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NASA Solar Sail Lost In Space 111

Posted by samzenpus
from the never-to-sail-again dept.
An anonymous reader writes "According to Spaceflight Now: 'NASA has not heard from the experimental NanoSail-D miniature solar sail in nearly a week, prompting officials to wonder if the craft actually deployed from a larger mother satellite despite initial indications it ejected as designed.' NanoSail-D's spring-ejection was indicated at 1:31 a.m. EST Monday, leading to a predicted release of the spacecraft's sail membrane around 1:30 a.m. EST Thursday."
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NASA Solar Sail Lost In Space

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  • Re:FASTSAT Post (Score:5, Informative)

    by david.given (6740) <dg@@@cowlark...com> on Sunday December 12, 2010 @06:58PM (#34530794) Homepage Journal

    All is not lost; JAXA's IKAROS is doing just fine. According to their blog (no link because accurséd Slashdot won't let me paste into text boxes) it did a flyby of Venus a few days ago and is now on its way... nowhere in particular (as a propulsion testbed it's more important that it is going than where it goes). But they've demonstrated deployment, acceleration, attitude control and power generation; it's now a fully functional interplanetary spacecraft powered purely by the sun.

    Of course, given that its tiny solar sail produces a thrust of about 1mN, which given IKAROS' 300kg mass comes out at about 3 um/s^2 or approximately 0.0000003g, I don't think it'll be blazing across the solar system any time soon; but it does show that the whole principle works. Now we need a full size one (and JAXA's planning a solar sail-powered Jupiter missing in the late 2010s).

  • Weight and telemetry (Score:5, Informative)

    by mangu (126918) on Sunday December 12, 2010 @07:21PM (#34530910)

    Given how small cameras are today, it seems like a no-brainer.

    Perhaps the name "NanoSail-D" will give a hint on how small this satellite is.

    However, the camera size itself is not all that matters. In order to send telemetry down there must exist a telemetry transmitter on board. It might surprise you to know that even large satellites often transmit telemetry at 1 kbps or so.

    Transmitting wide band, such as needed by a video signal, requires higher power. Sending high power down needs a bulkier and heavier transmitter. More power in the telemetry beacon requires more DC power, which means bigger batteries and bigger solar panels.

    These are the two main constraints in a spacecraft: mass and consumed power. Every piece of equipment on board must be screened for these two parameters, nothing is included unless it's absolutely certain that it couldn't be done with less mass and less power.

  • Re:um... (Score:2, Informative)

    by camperdave (969942) on Sunday December 12, 2010 @07:45PM (#34531040) Journal
    Well, the fact that the nano-sail was NOT a solar sail, but was essentially a parachute for slowing down a satellite in the thin, thin remnants of atmosphere at Low Earth Orbit altitudes seems to have slipped by the journalists and the fine people at Slashdot.

    ... or are you saying that a spring ejection won't happen for a few months?
  • by Kjella (173770) on Sunday December 12, 2010 @10:39PM (#34531634) Homepage

    Nope. Both Voyager probes are well over a light-day away from earth. Voyager 1 being over 31 light-hours away. So it's more like .0035 ly

    Check your sources [nasa.gov]. It's about 116 AU or 16 light hours away.

  • Re:FASTSAT Post (Score:5, Informative)

    by Kell Bengal (711123) on Sunday December 12, 2010 @11:45PM (#34531874)

    you cannot use them to go towards the sun, unfortunatly

    Not true at all! Due to the way that orbital mechanics works, you can use a solar sail to travel anywhere in orbit. If you tilt your solar sail so that the deflection of light occurs at an angle to the oncoming photons, you can produce a net force on the spacecraft retrograde to your orbital path. This slows your orbital velocity, causing you to spiral inward towards the star. To stabilise your orbit or to head outwards in a transfer orbit, you can tilt back the other way to apply prograde force.

    It's a simple and elegant means of getting around space. The only real problem is that it's a tremendously slow way of traveling across orbital distances.

  • by Muad'Dave (255648) on Monday December 13, 2010 @09:55AM (#34533570) Homepage

    Those things are a necessity when the camera is a mission-critical piece of kit ...

    Not really true - it only takes one piece of non launch-rated equipment to mess up the whole works. Imagine it shorting out or breaking into a zillion pieces on launch and getting into the science instruments.

    Your idea would work if it were physically and electrically separated from the main payload, but that would entail a lot of extra weight.

    The microswitch probably did its job - the sat probably moved enough to trigger that. The fact that no amateur satellite watchers [satobs.org] have seen it and the Air Force hasn't found it with radar are good indications that it hung up on deploy.

FORTRAN is a good example of a language which is easier to parse using ad hoc techniques. -- D. Gries [What's good about it? Ed.]

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