New Satellites Target Space Weather Threat

WHO’S AFRAID OF KILLER ELECTRONS?  “Killer electrons” from the Van Allen Belts are raining down on Earth’s atmosphere.

Last Saturday, a Delta II rocket blasted off at dawn from Vandenberg AFB in California. Soon thereafter NASA reported the successful deployment of the ICESat-2 satellite, designed to make 3D laser images of Earth’s surface. Here’s what most news stations did not report: A pair of tiny satellites were tucked inside the rocket, and they were successfully deployed as well. Built by students at UCLA, ELFIN-A and ELFIN-B are now orbiting Earth, monitoring the ebb and flow of “killer electrons” around our planet.

“We’ve just received our first downlink of data from ELFIN-A,” reports Ryan Caron, Development Engineer at UCLA’s Department of Earth, Planetary, and Space Sciences. Click to listen:


That may sound like ordinary static, but the signal is full of meaning. As mission controllers turn on ELFIN’s science instruments, the static-y waveforms will carry unique information about particles raining down on Earth from the inner Van Allen Radiation Belt.

“Sensors onboard our two cubesats detect electrons in the energy range 50 keV to 4.5 MeV,” says Caron. “These are the so-called ‘killer electrons,’ which can damage spacecraft and cause electrical disruptions on the ground. They also give rise to the majestic aurora borealis.”

“ELFIN is doing something new,” says Vassilis Angelopoulos, a UCLA space physicist who got his doctorate at UCLA and serves as ELFIN’s principal investigator. “No previous mission was able to measure the angle and energy of killer electrons as they rain down on Earth’s atmosphere. ELFIN will help us investigate how disturbances called ‘Electromagnetic Ion Cyclotron waves’ knock these electrons out of the Van Allen Belts and scatter them down toward Earth.”

ELFIN-A and ELFIN-B are cubesats, each weighing about eight pounds and roughly the size of a loaf of bread. They are remarkable not only for their cutting edge sensors, but also for their origin. The two satellites were almost completely designed and built by undergraduate students at UCLA. Working for more than 5 years, a succession of 250 students created the two Electron Losses and Fields Investigation CubeSats –“ELFIN” for short.

“Just seeing all the hundreds of hours of work, the many sleepless nights, the stressing out that you’re not going to make a deadline — just seeing it go up there … I’m probably going to cry,” says Jessica Artinger, an astrophysics major and geophysics and planetary science minor who helped build the satellites and witnessed their launch.

The ELFIN website has interactive tools so the public can track and listen to the spacecraft as it passes overhead twice a day. The CubeSats are expected to remain in space for two years, after which they will gradually fall out of orbit and burn up in the atmosphere like shooting stars.

ELFIN has been supported with funding from the National Science Foundation and NASA, with technical assistance from the Aerospace Corporation among other industry partners and universities.


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Sweet Old Bob
September 20, 2018 6:11 pm

Neat !

Steven Fraser
September 20, 2018 6:11 pm

To be known forthwith as ‘Effin-A’ and ‘Effin-B.

Rich Davis
Reply to  Steven Fraser
September 21, 2018 3:22 am

No no no. These ones don’t have the frickin laser beams on their heads. That was ICEsat2!

This space weather project is a bit mystifying to me. Where’s the tie-in to CO2-induced CACC? Surely they don’t deny that all weather is caused by the magik molekule? This sounds dangerously close to heresy, like maybe they really think the sun plays a role? Ridiculous! The sun has no CO2. What’s happening to science?

And all this talk about Van Halen Belts… do these millenials even know who David Lee Roth is? I never saw any belts.

Reply to  Steven Fraser
September 21, 2018 4:23 am

. “No previous mission was able to measure the angle and energy of killer electrons as they rain down on Earth’s atmosphere. ELFIN will help us investigate how disturbances called ‘Electromagnetic Ion Cyclotron waves’ knock these electrons out of the Van Allen Belts and scatter them down toward Earth.”
Hyping-up something that is already well known. Space crafts go through VABs without being affected by nonsense named “killer electrons”

Joel O'Bryan(@joelobryan)
September 20, 2018 6:21 pm

the next 2 years of Solar minimum will be a decidedly different space environment from the then follow-on next 8 years of the climb to SC25 max and decay. Hope they don’t draw the wrong conclusions from limited data.

Nah, the wrong conclusions from limited data, that would never happen.

Reply to  Joel O'Bryan
September 21, 2018 5:49 am

cube sats are really inexpensive to build, the hard part is getting space on a launch vehicle. They could probably put a couple more up in about 4 years to get a bit of comparison. The grant for the hardware would be easy to get, its the launch vehicle slot that is the hard part.

September 20, 2018 7:53 pm
Pop Piasa
Reply to  Stuart Large
September 20, 2018 8:04 pm

Thanks Stuart. That was a large contribution.

Chad Jessup
Reply to  Stuart Large
September 20, 2018 10:51 pm

A quick reading of that paper reveals that it ignores the “greenhouse” effect of water vapor, but the big issue I have with it is their concept of auto-compression which seems to me similar to the sky-dragons’ position.

Reply to  Chad Jessup
September 20, 2018 11:09 pm

seems to me similar to the sky-dragons’ position
I reached the same conclusion without reading the paper, just by looking at the title.

Reply to  Chad Jessup
September 20, 2018 11:30 pm

And by the way, the biggest problem that I have is not that it ignores the greenhouse effect, but that in the calculations, the actual incoming energy from the sun is not accounted for. The sun could shut down tomorrow and, from these calculations, the Earth’s surface temperature would remain the same. What could possibly be wrong with it?

Reply to  Chad Jessup
September 20, 2018 11:42 pm

I will correct myself, it is, in a way, accounting for the incomming energy, because it is, in a way, using the planet’s actual atmospheric temperature near the surface to calculate the planet’s atmospheric temperature near the surface. Which is a bit ridiculous. If you use pressure AND near-surface atmospheric density, of course you can calculate the temperature. Because the near-surface atmospheric density depends directly on temperature and pressure, for atmospheres of a similar average molecular mass. If the sun shut down tomorrow, earth’s temperature would go down a lot because near-surface atmospheric density (kg/m3) would go up a lot as well, due to the gas being colder. The study is a bit silly, as I said, because it uses a parameter that depends on temperature to calculate that temperature. If you know nothing about the temperature, you don’t have that parameter, and if you do, why are you calculating it again then?

Reply to  Chad Jessup
September 21, 2018 9:52 am

I’m not afraid of dragons. (^_^)

September 20, 2018 9:20 pm

Listened to the ‘killer’ electrons. GREAT achievement by these students. Salude!

Soooo. . .what now? Is this an old or new phenomenon? What are we to make of these ‘killer’ electrons? Is ‘killer’ a moniker NASA came up with? Will these ‘killer’ electrons kill . . . us? If so, how soon? How fast? In what way? Why now? What triggered them? ‘Killer’ electrons go right through steel, metal, plastic? Earth? Disrupt instruments? Pace makers? Hearts? Aerial tankers spraying the stratosphere? Spacecraft? If so, then how . . .

Reply to  Wrusssr
September 21, 2018 12:41 am

Why not just call them ‘high-energy’? The gaming upbringing of todays’s new cohort of scientists is giving us all sorts of alarmist nonsense names; my favourite is ‘explosive cyclogenisis’ for what I have always called a ‘secondary depression’.

Reply to  AngryScotonFraggleRock
September 21, 2018 4:51 am

‘Electromagnetic Ion Cyclotron waves’ of “killer electrons” sounds frighteningly deadly, but is an essential property of plasma dynamis.

Reply to  vukcevic
September 21, 2018 6:37 am


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