Power to the Voyager spacecraft!
Over the 45.6 years since launch, Voyager instruments have gradually been shut off as power from the RTG has reduced.
It is almost time for Voyager 2 to shut off another instrument, but #NASA engineers have found a way to keep it going for another 2-3 years. A voltage regulator circuit, that keeps the voltage within limits, will be shut off instead.
See graphic below for Voyager power levels and instrument status. https://www.jpl.nasa.gov/news/nasas-voyager-will-do-more-science-with-new-power-strategy #Voyager#Space
1/n
Plutonium Pu-238 has a half-life of 87.7 years, i.e., in 87.7 years, 50% of its atoms decay to uranium-234 and then to lead-206.
But the RTG has already lost half its power in ~45 years. Why?
That is because the bi-metallic thermocouples, which are quite inefficient to begin with, also degrade over time.
Every year, Pu-238 degrades by 0.7872%. The thermocouples must also degrade by a comparable amount to account for the net power loss rate. See graph below.
How much does the academic peer review cost in notional staff time?
This paper got me thinking about how much my time commitment to the review process has cost my employers over my career so far.
The authors in this paper suggest each paper review has a US dollar cost of $1272 of time commitment.
And a previous paper suggests a US dollar cost of $1900 per person per year for the lead author submitting a paper. That is the time taken to format and submit a paper and then revise it.
These figures blow out to more than one billion US dollar annual cost for peer review alone. Which of course is typically done for free and often poorly recognized.
The rings tower high over the midnight horizon with Saturn's shadow cast over them. A bit of artwork I made for @badastro last week.
This image combines Cassini imagery of Titan, Enceladus, and the Rings with a NASA star map, and a picture of overcast clouds I took from and airplane a few years ago. The rings were rerendered for the atmospheric perspective and the shadow.
Researchers have made a significant advance in designing a โmini geneโ treatment for Usher Syndrome (summary, and published paper below). Whatโs amazing about this is the level of understanding of the chemistry, genes, biochemistry, structural biology, etc. needed design the result. The work was funded directly by my family and many many others under the leadership of the Usher 1F collaborative. Money goes in one end, and science and therapies come out the other :-)
Had the pleasure of speaking with students at the University of Guelph about science communication today.
Back in the olden days when I was in grad school (the first round), #scicomm wasnโt usually considered a viable career path. Many scientists blogged under pseudonyms so they wouldnโt be penalized before tenure.
20yrs later, Iโm delighted as new generations of young scientists embrace the constantly changing media environment, including on #Mastodon.
My work day today: here are 100 new acronyms that, even after almost 20 years here, you still have not managed to ever see before and weโre not going to define them for you in the document youโre reading.
And weโre not including them in the Center Acronym Finder. Enjoy!
But I did learn that we have an Extended Ocean Vector Winds Mission in my futile search, so thereโs that ๐ #NASA and #NOAA!
โItโs like a living thing moving through the valley now, while the old, straightened river was just like a sad canal.โ
Ecologist Lee Schofield led a project to โrewiggleโ a UK stream by recreating its natural meandering shape โ which restored the gravel beds, riffles and pools that support fish and invertebrate habitats.