RADIO AMATEURS 'HACK' A NASA SPACECRAFT: Ham radio operators are picking up a strong signal from space. It's NASA's STEREO-A spacecraft returning home after 17 years.
"I'm having fun with STEREO-A," reports Scott Tilley (VE7TIL) of Roberts Creek, British Columbia. "The spacecraft is coming close to Earth this summer, and I can now receive its signal using a small 26-inch dish in my backyard." Here is what he picked up on July 2nd:
See also an animated version of these data. The X-flare is right here.
"We caught an X-flare in progress," Tilley says. "Naked-eye sunspot AR3354 was really crackling."
STEREO-A left Earth on Oct. 26, 2006, launched from Cape Canaveral with its sister ship STEREO-B. Both spacecraft were on a mission to the farside of the sun. Over the years, they would circle behind behind the sun, beaming images back to Earth so scientists could make 3D models of solar activity. In 2014, STEREO-B failed and was not heard from again. STEREO-A kept going, and now it is on its way back.
Earlier this summer, Tilley began hearing rumors that other radio operators were picking up signals from STEREO-A at 8443.580 MHz. He decided to check it out. "The central carrier is very loud, almost 30dB above the noise," he says. "I also noticed data sidebands, which are unusual to see on such a distant object for my small antenna."
Right: STEREO-A coronagraph images of Mercury passing the sun, eavesdropped by Scott Tilley.
At first, the signal was indecipherable. But Tilley found lots of information about its format posted by NASA on public websites; it wasn't a secret. Using a program called "SatDump" written by Alan Antoine (F4LAU), he successfully demodulated the data. Now Tilley is monitoring data streams from almost all of STEREO-A's science instruments including its extreme ultraviolet imager (EUVI), two coronagraphs (COR1 and COR2), the heliospheric imager (HI) and a solar radio burst receiver (S/WAVES).
At closest approach on August 17th, STEREO-A will be only 0.05 AU (7.5 million km) from Earth. By then, signals from the spacecraft will have more than doubled in strength, making it even easier to "hack."
"What started out as a passing curiosity is now turning into a summer pastime," says Tilley. "This is a unique time to play with STEREO-A."
Hams, would you like to monitor STEREO-A? A technic