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Sunday, 7 June 2015

The ballad of Lightsail-1, liquids self organising in microgravity, and more...

The ballad of Lightsail-1:

The problem with launching a miniaturised spaceship with a prototype for a revolutionary new kind of space drive is that the blasted thing keeps breaking down.

I don't write that based on personal experience (I would like to say that I was, but cruel Santa still hasn't bought me the multi-millions needed for my gerbil powered warp engine), I'm going off the struggles of The Planetary Society to keep in contact with their newly launched Lightsail-1 solar sailing space craft.

Above: A quick info graphic on Lightsail-1, courtesy of The Planetary Society

The diminutive (30cm long) spaceship was launched a little over two weeks ago, to test the technologies needed for solar sail space flight - which basically means unfurling a huge sail of reflective foil and capturing the push from sunlight itself. At first it all went fairly smoothly - the miniature ship contacted home and seemed to be happy enough in orbit. Then the tiny computer that runs Lightsail suffered the spaceship equivalent of  'blue screen of death', or as I like to think of it a computer tantrum:

Above: Imagine a spaceship doing this.

Luckily for TPS space is filled with high energy particles that can smash straight through the hull, structure, and microswitches on  a spacecraft's processors and make it reset. Usually this is a pain in the bum for a spacecraft operator, but in this case it was exactly what the space-doctor* ordered, and after a few days Lightsail-1 got pinged in the right part of it's microprocessor brain, and started talking to ground control again. Everyone went 'weee!' and after a bit of checking spaceship things they told the ship to open the panels that will allow the solar sail to be deployed. The plan was simple: Open the panels and get the sail deployed asap

Above: The inside of Lightsail, as seen by its internal camera.
Lightsail obliged, at least as far as the open the panels' part, but the engineers began to notice glitches in the spacecraft's battery. The battery is needed to unfurl the sail, even though the craft is solar powered: The solar panels store energy in the battery until it has enough to open the sail, and the battery didn't seem to be charging. The engineers decided to be cautious: Lightsail responded by shutting down. At this point (about two days ago) I'll admit that I figured the craft was dead, and I began manufacturing conspiracy theories to explain why TPS's attempts to launch their solar sail demonstrators seem to always end badly (they've been trying for years)

That's my usual reaction to a disappointment, so you can imagine what my fiancee and family have to put up with.

But, low and behold, I was wrong. Whilst my neuroses debate whether they're more annoyed about being wrong or happy that this potentially historic mission could yet succeed, I'll tell you that Lightsail-1 has begun communicating with Earth again. TPS engineers are working to figure out what's going wrong and how hey can fix it. One theory is that the solar panels are supplying too much energy when in sunlight (which means that the battery won't be allowed to charge for fear of damage), and not enough why in shade. Despite the difficulties the lightsail team have made one attempt at deploying the sail today - it doesn't seem to have worked, but if they've proved anything it's that they're a persistent bunch....

All we can do is follow the updates and twitter feeds with our fingers crossed...

Elsewhere in the Universe:

(Edit: I made a mistake in the video when I said this was an experiment done on the ISS,  it was actually done on a microgravity aeroplane) From a new kind of space drive to an unexpected discovery: In microgravity a mixture of two fluids will separate into columns if they're subjected to vibrations - whats more the columns get more distinct the longer the vibrations are applied.

Above: Water and alcohol separating under the influence of vibrations in microgravity. Courtesy of ESA.
This could have a big impact on how waste liquid is recycled in space - and as space agencies look to an uncertain financial future they can use every money saving technology they can get.

Above: Researchers on a 'reduced gravity aircraft'. Also known as a vomit comet. Courtesy of the university of Rochester.
Elsewhere on the Internet:

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