Dr. Roy Spencer reports that AMSR-E shut down today, too much torque on the rotating element, and all it needs to keep going is a lube job.
AMSR-E Ends 9+ Years of Global Observations
by Roy W. Spencer, Ph. D.
UPDATE #1: See update at end.
The Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) was automatically spun down to its designed 4 rpm safe condition last night after recent increases in the amount of power required to keep it spinning at its nominal 40 rpm were beginning to cause noticeable jitter in NASA’s Aqua satellite.
The instrument has over 480 pounds of spinning mass, and the lubricant in the bearing assembly gradually deteriorates over time. This deterioration has been monitored, and automatic shutdown procedures have been in place for years if the amount of torque required to keep AMSR-E spinning exceeded a certain threshold.
Starting about October 1, AMSR-E was causing yaw vibrations in the Aqua satellite attitude which were increasingly exceeding the +/- 25 arcsecond limits that are required by other instruments on the spacecraft. Last night, the 4.5 Newton-meter torque limit was apparently exceeded, and the instrument was automatically spun down to 4 rpm.
At this point it appears that this event likely ends the useful life of AMSR-E, which has been continuously gathering global data on a variety of parameters from sea ice to precipitation to sea surface temperature. It’s 9+ year lifetime exceeded its 6 year design life.
AMSR-E was provided to NASA by Japan’s Aerospace Exploration Agency (JAXA), and was built by Mitsubishi Electric Company. It was launched aboard the Aqua satellite from Vandenberg AFB on May 2, 2002. It has been an extremely successful experiment, and has gathered a huge quantity of data that will be revealing secrets of weather and climate as scientific research with the archived data continues in the coming years.
As the U.S. Science Team Leader for AMSR-E, I would like to congratulate and thank all of those who made AMSR-E such a success: JAXA, MELCO, NASA, the University of Alabama in Huntsville, the National Snow and Ice Data Center (NSIDC) in Boulder, and the U.S. and Japanese Science Teams who developed the algorithms that turned the raw data collected by AMSR-E into so many useful products.
The good news is that AMSR2, a slightly modified and improved version of AMSR-E, will be launched early next year on Japan’s GCOM-W satellite, and will join Aqua and the other satellites in NASA’s A-Train constellation of Earth observation satellites in their twice-daily, 1:30 a.m./p.m. sun-synchronous polar orbit. It is my understanding that those data will be shared in near-real time with U.S. agencies.
We had hoped that AMSR-E would provide at least one year over data overlap with the new AMSR2 instrument. It remains to be determined – and is only speculation on my part – whether there might be an attempt to gather some additional data from AMSR-E later to help fulfill this cross-calibration activity with AMSR2. [The Aqua satellite can easily accommodate the extra torque imparted to the spacecraft, and last night’s spin-down of AMSR-E was mostly to eliminate the very slight chance of sudden failure of the AMSR-E bearing assembly which could have caused the Aqua satellite to go into an uncontrolled and unrecoverable tumble.]
Again, I want to thank and congratulate all of those who made AMSR-E such a huge success!
UPDATE #1: As of early this morning, the torque required to keep AMSR-E spinning at 4 rpm was too large for its own momentum compensation mechanism to handle, with excessive amounts of momentum being dumped to the spacecraft. As a result, the instrument has now been spun down to 0 rpm. The satellite has shed the excessive momentum, and is operating normally, as are the other instruments aboard the spacecraft (MODIS, CERES, and AIRS).
I’m truly sorry to hear that Roy. The data will be missed. Its unfortunate that there will be no overlap with the new instrument.
The good new in this is that the town musicians in Grimm’s city of Bremen will not be able to do their dirty work, either.
Obummer
To bad Obummer & Congress shut down the US space program. I can just picture an astronaut with a lube gun doing a space walk ……
Bummer. And with no more space shuttle, we won’t be fixing it…
It’s too bad that such a valuable tool is lost due to the inavailability of a simple device: A grease gun.
Perhaps in the future, someone can invent a miniature device attached to spacecraft that can perform that function Then again, a miniature robot to do such mundane things can be sent up.
I was wondering the same thing. Presumably this is a sealed bearing. Is it not possible to build in a bearing-lubricating mechanism, with a supply of the appropriate lubricant? Or do they figure that it isn’t worth the trouble, since other components also have finite lifespans?
/Mr Lynn
A big aaaah from here for AMSR-E – even my wife felt sad when I told her the story.
I hope it can be ‘spun back up’ one last time when the new one comes on line next year or there will be a problem in correlating the two series. This is a serious oversight in not having the replacement already in service – made more glaring by the fact that AMSR-E only had a six-year life span in the first place. Surely continuity in such a time series is important enough to have some overlap between the lifetimes of these instruments?
melinspain says:
October 5, 2011 at 2:41 am
Thanks for the link but I only see a blank square. 🙁
I’m on IE8.
melinspain says:
October 5, 2011 at 2:41 am
Ooops… this time the link works! Nice picture. Thank you.
I wonder if the lubricant used was “non fossil” derived, green veggie sort of stuff, that has now gone off.
Shame all the same, back to huskies, sledges and poles I guess.
Why put another satellite up there before the old one goes to the nursing home? The climate question was settled don’t ya know. No incentive to gather more information. Just in case we might be wrong.
Those folks in NASA that promoted the “settled” nonsense ought to cough up part of their salary to launch the next one and be reprimanded for not promoting the need for more data instead of sitting on their cushion of homogenized data.
Maybe we should have the Mars rover people construct our satellites! Seems to me we should be able to build instrument carriers with a longer life than my living-room sofa. Or is extremely expensive space junk no longer a problem? GK
Am I the only person concerned that programs that measure the climate are being underfunded because the CAGW crowd don’t like the measurements.
Sad news indeed!
Thank goodness it was operational throughout the Arctic sea ice minimum period. Are there other observations or proxies which will be used to estimate area/extent during the next few months?
Must be some form (or a derivative) of the “Krytox” family of greases for vacuum-of-space use?
http://www2.dupont.com/Lubricants/en_US/index.html
Brief intro blurb from their Product Overview slick:
.
Curious why magnetic bearings aren’t used in an application like this, probably too much “play” ?
The satellite was designed for what – six years? Has run for 9+ according to the info above … I’d say that they exceeded “design life” by a healthy margin. Want more life? Put it into the design specs next time! Then a 9 or 10+ yr life will become upwards of 15 yrs actual use.
No mention of the degradation of other systems, like batteries, which are also ‘wear’ or ‘wear-out’ items.
Ideally ALL systems would fail on System_Design_Life + 1 (day) then the insurance held by the contractor would not have to pay off and an RFQ (Request for Quote) would be issued by NASA for a replacement bird (speaking from a contractor POV)!
.
The difference between ‘operational meteorology’ satellites (GOES series et al) and ‘research sats’; lower priority for research sats therefore lower budget and _no_ provisioning for spares program (note: we have spare GOES “operational meteorology” birds in orbit though).
Per NASA’s Objective webpage
The EOS AQUA AMSR-E measures geophysical parameters supporting several global change science and monitoring efforts, including precipitation, oceanic water vapor, cloud water, near-surface wind speed, sea surface temperature, soil moisture, snow cover, and sea ice parameters. All of these measurements are critical to understanding the Earth’s climate.
.
Good satellite, good instrument. Thanks for the update Roy. Like others here I checked the JAXA sea ice data once each morning. Sorry to see AMSR-E go. Guess we need to start considering having a permanent maintenance space station up there. The cost would be high, but maybe if all the worlds nations chipped in. We shouldn’t be loosing satellites over a little oil.
Bummer. Thanks and condolences to everyone involved! Good to hear that other instruments on the spacecraft are still providing data. Hope the launch of AMSR2 goes well. “The King is dead. Long live the King!”
I think we can trust that the designers went to every length to use the correct lubricant and design for the longest possible life under what are, frankly, conditions that would make most solutions useless in minutes to days.
That being said, it is sad to see a huge investment like that sidelined because of “a 30$ lube job” ( ok it might 3000$ worth of lube) …and the multimillion cost of getting the lube and a mechanic up there.
So looking forward to the day when someone has a “garage vehicle”, with staff or teleoperated fixit machines, parked in orbit and a maintenance run is – if non trivial – something you can order up. “Please schedule Sat 1234 for maintenance, schematics and specs to follow”.
It be nice to have something that can zap or “vacuum up” all the crap floating up there too that’s making things more dangerous, but I suspect a powerful enough laser to zap stuff to gas would raise concerns, perhaps it could be used to nudge ( zap, zap zap) things to decaying orbit?
At http://www.iup.uni-bremen.de:8084/amsr/ you can read:
The AMSR-E instrument has not produced data since Oct 4, 2011. Therefore, the sea ice maps cannot be updated. We are switching over to SSMIS data which might take a few days.
Like many others, I enjoy my morning coffee while pouring over AMSR-E data. And like many others I have many unanswered questions about whether other satellites can collect this information.
Does anyone know how ice will be measured before the replacement goes up?
Thanks Andres