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ISEE-3 Satellite Is Back Under Control

Posted by Soulskill on from the well-done-folks dept.

brindafella writes: "Over the last two days, the (Reboot Project for the International Sun/Earth Explorer 3 (ISEE-3) satellite has successfully commanded ISEE-3 from Earth, using signals transmitted from the Aricebo Observatory. Signals were also received by cooperating dishes: the 21-meter dish located at Kentucky's Morehead State University Space Science Center; the 20-meter dish antenna in Bochum Observatory, Germany, operated by AMSAT Germany; and SETI's Allen Telescope Array, California. ISEE-3 was launched in 1978, and last commanded in 1999 by NASA. On May 15, 2014, the project reached its crowdfunding goal of US$125,000, which will cover the costs of writing the software to communicate with the probe, searching through the NASA archives for the information needed to control the spacecraft, and buying time on the dish antennas. The project then set a 'stretch goal' of $150,000, which it also met with a final total of $159,502 raised. The goal is to be able to command the spacecraft to fire its engines to enter an Earth orbit, and then be usable for further space exploration. This satellite does not even have a computer; it is all 'hard-wired.'"

16 of 56 comments (clear)

  1. Congratulations! by Anonymous Coward · · Score: 5, Interesting

    I had written off this project as an impossible dream. Glad to say I was wrong.
    This is an awesome accomplishment.

  2. hard-wired can be a computer by Virtucon · · Score: 4, Insightful

    This satellite does not even have a computer; it is all 'hard-wired.'"

    A lot of early computer systems were hard-wired in terms of instructions and logic paths. It didn't make them unusable, just arcane considering newer technologies like SoCs. We have come a long way.

    --
    Harrison's Postulate - "For every action there is an equal and opposite criticism"
    1. Re:hard-wired can be a computer by brindafella · · Score: 2

      Yes, I understand what you say. In this case, there is no "computer in the middle", just hard-wired resistors, capacitors, inductors, etc. That the Reboot Project has found it to be active and responsive is VERY exciting to an old-school electronics person like me. :-)

      --
      Looking at space, radio, science and computing from a 'down-under' amateur enthusiast perspective.
    2. Re:hard-wired can be a computer by Charliemopps · · Score: 2

      This satellite does not even have a computer; it is all 'hard-wired.'"

      A lot of early computer systems were hard-wired in terms of instructions and logic paths. It didn't make them unusable, just arcane considering newer technologies like SoCs. We have come a long way.

      Right. It has no integrated circuits. There's no way it doesn't have a computer. It couldn't receive signals and fire its thrusters otherwise. If there are no IC's out there that do what you need (which I assume is often the case with space craft) there's not much need for them. A lot of electronics I've built in the past has been simple enough that I did what we always called "Point to Point" meaning you have a board (like real wood!) with holes drilled into it, or metal posts... and you solder your components "point to point" with each other. There aren't even wires.

      Here's a random image I found as an example: http://bgmb55.files.wordpress....
      You use the physical shape of the component to design your board. There are often components on both sides of the board.
      This doesn't lend itself well to very complicated circuits however. If you get too many components going, you can easy create a short hazard for yourself. But it makes simple circuits a lot easier to build and maintain. It also makes each components function a lot easier to understand at a glance. This picture is clearly a Tube Amplifer for example. You can see that just by glancing at it (and the tube sockets help to)

    3. Re:hard-wired can be a computer by PPH · · Score: 2

      'Computer', 'hard-wired' and 'integrated circuit' are unrelated. There were computers which were programmable but had no ICs (some even had vacuum tubes). There are also hard wired systems, complete with modern CPUs in use today (stretching the definition of hard wired). In the past, these were programmed by burning open fusible links on the chip, so they were for all intents and purposes 'hard wired'.

      --
      Have gnu, will travel.
    4. Re:hard-wired can be a computer by mmell · · Score: 2

      Perhaps you'd better define what you mean by 'computer'. Computers existed before solid-state circuitry, and long before LSI (Large Scale Integration, or more commonly 'integrated curcuit' electronics).

  3. depends on definition of "computer" by iggymanz · · Score: 4, Interesting

    some gates and circuits to detect and act on series of correct "control tones", the old definition of computer was anything that had input, transformed information, and presented to output (like analog computer, for instance).

    Many young-uns think a "computer" needs to be a certain type of digital system with CPU, memory, IO bus and ports, etc.

    As a young teen I read the manuals for a (defunct) satellite old retired engineer had, funny as electronics hobbyist I could understand it.

    1. Re:depends on definition of "computer" by brindafella · · Score: 3, Interesting
      > As a young teen I read the manuals for a (defunct) satellite old retired engineer had, funny as electronics hobbyist I could understand it.

      :-) I've been there, too. My first computer was an IBM 1130, with 8kB of 'ram'. From what I can tell, here, we have 0kB and all hard-wired to the devices attached to the receivers and transmitters. The satellite just 'talks' via the transmitter and Earth has to listen, or lose the data. That is "how it was" in 1978 (earlier for the finalisation of the design, and the satellite's set-up of the NSA Deep Space Network ground stations).

      --
      Looking at space, radio, science and computing from a 'down-under' amateur enthusiast perspective.
    2. Re:depends on definition of "computer" by drainbramage · · Score: 3, Funny

      You are likely to be eaten by a Gru.

      --
      No brain, no pain.
    3. Re:depends on definition of "computer" by GTRacer · · Score: 2

      Why would a one-time supervillain wannabe turned adoptive father want to eat a poor, endarkened Slashdotter?

      --
      Defending IP by destroying access to it? That makes sense, RIAA/MPAA. Go to the corner until you can play nice!
  4. Arecibo Observatory by Anonymous Coward · · Score: 3, Informative

    It's the Arecibo Observatory, not "Aricebo". Does it hurt to check the spelling?

  5. Holy good gravy... by MrLogic17 · · Score: 5, Interesting

    I thought this was all an idealistic dream of some space nerds.
    It looks like they just might pull this off ! I'm seriously impressed!

    And as for not having a computer on board - that probably greatly increases the odds of it working after all these years. Space is harsh on electronics...

    1. Re:Holy good gravy... by Anonymous Coward · · Score: 2, Insightful

      I thought this was all an idealistic dream of some space nerds.

      It was. Competence and hard work turns idealistic dreams into reality.

      +1 Engineers.

  6. Obligatory XKCD... by johanwanderer · · Score: 4, Funny

    http://xkcd.com/1337/

  7. Re:Bravo! by Nightwraith · · Score: 3, Insightful

    It was certainly nice that this was approved with a great deal of speed by all the agencies involved. Good news too that they were able to preempt other previously approved projects.

    But in reality, it sounds like they had an excellent plan and at least some proof-of-concept design done when it was pitched to those agencies. Also, it's pretty time-sensitive and a great PR win if it succeeds, which the space industry desperately needs right now.

    When the grease is available, all those wheels of government can turn pretty quickly!

  8. Avoided moon impact as well by Dishwasha · · Score: 5, Informative

    As a proud contributor to the ISEE-3 reboot project, I'd like to highlight that after communicating with the satellite, they discovered that the trajectory was over 200,000 km off where the predictions indicated it should be and its trajectory was specifically placing it in danger of impacting the moon. I would like to congratulate the ISEE-3 team on helping avoid a man-made impact with our moon.

    (double post due to not being logged in)