The real goals should be to get launch costs low enough for a station that can assemble and fuel robotic spacecraft, use those to set up waystations where we want to go and assemble what we need there. And then the trip is still pure PR because the robots could have done the actual research on site. But its a good start for actual meaningfull exploration. If we could extract, refine and use materials in space that would be huge. Even just getting a large chunk of water into orbit that could be split into hydrogen and oxygen would be amazing.
NASA and the Private Sector - Page 114
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CuddlyCuteKitten
Sweden2351 Posts
The real goals should be to get launch costs low enough for a station that can assemble and fuel robotic spacecraft, use those to set up waystations where we want to go and assemble what we need there. And then the trip is still pure PR because the robots could have done the actual research on site. But its a good start for actual meaningfull exploration. If we could extract, refine and use materials in space that would be huge. Even just getting a large chunk of water into orbit that could be split into hydrogen and oxygen would be amazing. | ||
LegalLord
United Kingdom13774 Posts
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thePunGun
598 Posts
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LegalLord
United Kingdom13774 Posts
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CuddlyCuteKitten
Sweden2351 Posts
On March 30 2017 03:42 thePunGun wrote: Well, getting water into orbit will probably be impractical and again..expensive, there's plenty of hydrogen on the moon. I mean something more like finding it in the asteroid belt and towing it (actually probably converting chunks of it into mini spacecraft that drive themselves home). Mining the moon could work too. Just anything that avoids the massive energy sink of getting shit into earth orbit. | ||
ShoCkeyy
7814 Posts
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LegalLord
United Kingdom13774 Posts
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zatic
Zurich15227 Posts
I personally find it pretty depressing that we have to leave all space exploration to the robots, and might be stuck on Earth for who knows how long | ||
ShoCkeyy
7814 Posts
On March 30 2017 04:16 zatic wrote: Well, that's exactly what all estimates seem to be saying. But in reality that means to travel for any extended amount of time away from Earth safely, we would have to sorround us with so much water for shielding, that it's just not going to happen until really scifiy stuff like space elevator or lunar mass driver. I personally find it pretty depressing that we have to leave all space exploration to the robots, and might be stuck on Earth for who knows how long What about a space suit with a layer of water? Less weight, can last a lot longer for shielding purposes. | ||
LegalLord
United Kingdom13774 Posts
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m4ini
4215 Posts
On March 30 2017 04:25 LegalLord wrote: Why not just lead? Shielding is generally a function of density so you're hardly going to be able to overcome the mass problem. Half truth. How well something shields radiation is a mix of density and number in the atomic table. Second, lead actually would be bad as a radiation shield for interplanetary travel. Not because of weight/mass, but simply because it's good as a shield against x-ray and gamma-ray radiation - which are not the primary problem. Cosmic background radiation is, next to highly penetrative neutron radiation, beta particles etc. It also changes some radiation into worse stuff, for example beta radiation will hit on one side, unshielded x-ray radiation comes out the other (the inside of the ship in that case). You'd also have to make it easy to access and easy to switch out (like the tiles on the shuttle), since it will degrade. Lead won't happen. My bet is on LOX/Water as well. Mainly because it's effective and relatively easy to refurbish. | ||
LegalLord
United Kingdom13774 Posts
The biggest problem with water is that it's too bulky for the purposes desired. Container mass is going to cause trouble, but if you need a meter-thick water shield (based on that SE calculation)... well I guess you can be a blob in a space suit? Fair point on the issues of lead though. | ||
m4ini
4215 Posts
On March 30 2017 04:59 LegalLord wrote: LOX... that's an odd one. You'd have to cool it if you wanted it to stay liquid for a prolonged period of time. The biggest problem with water is that it's too bulky for the purposes desired. Container mass is going to cause trouble, but if you need a meter-thick water shield (based on that SE calculation)... well I guess you can be a blob in a space suit? I wasn't talking space suits, the ship needs to be shielded, or at least the "compartment" where electronics/humans sit. On mars, i'd assume that a normal space suit will do the trick since you'll be outside shielded stuff only for a short while, but don't quote me on that. Again, mars colonisation/exploration doesn't really excite me much anymore. I agree, water is very bulky, and comparatively very heavy (not compared to lead, but compared to what we're able to shoot up without prolonged orbital construction). LOX is odd because i'm dumb, i meant LH2. | ||
LegalLord
United Kingdom13774 Posts
General background of the issue for those curious: Nearly everything we know about the radiation exposure on a trip to Mars we have learned in the past 200 days. For much longer, we have known that space is a risky place to be, radiation being one of many reasons. We believed that once our explorers safely landed on the surface of Mars, the planet would provide shielding from the ravages of radiation. We didn’t how much, or how little, until very recently. Radiation and its variations impact not only the planning of human and robotic missions, but also the search for life taking place right now. The first-ever radiation readings from the surface of another planet were published last month in the journal Science. The take-home lesson, as well as the getting-there lesson and the staying-there lesson, is this: don’t forget to pack your shielding. [Mars Radiation Threat to Astronauts Explained (Infographic)] "Radiation is the one environmental characteristic that we don’t have a lot of experience with on Earth because we’re protected by our magnetosphere and relatively thick atmosphere. But it’s a daily fact of life on Mars," said Don Hassler, the lead author on the paper, "Mars’ Surface Radiation Environment Measured with the Mars Science Laboratory’s Curiosity Rover." Source NASA commentary: On Aug. 7, 1972, in the heart of the Apollo era, an enormous solar flare exploded from the sun’s atmosphere. Along with a gigantic burst of light in nearly all wavelengths, this event accelerated a wave of energetic particles. Mostly protons, with a few electrons and heavier elements mixed in, this wash of quick-moving particles would have been dangerous to anyone outside Earth’s protective magnetic bubble. Luckily, the Apollo 16 crew had returned to Earth just five months earlier, narrowly escaping this powerful event. In the early days of human space flight, scientists were only just beginning to understand how events on the sun could affect space, and in turn how that radiation could affect humans and technology. Today, as a result of extensive space radiation research, we have a much better understanding of our space environment, its effects, and the best ways to protect astronauts—all crucial parts of NASA's mission to send humans to Mars. "The Martian" film highlights the radiation dangers that could occur on a round trip to Mars. While the mission in the film is fictional, NASA has already started working on the technology to enable an actual trip to Mars in the 2030s. In the film, the astronauts’ habitat on Mars shields them from radiation, and indeed, radiation shielding will be a crucial technology for the voyage. From better shielding to advanced biomedical countermeasures, NASA currently studies how to protect astronauts and electronics from radiation – efforts that will have to be incorporated into every aspect of Mars mission planning, from spacecraft and habitat design to spacewalk protocols. “The space radiation environment will be a critical consideration for everything in the astronauts’ daily lives, both on the journeys between Earth and Mars and on the surface,” said Ruthan Lewis, an architect and engineer with the human spaceflight program at NASA's Goddard Space Flight Center in Greenbelt, Maryland. “You’re constantly being bombarded by some amount of radiation.” ... Using materials that shield more efficiently would cut down on weight and cost, but finding the right material takes research and ingenuity. NASA is currently investigating a handful of possibilities that could be used in anything from the spacecraft to the Martian habitat to space suits. “The best way to stop particle radiation is by running that energetic particle into something that’s a similar size,” said Pellish. “Otherwise, it can be like you’re bouncing a tricycle off a tractor-trailer.” Because protons and neutrons are similar in size, one element blocks both extremely well—hydrogen, which most commonly exists as just a single proton and an electron. Conveniently, hydrogen is the most abundant element in the universe, and makes up substantial parts of some common compounds, such as water and plastics like polyethylene. Engineers could take advantage of already-required mass by processing the astronauts’ trash into plastic-filled tiles used to bolster radiation protection. Water, already required for the crew, could be stored strategically to create a kind of radiation storm shelter in the spacecraft or habitat. However, this strategy comes with some challenges—the crew would need to use the water and then replace it with recycled water from the advanced life support systems. Polyethylene, the same plastic commonly found in water bottles and grocery bags, also has potential as a candidate for radiation shielding. It is very high in hydrogen and fairly cheap to produce—however, it’s not strong enough to build a large structure, especially a spacecraft, which goes through high heat and strong forces during launch. And adding polyethylene to a metal structure would add quite a bit of mass, meaning that more fuel would be required for launch. “We’ve made progress on reducing and shielding against these energetic particles, but we’re still working on finding a material that is a good shield and can act as the primary structure of the spacecraft,” said Sheila Thibeault, a materials researcher at NASA’s Langley Research Center in Hampton, Virginia. One material in development at NASA has the potential to do both jobs: Hydrogenated boron nitride nanotubes—known as hydrogenated BNNTs—are tiny, nanotubes made of carbon, boron, and nitrogen, with hydrogen interspersed throughout the empty spaces left in between the tubes. Boron is also an excellent absorber secondary neutrons, making hydrogenated BNNTs an ideal shielding material. Computer simulation of Martian polar plume This computer simulation, based on data from NASA’s Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft, shows the interaction of the streaming solar wind with Mars’ upper atmosphere. MAVEN is gathering information on the space environment at Mars—information that will be key to planning a human mission to Mars in the 2030s. Credits: X. Fang, University of Colorado, and the MAVEN science team Read more about MAVEN's atmospheric particle mapping “This material is really strong—even at high heat—meaning that it’s great for structure,” said Thibeault. Remarkably, researchers have successfully made yarn out of BNNTs, so it’s flexible enough to be woven into the fabric of space suits, providing astronauts with significant radiation protection even while they’re performing spacewalks in transit or out on the harsh Martian surface. Though hydrogenated BNNTs are still in development and testing, they have the potential to be one of our key structural and shielding materials in spacecraft, habitats, vehicles, and space suits that will be used on Mars. Source Also force fields. | ||
m4ini
4215 Posts
That's what it boils down to, i'm by no means what i'd even call a layman in rocket science. I'm a 1000 hours KSP veteran, is the best way to put it. :D edit: force fields actually are possible. They just consume too much energy for now, with which comes heat as well. If we ever were to harness fusion, "force fields" (artificial electromagnetic shielding) are actually the best solution. We just take our magnetosphere with us. | ||
ShoCkeyy
7814 Posts
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zatic
Zurich15227 Posts
Even if we could ship that much mass into hypothetical orbit assembly, the prospect of flying around in a giant blob of hydrogen is decidedly unsexy. | ||
thePunGun
598 Posts
A team at CERN is working with the European Space Radiation Superconducting Shield (link is external) (SR2S) project to develop a superconducting magnet that could protect astronauts from cosmic radiation during deep-space missions. The idea is to create an active magnetic field to shield spacecraft from high-energy particles. The superconductor coils for the prototype magnet will be made of magnesium diboride (MgB2), the same type of conductor that was developed in the form of wire for the High Luminosity Cold Powering project at CERN's Large Hadron Collider. .... Source | ||
m4ini
4215 Posts
On March 30 2017 05:17 zatic wrote: According to the NASA study citied here https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays#Mitigation you would need several tons of shielding material per square meter. Even if we could ship that much mass into hypothetical orbit assembly, the prospect of flying around in a giant blob of hydrogen is decidedly unsexy. Erm.. You do know what space station this is quoting, right? edit: this one here. https://en.wikipedia.org/wiki/O'Neill_cylinder And yeah.. I'd not go with those estimates. ^^ | ||
Sn0_Man
Tebellong44238 Posts
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