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santecarloni

Antimatter Propulsion Engine Redesigned Using CERN's Particle Physics Simulat... - 1 views

www.technologyreview.com/...27847

propulsion physics technology

shared by santecarloni on 15 May 12 - No Cached
  • santecarloni on 15 May 12
     
    Latest simulation shows that the magnetic nozzles required for antimatter propulsion could be vastly more efficient than previously thought--and built with today's technologies
Ma Ru

Dark Matter or Black Hole Propulsion? - 1 views

www.newscientist.com/...s-for-interstellar-travel.html

NRG propulsion star travel space PHY

shared by Ma Ru on 25 Nov 09 - Cached
  • Ma Ru on 25 Nov 09
     
    Anyone out there still doing propulsion stuff? Two more papers just waiting to get busted... http://arxiv.org/abs/0908.1429v1 http://arxiv.org/abs/0908.1803
  • ...5 more comments...
  • Luzi Bergamin on 26 Nov 09
     
    What an awful bunch of complete nonsense!!! But I don't think anybody wants to hear MY opinion on this...
  • pacome delva on 26 Nov 09
     
    wow, is this serious at all...!?
  • Luzi Bergamin on 26 Nov 09
     
    Are you joking?? The BH drive propses a BH with a lifetime of about an year, just 10^7 tons, peanuts!! Then you have to produce it, better not on Earth, so you do this in space, with a laser that produces an equivalent of 10^9 tons highly foucussed, even more peanuts!! Reasonable losses in the production process (probably 99,999%) are not yet taken into account. Engineering problems... :-) The DM drive is even better, they want to collect DM and compress it in a propulsion chamber. Very easy to collect and compress a gas of particles that traverse the Earth without any interaction. Perhaps if the walls of the chamber are made of artificial BHs?? Who knows??
  • LeopoldS on 26 Nov 09
     
    WRONG!!! we are all just WAITING for your opinion on this ....!!!
  • pacome delva on 27 Nov 09
     
    well, yes my remark was ironic... I'm surprised they did a magazine on these concepts...! But the press is always waiting for sensational. They do not even wait for the work to be peer-reviewed now to make an article on it ! This is one of the bad sides of arxiv in my opinion. It's like a journalist that make an article with a copy-paste in wikipedia ! Anyway, this is of course complete bullsh..., and I would have laughed if I had read this in a sci-fi book... but in a "serious" article i'm crying... For the DM i do not agree with your remark Luzi. It's not dark energy they want to use. The DM is baryonic, it's dark just because it's cold so we don't see it by usual means. If you believe the in the standard model of cosmology, then the DM should be somewhere around the galaxies. But it's of course not uniformly distributed, so a DM engine would work (if at all...) only in the periphery of galaxies. It's already impossible to get there...
  • Luzi Bergamin on 27 Nov 09
     
    One reply to Pacome, though the discussion exceeds by far the relevance of the topic already. Baryonic DM is strictly limited by cosomology, if one believes in these models, of course. Anyway, even though most DM is cold, we are constantly bombarded by some DM particles that come together with cosmic radiation, solar wind etc. etc. If DM easily interacted with normal matter, we would have found it long ago. In the paper they consider DM as neutralinos, which are neither baryonic nor strongly or electromagnetically interacting.
  • pacome delva on 27 Nov 09
     
    well then I agree, how the fu.. they want to collect them !!!
LeopoldS

NASA DARPA beamed energy propulsion report - 1 views

ntrs.nasa.gov/...20120002761_2012003334.pdf

shared by LeopoldS on 19 Mar 12 - No Cached
  • LeopoldS on 19 Mar 12
     
    Comprehensive report on beamed energy propulsion
  • dejanpetkow on 20 Mar 12
     
    whatever you want to know about bep you will find it somewhere at these 650 pages.
Lionel Jacques

NASA studying solar-electric propulsion for "space tugboat" - 0 views

www.gizmag.com/...21289

Space

shared by Lionel Jacques on 01 Feb 12 - No Cached
  • Lionel Jacques on 01 Feb 12
     
    NASA announced it was seeking proposals for mission concept studies of a high-power solar electric propulsion (SEP) system that could be used in a "space tugboat." Such a ship would be used ferry payloads in low Earth orbit (LEO) into higher energy orbits,
johannessimon81

Ionic propulsion for small satellites - 0 views

nextbigfuture.com/...sion-for-small-satellites.html

ionic propulsion satellites space technology

shared by johannessimon81 on 15 Jun 12 - No Cached
  • johannessimon81 on 15 Jun 12
     
    Ionic fluids in thrusters for microsatellites. Here also a link to a paper on the topic: .pdf
LeopoldS

Interacting Gears Synchronize Propulsive Leg Movements in a Jumping Insect - 0 views

www.sciencemag.org/...1254

bio biomimetics

shared by LeopoldS on 12 Sep 13 - No Cached
  • LeopoldS on 12 Sep 13
     
    not even gears are a human invention it seems ... Gears are found rarely in animals and have never been reported to intermesh and rotate functionally like mechanical gears. We now demonstrate functional gears in the ballistic jumping movements of the flightless planthopper insect Issus. The nymphs, but not adults, have a row of cuticular gear (cog) teeth around the curved medial surfaces of their two hindleg trochantera. The gear teeth on one trochanter engaged with and sequentially moved past those on the other trochanter during the preparatory cocking and the propulsive phases of jumping. Close registration between the gears ensured that both hindlegs moved at the same angular velocities to propel the body without yaw rotation. At the final molt to adulthood, this synchronization mechanism is jettisoned.
pacome delva

The Coolest Antiprotons - 2 views

focus.aps.org/st1

phy antiprotons antihydrogen

shared by pacome delva on 05 Jul 10 - Cached
  • Researchers cooled a cloud of about 4,000 antiprotons down to 9 kelvin using a standard approach for cooling atoms that has never been used with charged particles or ions. The technique could provide a new way to create and trap antihydrogen, which could help researchers probe a basic symmetry of nature.
  • hydrogen and antihydrogen should share many basic traits, like mass, magnetic moment, and emission spectrum. If antihydrogen and hydrogen have even slightly different spectra, it indicates some new physics principles beyond the standard model, a very big deal.
  • pacome delva on 05 Jul 10
     
    antihydrogen propulsion...?
  • ...1 more comment...
  • LeopoldS on 05 Jul 10
     
    how to efficiently direct it?
  • Nicholas Lan on 06 Jul 10
     
    didn't roger write an assessment of antimatter propulsion when he was in the ACT?
  • pacome delva on 06 Jul 10
     
    yeah the problem is the amount of antimatter you can get and more specifically how to trap it. I found that you would need around one gram to go to the outer Solar System. So we are far from that, but finding an efficient way to trap it, with an electromagnetic trap rather than solid walls is a first step !
Juxi Leitner

SPACE.com -- Solar Sail Spacecraft Steers with Sunlight for First Time - 0 views

www.space.com/...ail-sunlight-steer-100806.html

technology space propulsion attitude control

shared by Juxi Leitner on 11 Aug 10 - Cached
  • Juxi Leitner on 11 Aug 10
     
    The Japan Aerospace Exploration Agency spacecraft Ikaros now represents the first solar sail to have harnessed sunlight for both attitude control and propulsion, after it first launched May 21 alongside the Venus-bound orbiter Akatsuki.
Isabelle DB

Electric solar wind sail spacecraft propulsion - 6 views

www.electric-sailing.fi

propulsion energy

shared by Isabelle DB on 15 Oct 10 - No Cached
LeopoldS liked it
  • Isabelle DB on 15 Oct 10
     
    Do you know this one ? (no time to go through the bookmarks...)
  • ...2 more comments...
  • duncan barker on 15 Oct 10
     
    Not sure whether the group has seen this idea before, but it seems interesting. I like it
  • LeopoldS on 18 Oct 10
     
    yes, we did have a look at it, I think back in 2007 but its maybe time to re-assess it ... will put it on the miscellaneous list for Dejan, the new propulsion and plasma RF to come in January ...
  • Luís F. Simões on 09 Dec 10
     
    They just got 1.7 million euros from the EU "to build the laboratory prototypes of the key components of the electric sail": http://en.ilmatieteenlaitos.fi/press-release/121643
  • LeopoldS on 11 Dec 10
     
    very interesting info indeed!!
ESA ACT

Gravitational Propulsion - 0 views

arxiv.org/...0207123v1.pdf

PHY PRO

shared by ESA ACT on 24 Apr 09 - No Cached
  • ESA ACT on 24 Apr 09
     
    New Propulsion Systems
Thijs Versloot

Octopus robot makes waves with ultra-fast propulsion - 2 views

phys.org/...bot-ultra-fast-propulsion.html

technology octopus BIO robot

shared by Thijs Versloot on 06 Feb 15 - No Cached
LeopoldS liked it
  • Thijs Versloot on 06 Feb 15
     
    Technology/Robotics Scientists have developed an octopus-like robot, which can zoom through water with ultra-fast propulsion and acceleration never before seen in man-made underwater vehicles. Most fast aquatic animals are sleek and slender to help them move easily through the water but cephalopods, such as the octopus, are capable of high-speed escapes by filling their bodies with water and then quickly expelling it to dart away.
Thijs Versloot

Fission powered pulsed Z-pinch fusion propulsion concept - 1 views

www.sciencedirect.com/...S0094576512000458

propulsion

shared by Thijs Versloot on 19 Nov 13 - No Cached
  • Thijs Versloot on 19 Nov 13
     
    Pulsed device providing an Isp=20.000 with thrust of 40kN. There is an onboard fission reactor including shielding. Roundtrip to Mars in 30 days requires 350Mt of propellant, equivalent to delta_v=93200m/s
Joris _

A Singularity Approach to Space: Beamed Propulsion, AI, and Iridium on Steroids | Parab... - 8 views

www.parabolicarc.com/...ed-propulsion-iridium-steroids

technology

shared by Joris _ on 31 Aug 10 - Cached
Juxi Leitner liked it
  • Christos Ampatzis on 01 Sep 10
     
    you know what? if you exclude the title it is not so much bullshit! "Send a robot out into space - allow people to experience space via a virtual environment" I have always loved this idea!
  • ...2 more comments...
  • Juxi Leitner on 05 Sep 10
     
    do you want to add some of that to the humanoids in space acta futura article?
  • Joris _ on 06 Sep 10
     
    I looked at the wiki input on this, but I don't know what I should do. Aren't you writing the article. I definitely think there are some stuffs to pick up on the list and develop further.
  • Juxi Leitner on 06 Sep 10
     
    yeah i do but input is always more than welcome =)
  • LeopoldS on 07 Sep 10
     
    "I have always loved this idea!" - me too!!!
Joris _

NASA Developing Tech to Reach and Colonize Other Worlds | Gadget Lab | Wired.com - 4 views

www.wired.com/...each-and-colonize-other-worlds

technology space future

shared by Joris _ on 20 Oct 10 - No Cached
  • The most important near-term development is electric propulsion.
  • using high-density batteries powered off ground-based solar grids
  • microwave thermal propulsion
  • LeopoldS on 20 Oct 10
     
    "Within a few years we will see the first true prototype of a spaceship that will take us between worlds," Worden said. this sounds to me a bit too much like Pete Worden :-) but I really like this one :-) One of those billionaires might be Google's Larry Page, who is keenly interested in space travel and NASA Ames's research. "Larry asked me a couple weeks ago how much it would cost to send people one way to Mars and I told him $10 billion, and his response was, 'Can you get it down to 1 or 2 billion?,'" Worden told the Long Now audience. "So now we're starting to get a little argument over the price."
LeopoldS

Experimental Detection of Trinitramide, N(NO2)3 - Rahm - 2010 - Angewandte Chemie Inter... - 0 views

onlinelibrary.wiley.com/...abstract

PHY PRO propulsion space NRG

shared by LeopoldS on 09 Jan 11 - No Cached
  • LeopoldS on 09 Jan 11
     
    Dejan have a look at this ...
  • dejanpetkow on 10 Jan 11
     
    Would be nice to have some cross sections or transition probabilities for the possible transition (or decomposition) channels. But anyway, HEDM is one of the key short/mid-term topics in advanced energy, power, and/or propulsion.
santecarloni

Breakthrough Propulsion Physics - 7 views

www.grc.nasa.gov/bpp

propulsion physics space

shared by santecarloni on 26 Jan 11 - Cached
  • santecarloni on 26 Jan 11
     
    The competition is open....
  • Luzi Bergamin on 26 Jan 11
     
    And what does one win in the end? Yet another unfeasible concept to be archived somewhere in a journal? Look at "Millis hypothetical drives"... Give me a break, for sure!!
  • Dario Izzo on 26 Jan 11
     
    I like the sentence "16 peer-reviewed journal articles, and an award-winning website (Warp-When), all for a total investment of less than $1.6M". This gives 100.000 dollars per peer-reviewed paper (we neglect the award-winning web-site under the assumption that is the easy part....). With these number the ACT in 2010 cashed 1.4 millions only in research papers making it an obvious good investment for the European Space Agency also in austerity times!!!
anonymous

Nasa validates 'impossible' space drive (Wired UK) - 3 views

www.wired.co.uk/...lidates-impossible-space-drive

PHY space nasa propulsion emdrive

shared by anonymous on 31 Jul 14 - No Cached
  • anonymous on 31 Jul 14
     
    NASA validates the EmDrive (http://emdrive.com/) technology for converting electrical energy into thrust. (from the website: "Thrust is produced by the amplification of the radiation pressure of an electromagnetic wave propagated through a resonant waveguide assembly.")
  • ...3 more comments...
  • LeopoldS on 01 Aug 14
     
    I would be very very skeptic on this results and am actually ready to take bets that they are victims of something else than "new physics" ... some measurement error e.g.
  • anonymous on 02 Aug 14
     
    Assuming that this system is feasible, and taking the results of Chinese team (Thrust of 720 mN http://www.wired.co.uk/news/archive/2013-02/06/emdrive-and-cold-fusion), I wonder whether this would allow for some actual trajectory maneuvers (and to which degree). If so, can we simulate some possible trajectories, e.g. compare the current solutions to this one ? For example, Shawyer (original author) claims that this system would be capable of stabilizing ISS without need for refueling. Other article on the same topic: http://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results
  • Thijs Versloot on 04 Aug 14
     
    To be exact, the chinese reported 720mN and the americans found ~50microN. The first one I simply do not believe and the second one seems more credible, yet it has to be said that measuring such low thrust levels on a thrust-stand is very difficult and prone to measurement errors. @Krzys, the thrust level of 720mN is within the same range of other electric propulsion systems which are considered - and even used in some cases - for station keeping, also for the ISS actually (for which there are also ideas to use a high power system delivering several Newtons of thrust). Then on the idea, I do not rule out that an interaction between the EM waves and 'vacuum' could be possible, however if this would be true then this surely would be detectable in any particle accelerator as it would produce background events/noise. The energy densities involved and the conversion to thrust via some form of interaction with the vacuum surely could not provide thrusts in the range reported by the chinese, nor the americans. The laws of momentum conservation would still need to apply. Finally, 'quantum vacuum virtual plasma'.. really?
  • annaheffernan on 04 Aug 14
     
    I have to join the skeptics on this one ...
  • Marcus Maertens on 09 Aug 14
Thijs Versloot

Relativistic rocket: Dream and reality - 3 views

www.sciencedirect.com/...S009457651400040X

propulsion antimatter relativistic

shared by Thijs Versloot on 27 Mar 14 - No Cached
  • Thijs Versloot on 27 Mar 14
     
    An exhaustive overview of all possible advanced rocket concepts, eg.. "As an example, consider a photon rocket with its launching mass, say, 1000 ton moving with a constant acceleration a =0.1 g=0.98 m/s2. The flux of photons with E γ=0.5 MeV needed to produce this acceleration is ~1027/s, which corresponds to the efflux power of 1014 W and the rate of annihilation events N'a~5×1026 s−1 [47]. This annihilation rate in ambiplasma l -l ann corresponds to the value of current ~108 A and linear density N ~2×1018 m−1 thus any hope for non-relativistic relative velocity of electrons and positrons in ambiplasma is groundless." And also, even if it would work, then one of the major issues is going to be heat dispersal: "For example, if the temperature of radiator is chosen T=1500 K, the emitting area should be not less than 1000 m2 for Pb=1 GW, not less than 1 km2 for Pb=1 TW, and ~100 km2 for Pb=100 TW, assuming ε=0.5 and δ=0.2. Lower temperature would require even larger radiator area to maintain the outer temperature of the engine section stable for a given thermal power of the reactor."
  • ...2 more comments...
  • johannessimon81 on 27 Mar 14
     
    We were also discussing a while ago a propulsion system using the relativistic fragments from nuclear fission. That would also produce an extremely high ISP (>100000) with a fairly high thrust. Never really got any traction though.
  • dejanpetkow on 29 Mar 14
     
    I absolutely do not see the point in a photon rocket. Certainly, the high energy releasing nulcear processes (annihilation, fusion, ...) should rather be used to heat up some fluid to plasma state and accelerate it via magnetic nozzle. This would surely work as door-opener to our solar system...and by the way minimize the heat disposal problem if regenerative cooling is used.
  • Thijs Versloot on 31 Mar 14
     
    The problem is not achieving a high energy density, that we can already do with nuclear fission, the question however is how to confine or harness this power with relatively high efficiency, low waste heat and at not too crazy specific mass. I see magnetic confinement as a possibility, yet still decades away and also an all-or-nothing method as we cannot easily scale this up from a test experiment to a full-scale system. It might be possible to extract power from such a plasma, but definitely well below breakeven so an additional power supply is needed. The fission fragments circumvent these issues by a more brute force approach, thereby wasting a lot of energy for sure but at the end probably providing more ISP and thrust.
  • dejanpetkow on 03 Apr 14
     
    Sure. However, the annihilation based photon rocket concept unifies almost all relevant drawbacks if we speak about solar system scales, making itself obsolete...it is just an academic testcase.
Daniel Hennes

CubeSat Ambipolar Thruster - 2 views

www.kickstarter.com/...er-for-interplanetary-cubesats

space technology

shared by Daniel Hennes on 04 Jul 13 - No Cached
LeopoldS liked it
  • Daniel Hennes on 04 Jul 13
     
    "Cast your name into deep space in style!"
  • dejanpetkow on 04 Jul 13
     
    Interesting approach, but with 99.9% probability they will miserably fail (at least in terms of their time schedule) simply because the technology is untested. I haven't read the refs (which miss by the way important works of E. Ahedo et al. on magnetic nozzle acceleration by ambipolar effects), but 1. using water means that you produce oxygen radicals which will erode chamber walls (ionisation efficiency is not 100% and experimental tests haven't been performed yet). 2. Electronic excitation (and radiation), rotational excitation, vibrational excitation, and dissociation are all processes which consume energy and reduce ionisation efficiency drastically. 3. It is a miniaturised Helicon thruster. Theoretical analysis probably does not consider near field effects. Far field models are probably not applicable due to the size of the thruster. I expect some surprises during thruster testing. In any case - good luck!
  • dejanpetkow on 05 Jul 13
     
    Apparently, there is only one qualification constraint regarding CubeSat propulsion which is related to volatile propellant. Since they use water as propellant and are also the owner of the CubeSat it is actually up to them how they qualify their thruster. Given that it is also possible to qualify the thruster within 18 months - since they define what "qualification" means.
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