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Topic: Bussard ramjet


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In the News (Thu 24 Jul 14)

  
 interstellar ramjet
Set against the desirability of achieving speeds for star travel that are a significant fraction of the speed of light is the perennial problem of rocketry – having to carry, in addition to the payload, the reaction mass needed for propulsion.
The interstellar ramjet neatly avoids this problem by harvesting hydrogen for use as a propellant from the interstellar medium.
Finally, the Bussard ramjet will only work when the vehicle is moving fast enough to collect interstellar mass in usable amounts.
www.daviddarling.info /encyclopedia/I/interstellar_ramjet.html   (884 words)

  
 Ask Us A Question   (Site not responding. Last check: 2007-11-05)
The idea of the ramjet (not to be confused with the Pulse jet engine of V-1 flying bomb fame, or with the Scramjet) was patented as early as 1908 by René Lorin.
In a ramjet, owing to the high flight speed, the ram compression is sufficient to dispense with the need for a compressor and a turbine to drive it.
Ramjets generally give little or no thrust below about half the speed of sound, and they are inefficient (less than 600 seconds due to low compression ratios) until the airspeed exceeds 1000 km/h (600 mph).
www.cloverdalecaus.com /section/Ramjet   (1964 words)

  
 Bussard ramjet - Wikipedia, the free encyclopedia
For example, a ramjet might collect 1 gram of incoming ions per second from interstellar space beyond the heliopause, at a velocity of 50 km/s relative to the ramjet driven spacecraft.
One useful modification of the ramjet design is to use an electrostatic ion scoop, instead of an electromagnetic ion scoop to achieve the ion collection from space.
In Coyote by Allen Steele the Starship Alabama uses a Bussard ramjet for propulsion on the journey to 47 Ursae Majoris.
en.wikipedia.org /wiki/Bussard_ramjet   (2506 words)

  
 Bussard ramjet - Engineering - A Wikia wiki   (Site not responding. Last check: 2007-11-05)
The Bussard ramjet method of spacecraft propulsion was proposed in 1960 by the physicist Robert W. Bussard and popularized by Carl Sagan in the television series and subsequent book Cosmos as a variant of a fusion rocket capable of fast interstellar spaceflight.
However, in their calculations they assumed that: 1, the exhaust velocity of their interplanetary ion propulsion ramjet could not exceed 100,000 m/s which is 100 km/s; and, 2, that the largest available energy source could be a 500 kilowatt nuclear fission reactor.
The key condition that determines whether or not an interstellar ramjet will accelerate forward in the direction of its thrust is that the thrust of the ramjet must exceed drag that results from scooping up ions from space.
engineering.wikia.com /wiki/Bussard_ramjet   (1564 words)

  
 Bussard Ramjet (George Herbert; Henry Spencer)
It is reasonably obvious to anyone who does a real analysis of the Bussard ramjet instead of relying on analogy from "ordinary" jets.
Bussard himself suspected that the interstellar medium near the Sun might be too thin to run his ramjet.
The key problem for bussard ramjets has always been trying to deal with the energy lost accellerating the interstellar medium to ramship speed.
yarchive.net /space/exotic/bussard_ramjet.html   (1340 words)

  
 Bussard ramjet
The Bussard ramjet design was proposed in 1960 by the physicist Robert W. Bussard[?] as a variant of a fusion rocket.
It would use a large scoop to compress hydrogen from the interstellar medium and fuse it.
A problem which will have to be overcome is that most interstellar hydrogen is ordinary hydrogen-1, instead of the easier-to-fuse deuterium and tritium isotopes, and so makes a poor fusion fuel; it is possible that this could be overcome by using a carbon-nitrogen-oxygen catalysed nuclear cycle.
www.ebroadcast.com.au /lookup/encyclopedia/bu/Bussard_ramjet.html   (210 words)

  
 Webpage2
Bussard (1960) is usually credited with the first published mention of a ramjet, although he credits the idea to Ackeret (1946) in an earlier paper.
Bussard considered an idealized vehicle that moves in one dimension; he purposely ignored the conceptual engineering problems, and restricted his analysis to the acceleration capabilities.
Bussard notes that in principle this parameter is under the control of the reactor designer, whereas 'a' is controlled by the laws of nature.
homepage.ntlworld.com /andy-nimmo/Webpage2d.htm   (907 words)

  
 ITSF Brochure: Propulsion Techniques: Ram Scoop Devices
The ramjet or ram scoop is a device that uses a powerful magnetic field to collect interstellar hydrogen during flight.
The top speed of a Bussard ramjet is theoretically very close to the speed of light, but practically it may be hindered by the density of interstellar matter, the drag of the magnetic field and the braking of the incoming protons.
Modifications of the original ramjet concept include charging incoming neutral particles using a laser, getting the ramjet to ram speed using a light sail, boosting the thrust of the craft by anti-matter/ matter reactions, using an accelerator as an alternative reaction-mass drive – the last concept could be enhanced using fusion or anti-matter catalysation.
www.itsf.org /brochure/ramscoop.html   (1001 words)

  
 Bussard Interstellar Ramjet
Ramjets have been used for many years to propel aircraft and missiles to very high speed.
Like the RAIR the ramjet would scoop up the tenuous hydrogen gas filling interstellar space, but now it would go a stage further.
Instead of using it simply as a mass to accelerate (the change of momentum providing the thrust), it would actually employ it as nuclear fuel as well, fusing four hydrogen atoms into a helium atom.
www.bisbos.com /rocketscience/spacecraft/bussardramjet/bussard.html   (1103 words)

  
 Final Gallery
Dr. Bussard noted that the problem with most rockets and rocket designs was that they had to carry tremendous amounts of fuel just for short trips into orbit, and his incredible design would be the trick to solve the problem of heavy fuel tanks on board.
A ramjet is typically a jet engine that has a continuous inlet of air coming from the forward end that depends on the speed of flight for the compressing effect produced on the air rather than on a mechanical compressor.
Also, the acceleration of the Bussard Ramjet is only dependent on the size of the collecting funnel, the density of the interstellar hydrogen isotopes, the efficiency of the nuclear fusion reactors, and the mass of the ship.
aerospacescholars.jsc.nasa.gov /has/Students/finalgall.cfm?id=305   (1035 words)

  
 Articles: Cruising the Infinite: Strategies for Human Interstellar Travel, by Paul Lucas
The Bussard Ramjet concept relies on the fact that the vacuum of space is not quite as empty as we think.
Very efficient ramjet drives could come to within a hairbreadth's of the speed of light, though some source say that a ramjet's more practical limit may be between 50% and 85% of lightspeed.
One of the main difficulties in building a Bussard Ramjet (aside from getting it up to the minimal operational velocity of one to six percent of lightspeed) is creating magnetic fields large enough to gather enough fuel to be strong enough to handle the stresses of scooping and fusing hydrogen at significant fractions of lightspeed.
www.strangehorizons.com /2004/20040621/travel.shtml   (3947 words)

  
 Bussard Ramjets
A Bussard ramjet (named after R. Bussard, who first postulated the idea) is a rocket engine which collects its fuel and reaction mass from the interstellar medium as it moves through space.
This means the acceleration of a ramjet is dependent only on the size of the collecting funnel, density of the interstellar medium, efficiency of the nuclear fusion reaction, and mass of the ship, and is a constant over time.
Normally a Bussard ramjet needs to be moving at a certain threshold speed before the ramjet engine can begin operation.
www.dangermouse.net /gurps/science/ramjet.html   (906 words)

  
 Interstellar Rocketry   (Site not responding. Last check: 2007-11-05)
Bussard, such a vehicle would have a large scoop mounted on its fore end which sweeps up interstellar hydrogen as it travels and shunts it to a fusion reactor.
As conceived, the Bussard Ramjet involves considerable challenges in designing the intake fields and reactor.
In its basic configuration, it is a fusion rocket which enhances its performance by scooping the interstellar medium much like a Bussard Ramjet and uses the momentum and kinetic energy of the resulting mass flow to augment the performance of the fusion drives.
www.scientium.com /specials/sotm/starship/rockets.htm   (2797 words)

  
 BBC - h2g2 - The Bussard Ramjet - an Interstellar Drive? - A600436
The Bussard ramjet (or 'ramscoop') was first proposed in 1960 by the American physicist Robert W Bussard.
This is the 'medium' for the Bussard ramjet.
It has been called 'the ultimate in hard science fiction' and is strongly recommended to anyone with an interest in the concept of the Bussard ramjet.
www.bbc.co.uk /dna/h2g2/alabaster/A600436   (1131 words)

  
 Atomic Rocket: Slower Than Light
Accelerating at 1 g a Bussard ramjet could reach the center of the galaxy in a mere twenty years of proper time, and could theoretically circumnavigate the entire visible universe in less than a hundred years.
The Bussard ramjet concept has gotten a lot of scrutiny, trying to derive a spin-off concept without the crippling flaws but with most of the benefits.
In a pure Bussard ramjet, the hydrogen scooped up has to be braked to a stop, creating drag (unless you can manage to make the hydrogen fuse while it is still travelling at whatever percentage of lightspeed the starship is travelling, which is pretty darn close to being impossible).
www.projectrho.com /rocket/rocket3aj.html   (8510 words)

  
 Bussard Ramjet
This was first proposed in a 1960 paper by Robert W. Bussard and popularised by Carl Sagan in the Cosmos television series (1980).
Then there is the size of the magnetic scoop, which needs to be upwards of 50,000 kilometers in diameter to collect the needed fuel and even in the vacuum of interstellar space that can produce drag like trying to go swimming underwater while pushing a washtub in front of you.
This has lead to some calculations that the ramjet might not be able to go faster than 16% of the speed of light.
www.davidszondy.com /future/space/bussard.htm   (386 words)

  
 Robert W Bussard: Electrostatic Confinement Fusion
In 1960, Bussard famously conceived the Bussard ramjet, an interstellar space drive powered by hydrogen fusion using hydrogen collected using a magnetic field from the interstellar gas.
Bussard proposed using a large magnet to "scoop" up the ionized hydrogen and funnel it into a fusion reactor, using the exhaust from the reactor as a rocket engine.
Bussard claimed on the fusor.net forum that his company had developed an inertial electrostatic confinement fusion process that is 100000 times more...
www.rexresearch.com /bussard/bussard.htm   (4387 words)

  
 Bussard, Robert W.
Bussard, Robert W. An American physicist who, in 1960, while working for the TRW Corporation of Los Angeles, suggested a form of interstellar propulsion based on the principle of the ramjet.
This is now often referred to as the Bussard ramjet or the interstellar ramjet.
Bussard, R. "Galactic Matter and Interstellar Flight," Astronautica Acta, 6, 179 (1960).
www.daviddarling.info /encyclopedia/B/Bussard.html   (130 words)

  
 BBC - h2g2 - The Bussard Ramjet - An Interstellar Drive?
As with conventional ramjets, the Bussard ramjet cannot accelerate from a standing start.
The pilot of a Bussard ramjet could conceivably set it to accelerate at a constant 1g.
The short story is more of a cautionary tale of the unforeseeable consequences of cryonic preservation, and the novel is a fantasy of the far future, but both rely on the concept of the Bussard ramjet in passing.
www.bbc.co.uk /dna/h2g2/A578153   (1018 words)

  
 [No title]
One concept that was proposed over 20 years ago was the Bussard ramjet.
The Bussard Ramjet collects and uses the hydrogen of interstellar space as a propellant.
The Bussard ramjet will only work when the vehicle is moving fast enough to collect enough interstellar mass.
zebu.uoregon.edu /~js/space/lectures/lec28.html   (1209 words)

  
 Lorem Ipsum: Bussard on safe cheap fusion
Robert Bussard, best known in the sf world as inventor of the Bussard ramjet, has spent the past 15+ years working on building a cheap, safe fusion reactor.
If you don’t have time to watch the (90-minute-long) video, there’s a posting from June at randi.org (written by Bussard, posted by someone else) that provides a brief summary of what happened.
Bussard’s group had what appeared to be a huge breakthrough late in 2005, literally days before they had to shut down the lab because their funding had run out.
www.kith.org /journals/jed/2006/11/16/3729.html   (737 words)

  
 Bussard buzz-bomb (Jordin Kare)   (Site not responding. Last check: 2007-11-05)
Very briefly, the Bussard Buzz-Bomb is the catchy name for a concept I came up with a few years ago (in the middle of a conference on robotic interstellar probes, in fact); the formal paper is titled Impact Fusion Runway for Interstellar Propulsion.
(Bussard's current project, electrostatic confinement fusion, would solve the first problem if it works, but I will be surprised if it does).
Because it's a distant descendant of Bussard's original ramjet interstellar vehicle, and it's a pulse jet, just like the V-1.
yarchive.net /space/exotic/bussard_buzz-bomb.html   (496 words)

  
 Holistic Design Forums - Pre-2nd republic Ships plus Antinomist Raiders
The Daedalus and Bussard ramjet ships would have been used for interplanetary travel in Earth's solar system during the pre-jumpgate period of the 1st Republic (2100-2305) and would be used as the slower-than-light ships for the republic's interstellar colonization effort, with crew and tens of thousands of passengers kept in cryogenic sleep.
After all, the Daedalus and Bussard ramjet ship designs would provide a very good idea about how 1st republic spacecraft were more primitive and larger/bulkier/cumbersome than 2nd Republic ships.
The Antinomist starships would be based upon the Daedalus and Bussard ramjet ship models, but also would have short-range shuttlecraft of the type designed and built by First Republic government and zabaitzu.
forums.holistic-design.com /topic.asp?TOPIC_ID=477   (2685 words)

  
 Advanced-starships
The Bussard ramjet would collect thin plasma from space, fuse some of it for energy and reach high speeds without carrying any propellant at all on the ship.
A ramjet will inhale plasma from space and even small objects and the magnetic field wil deflect other small objects, so it has it's own collision protection system.
If the ramjet is possible, we could get away from propulsion beams and tugs altogether and build a starship with more independent manueverability.
www.moonminer.com /Advanced-starships.html   (898 words)

  
 Bussard Ramjet by Larry Niven from A World Out of Time
They caught interstellar hydrogen in immaterial nets of electromagnetic force, compressed and guided it into a ring of pinched force fields, and there burned it in fusion fire.
Potenially there was no limit at all on the speed of a Bussard ramjet.
The Bussard ramjet design was originally proposed in 1960 by physicist Robert W. Bussard.
www.technovelgy.com /ct/content.asp?Bnum=324   (393 words)

  
 Bussard ramjet - Science Watch - Science forums
All their reaction mass is provided by the atmoshere through which they are flying (that same atmosphere that’s reducing their top speed with friction.
And, in the sixties, a gentleman named Robert Bussard proposed the same solution for interstellar travel.
In the more likely case that the hydrogen couldn't be converted entirely into energy, the maximum velocity that could be attained by the vessel (after an infinite acceleration time) would be just slightly lower than the ejection speed of the plamsolised reaction mass.
sciencewatch.co.uk /showthread.php?p=207777   (1882 words)

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