral. I was still in high school then. Now I have 3 kids, the oldest half-way through primary. And the mission lasted for that long. Amazing.

From the mission ops blog:

While Goldstone is down, the torch has been passed to the Canberra DSN.
We are uplinking to Ulysses and Madrid will be receiving its last telemetry before bye, bye.
(this is the second time we've said goodbye, and most likely the last)

So long Ulysses and thanks for all the data!

"The thunder and the sunshine, and opposed
Free hearts, free foreheads you and I are old;
Old age had yet his honour and his toil;
Death closes all: but something ere the end,
Some work of noble note, may yet be done,
Not unbecoming men that strove with Gods.
The lights begin to twinkle from the rocks:
The long day wanes: the slow moon climbs: the deep
Moans round with many voices. Come, my friends,
'Tis not too late to seek a newer world.
Push off, and sitting well in order smite
The sounding furrows; for my purpose holds
To sail beyond the sunset, and the baths
Of all the western stars, until I die."

Excert from Ulysses by Alfred Lord Tennyson

Ulysses has just been switched off in good config (i.e. all off except receiver and sun tracker) if I understood the broadcast correctly. Farewell

Thank you and farewell Ulysses