Reviving the "Little Satellite that Could" ISEE-3

[pj]

Lots of excitement being generated around this grass-roots effort to contact and regain control of the ISEE-3 / ISC spacecraft! Especially since they successfully contacted and commanded the s/c on Friday

See the summary of event here and google "ISEE-3 Reboot" for more information.

I especially like the revival of the abandoned McDonald's for the operations center at Moffit

Wishing great successes for these guys (and gals).
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PJ in (sunny, stormy, just plain ...) FL

[Tuxman]

How is that interesting? I mean, wow, they are able to gain control over a machine with a remote controller for that machine.

[pj]

Guess you have to be in the industry to understand the difficulty of getting the machine to respond, if it could even respond after nearly 40 years, in one of the most difficult environments.

Have anything around that's still working after 39 years without any assistance, upkeep, repair, etc., that's traveled 23.4 billion miles in space since you last communicated with it?

By the way, hooking up amplifiers, SCRs etc. to Arecibo's antenna and getting the communications working is anything but trivial.

Anyway, thanks for reading and replying...

[Tuxman]

I'm not a space technician; after all, I find it wrong to just shoot stuff onto some rocks and leave it there to die (and, sometimes, wake up again just to let it die a couple of years later). Guess what we'd think of aliens who place their dead metal machines in our gardens.

[IHAVEBALLSNOTAPPLES]

This appears to be a simple case of "If you have to ask, you wouldn't understand".

As an amateur radio operator I find this to be quite an accomplishment.

I suppose it is as big an accomplishment as it is being able to post lame comments on internet forums is for some people..

Curt {K7ETF}

[pj]

ISEE-3 Reboot team ALMOST completed their first engine firing yesterday - a single pulse to test the spin-up thrusters. The spacecraft needs to be spinning at a very precise rate as the spacecraft is spin stabilized and the thruster pulses are time-sequenced to a very precise rate.

Not as exciting as watching the Mars Science Laboratory team successfully land the rover on Mars in August of 2012, but still lots of fun to see these guys work with this "instrumented toaster".

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PJ in FL

[Kilmatead]

Not as exciting as watching the Mars Science Laboratory team successfully land the rover on Mars in August of 2012

As poor Beagle 2 rolls quietly in its... its... um... crushed pile of metal-bits... Even mechanical objects can be jealous... wonder if they still send messages to him, in the vain hope that only the hopeless at heart can truly endure...

[pj]

ISEE-3 -- Out of gas.

... ISEE-3 had enough juice to do a power-up spin to reach its optimal rotation rate, the nitrogen propellant has bled away. The aging craft is willing, but after 30 billion miles, it just doesn't have enough gas to change its trajectory. Instead, it'll do a lunar flyby, and resume its heliocentric orbit, this time blazing a trail ahead of us instead of stalking the Earth.

Although the ISEE-3 Reboot team is spinning the set-back as "Hurray for science", the actual time the data can be received will end quickly as the craft's transmitters can only reach so far. It's currently just coming in range of smaller receiving dishes, which is why the original contact was made with the giant dish at Arecibo.

[Kilmatead]

...the craft's transmitters can only reach so far.

It's not the quantity, but the quality that counts - and that does not always mean data-for-boffins. To juxtapose with the legacy of its elder brethren, it's worthwhile to note that while the geeks get a real-time odometer to amuse themselves, that's nothing compared to what the humanistic poets got.

The full story of ISEE-3 has not yet been written. To that end, it's funny how the phrase "...blazing a trail ahead of us..." was meant to add poetic embellishment, yet is actually rather painfully conservative - for the phrase "...stalking the Earth..." is far more evocative of a darkened orphan who can no longer speak to (or "of") its progenitor. (But that's just between me and the humanistic poets.)

[FrizzleFry]

I read about the satellite being out of propellant fuel a few days ago... what a shame but fun while it lasted

I'm amazed that scientists are still talking to the Voyagers way out there on the edge of the Solar system.

[Kilmatead]

I'm amazed that scientists are still talking to the Voyagers...

Plutonium-238 (not be be confused with "the other gunk" [239] which happily blows things up) is useful stuff, with the added attraction of humour: it was originally posited (outside of space-missions) as a means of powering artificial hearts, except for a few minor drawbacks - if the patient was shot through said heart with a 30-callibre bullet (hey, these things happen), the casing would break, revealing something worse. And just in case it didn't break there, if someone lost the paperwork and the poor bloke was cremated the shielding would melt, which would be unfortunate for the undertaker. That said, they made 25 successful ones anyway.

So, to make the Earth safe for undertakers and deer-rifles, they combined rather large chunks of plutonium with 40KB of RAM, a 23-watt radio, the aforementioned music and (with the help of $988 million to date) threw it in the Voyagers.

I especially like the part where they sell the voyager missions as "currently studying exotic interstellar particles"... as I seem to remember my physics professor telling me that there wasn't much out there (between the "good bits") besides the odd hydrogen atom per square-centimetre... but he could have been wrong...

Interestingly (back on topic), ISEE doesn't have one of these batteries (though Casini did, so they're still being used), though its solar-bits seem a little wonky...

Telemetry also shows that ISEE-3 has a power margin of +28 watts - after 36 years. It is important to note that ISEE-3 has not had a functioning battery for decades. Indeed, this power capacity is what was projected for the spacecraft to have had in 1982 after 4 years in space.

Which (to be honest) doesn't make sense to me, but then again I failed miserably at Kerbal Space Program.