NASA has used Voyager 1's trajectory correction maneuver (TCM) thrusters in place of its attitude control thrusters. The move could extend the amount of time NASA can communicate with Voyager 1 by two to three years:
NASA scientists needed to reorient the 40-year-old Voyager 1 -- the space agency's farthest spacecraft -- so its antenna would point toward Earth, 13 billion miles away. But the "attitude control thrusters," the first option to make the spacecraft turn in space, have been wearing out.
So NASA searched for a Plan B, eventually deciding to try using four "trajectory correction maneuver" (TCM) thrusters, located on the back side of Voyager 1. But those thrusters had not been used in 37 years. NASA wasn't sure they'd work.
Tuesday, engineers fired up the thrusters and waited eagerly to find out whether the plan was successful. They got their answer 19 hours and 35 minutes later, the time it took for the results to reach Earth: The set of four thrusters worked perfectly. The spacecraft turned and the mood at NASA shifted to jubilation.
Also at Space.com.
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Voyager 1 is still alive out there, barreling into the cosmos more than 15 billion miles away. However, a computer problem has kept the mission's loyal support team in Southern California from knowing much more about the status of one of NASA's longest-lived spacecraft.
The computer glitch cropped up on November 14, and it affected Voyager 1's ability to send back telemetry data, such as measurements from the spacecraft's science instruments or basic engineering information about how the probe was doing. [...] "It would be the biggest miracle if we get it back. We certainly haven't given up," said Suzanne Dodd, Voyager project manager at NASA's Jet Propulsion Laboratory, in an interview with Ars. "There are other things we can try. But this is, by far, the most serious since I've been project manager."
Dodd became the project manager for NASA's Voyager mission in 2010, overseeing a small cadre of engineers responsible for humanity's exploration into interstellar space. Voyager 1 is the most distant spacecraft ever, speeding away from the Sun at 38,000 mph (17 kilometers per second). [...] The latest problem with Voyager 1 lies in the probe's Flight Data Subsystem (FDS), one of three computers on the spacecraft working alongside a command-and-control central computer and another device overseeing attitude control and pointing. [...] In November, the data packages transmitted by Voyager 1 manifested a repeating pattern of ones and zeros as if it were stuck, according to NASA. Dodd said engineers at JPL have spent the better part of three months trying to diagnose the cause of the problem. She said the engineering team is "99.9 percent sure" the problem originated in the FDS, which appears to be having trouble "frame syncing" data. [...] "It's likely somewhere in the FDS memory," Dodd said. "A bit got flipped or corrupted. But without the telemetry, we can't see where that FDS memory corruption is."
[...] "We have sheets and sheets of schematics that are paper, that are all yellowed on the corners, and all signed in 1974," Dodd said. "They're pinned up on the walls and people are looking at them. That's a whole story in itself, just how to get to the information you need to be able to talk about the commanding decisions or what the problem might be." [...] "It is difficult to command Voyager," Dodd said. "We don't have any type of simulator for this. We don't have any hardware simulator. We don't have any software simulator... There's no simulator with the FDS, no hardware where we can try it on the ground first before we send it. So that makes people more cautious, and it's a balance between getting commanding right and taking risks."
[...] The spacecraft's vast distance and position in the southern sky require NASA to use the largest 230-foot (70-meter) antenna at a Deep Space Network tracking site in Australia, one of the network's most in-demand antennas.
"The data rates are very low, and this anomaly causes us not to have any telemetry," Dodd said. "We're kind of shooting in the blind a little bit because we don't know what the status of the spacecraft is completely."
Previously on SoylentNews:
Engineers Work to Fix Voyager 1 Computer - 20231215
(Score: 1, Funny) by Anonymous Coward on Tuesday December 05 2017, @05:18AM (6 children)
Hmmm. Haven't used a slide rule in at least 37 years. I wonder if I could make one work if I fired it off today?
(Score: 0) by Anonymous Coward on Tuesday December 05 2017, @07:12AM
I downloaded a slide-rule app.
(Score: 2) by FatPhil on Tuesday December 05 2017, @10:07AM (4 children)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by RS3 on Tuesday December 05 2017, @04:24PM (3 children)
I not only still have and often use my 1978-ish Casio calculator, but many other significantly older PC board based electronics. As a hands-on electronics hobbyist / tech (and EE) I've never seen solder whiskers, but I don't doubt their existence. From a bit of research, I gather that solder whiskers form from a fairly rare combination of factors, so are likely overall fairly rare. I've seen corrosion cause resistive shorts, usually due to condensing humidity or some kind of liquid intrusion.
Yes, I've had to clean the rubber LCD connectors in the Casio and many other devices with LCD displays. It's generally not too difficult to do.
(Score: 2) by Unixnut on Tuesday December 05 2017, @05:24PM (2 children)
> As a hands-on electronics hobbyist / tech (and EE) I've never seen solder whiskers, but I don't doubt their existence.
My understanding is that solder whiskers (I know them as "Tin whiskers") are a relatively new phenomenon, caused by the removal of lead from solder (for environmental reasons).
So anything that is "RoHS Compliant" will basically fail due to such whiskers, while older tech that still used lead in the components and solder will last a lot longer, and will generally fail for other reasons (most usually Capacitors).
It is pretty much impossible to find anything other than lead free solder/components nowadays (outside of aerospace/defense), so I guess we just have to resign ourselves to electronic goods having a "shelf life" (and of course, more landfill due to electronics lasting shorter).
(Score: 1, Interesting) by Anonymous Coward on Tuesday December 05 2017, @08:16PM (1 child)
Well, sortof. Tin whiskers is a very old problem discovered in early telephone systems, and the addition of lead to solder has been known to reduce (but not eliminate) the problem for a similarly long time. My impression is the physics behind this process and even the reasons why lead actually makes a difference are not very well understood.
Lead-free solders use different methods to mitigate the problem, which seem to mostly work just fine, but we have only ~12 years of experience with RoHS. Time will tell.
(Score: 1) by toddestan on Friday December 08 2017, @03:04AM
Anecdotally, I've found a lot of the DDR2-era hardware to not be particularly long lasting. That would be about the time ROHS rolled out. By the time DDR3 came out, they must have figured it out, as I haven't seen the same problems - though that stuff is newer, of course.
The previous generation DDR hardware seems to be more reliable, though with that stuff you have to worry about bad capacitors. Though at least that's something I've had luck repairing.
(Score: -1, Troll) by Anonymous Coward on Tuesday December 05 2017, @06:59AM
Cool story, nasa.
(Score: 1, Funny) by Anonymous Coward on Tuesday December 05 2017, @07:20AM (3 children)
That violates the EULA.
(Score: 5, Funny) by maxwell demon on Tuesday December 05 2017, @08:34AM (1 child)
Right. Let's send an army of lawyers to Voyager 1!
The Tao of math: The numbers you can count are not the real numbers.
(Score: 4, Touché) by Shimitar on Tuesday December 05 2017, @09:34AM
Please, not an army... SEND THEM ALL!!
Coding is an art. No, java is not coding. Yes, i am biased, i know, sorry if this bothers you.
(Score: 2) by ledow on Tuesday December 05 2017, @09:54AM
Luckily, I don't think they pay by annually-recurring licence.
(Score: 3, Informative) by inertnet on Tuesday December 05 2017, @09:18AM (3 children)
That's the one way time. They had to wait twice as long after sending their commands.
(Score: 5, Interesting) by isostatic on Tuesday December 05 2017, @01:35PM (2 children)
They knew the thrusters wouldn't ignite until Tuesday 04:14. At 04:13 they knew the thrusters were off and hadn't been turned on. Then from 04:14 they had no idea if the thrusters had turned on or not, and didn't until 23:49.
The question I suppose is what does 'now' mean. Did they fire up the thrusters at Tuesday 04:14, when the command reached the ship, or did they fire them up the Monday at 09:39 when they issued the command on their keyboard.
(Times changed to protect the innocent)
(Score: 2) by crafoo on Tuesday December 05 2017, @06:06PM
In terms of relativity, now means whatever it means from your reference frame. There is no "prime" reference frame. Now means different things depending on your reference frame.
In terms of voyager and the distances involved: just think of it as really bad display lag. like, really pretty bad. about as bad as a Sony, not quite as bad as Samsung.
In terms of Voyager 1, it fired it's thrusters when the signal was received telling it to do so. We found out about it some time later, at approximately distance/c later in voyager's frame (voyager isn't traveling at a significant fraction of c).
(Score: 2) by inertnet on Tuesday December 05 2017, @10:22PM
The context is that the engineers fired up the thrusters and started waiting. The clock started ticking when the command was sent and stopped when the answer was received. To me that's a round trip.
(Score: 0) by Anonymous Coward on Tuesday December 05 2017, @03:06PM
Here is a link with more information
https://space.stackexchange.com/questions/23895/how-do-voyager-1s-trajectory-control-thrusters-differ-from-its-attitude-control/23896#23896 [stackexchange.com]
It seems that these are all hydrazine thrusters.