Posts Tagged‘laser’

Scientists Plan to Strap a Laser to the ISS to Shoot Down Space Junk.

Space debris is becoming more of an issue as time goes on with the number of objects doubling in the last 15 years. Part of that problem is inevitable as the stage based approach to rocketry, whilst being the most efficient way to transport mass to orbit, unfortunately leaves behind a considerable amount of mass. This, combined with the numerous defunct satellites and other bits of junk, means that our lower orbits are littered with objects hurtling through space with enough force to cause some rather significant damage to anything else we put up there. Solving this problem isn’t easy as just picking it up is far more complicated than it sounds. Thus researchers have long thought of ideas to tackle this issue and scientists working at the RIKEN institute may have come up with a workable solution for some of the most dangerous and hardest to remove debris out there.

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The idea comes off the back of the Japanese Experiment Module – Extreme Universe Space Observatory (JEM-EUSO) telescope which is slated to be launched and installed on the International Space Station sometime in 2017. The telescope is designed to use the Earth’s atmosphere as a giant detector for energetic particles which will leave a trail of light behind them as they decay in the Earth’s atmosphere. The design of the telescope, which consists of three large lenses that direct the light to some 137 photodetector modules, means it has an extremely wide field of view. Whilst this is by design for its primary mission it also lends itself well to detecting space debris over a large area, something which is advantageous to the ISS which needs to do everything it can to avoid them.

However that’s only half the solution; the other half is a freaking laser.

Scientists at the RIKEN institute have posited that using something like the CAN laser, which is a fibre based laser that was originally designed for use in particle accelerators, could then be used to zap space junk and send it back down to Earth. This kind of approach only works for debris that are centimeters in size however they’re among some of the most devastating pieces of junk due to the difficulty in detecting them. With the JEM-EUSO however these bits of debris could be readily identified and, if they’re within the reach of the laser, heated up so their orbit begins to decay.

The current plan is to develop a proof of concept device that uses a 1/10th scale version of the current JEM-EUSO telescope combined with a 100 fiber laser. Whilst they haven’t provided any specifications beyond that going off their full scale design (10,000 fibers) the concept should be able to deorbit debris up to a kilometer away. The full scale version on the other hand would be able to zap space junk at a range of up to 100km, an incredible feat that would dramatically help in cleaning up Earth’s orbit. The final stage would be to develop a standalone satellite that could be put into a 800km polar orbit, one of the most cluttered orbits above Earth.

Our approach to tackling space debris is fast becoming a multi-faceted approach, one that will require many different methods to tackle the various types of junk that we have circling our Earth. Things like this are the kind of approach we’ll need going forward as one launch will be able to eliminate several times its own mass in debris before its useful life is over. It’s far from an unsolvable problem however whatever solutions we develop will need to be put to use soon lest our low orbits become a place that no man can ever venture through again.

New Atomic Clock Almost Too Precise to be Useful.

Time is a strange beast. As far as we know it always appears to go forward although strange things start to occur in the presence of gravity. Indeed if you synchronized two atomic clocks together then took one of them on a trip around the world with you by the time you got back they’d be wildly out of sync, more than they ever could be through normal drift. This is part of Einstein’s theory of general relativity where time appears to speed up or slow down due to the differing effects of gravity on the two objects which results in time dilation. This effect, whilst so vanishingly small as to be inconsequential in day to day life, becomes a real problem when you want to tell super accurate time, to the point where a new atomic clock might be worthless for telling the time.

Sr-lattice-optical-atomi-clock_optMost atomic clocks in the world use a caesium atom to tell time as they transition between two states with an exact and measurable frequency. This allows them to keep time with incredible precision, to the point of not losing even a second of time over the course of hundreds of millions of years. Such accurate time keeping is what has allowed us to develop things like GPS where accurate time keeping allows us to pinpoint locations with amazing accuracy (well, when it’s not fuzzed). However a new type of atomic clock takes accuracy to a whole new level, being able to keep time on the scale of billions of years with pinpoint precision.

The Strontium Optical Atomic Clock comes from researchers working at the University of Colorado and can hold perfect time for 5 billion years. It works by suspending strontium atoms in a framework of lasers and then giving them a slight jolt, sending the atoms oscillating at a highly predictable rate. This allows the researchers to keep time to an incredibly precise level, so precise in fact that minor perturbations in gravity fields have a profound impact on how fast it ticks. As it turns out Earth is somewhat of a gravitational minefield thanks to the tectonic plates under its surface.

You see the further away you are from the Earth’s core the weaker its gravitational pull is and thus time passes just a little bit faster the further away you get. For us humans the difference is imperceptible, fractions of a fraction second that would barely register even if you found yourself floating billions of kilometres away in almost true 0g. However for a time instrument as sensitive as the one the researchers created minor changes in the Earth’s makeup greatly influence its tick rate, making accurate time keeping an incredibly difficult job. Indeed the researchers say that these clocks are likely to only be able to truly useful once we put one in space, far beyond the heavy gravitic influences that are found here on Earth.

It’s amazing that we have the ability to create something like this which throws all our understanding and perceptions around such a common and supposedly well understood phenomenon into question. That, for me, is the true heart of science, uncovering just how much we don’t know about something and then hunting down answers wherever they may lie. Sure, often we’ll end up having more questions when we come out of the end of it but that’s just a function of the vastness of the universe we live in, one that’s filled with ceaseless wonders that we’re yet to discover.

 

Lasers Increase the Efficacy of Vaccines.

A common misconception that many people have around vaccines is that they’re a one shot deal that provides you with complete immunity from the disease in question. The efficacy of a vaccine is judged by how much it lowers the incident rate of a particular disease given ideal conditions and typically that number is high enough that herd immunity takes care of the rest. The flu vaccine is a great example of a vaccine that doesn’t provide full immunity to the disease in question (due to its highly mutable nature) but it does however give your immune system some tools with which to fight off variants of the disease should you get infected. Thus anything we can do to improve the efficacy of vaccines is important and it just so happens that lasers might be the next big thing.

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Researchers at the Massachusetts General Hospital in conjunction with the Harvard-MIT Division of Health Science and Technology investigated the application of a cosmetic laser to an injection site prior to administering a vaccine. The research was primarily focused on improving the efficacy and duration of the protection offered by the influenza vaccine as its current levels could do with some improvement. The results they found were quite interesting, showing a 4 to 7 fold increase in immune response to the vaccine. Interestingly the results could not be replicated by simply increasing the dose of the vaccine, signalling that there was another mechanism in effect. The results also lend credence to one line of thinking of how adjuvants work, opening up new avenues for research.

Cosmetic lasers work by stimulating the body’s in built healing processes. Essentially they damage your dermis (without damaging the outer layer of skin) which causes an inflammation response at the site. For cosmetic purposes this is desirable as it promotes the renewal of skin cells at that site, making the skin look more youthful. For vaccines however this inflammatory response brings antigen-presenting cells to the site, the cells which are responsible for binding to pathogens or other harmful cells, which when faced with the vaccine rapidly bind to it. Interestingly enough the effect is most pronounced when used in conjunction with a typical adjuvant (Imiquimod, a topical cream) which also promotes an immune response at the site.

Interestingly this isn’t the first time that trauma at the injection site was used to promote the immune response. The smallpox vaccine used a bifurcated (split in two) needle which caused a rather unnerving wound at the injection site. This reduced the amount of vaccine required by about 4 times and resulted in the same effect, drastically reducing the cost required to vaccinate large populations. The cosmetic laser is a better approach due to the way it’s administered, reducing the chance for opportunistic infections and nocebo effects that might arise from the treatment.

Best of all whilst the research focused primarily on the influenza vaccine the same method appears to work for some of the other common vaccines. It’s still early days though as there’s a wide range of vaccines out there that will need to be tested with this method before it becomes standard procedure. Still anything that increases the effectiveness of an already high effective tool is great news as it means that these diseases will become less prevalent and, hopefully, we can reduce our mortality rates from them as well.

But also it’s just so freaking cool that lasers (LASERS!) are the things making vaccines better. It makes me unreasonably happy, for some reason… 🙂

Luna Ring Could Bring Terawatts of Energy to Earth.

Do you remember the Microwave Power Plant in Sim City 2000? The idea behind them was an intriguing one, you launched a satellite into orbit with a massive solar array attached and then beamed the power back down to Earth using microwaves that were collected at a giant receiver. Whilst it worked great most of the time there was always the risk that the beam would stray from its target and begin setting fire to your town indiscriminately, something which the then 11 year old me thought was particularly hilarious. Whilst we’ve yet to see that idea (or the disasters that came along with it, but more on that in a moment) the idea of putting massive solar arrays in orbit, or on a nearby heavenly body, are attractive enough to have warranted significant study.

Shimizu Master Plan Luna RingThe one limiting factor of most satellite based designs though is that they can’t produce power constantly due to them getting occluded for almost half their orbital period by Earth. Shimizu Corporation’s idea solves this issue in the most fantastical way possible: by wrapping our moon in a wide band of solar panels, enabling it to generate power constantly and beam it back down to Earth. Such an endeavour would seem like so much vapourware coming from anyone else but Shimizu is one of Japan’s leading architectural and engineering firms with annual sales of $14 billion. If there’s anyone who could make this happen it’s them and it aligns with some of the more aggressive goals for space that the Japanese government has heavily invested in of late.

The idea is actually quite similar to that of its incarnation in Sim City. Since the Moon is tidally locked with Earth (I.E. one side of the moon always points towards us) there only needs to be a single base station on the moon. Then a ring of solar panels would then be constructed all the way around the Moon, ensuring that no matter what the position of Moon, Earth and the Sun there will always be an illuminated section. There would have to be multiple base stations on Earth to receive the constantly transmitted power but since the power beams would be pointable they needn’t be placed in any particular location.

Of course such an idea begs the question as to what would happen should the beam be misaligned or temporarily swing out of alignment, potentially roasting anything in the nearby vicinity. For microwaves this isn’t much of a threat since the amount of power delivered per square meter is relatively low with a concentrated burst of 2 seconds barely enough to raise your body temperature by a couple degrees. A deliberately mistargeted beam could do some damage if left unchecked but you could also combat it very easily by just putting up reflectors or the rectilinear antennas to absorb it. The laser beams on the other hand are designed to be “high density” so you’d want some rigorous safety systems in place to make sure they didn’t stray far from the course.

Undertaking such a feat would require several leaps in technology, not least of which would be in the automation of its construction, but it’s all based on sound scientific principles. It’s unlikely that we’ll even see the beginnings of something like this within the next couple decades but as our demand for power grows options like this start to look a lot more viable. I hope Shimizu pursues the idea further as they definitely have the resources and know how to make it happen, it’s all a question of desire and commitment to the idea.

 

Ok Planetary Resources, You’ve Won Me Over.

When I first wrote about Planetary Resources early last year I was erring on the side of cautious optimism because back then there wasn’t a whole lot of information available regarding how they were actually going to achieve their goal. Indeed even their first goal of building and launching multiple space telescopes sounded like it was beyond the capabilities of even veteran players in this industry. Still the investors backing them weren’t the type to be taken for a ride so I figured they were worth keeping an eye on to see how they progressed towards their goal.

And boy have they ever:

The above video shows off one of their prototypes of the Arkyd-100 space based telescope. Now back when Planetary Resources first started talking about what they were going to do I wasn’t expecting something of this size. Indeed I don’t believe anyone has attempted to make a space based telescope that small before as you’re usually trying to amp up your light gathering potential with a large mirror. Still despite the relatively small mirror size they should be quite capable of doing the required imagery that will lead them to potential mineable asteroids.

Their communications set up is also highly intriguing as traditional space communications require large dishes and costly receiving equipment back here on earth. Planetary Resources are instead looking to use lasers for their deep space communications an idea that I didn’t think would be possible. A quick bit of research turns up this document from NASA’s Jet Propulsion Lab which goes into some detail about their feasibility and shockingly it appears to only be an engineering challenge at this point. How long it will take to turn it into something usable remains to be seen but considering Planetary Resources are looking to launch within the next couple years I’d hazard a guess that they’re already pretty close to getting it working.

Looking at all this you’d think I’d be ashamed of my initial scepticism but I’m not, I love it when people prove me wrong like this. Indeed the work that Planetary Resources are doing closely resembles that of the early days of SpaceX, a company which has gone on to achieve things that no other private company has done before. Given enough time it’s looking like Planetary Resources will be able to do the same and that gets me all kinds of excited.