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LeopoldS

Meteorite Crashes In Russia, Panic Spreads (Updating) - 5 views

gizmodo.com/...rashes-in-russia-panic-spreads

shared by LeopoldS on 15 Feb 13 - No Cached
  • Joris _ on 15 Feb 13
     
    Latest update: the European Space Agency says their experts "confirm there is no link between the meteor incidents in Russia and asteroid 2012DA14 flyby tonight". How did they find this? As they did not see this one coming, how could they come to that conclusion that early!
  • ...5 more comments...
  • johannessimon81 on 15 Feb 13
     
    As you can see from the videos of this meteorite it is coming in from an east to south-east direction (i.e. the direction of the sunrise, more or less). 2012DA14 is coming from due south as you can see here: http://www.wired.com/wiredscience/2013/02/how-to-watch-asteroid-2012-da14/ So the two objects seem to be coming from different directions - at least that would be my explanation.
  • Joris _ on 15 Feb 13
     
    My point is, that if you want to come to such a conclusion (that it is not rubble) you need to be able to construct back the orbits of both objects. 2012DA14 has been observed for one year only, but it is well enough. When the meteor has been observed for the first time, such that we knew its orbit? has it been observed before? if yes, why the impact has not been predicted?
  • johannessimon81 on 15 Feb 13
     
    If you can show that they come from different directions you know that they are not associated, even if you don't reconstruct their orbits.
  • Joris _ on 15 Feb 13
     
    I don't think so. If both objects were part of the same, they would be on different but intersecting orbits anyway, hence different directions. Anyway, I am not knowledgeable in atmospheric entry ... But, with so few information about the object, I am surprised they are 100% certain it is not related to DA14. I think science requires more cautions ... With only the direction they are 100% sure, while the probability of such event is itself extremely small, I am amazed... They can't even predict with 100% certainty where a space debris will fall... plus, nobody consider the object being part of a bigger one that broke up during early entry (which has not been observed) ... so many uncertainties and possible hypothesis... and i am not the only one :) http://www.infowars.com/russian-meteor-linked-to-da14-asteroid/
  • LeopoldS on 17 Feb 13
     
    was not that evident to me also but apparently with the right understanding it was quite clear; was amazed also how quickly NASA has published the likely trajectory of the russian object - have a look at it: quite evident that these are not coming from the same body
  • Joris _ on 17 Feb 13
     
    yes, now i get my 100% certainty with the reconstructed orbits nothing else (http://wiki.nasa.gov/cm/blog/Watch%20the%20Skies/posts/post_1361037562855.html) ... I still think that esa anouncemement was highly premature but with a high probability of being right...
  • Ma Ru on 26 Feb 13
     
    Some more results on the topic (link to an arxiv article inside): http://www.bbc.co.uk/news/science-environment-21579422
jmlloren

Experimental verification of the feasibility of a quantum channel between space and Earth - 0 views

www.iop.org/...njp8_3_033038.html

NAN MAD technology

shared by jmlloren on 14 Jul 09 - Cached
  • jmlloren on 14 Jul 09
     
    Extending quantum communication to space environments would enable us to perform fundamental experiments on quantum physics as well as applications of quantum information at planetary and interplanetary scales. Here, we report on the first experimental study of the conditions for the implementation of the single-photon exchange between a satellite and an Earth-based station. We built an experiment that mimics a single photon source on a satellite, exploiting the telescope at the Matera Laser Ranging Observatory of the Italian Space Agency to detect the transmitted photons. Weak laser pulses, emitted by the ground-based station, are directed toward a satellite equipped with cube-corner retroreflectors. These reflect a small portion of the pulse, with an average of less-than-one photon per pulse directed to our receiver, as required for faint-pulse quantum communication. We were able to detect returns from satellite Ajisai, a low-Earth orbit geodetic satellite, whose orbit has a perigee height of 1485 km.
  • pacome delva on 16 Jul 09
     
    hello Jose! Interesting it was proposed to do the same with the ISS as part of the ACES experiment. I don't remember the paper but i can look if you're interested
santecarloni

[1101.6015] Radio beam vorticity and orbital angular momentum - 1 views

arxiv.org/1101.6015

radio light antennas technology

shared by santecarloni on 20 Oct 11 - No Cached
  • It has been known for a century that electromagnetic fields can transport not only energy and linear momentum but also angular momentum. However, it was not until twenty years ago, with the discovery in laser optics of experimental techniques for the generation, detection and manipulation of photons in well-defined, pure orbital angular momentum (OAM) states, that twisted light and its pertinent optical vorticity and phase singularities began to come into widespread use in science and technology. We have now shown experimentally how OAM and vorticity can be readily imparted onto radio beams. Our results extend those of earlier experiments on angular momentum and vorticity in radio in that we used a single antenna and reflector to directly generate twisted radio beams and verified that their topological properties agree with theoretical predictions. This opens the possibility to work with photon OAM at frequencies low enough to allow the use of antennas and digital signal processing, thus enabling software controlled experimentation also with first-order quantities, and not only second (and higher) order quantities as in optics-type experiments. Since the OAM state space is infinite, our findings provide new tools for achieving high efficiency in radio communications and radar technology.
  • santecarloni on 20 Oct 11
     
    It has been known for a century that electromagnetic fields can transport not only energy and linear momentum but also angular momentum. However, it was not until twenty years ago, with the discovery in laser optics of experimental techniques for the generation, detection and manipulation of photons in well-defined, pure orbital angular momentum (OAM) states, that twisted light and its pertinent optical vorticity and phase singularities began to come into widespread use in science and technology. We have now shown experimentally how OAM and vorticity can be readily imparted onto radio beams. Our results extend those of earlier experiments on angular momentum and vorticity in radio in that we used a single antenna and reflector to directly generate twisted radio beams and verified that their topological properties agree with theoretical predictions. This opens the possibility to work with photon OAM at frequencies low enough to allow the use of antennas and digital signal processing, thus enabling software controlled experimentation also with first-order quantities, and not only second (and higher) order quantities as in optics-type experiments. Since the OAM state space is infinite, our findings provide new tools for achieving high efficiency in radio communications and radar technology.
  • LeopoldS on 20 Oct 11
     
    and how can we use this?
LeopoldS

Effective Space Solutions Ltd - YouTube - 3 views

www.youtube.com/watch

debris

shared by LeopoldS on 21 Sep 14 - No Cached
  • LeopoldS on 21 Sep 14
     
    israeli startup betting on an orbital tug to put telecom sats into graveyard orbit ...
Juxi Leitner

Rogue satellites to be cleared from Earth's orbit by German robots | Science | The Obse... - 1 views

www.guardian.co.uk/...-robots-clear-rogue-satellites

satellites orbital debris security technology

shared by Juxi Leitner on 14 Oct 09 - Cached
  • Their robots will dock with failing satellites to carry out repairs or push them into "graveyard orbits", freeing vital space in geostationary orbit.
  • meant that the German robots will be "ready to be used on any satellite, whether it's designed to be docked or not".
  • Juxi Leitner on 14 Oct 09
     
    I am not sure the military will like this...
Joris _

Japan probe overshoots Venus, heads toward sun - 0 views

www.washingtonpost.com/...AR2010120701077.html

MAD venus robust

shared by Joris _ on 08 Dec 10 - No Cached
sreejanag liked it
  • A Japanese probe to Venus failed to reach orbit Wednesday and was captured by the sun's gravitational pull
  • Akatsuki's engines did not fire long enough to attain the proper orbiting position
  • may be able to try again when it passes by Venus six years from now.
  • Joris _ on 08 Dec 10
     
    The usefulness of having a robust trajectory :) ... They have to wait 6 more years for another date with Venus ...
  • ...2 more comments...
  • Joris _ on 09 Dec 10
  • LeopoldS on 11 Dec 10
     
    I agree in general but just out of the stomach: is there really an optimised trajectory that would be able to avoid this kind of scenarios when main thrusters don't perform properly? Wouldn't you in any case end up in a sun-orbiting trajectory and have to come back after years??
  • Joris _ on 11 Dec 10
     
    "optimised trajectory" of course not, robust definitely! It was the subject of my paper presented at the AAS (the one in San Diego) "Designing robust interplanetary trajectories subject to one temporary engine failure". The problem here is that they do not have enough fuel for a correction maneuver that would allow to come back to Venus earlier, and break for a VOI. A robust scenario could have alloted the best amount of fuel and time to be able to recover from almost all possible unplanned events. In the paper, I introduce some confidence regions such that I get the robust control for p% chance of mission success in case m% chance of problem with the propulsion system.
  • Dario Izzo on 12 Dec 10
     
    You should run your method on this scenario and see if you could get a trajectory with a shorter come back time using the same spacecraft.... would be a big selling point for a new trajectory design approach
Nina Nadine Ridder

To save on weight, a detour to the moon is the best route to Mars - 1 views

phys.org/...ht-detour-moon-route-mars.html

technology space lunar_base fuel Mars_missions

shared by Nina Nadine Ridder on 15 Oct 15 - No Cached
Ethan Evan liked it
  • Nina Nadine Ridder on 15 Oct 15
     
    More arguments for a lunar base? "They found the most mass-efficient path involves launching a crew from Earth with just enough fuel to get into orbit around the Earth. A fuel-producing plant on the surface of the moon would then launch tankers of fuel into space, where they would enter gravitational orbit. The tankers would eventually be picked up by the Mars-bound crew, which would then head to a nearby fueling station to gas up before ultimately heading to Mars."
  • Alexander Wittig on 16 Oct 15
     
    There was a paper with a very similar concept (reaching Mars via DRO) at the AAS meeting in January by Conte et al. First, the total Delta V required for a trip Earth -> LLO -> MLO is higher than Earth -> MLO. The trick is that Earth -> LLO requires less Delta V than Earth -> MLO and hence less mass has to be carried along *from Earth*. Essentially what both approaches have in common is that they say "if there's a free gas station orbiting the moon, it's cheaper to fly empty and fill up there on the way". The AAS paper actually does a decent job at estimating the "real" cost by also including estimates of the cost of a lunar base. https://pure.strath.ac.uk/portal/files/44275737/Conte_etal_AAS2015_Earth_Mars_transfers_through_Moon_distant_retrograde_orbit.pdf
Luís F. Simões

Timelapse video of asteroid discoveries in our solar system from 1980-2010 (watch in 10... - 5 views

www.youtube.com/watch

asteroid detection solar system WISE

shared by Luís F. Simões on 13 Sep 10 - No Cached
Joris _ liked it
  • Ma Ru on 14 Sep 10
     
    Nice... Now I have a lame question: after you have discovered ~500k asteroids, all moving (I assume more or less) chaotically in that asteroid belt, how do you tell one from another?
  • ...1 more comment...
  • Joris _ on 14 Sep 10
     
    hmm, not very chaotic indeed - laws of Kepler plus some perturbations.
  • Ma Ru on 15 Sep 10
     
    That's what I thought but when presented as a green "goo" in the video, it appears rather unordered... so I guess this is just an impression evoked by a not-to-scale presentation?
  • Francesco Biscani on 19 Sep 10
     
    It depends... orbits can be chaotic if the orbital period is in a resonance with Jupiter, although such orbits are not stable. Such configurations tend to get disrupted pretty quickly (in cosmic terms :P) http://en.wikipedia.org/wiki/Kirkwood_gap
Luís F. Simões

Boeing probes international market for human spacecraft - 1 views

spaceflightnow.com/...10cst100

human spaceflight commercial spaceflight

shared by Luís F. Simões on 11 Feb 11 - No Cached
  • The aerospace powerhouse is designing and testing systems for its CST-100 space capsule, a craft the company says could begin flying astronauts to low Earth orbit by 2015. It will launch on existing rockets to lessen development risk and costs.
  • "The spacecraft that we're designing is rocket-agnostic. It would be possible to sell this like a commercial airplane to countries who perhaps have a launch vehicle who would like to launch it in their own country."
  • Luís F. Simões on 11 Feb 11
     
    ...and hitting the news in the same day: A Rocket Built from U.S. and European Parts "A new rocket that would combine parts from NASA's canceled Ares I rocket as well as the Ariane 5 , a well-proven European satellite launcher, could provide a low-cost option for taking crew and cargo to the space station. The rocket proposal was announced this week by ATK, an aerospace and defense company that manufactures the solid rocket motors for NASA's space shuttles, and Astrium, the European company that makes the Ariane 5. They say the rocket, called Liberty, would be ready for flight by 2015." "Other commercial companies, including Boeing and Orbital Sciences Corporation, are looking to use low-end versions of the Atlas V to carry the capsules they are building. Liberty could carry any capsule at a cost less than that of the Atlas V, according to ATK." Look! Competition! :)
Dario Izzo

Black Holes play drums - 8 views

www.jannalevin.com/science.html

shared by Dario Izzo on 08 Jun 11 - No Cached
  • Dario Izzo on 08 Jun 11
     
    Another great presentation at this conference!! Plus I always wanted to enter the numerical computations of orbit around black holes.... with Luzi we had a project on formation flying around black holes .... revolutionary idea (of course we did not do it!!!)
  • ...1 more comment...
  • Ma Ru on 08 Jun 11
     
    formation flying around black holes... so practical...
  • pacome delva on 08 Jun 11
     
    nice movie, and song :) we should definitely implement GR orbits in pagmo !
  • Dario Izzo on 08 Jun 11
     
    I agree Marek, yet was it practical for Apollonio to study conic sections more than 1500 years before Kepler found his three laws? And here is a good paper to start with: http://prd.aps.org/abstract/PRD/v77/i10/e103005, making an analogy between the periodic table and the taxomony of all orbits around a black hole.
joergmueller

Caltech Researchers Find Evidence of a Real Ninth Planet | Caltech - 0 views

www.caltech.edu/...idence-real-ninth-planet-49523

PHY space science

shared by joergmueller on 21 Jan 16 - No Cached
  • joergmueller on 21 Jan 16
     
    Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles).
Alexander Wittig

Picture This: NVIDIA GPUs Sort Through Tens of Millions of Flickr Photos - 2 views

blogs.nvidia.com/...flickr

AI

shared by Alexander Wittig on 21 Jul 15 - No Cached
LeopoldS liked it
  • Alexander Wittig on 21 Jul 15
     
    Strange and exotic cityscapes. Desolate wilderness areas. Dogs that look like wookies. Flickr, one of the world's largest photo sharing services, sees it all. And, now, Flickr's image recognition technology can categorize more than 11 billion photos like these. And it does it automatically. It's called "Magic View." Magical deep learning! Buzzword attack!
  • ...4 more comments...
  • LeopoldS on 21 Jul 15
     
    and here comes my standard question: how can we use this for space? fast detection of natural disasters onboard?
  • Alexander Wittig on 22 Jul 15
     
    Even on ground. You could for example teach it what nuclear reactors or missiles or other weapons you don't want look like on satellite pictures and automatically scan the world for them (basically replacing intelligence analysts).
  • Alexander Wittig on 23 Jul 15
     
    In fact, I think this could make a nice ACT project: counting seals from satellite imagery is an actual (and quite recent) thing: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0092613 In this publication they did it manually from a GeoEye 1 b/w image, which sounds quite tedious. Maybe one can train one of those image recognition algorithms to do it automatically. Or maybe it's a bit easier to count larger things, like elephants (also a thing).
  • jcunha on 23 Jul 15
     
    In HiPEAC (High Performance, embedded architecture and computation) conference I attended in the beginning of this year there was a big trend of CUDA GPU vs FPGA for hardware accelerated image processing. Most of it orbitting around discussing who was faster and cheaper with people from NVIDIA in one side and people from Xilinx and Intel in the other. I remember of talking with an IBM scientist working on hardware accelerated data processing working together with the Radio telescope institute in Netherlands about the solution where they working on (GPU CUDA). I gathered that NVIDIA GPU suits best in applications that somehow do not rely in hardware, having the advantage of being programmed in a 'easy' way accessible to a scientist. FPGA's are highly reliable components with the advantage of being available in radhard versions, but requiring specific knowledge of physical circuit design and tailored 'harsh' programming languages. I don't know what is the level of rad hardness in NVIDIA's GPUs... Therefore FPGAs are indeed the standard choice for image processing in space missions (a talk with the microelectronics department guys could expand on this), whereas GPUs are currently used in some ground based (radio astronomy or other types of telescopes). I think that on for a specific purpose as the one you mentioned, this FPGA vs GPU should be assessed first before going further.
  • Paul N on 29 Jul 15
     
    You're forgetting power usage. GPUs need 1000 hamster wheels worth of power while FPGAs can run on a potato. Since space applications are highly power limited, putting any kind of GPU monster in orbit or on a rover is failed idea from the start. Also in FPGAs if a gate burns out from radiation you can just reprogram around it. Looking for seals offline in high res images is indeed definitely a GPU task.... for now.
  • jcunha on 31 Jul 15
     
    The discussion of how to make FPGA hardware acceleration solutions easier to use for the 'layman' is starting btw http://reconfigurablecomputing4themasses.net/.
Isabelle Dicaire

Measuring height by connecting clocks - 2 views

www.sciencedaily.com/...131002103036.htm

shared by Isabelle Dicaire on 06 Oct 13 - No Cached
annaheffernan liked it
  • Isabelle Dicaire on 06 Oct 13
     
    They were able to compare the ticking rates of two optical clocks separated by 2000 km, with the objective of computing sea level based on the effect gravity has on the clock ticking rate. They did the experiment using glass optical fibers, but I wonder if we could one day do the same from orbit, to measure the gravitational field around Earth.
  • Nicholas Lan on 09 Oct 13
     
    isn't this is effectively what pacome has been doing with his time for the last few years? e.g. http://arxiv.org/pdf/1308.6766v1.pdf also mentioning the ACES experiment
andreiaries

NASA Face in Space - 4 views

faceinspace.nasa.gov

space face

shared by andreiaries on 08 Jun 10 - Cached
  • Ma Ru on 08 Jun 10
     
    Even after reading this sentence: "NASA wants to put a photograph of your face on one of the remaining space shuttle missions and launch it into orbit." it's not clear to me what exactly they plan to do... anyone?
  • ...1 more comment...
  • Joris _ on 08 Jun 10
     
    I guess it is a symbolic way of flying the space shuttle for the last time! as JAXA does it with your name - if you want to - for all their scientific missions. Nice initiative indeed!
  • Ma Ru on 09 Jun 10
     
    Wow, they even mentioned it in the news on the Polish radio yesterday... What I am curious is if they really take the physical (or at least digital) photo and name to the orbit, or is this just, as you called it, "symbolic" ...
  • Joris _ on 09 Jun 10
     
    It is usually for real. Sometimes it is on a plate or slab, sometimes on a DVD, ... I will have my name on STS-134 :-)
Joris _

NASA International Space Station Longeron Marathon Challenge - 1 views

www.topcoder.com/iss

MAD optimization

shared by Joris _ on 18 Jan 13 - No Cached
LeopoldS liked it
  • LeopoldS on 19 Jan 13
     
    nice - did not know about it. GTOC on steroids and with loads of cash. concerning this specific challenge and especially the last condition: doesn't this hint towards a flawed design? In addition to maximizing the total power output there are some constraints on the possible movements: Each SARJ and BGA is limited to a maximum angular velocity and to a maximum angular acceleration. Each SAW must produce at least some minimum average power over the orbit (which is different for each SAW). The sequence of positions must be cyclic, so it can be repeated on the next orbit. The maximum amount of BGA rotation is not limited, but exceeding a threshold will result in a score penalty. Some structural members of the SAW mast (called Longerons) have restrictions on how they can be shadowed.
  • Joris _ on 26 Jan 13
     
    The longerons will expand and contract with exposition to sun (I think whatever the material they are made of). Because you have 4 longerons in a mast, you just need to be carefull that the mast is well balanced, and that the 4 longerons support each other, basically, you need an even number of shadowed longerons, possibly 0 too. I would call this an operational constraint.
Joris _

DARPA Looking for Partner On Wireless Spacecraft Demo | SpaceNews.com - 1 views

www.spacenews.com/...-wireless-spacecraft-demo.html

darpa technology fractionned

shared by Joris _ on 27 Apr 10 - Cached
LeopoldS liked it
  • DARPA for several years has been working on a program dubbed System F6 that seeks to prove that a cluster of small spacecraft can perform the mission of a large spacecraft by communicating wirelessly with one another in space
  • DARPA plans to launch three dedicated System F6 spacecraft either to low Earth orbit or geostationary orbit in mid-2013 to 2014
  • semi-autonomous cluster reconfiguration
nikolas smyrlakis

China breaks ground on space launch center - Yahoo! News - 0 views

news.yahoo.com/...as_china_space

space centre china

shared by nikolas smyrlakis on 14 Sep 09 - Cached
  • nikolas smyrlakis on 14 Sep 09
     
    China broke ground on its fourth space center Monday, highlighting the country's soaring space ambitions six years after it sent its first man into orbit. - .6.000 people had to be relocated for the construction
  • Ma Ru on 14 Sep 09
     
    > 6.000 people had to be relocated So what? It's less than 0.0005% of the population...
Dario Izzo

Optimal Control Probem in the CR3BP solved!!! - 7 views

math.u-bourgogne.fr/...research

OCP CR3BP trajectory MAD

shared by Dario Izzo on 07 Jun 11 - No Cached
  • Dario Izzo on 07 Jun 11
     
    This guy solved a problem many people are trying to solve!!! The optimal control problem for the three body problem (restricted, circular) can be solved using continuation of the secondary gravity parameter and some clever adaptation of the boundary conditions!! His presentation was an eye opener ... making the work of many pretty useless now :)
  • ...13 more comments...
  • Ma Ru on 08 Jun 11
     
    Riemann hypothesis should be next... Which paper on the linked website is this exactly?
  • Joris _ on 08 Jun 11
     
    hmmm, last year at the AIAA conference in Toronto I presented a continuation approach to design a DRO (three-body problem). Nothing new here unfortunately. I know the work of Caillau, although interesting what is presented was solved 10 years ago by others. The interest of his work is not in the applications (CR3BP), but in the research of particular regularity conditions that unfortunately make the problem limited practically. Look also at the work of Mingotti, Russel, Topputo and other for the (C)RTBP. Smart-One inspired a bunch of researchers :)
  • Dario Izzo on 08 Jun 11
     
    Topputo and some of the others 'inspired' researchers you mention are actually here at the conference and they are all quite depressed :) Caillau really solves the problem: as a one single phase transfer, no tricks, no misconvergence, in general and using none of the usual cheats. What was produced so far by other were only local solutions valid for the particular case considered. In any case I will give him your paper, so that he knows he is working on already solved stuff :)
  • Dario Izzo on 08 Jun 11
     
    Answer to Marek: the paper you may look at is: Discrete and differential homotopy in circular restricted three-body control
  • Joris _ on 08 Jun 11
     
    Ah! with one single phase and a first order method then it is amazing (but it is still just the very particular CRTBP case). The trick is however the homotopy map he selected! Why this one? Any conjugate point? Did I misunderstood the title ? I solved in one phase with second order methods for the less restrictive problem RTBP or simply 3-body... but as a strict answer to your title the problem has been solved before. Nota: In "Russell, R. P., "Primer Vector Theory Applied to Global Low-Thrust Trade Studies," JGCD, Vol. 30, No. 2", he does solve the RTBP with a first order method in one phase.
  • Joris _ on 08 Jun 11
     
    I think what is interesting is not what he solved, but how he solved the problem. But, are means more important than end ... I dunno
  • Dario Izzo on 08 Jun 11
     
    I also loved his method, and it looked to me that is far more general than the CRTBP. As for the title of this post, OK maybe it is an exageration as it suggests that no solution was ever given before, on the other end, as Marek would say "come on guys!!!!!"
  • Joris _ on 09 Jun 11
     
    The generality has to be checked. Don't you think his choice of mapping is too specific? he doesn't really demonstrate it works better than other. In addition, the minimum time choice make the problem very regular (i guess you've experienced that solving min time is much easier than mass max, optimality-wise). There is still a long way before maximum mass+RTBP, Topputo et al should be re-assured :p Did you give him my paper, he may find it interesting since I mention the homotopy on mu but for max mass:)
  • Dario Izzo on 09 Jun 11
     
    Joris, that is the point I was excited abut, at the conference HE DID present solutions to the maximum mass problem!! One phase, from LEO to an orbit around the moon .. amazing :) You will find his presentation on line.... (according to the organizers) I gave him the reference to you paper anyway, but no pdf though as you did not upload it on our web pages and I could not find it in the web. So I gave him some bibliography I had with be from the russians, and from Russell, Petropoulos and Howell, As far as I know these are the only ones that can hope to compete with this guy!!
  • Joris _ on 09 Jun 11
     
    for info only, my phd, in one phase: http://pdf.aiaa.org/preview/CDReadyMAST08_1856/PV2008_7363.pdf I prefered Mars than the dead rock Moon though!
  • Dario Izzo on 09 Jun 11
     
    If you send me the pdf I can give it to the guy .. the link you gave contains only the first page ... (I have no access till monday to the AIAA thingy)
  • LeopoldS on 11 Jun 11
     
    this is why I like this Diigo thingy so much more than delicious ...
  • tvinko on 17 Jun 11
     
    What do you mean by this comment, Leopold? ;-) Jokes apart: I am following the Diigo thingy with Google Reader (rss). Obviously, I am getting the new postings. But if someone later on adds a comment to a post, then I can miss it, because the rss doesn't get updated. Not that it's a big problem, but do you guys have a better solution for this? How are you following these comments? (I know that if you have commented an entry, then you get the later updates in email.) (For example, in google reader I can see only the first 5 comments in this entry.)
  • LeopoldS on 18 Jun 11
     
    I like when there are discussions evolving around entries
  • LeopoldS on 18 Jun 11
     
    and on your problem with the RSS Tamas: its the same for me, you get the comments only for entries that you have posted or that you have commented on ...
Luís F. Simões

NASA Turns to 3D Printing for Self-Building Spacecraft | Space.com - 4 views

www.space.com/sa-spacecraft-3d-printing.html

cubesat 3D printing NIAC

shared by Luís F. Simões on 17 Sep 12 - No Cached
LeopoldS liked it
  • SpiderFab Concept CREDIT: Unlimited Tethers
  • Luís F. Simões on 17 Sep 12
     
    CubeSats + 3D printing... for space. I'm surprised this isn't an ACT project :) more info: SpiderFab: Process for On-Orbit Construction of Kilometer-Scale Apertures
  • Dario Izzo on 18 Sep 12
     
    $100,000 from NASA's Innovative Advanced Concepts program to hammer out a design and figure out whether spacecraft self-construction makes business sense .... I can answer for 0$ ..... NO Infact the question is just stupid: a) spacecraft self-construction exist: then it is a no brainer to decide wether it makes business sense b) it does not: then there is no business
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