See Voyager’s 1990 ‘Solar System Family Portrait’ Debut

It’s been just over 48 years since Voyager 1 was launched on September 5, 1977 from Cape Canaveral, originally to study our Solar System’s planets. Voyager 1 would explore Jupiter and Saturn, while its twin Voyager 2 took a slightly different route to ogle other planets. This primary mission for both spacecraft completed in early 1990, with NASA holding a press conference on this momentous achievement.

To celebrate the 48th year of the ongoing missions of Voyager 1 and its twin, NASA JPL is sharing an archive video of this press conference. This was the press conference where Carl Sagan referenced the pinpricks of light visible in some images, including Earth’s Pale Blue Dot, which later would become the essay about this seemingly insignificant pinprick of light being the cradle and so far sole hope for the entirety of human civilization.

For most people in attendance at this press conference in June of 1990 it would likely have seemed preposterous to imagine both spacecraft now nearing their half-century of active service in their post-extended Interstellar Mission. With some luck both spacecraft will soon celebrate their 50th launch day, before they will quietly sail on amidst the stars by next decade as a true testament to every engineer and operator on arguably humanity’s most significant achievement in space.

Thanks to [Mark Stevens] for the tip.

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The Long Goodbye: More Instruments Shut Down On The Voyagers As End Nears

Saying farewell is hard, and in the case of the Voyager 1 & 2 spacecraft doubly so, seeing as how they have been with us for more than 47 years. From the highs of the 1970s and 1980s during their primary mission in our Solar System, to their journey into the unknown of Deep Space, every bit of information which their instruments record and send back is something unique that we could not obtain any other way. Yet with the shutting down of two more instruments, both spacecraft are now getting awfully close to the end of their extended missions.

Last February 25 the cosmic ray system (CRS) on Voyager 1 was disabled, with the Low Energy Charged Particle Instrument (LECP) on Voyager 2 to follow on March 24. With each spacecraft losing about 4 watts of available power per year from their RTGs, the next few instruments to be turned off are already known. Voyager 1’s LECP will be turned off next year, with that same year Voyager 2’s CRS also getting disabled.

This would leave both spacecraft with only their magnetometer (MAG) and plasma wave subsystem (PWS). These provide data on the local magnetic field and electron density, respectively, with at least one of these instruments on each spacecraft likely to remain active until the end of this decade, possibly into the next. With some luck both spacecraft will see their 50th birthday before humanity’s only presence in Deep Space falls silent.

Thanks to [Mark Stevens] for the tip.

Voyager 2’s Plasma Spectrometer Turned Off In Power-Saving Measure

The Voyager 2 spacecraft’s energy budget keeps dropping by about 4 Watt/year, as the plutonium in its nuclear power source is steadily dropping as the isotope decays. With 4 Watt of power less to use by its systems per year, the decision was made to disable the plasma spectrometer (PLS) instrument. As also noted by the NASA Voyager 2 team on Twitter, this doesn’t leave the spacecraft completely blind to plasma in the interstellar medium as the plasma wave subsystem (PWS) is still active. The PLS was instrumental in determining in 2018 that Voyager 2 had in fact left the heliosphere and entered interstellar space. The PLS on Voyager 1 had already broken down in 1980 and was turned off in 2007.

After saving the Voyager 1 spacecraft the past months from a dud memory chip and switching between increasingly clogged up thrusters, it was now Voyager 2’s turn for a reminder of the relentless march of time and the encroaching end of the Voyager missions. Currently Voyager 2 still has four active instruments, but by the time the power runs out, they’ll both be limping along with a single instrument, probably somewhere in the 2030s if their incredible luck holds.

This incredible feat was enabled both by the hard work and brilliance of the generations of teams behind the two spacecraft, who keep coming up with new tricks to save power, and the simplicity of the radioisotope generators (RTGs) which keep both Voyagers powered and warm even in the depths of interstellar space.

Voyager 1 In Trouble As Engineers Scramble To Debug Issue With Flight Data System

Recently the team at JPL responsible for communication with the Voyager 1 spacecraft noticed an issue with the data it was returning from the Flight Data System (FDS). Although normally the FDS is supposed to communicate with the other subsystems via the telecommunications unit (TMU), this process seems to have broken down, resulting in no payloads from the scientific instruments or engineering sensors being returned any more, just repeating binary patterns. So far the cause of this breakdown is unknown, and JPL engineers are working through potential causes and fixes.

This situation is not unlike a similar situation on Voyager 2 back in 2010 when the returned data showed a data pattern shift. Here resetting the memory of the FDS resolved the garbled data issue and the engineers could breathe a sigh of relief. This time the fix does not appear so straightforward, as a reset of the FDS on Voyager 1 did not resolve the issue with, forcing the team to consider other causes. What massively complicates the debugging is that each transmission to and from the spacecraft takes approximately 22.5 hours each way, making for an agonizing 45 hour wait to receive the outcome of a command.

We wish the JPL engineers involved all the luck in the world and keep our collective appendages crossed for Voyager 1.

NASA JPL’s Voyager Team Is Patching Up Both Voyagers’ Firmware

It’s not every day that you get to update the firmware on a device that was produced in the 1970s, and rarely is said device well beyond the boundaries of our solar system. This is however exactly what the JPL team in charge of the Voyager 1 & 2 missions are facing, as they are in the process of sending fresh firmware patches over to these amazing feats of engineering. These patches should address not only the attitude articulation and control system (AACS) issues that interrupted Voyager 1’s communication with Earth a while ago, but also prevent the thruster propellant inlet tubes from getting clogged up as quickly.

Voyager 2 is the current testbed for these patches, just in case something should go wrong despite months of Earth-based checking, testing and validation. As Voyager 1 is the furthest from Earth, its scientific data is the more valuable, but ideally neither spacecraft should come out worse for wear after this maintenance session.

The AACS fixes are more of an insurance policy, as the original cause of the issue was found to be that the AACS had entered into an incorrect mode, yet without a clear understanding of how this could have happened. With these changes in place, recovery should be much easier. Similarly, the changes to the use of the thrusters are relatively minor, in that they will mostly let the spacecraft drift a bit more out of focus before the thrusters engage, reducing total thruster firings and thus the build-up of material in these inlet tubes.

With these changes the antennae of both spacecraft should remain trimmed firmly towards the blue planet which they left over forty-five years ago, and enable them to hopefully reach that full half century mark before those of us who are still listening have to say our final farewells.

Voyager 2: Communication Reestablished With One Big Shout

You could practically hear the collective “PHEW!” as NASA announced that they had reestablished full two-way communications with Voyager 2 on Friday afternoon! Details are few at this point — hopefully we’ll get more information on how this was pulled off, since we suspect there was some interesting wizardry involved. If you haven’t been following along, here’s a quick recap of the situation.

As we previously reported, a wayward command that was sent to Voyager 2, currently almost 19 light-hours distant from Earth, reoriented the spacecraft by a mere two degrees. It doesn’t sound like much, but the very narrow beamwidth on Voyager‘s high-gain antenna and the vast distance put it out of touch with the Canberra Deep Space Network station, currently the only ground station with line-of-sight to the spacecraft. While this was certainly a problem, NASA controllers seemed to take it in stride thanks to a contingency program which would automatically force the spacecraft to realign itself to point at Earth using its Canopus star tracker. The only catch was, that system wasn’t set to engage until October.

With this latest development, it appears that mission controllers weren’t willing to wait that long. Instead, based on what was universally referred to in the non-tech media as a “heartbeat” from Voyager on August 1– it appears that what they were really talking about was the use of multiple antennas at the Canberra site to pick up a weak carrier signal from the probe — they decided to send an “interstellar shout” and attempt to reorient the antenna. The 70-m DSS-43 dish blasted out the message early in the morning of August 2, and 37 hours later, science and engineering data started streaming into the antenna again, indicating that Voyager 2 was pointing back at Earth and operating fine.

Hats off to everyone involved in making this fix and getting humanity’s most remote outpost back online. If you want to follow the heroics in nearly real-time, or just like watching what goes on at the intersection of Big Engineering and Big Science, make sure you check out the Canberra DSN Twitter feed.

Just How Is Voyager 2 Going To Sort Out Its Dish Then?

Anybody who has set up a satellite TV antenna will tell you that alignment is critical when picking up a signal from space. With a satellite dish it’s a straightforward task to tweak the position, but what happens if the dish in question is out beyond the edge of the Solar System?

We told you a few days ago about this exact issue currently facing Voyager 2, but we’re guessing Hackaday readers will want to know a little bit more about how a 50+ year old spacecraft so far from home can still sort out its antenna. The answer lies in NASA Technical Report 32-1559, Digital Canopus Tracker from 1972, which describes the instrument that notes the position of the star Canopus, which along with that of the Sun it can use to calculate the antenna bearing to reach Earth. The report makes for fascinating reading, as it describes how early-1970s technology was used to spot the star by its specific intensity and then keep it in its sights. It’s an extremely accessible design, as even the part numbers are an older version of the familiar 74 logic.

So somewhere out there in interstellar space beyond the boundary of the Solar System is a card frame full of 74 logic that’s been quietly keeping an eye on a star since the early 1970s, and the engineers from those far-off days at JPL are about to save the bacon of the current generation at NASA with their work. We hope that there are some old guys in Pasadena right now with a spring in their step.

Read our coverage of the story here.