How can you send something like that a wrong command without checking it a million times???

SOP for spacecraft (near and far) pretty much from day 1: if you haven't heard from us for xxx, do a reset of the communication system (and perhaps some other things).

If you still don't hear from us there's this bunch of other stuff …

It's the equivalent of the "Oh sh*t" moment when you press return on the computer keyboard without double checking what you are about to tell the computer to do.

Did that once when trying to add a back-up hard drive to my PC and lost all access to the original hard drive, which of course contained the Windows start-up and files and tools. So I had to recover it via MS-DOS and the BIOS.

A computer expert could not sort it out, but I managed to get it all back. The data had not gone, just that the computer had "forgotten" that it had a hard drive. I was eventually able to jog its memory and get it to look and find the drive. All was back to normal after that.

The people at NASA must be in a terrible state about Voyager – I would hate to be in their shoes right now. I hope the dish panning mechanism on the spacecraft doesn't jam when it tries to motor the dish back.

.

What you describe doesn’t read like a ‘periodic reset’ to me

… they currently seem to be waiting for a pre-scheduled in the calendar reset to take place, not some logically-triggered one..

MichaelG.

Come on chaps….

Most of us here might have had academic and working careers very different from Engineering, but we still like to think ourselves "Engineers", so let's not stoop to the level of the "red-top" newspapers.

I would be very surprised (at Clive's implication about NASA, not Mrs. Ady's complaint about 'Im Indoors!).

Surely all the specification, operations, commands, etc. would be compiled into hand-books, probably both .pdf and real paper?

Also although it's very likely most of the original team would have retired by now,. that would be a slow, steady progress so keeping continuation of accumulated experience.

I have had no sight of any NASA documents but do have some experience with using both Hewlett-Packard and RN-issue instrument-operating manuals so would envisage NASA having something similar. These assume the reader understands the subject, but are written in very clear, logical and unambiguous styles. A bit like a Haynes Manual but more formally set out – and a darn sight easier to follow than a certain booklet with orange printing on a white cover!

Anyway, anyone can make a mistake. Just look at the spare holes in my steam-lorry chassis! Though for something like a space flight you'd expect tight error-traps and command-verifying.

The point perhaps is not that someone in NASA made a mistake – whilst Voyager's flight is extremely costly and future information-gathering lost by an operating-error would be serious scientifically, no-one's lives are at stake.

As SpeedyBuilder says, it is a magnificent achievement that something man-made, nearly 50 years old and so far away is still working and still controllable at all without any physical overhaul since being placed atop a rocket. It will be very sad if Voyager disappears from the world's radio-telescopes prematurely by irretrievably facing the wrong way, but human error or not, no human will have been harmed.

Whatever actually went wrong I hope they can correct, and 'Voyager' will still be 'phoning home for as long as she can before vanishing for ever from radio-telescope receiving-range.

They're not really separable. You don't necessarily want to do a reset simply because it's scheduled on Jan 5 (or whatever) if at that time the spacecraft is functioning as expected and you have good communications. It won't achieve anything and actually represents a risk.

As someone who in one career has spent many years pointing mobile 1.5m 12GHz dish antennas at geostationary satellites, or terrestrial microwave dish antennas at other terrestrial dish antennas 60 miles away; and in another career flying modern airliners, which can nevertheless show navigational position errors of up to a nautical mile after a flight; it completely boggles my brain that NASA can keep Voyager's communication dish antenna panned to the Earth at this range at all.

Absolutely mind blowing ! I hope they get it back, and I feel for them right now.

I have nothing but admiration for the project, and the people involved in it [which may, for all I know, include Peter Greene] … But what concerns me is that Peter and I have such different interpretations of two simple words which appeared to be quite explicit.

My actual knowledge of the term ‘periodic reset’ in NASA-speak is minuscule, but I presumed to understand the meaning; based on the News Reports, and on my ‘Plain English’ interpretation of the phrase.

Peter’s interpretation differs greatly .

MichaelG.

Just a guess about 'periodic reset' but there are two ways the antenna could be aligned.

One is by calculating the X,Y,Z angle the antenna has to be pointed to target planet earth. This requires knowing where the satellite is and its attitude. Both can be obtained from the telemetry. The calculation is probably too much work for Voyager's tiny computer, so better done back on earth. Having done the sums, the ground station sends a command to move the antenna. All that's needed is to send the right value, and minimum power is consumed making the adjustment by the antenna motors. (Voyager's battery is tiny too.)

Given Voyager's age I bet the command was sent manually, and someone fluffed. They will never hear the end of it!

The second method is for the satellite to adjust the antenna for maximum signal. At an agreed time, normal operation stops and the satellite listens continually for a powerful 'here I am' signal sent from earth. If nothing is heard, the antenna manoeuvres until the signal is received, and then the satellite fine adjusts for a maximum.

Not hearing earth during a 'periodic reset' probably causes the satellite to keep searching until it picks something up. Having to scan the antenna probably thrashes the battery, which might go flat before normal service is resumed.

Dave