Space Radiation and Human Exploration

Recently, scientists have shown that mice who had a high energy particle beam shot through their brains suffered some loss of curiosity and ability to do work. Now your response might be “well duh, you just shot the mice with a particle beam, of course it’ll have problems.” To most of us it’s just an interesting or slightly cruel science experiment. However to astronauts and the engineerings and scientists looking over them or trying to get them to Mars, it’s a serious concern.

Space is abound with radiation. Every time we send something up there, it will get hit by high energy radiation. We just design equipment to have redundancy and still be able to operate if one system goes down. However we can’t build redundancy into humans. Astronauts on the space station regularlly see flashes in their vision when they close their eyes to go to sleep. Those flashes are due to a high energy radiation particle striking the astronaut’s optic nerve. Luckily a few strikes don’t cause long term harm, as far as we know. Additionally, the space station is protected from the the majority of the harmful radiation by the Earth’s magnetic field, which also protects us here on the ground. But if we send people to Mars, they will spend a few months outside the Earth’s protective field and in direct exposure to whatever is out there. So engineers and scientists are trying to figure out ways to protect human during long space trips.

There are two types of radiation in space, Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE). SPEs are generated by the Sun and consist mostly of electrons, hydrogen nuclei, and helium nuclei. The Sun throws out these particles as part of its regular nuclear fusion process. During solar flares, it gets really bad and becomes a high energy particle bombardment. GCRs are even higher energy particles of all elements up to iron. These particles are stripped of all their electrons and zoom through space at incredible speeds with hugh energy. GCRs comes from outside our solar system. Currently theory says GCRs are created by the destruction of stars and the resulting novas or supernovas that accelerate these particles to extremely high speeds. SUPERNOVAS! That’s pretty damn amazing I think.

So these particles can greatly threaten our future human presence in space outside of Earth’s orbit. Even if we go to the Moon, space radiation will still be a concern because the Moon doesn’t have much of a protective magnetic field. For a Moon base, an “easy” solution would be to build the based underground and let the Lunar dirt protect the astronauts. For space travel though, we can’t bring a huge pile of dirt. On Earth, nuclear reactors and waste are shielded with thick layers of lead, steel, and concrete. All of those materials are incredibly heavy, and not really feasibly to take with on a space trip. A spaceship would require a few inch thick layer of lead or steel, which would make the ship extremely heavy. An alternative is to use water as shielding material. In fact any material with a large amount of hydrogen is a good shielding material. Water is used on earth for nuclear reactors to both cool and shield the radioactive fuel rods. There was even a recent NASA study to examine the use of a water recycling bladder as the external hull of the spacecraft.

Massive spacecraft shielding may not be the only solution for the problem of radiation for travel to other planets. You see the primary problem is how long you spend in the unprotected regions of space between planets. So if you could greatly cut down on the travel time from say here to Mars, then you can get away with much less spacecraft shielding. So there is a trade between more shielding and more fuel for the engines. Now if we had much better engines that can do more with less fuel, that would be the best option. However the current high power engines are typically based on nuclear power, which has its own radiation and other issues. So what’s the answer? Right now with our current technology, most likely a compromise between existing propulsion systems carrying more fuel and a moderate amount of shielding. But there will undoubtedly be some exposure to space radiation, and I’m sure it’s something the astronauts, scientists, and doctors will be expecting and prepared for. Who knows though, one of the current mission concepts for NASA’s Space Launch System has a manned mission to Mars in the 2030-2045 time frame, and by then we may have discovered some brand new propulsion system or way to protect astronauts from radiation either with shielding or maybe a medical alternative that makes humans more resistant to radiation.


Catch-22 of Space Ventures

Recently, the Mars Society Convention had a debate between the Mars One co-founder Bas Lansdorp and two of the company’s critics from MIT. Gizmodo had a summary piece with some op-ed. I think the writer came off a bit mean, but I get where she’s coming from. To make sure we’re all on the same page, Mars One is a commercial startup venture that plans to send humans to Mars by 2024 and then every 2 years or so in order to build a colony. They’re probably most famous for their open call for astronaut and the subsequent down-selections that have been going one for a few years now. Now Mars One is a one-way trip, no returns. So these people are knowing volunteering to dedicate the rest of their lives to this mission. That has a certain amount of inspiration, though not everyone agrees. Last year, graduate students at MIT conducted a systems and feasibility analysis of the Mars One plan. Their findings say the astronauts will quickly perish on Mars, whether from starvation, dehydration, destruction of the habitat, break down of equipment, and various other grim scenarios. So as you can imagine, there’s some heated debate and antagonism between the company and the academics. This report is directly hurting the ability of Mars One to raise money to support the development of the necessary technology to prove their goal, which builds confidence and get more funding. And there’s the catch-22 for Mars One, or any commercial technology venture: they need money to develop the technology, but need the technology to build investor confidence so they’ll give money.

For any commercial entity who’s business is based on a product, whether it’s physical or digital, you need something to show potential investors in order to get their confidence. Investors are obviously looking for a return on investment, thus the name. They can invest in established products like toilet paper, but there’s probably very little gain to be had there. In the riskier markets like technology, the internet, and space, there is a greater potential for profit if the company succeeds. But they need to believe you will succeed, and not believe in a take-my-word-for-it manner, but in a data-backed-and-sound-business-strategy manner. That’s what’s currently hurting Mars One, the data is not going their way.

If we’re talking space ventures like Mars One, Planet Labs, Planetary Resources, Rocket Labs, Firefly, etc, then product or service is or requires some advanced technology, like a launch vehicle. Rockets and spacecrafts aren’t cheap. They’re probably one of the most expensive items you can buy that you don’t get to keep. Fancy houses and artwork go for hundreds of millions of dollars, but they get to be enjoyed for years. A rocket costing $50 million is used and lost in a day. And if the first rocket fails, that’s a lot of money down the drain, and no return on investment. So investors are logically wary of such a high risk venture. To help alleviate those fears, the company ideally wants to have the technology developed and tested, a clear plan for moving forward, an existing customer base, and knowledge of what’s the return on investment. But, real life is not so easy. Mars One is missing in all those categories. The necessary technology for in-situ resource utilization, habitats, food growth, and parts manufacturing on Mars are still a ways from being ready. They do have a plan forward, but it’s highly dependent on the technology. I don’t think there is a customer for the trip, since it is one way and they’re not bringing resources back. Thus I don’t know how investors would get a profit.

I don’t know if Mars One will fail or not. I don’t wish for them to fail, for they’re putting a goal out there. And difficult goals is what drives innovation and civilization. But theirs is a cautionary tale for other aerospace startups, especially in the commercial space business. To get funding, you have to demonstrate capability and a high probability of success. Before asking for money, develop the technology, at least part way, to show the potential you have. Of course you need money to do the development. Chicken and the egg problem all over again. The solution? I don’t really know. The best I can come up with is government funding as the government is not in the business of making money. So they can and do fund small enterprises to get them off the ground.

Sunset on Mars

NASA recently release a video of the sun set on Mars as seen by the Curiosity rover.
It’s more a set of time lapsed images as the rover doesn’t take full motion videos. The engineers color corrected the images since the rover’s camera is black and white only. However they know the spectral data of the light, so we know what the color is supposed to be. Thus we see what the actual colors would be of the Martian sunset. Turns out the sunset is blue-ish on Mars. This is caused by the presence of a lot of dust in the Martian atmosphere that scatter the light and makes blue come through instead of red. This is Rayleigh scattering, the same phenomenon that gives up blue skies and red sunsets, kind of the opposite of Mars actually.

Rayleigh scattering is the bouncing of light photons from atoms, molecules, and dust particles. When a photon hits a particle, it can bounce off the particle in a different direction. The wavelength of the deflected photon can change depending on the angle. On Earth, the photons bounce off mostly nitrogen. If the photons are deflected by around 90 degrees, then the light turns blue. If instead the photons are deflected straight forward, then the light turns red. So we have blue days and red sunsets. The Martian atmosphere is mostly CO2, which has different behaviors, thus the blue sunset.

Of all the images that have come back from Mars, these are one of the most inspiring and awe-inducing for me. The desert landscapes of Mars, the geological samples, the chemical data, and all the other data are very interesting scientifically. However they all seem so far removed from our everyday human experiences. But the sunset is something we have all seen many times. Songs, poems, and paintings have been made about the beauty of sunsets. It has romantic connotations. The fact the sun sets on Mars is a given, but it’s probably not a fact we’ve really thought about. It’s a piece, a tie, to our Earthly lives. One day, the first men and women to step foot on Mars will see the sunset and feel a bit more human and closer to home.

Consummerization of Aerospace Startups

This is a follow-up or continuation of the previous post on small satellites and turning them into an entertainment service. The idea is based on the fact there is a lot more money available in the consumer’s pockets than government or big business. Today, the government funds the majority of work by businesses or academics, especially in space related areas. Aeronautics (airplanes and the like) does have it’s own commercial sector from the airlines and transpiration. However even there the government spends money to support their military aircraft. Now I am not advocating for small government or anything political. In fact I believe the government has a key role to play in technology development. But I think we as a society and the aerospace field need to start thinking outside the box, and it will likely being with startups.

There was an article in 2013 back on whether startups will revitalize the aerospace industry. This would have been during the meteoric rise of SpaceX who now has a major stake in space launches. But even Elon Musk’s SpaceX is still a government contractor, serving primarily NASA and soon the military. Other startups like Planet Labs or Planetary Resources have move away from pure government support and their business cases seems to focus more on providing cheaper orbital observation or other services. But those services will still likely be bought and used heavily by the government or business, so still not consumer focused..

Consumerization is designing products and services focused on and marketed to individual consumers/end users. This is in contrast with produces and services focuses mainly for the business or government market. Space tourism is marketed to individuals while space cargo is marketed towards government.

The most successful startups are in the internet/software, small electronics, and medical devices sectors. On the internet side you have companies like Twitter, Minecraft, Instagram. In small electronics you can find examples in Pebble smart watch, Nest smart home thermostat. In medical devices there are small companies such as AdhereTech, Pixie Scientific, and even Fitbit. All of these startups have a product that directly serves and is bought by the individual consumer, your average Joe. And there are lot more Joes out there than government agencies. So if we take the same idea and apply it to aerospace, would it work? To consummerize anything, it needs to have two key factors: affordable, and appealing/useful.

Lets take the example of launch vehicles and satellites. Getting a rocket into space is dangerous, complex, and expensive. The cheapest rocket you can get today is likely the Minotaur 1 at about $40 million. There are a few small companies such as Firefly and Rocket Labs who are developing small launch vehicles to deliver single CubeSats. But even thre the launchs cost >$1 million. If those costs can be reduced to <$100k, then you’d be approaching the price range that’s affordable by private citizens, though very rich ones still. Some may say that’s crazy, and not possible, but consider the hobby rocketry community. Hobby rockets can reach altitudes of a few miles using simple solid motors for hundreds of dollars. So there is already a group of people who are interested in launching rockets and do it for a very reasonable price.

Now we come to the second question: appeal. The hobby rocket community is strong, but relatively small. They launch for the thrill and the challenge. Your average person spends their money mainly for thrills and fun, not so much to be challenged. So the biggest question that needs to be answered for the consummerization of aerospace is how do you sell it to the individual? What does the average person want? How do you make space fun? My instinct says the answer can be found by looking at sport (football, baseball, racing, etc), but I don’t quite see the solution yet. But it’s some food for thought.

How Plasma, a.k.a. “Science Lightning” Will Change the World, a humor site, posted an article today on 4 awesome plasma based technologies that exist today, in some form. The article used the term “science lightning” for plasma, which I liked. The technologies are:

1. Plasma arc remediation of waste
2. Plasma wave particle accelerator
3. Plasma scalpel
4. Matter-antimatter plasma

The list mostly goes from existing and in use to known about but not common by any means. It’s pretty cool that plasma technologies and applications has crossed the desk of an internet humor site like Cracked. I’ll briefly explain each one, though not nearly with as much humor as they did. Serious, go read it, it’s hilarious.

Plasma arc remediation
Today our waste is either dumped into landfills and allowed to decompose slowly over time, or thrown into industrial burners to be turned into gas and ash. The first is slow and takes up a lot of space, and no one likes smelly garbage dumps. The second is faster, but burning waste is terrible for the environment. Whether you believe in global warming or not, you have to admit that the smell of burning plastic is bad, and you can imagine there’s some toxic materials being emitted. Plasma remediation follows the logical progression of fire burning, by really turning up the temperature. A fire is hot enough to will break down the waste and cause it to evaporate as gaseous molecules like CO2, NO, or more complex and toxic molecules. If you keep turning up the heat, those molecules will split more and eventually turn into the basic atoms of carbon, oxygen, nitrogen, and whatever else is in the waste. A plasma arc is great at doing this since it’s essentially using lighting bolts, which are about the temperature of the surface of the sun, to blast the waste into its basic building blocks. Since most of our waste tends to be food, paper, and plastics, all of which are made from combinations of carbon, hydrogen, oxygen, and nitrogen, then that’s what you’d get after the plasma is done. The basic atoms aren’t harmful to the environment and can actually be turn back into useful things. For example hydrogen could be used to run fuel cells or an engine.

Plasma wave accelerator
This little device, not really little, is used to help particle accelerators increase the speed of the particle they throw around. In a plasma, the negative electrons and positive ions naturally generate electric field between themselves in order to stay together and keep a balance between negative and positive charges. Thus plasma is typically called a quasi-neutral state. So if you can create a sudden separation between the charges, they create a massive electric field in order to restore balance, and that field can be harnessed to help accelerate your particles of interest. So your particles get to “surf” the plasma wake. This is used in conventional particle accelerators to get that extra boost closer to the speed of light. Yes, there are “conventional” particle accelerators. The article make the same point, and it goes to show how far we have come.

Plasma scalpel
This is an interesting application that covers two very different regimes of plasma. As the name would suggest, a plasma can be used like a surgery scalpel to cut flesh. Just like the plasma arc waste blaster, a high temperature and very thing plasma jet can be used to cut flesh. The main advantage of the plasma scalpel is that it is so hot it can cauterize and kill any bacteria. This is great for certain applications like combat medics on the battlefield where dirt and bacteria are common and sticking a physical blade into a wound could be dangerous.

The second use of a plasma for medical use is a much low temperature plasma, like room temperature, to cause biological and chemical reactions. This is the field of plasma medicine, which we are also studying in our research in the lab. A cold plasma may be a misnomer. The plasma is cold to the touch because the ions and neutral are at room temperature, but the electrons are some 10,000+ degrees Celsius. Luckily electrons are very very small so can’t heat you up, kind of like sparks. Those high energy electrons can cause useful chemical reactions like a chemical catalyst. Plasma medicine research has looked a cancer treatment, wound healing, and other applications. Though the current issue is selectivity, since the plasma will kill cancer cells, but also any other healthy cells nearby. But this is still a fast growing field and poised to make breakthroughs for future medicine.

Matter-antimatter plasma
And here we’ve entered into the slightly futuristic realm. Antimatter is the fuel of the spaceships in Star Trek, and the crux of the threat in the Angels and Demons book. Antimatter as most people know is the opposite of our regular matter. And when a matter and antimatter particle meet, they mutually destroy each other an release a heck of a lot of energy according to Einstein’s E=mc2 equation. That reaction release a lot of energy, and most of that turns into heat, which will turn any object into a plasma. Matter-antimatter plasma are likely the hottest ones known. For propulsion that heat is use to move the ship. For the bomb in Dan Brown’s book, the heat is used for not so nice purposes. There’s no need to worry though, we can’t make enough antimatter to destroy anything besides maybe a beaker. CERN can only make some 1 billionth of a gram a year. Unfortunately that means we’re not going to get the Star Trek warp engines anytime soon.

What, Why, How, and So What of Paper Writing

One of the most difficult and perplexing part of research and by extension graduate school is writing and publishing your work. It’s a key part of the research process and important for building your own career. But how to write a technical paper well is often unclear to new students. It took me a few papers before I got there hang of it, and sometimes it’s still hard to figure out where to start. The easier part for a student to write is usually the results since they have the data. But just data is not enough. You can tell you’re getting better when there are fewer revisions between you and your advisor and they make fewer red marks.

Your research paper or presentation is a bit like a sales pitch and debate rolled into one. You want to give a clear, concise, and logical argument for the validity and impact of your work. On one hand you want to convince the audience that your work and results are significant and add to the greater body of knowledge like a sale’s pitch. On the other hand you need to defend your techniques, results, and theories like a debate. For my students, I tell them the paper and/or presentation should answer the “What, Why, How, and So What” of the research. These are usually what the reader or audience is looking for, consciously or not.

What: What are you doing/what did you do? This is the simplest question to address. This could be a few sentences in the abstract or intro that talks about what the work you’re taking about is and the goal of the project.

For example: “This work conducted experimental measurements of the size distribution of the Whos in Whoville using electron microscopy. The goal is to determine if exposure to elephants alters their growth patterns.” (I recently watch the movie Horton Hears a Who.)

Why: Why are you doing this work? The immediate answer maybe “because my advisor/boss told me to.” That is not the answer you’re looking for. The why question address the big picture. Why is this work important? What kind of impact can it have if successful? This is your selling point if you will. Maybe your work can lead to a cure for cancer, or more efficient car engines, or a better way to do space travel, or a better technique to teach children. The why question gives the reader and audience the reason to care about your work.

To continue the example: “This work is important because Whos are an endangered species that is easily affected by outside forces. The recent exposure to Horton the elephant is a major change to their environment, so we need to know if that event changed their anatomy.”

How: How did you do your work? This question covers the methods and techniques you use. You may have done experiments that used a particular probe or calculation, or developed an equation using a set of theories. So the how question address the validity of your process. In answering the “how”, you need to put on the debate hat and provide logical and technical backing and justification for the steps you too.

Example: “The size measurements were done using electron microscopy. Volunteers from Whoville were recruited to participate in exchange for ipods. A survey of each Who’s daily routine and their activities during the Horton incident were done.”

So What: So what’s the significance of your results? The last question is the take away the audience should have from your work. Until now you have presented on what you did, why it’s important, and how you did the work, and presumably the actual results. Now you need to bring it back to the larger picture and answer the question of “so what’s the point?”

Example: “The results have shown that the Horton incident caused the Whos to growth 5 microns taller on average, based on the sample measured. This indicates that the Whos are greatly affected by external factors. However it is not yet clear if the elephant was the primary factor in the height increase. Another external factor may be the high altitude of Whoville’s current location that increases their exposure to UV radiation compared to their previous sea level location. Further research is need to clarify the triggers.”

Amusing example aside, this is my technique in a nutshell for writing papers, and it generally lays out the paper in a logical order. What and Why would be in the abstract or into. How would be in the experimental setup or theoretical background. Then there’s the results section which is usually the first thing students think about. Finally the So What covers the discussion and conclusion. As you gain experience in paper writing, you’ll develop your own methods and you’ll recognize how others write. The goal is always to present a clear, concise, and logical argument for your work.

We are made of star-stuff

The title is a quote from Carl Sagan’s famous book “Cosmos” which led to the original Cosmos TV show, which led to it’s recent incarnation with Neil deGrasse Tyson. I first read Cosmos one winter break when I was a graduate student. My wife had given it to me as a Christmas present. I very much enjoyed the book as it was a glimpse into history and the future. I like that quote so much it’s included in my Ph.D. dissertation. I feel that it perfectly encompasses the vastness of human life and its relation to the universe. But more on that later.

I recall commenting to my wife later that the book both uplifted and depressed me. The book was written in 1985, less than a decade after the Voyager probes left on their interstellar journey. The Galileo mission was still in the planning stages at the time. Dr. Sagan was thus writing from a time when these and other important space missions were just starting or being planned. He talked about the things these missions would accomplish and what we would learn about the universe. And he was right. It was uplifting to see all that we had accomplished today.

It was also depressing to see all that we had failed to accomplish from the visions of that time. Sagan envisioned a much expanded space exploration effort as well as a greater focus on science. He discussed missions that never occurred. He believed in the continued progress of science and the human drive to learn. But predicting the future is always a loosing game. I doubt at the time he could have predicted the turns and twists the US culture and politics have taken in the last 30 years. Science and space have been demonized as contributing to the degradation of society. Funding for space exploration is ever hard to come by these days. Fewer and fewer citizens are energized by the idea of exploring the universe. They see it as a waste of resources. My belief is that exploration is one of the greatest endeavors we can undertake as a species. It challenges our knowledge, industry, spirit, and ability to work with others. Space exploration brings out the best in people and teaches us more about our place in the universe and gives us tools to control our destiny. Now I think those are some great reason to support space exploration and meet Dr. Sagan’s vision.