In order to get up to 72% of light speed within a 75 year acceleration period the ramjet must generate a thrust eqaul to 1 tenth the mass of the ramjet vehicle. Become a ufo contactee by joining the real space program vintage humor. If they cant do that, then its going to take them over a decade to achieve relativistic speed, which i dont consider very practical. Robert bussard theorized that spacecraft fuel could be gathered up en route using strong magnetic. Sagan summarized this paper in intelligent life in the universe in 1966 5, probably the best popularization of the ramjet.
Bussard ramjet by larry niven from a world out of time. His ramjet is a common propulsion system in science fiction novels, if not in real spacecraft. There they would be compressed and used to fuel a fusion reaction to propel the starship at relativistic speeds. A ramjet, sometimes referred to as a flying stovepipe or an athodyd aero thermodynamic duct, is a form of airbreathing jet engine that uses the engines forward motion to compress incoming air without an axial compressor or a centrifugal compressor. Is the behavior of the bussard ramjet as described in poul andersons novel tau zero accurate. Shown above are pictures of an x15 rocketpowered airplane with a ramjet slung underneath the body and a wind tunnel test of a ramjet inlet used on a missile. But reading about the bussard ramjet a few minutes ago, it seems that this might be theoretically possible given adequate speed has anyone calculated the minimum velocity necessary for a bussard ramjet to be able to achieve hydrogen fusion with a net positive. Complicated the system by introducing primitive edge effects. It is intended to circumvent the problems of rocket economics by collecting fuel as it goes along. Heppenheimer analyzed bussards original suggestion of fusing protons, but found the bremsstrahlung losses bremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charge.
What if we used a bussard ramjet scoop and got our propellant from the. Equation of motion of an interstellar bussard ramjet with radiation. Jun 14, 2014 have you ever imagined how interstellar travel could work. We have obtained estimates of the capabilities of the ramjet 3. Right up to his dying day, he was trying to raise funds, to build a full scale prototype, of his polywell nuclear fusion reactor design. Tau zero, by poul anderson, is a hard science fiction novel from 1970 the novel was expanded from a 1967 short story, to outlive eternity. Jun 02, 20 the bussard ramjet is a theoretical method of spacecraft propulsion proposed in 1960 by the physicist robert w. This engine is assembled using brand new, premium quality components. One such system was the bussard interstellar ramjet, which was proposed in the early 1960s by robert bussard.
Because the ramjet uses external air for combustion, it is a more efficient. An alternative to the bussard ramjet was presented in 1977 8. Jan 08, 2014 tau zero, by poul anderson, is a hard science fiction novel from 1970 the novel was expanded from a 1967 short story, to outlive eternity. In both propulsion systems, a rocket is used to bring the ramjet up to speed before it produces thrust. Bussard ramjets are also used as a weapon to accelerate blocks of ice to near lightspeed by yang wenli in episode 24 of the anime, legend of the galactic heroes. When a mass loss appears, the limit speed of the ramjet is more strongly reduced. The bussard ramjet got a boost in 1963 when carl sagan noted that there was a solution to the mass ratio problem for interstellar flight 4. Interstellar ramjets initiative for interstellar studies.
I guess this cant be a bussard ramjet because its from before 1960 1941 in fact, but it seems like the same general idea, or at least close enough for science fiction. It took magellans ships three years to sail around the world. We have opened questions about nonrelativistic and relativistic plasma flowing problems 4. Bussard ramjet, then they should be capable of sustained accelerations of at least 0. N92 527 supercharged ejector ramjet jerry rosevear kaiser marquardt van nuys, ca 91406 i. Nuclear rocket propulsion mcgraw hill series in missile and space technology.
The bussard ramjet now enters the shklovskiisagan discussion, in the context of other problematic starship ideas. Oct 01, 2007 an interstellar bussard ramjet is a spaceship using the protons of the interstellar medium in a fusion engine to produce thrust. Bussard proposed a ramjet variant of a fusion rocket capable of reasonable interstellar spaceflight, using enormous electromagnetic fields ranging from kilometers to many thousands of kilometers in diameter as a ram scoop to collect and compress hydrogen from the interstellar medium. Bussard ramjet in science fiction retrospeculative. Bussard, popularized by poul andersons novel tau zero, larry niven in his known space series of books, vernor vinge in his zones of thought series, and referred to by carl sagan in the television series and book cosmos bussard proposed a ramjet variant of a. This digital image shows a venerable design for an interstellar vehicle. We derive the equation of motion of such a spaceship for a given mass density in space and the fusion mass defect. As i have sugested before a bussard ramjet could by much more efficient if you make it an electro static scoop ir in other words using a laser to ionize atoms of hydrogyn and attracting them with an oppositly charged plate istead of the energy hoging and drag inducing magnetoscoop. The bussard ramjet design was originally proposed in 1960 by physicist robert w.
Obtained an integrated numerical model for a simplified engine 5. The bussard ramjet, suggested by physicist robert bussard in 1960, neatly solves this problem. Design and fabrication of a ramjet inlet clinton humphrey 1 california polytechnic state university, san luis obispo, ca, 93405 in this report, the design and fabrication of the inlet to a ramjet engine is described. But reading about the bussard ramjet a few minutes ago, it seems that this might be theoretically possible given adequate speed. Nov 17, 2017 a bussard ramjet is a relativistic spacecraft, fueled by fusion energy of cosmic matter that is collected during the flight. To get to even the closest stars in a reasonable amount of time, e. If we reduce the scramjet engine starting mach number to say 3. A bussard ramjet is a relativistic spacecraft, fueled by fusion energy of cosmic matter that is collected during the flight. The probable originator of the interstellarramjet concept is robert bussard, who.
Mar 26, 2012 the bussard ramjet now enters the shklovskiisagan discussion, in the context of other problematic starship ideas. Minimum velocity to achieve fusion with bussard ramjet. I think that other than in a star, nobody has achieved any fusion process with a net positive energy output. A ramjet combustion chamber is designed and some initial assembly fabrication and test completed as a component of a ramjet graduate project for california polytechnic state university, san luis. Two ramjet engine scenarios, where the thrust for propulsion is generated by emission of photons or acceleration of matter, are. Jul 02, 2002 the ramjet propulsion system, and its power sources.
Hamiltons nights dawn an alien race, inhabiting massive cities orbiting a red giant, uses a bussard ramjet with an electromagnetic scoop. However, when food is scarce, they merge together via chemical. Bussard, popularized by larry niven in his known space series of books, and referred to by carl sagan in the television series and book cosmos bussard proposed a ramjet variant of a fusion rocket capable of fast interstellar spaceflight, using enormous electro. Bussard ramjet science digest, may 1983, illustrating my article on the thencurrent situation in interstellar studies. Three popular clustering methods and when to use each. Bussard s ramjet ideas, followed by whitmires modifications, really did open up the idea of practical interstellar flight some fifty years ago, but. Has anyone calculated the minimum velocity necessary for a bussard ramjet to be able to achieve hydrogen fusion with a net positive energy output.
Information and translations of bussard ramjet in the most comprehensive dictionary definitions resource on the web. Bussard interstellar ramjet the problem with travelling to the stars is that theyre so far away. Throughout his spectacular career he had worked on many interesting things, including the thermonuclear rocket program in the 1950s, called project rover. Bussard, popularized by poul andersons novel tau zero, larry niven in his known. The late physicist robert bussard worked for decades to try to show polywell fusion could work, using a variety of wiffleball configurations. Because ramjets cannot produce thrust at zero airspeed, they cannot move an aircraft from a standstill. Throughout his spectacular career he had worked on many interesting things, including the nuclear thermal rocket program in the 1950s, called project rover. May 05, 2015 shown above are pictures of an x15 rocketpowered airplane with a ramjet slung underneath the body and a wind tunnel test of a ramjet inlet used on a missile. The bussard ramjet or ramscoop was first proposed in 1960 by the american physicist robert w bussard. Andrewjin she said she was studying in xian in some thread.
Ramjet design bussard found that an ideal ramjet for such interstellar travel would have a mass of tons and an ion intake area of km2 that would move through protons with a density of 1 billion meters3. Three interstellar ram jets lunar and planetary institute. The bussard ramjet is a theoretical method of spacecraft propulsion proposed in 1960 by the physicist robert w. In a recent paper, it was shown that the relativistic equation of. Bussard interstellar ramjet well, rather than bring your fuel along, why not get it as you go. The visionary robert bussard started his career at lanl designing nuclear positionfloatpowered rocket engines, including the bussard ramjet, which uses a magnetic field to scoop up interstellar hydrogen to fuel its fusion engine. Nuclear rocket propulsion mcgrawhill series in missile. A way out of these difficulties which approaches elegance in its conception has been provided by the american physicist robert w. Unfortunately, a fusion reactor that could combine protons directly to obtain. Bussard proposed a ramjet variant of a fusion rocket capable of reasonable interstellar travel, using enormous electromagnetic fields ranging from kilometers to many thousands of kilometers in diameter as a ram scoop to collect and compress hydrogen from the interstellar medium. He built a small prototype using a grant from the us navy. A single thermodynamic cycle is incapable of satisfying these broad requirements. Jul 30, 2018 the bussard ramjet promised the stars, if one were willing to invest a little time. The bussard ramjet promised the stars, if one were willing to invest a little time.
Mar 31, 2015 bussard at the end of his life, claimed to have solved these problems. Of course, we literally cannot imagine the capabilities of future technology, so the stated objections may eventually seem trivial. The ramjet 502 engine is manufactured on current production tooling. Pdf the mass ratio problem in interstellar flight presents a major problem1,2. Jul 25, 2012 it was in 1960 that the physicist robert w. The inlet utilizes a single ramp and single sided three shock internal compression to slow the. Later, he joined forces with brain cap, a fusion researcher from.
The design for such a scramjet engine is carried out. Interstellar vasimr bussard ramjet scoop powered by fusion. This forum is full of stupid rssers, i think she was bored. It took magellans ships three years to sail around the. In studies where the merged organism is placed on a grid depicting a city like. Heppenheimer analyzed bussard s original suggestion of fusing protons, but found the bremsstrahlung losses bremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charge. Im referring to robert heinleins novel methuselahs children, originally published as a serial in astounding sciencefiction. Bussard first proposed the interstellar ramjet in his seminal paper 1. Magnetic fields would collect stray hydrogen atoms and draw them into the funnel in the front. Two ramjet engine scenarios, where the thrust for propulsion is generated by emission of photons or acceleration of matter, are outlined. Tau zero by poul anderson is the quintessential ramjet story. Have you ever imagined how interstellar travel could work. Sep 18, 2001 unless these and other serious problems can be addressed, the bussard ramjet will remain a science fiction concept.
In recent papers, it was shown that the relativistic equation of motion of an ideal ramjet and of a ramjet with radiation loss are analytical. Interstellar vasimr bussard ramjet scoop powered by fusion on. This vehicle consisted of the payload, a fusion reactor, and a large electrical or magnetic scoop to collect onrushing charged particles along the flight path. Bussard ramjet plural bussard ramjets astronautics a fusion rocket that gathers fuel from the interstellar medium through attraction via a magnetic field, functioning akin to a regular ramjet. Electrostatic ion scoop one possible modification of the ramjet. Equation of motion of an interstellar bussard ramjet with. Because ramjets cannot produce thrust at zero airspeed, they cannot move an aircraft from a. Its just a combustion chamber, inlet diffuser some designs even go without, fuel injector, igniter, and flame guard. Sep 21, 2018 three popular clustering methods and when to use each.
One such system was the bussard interstellar ramjet, which was proposed. Well, rather than bring your fuel along, why not get it as you go. Nuclear rocket propulsion mcgraw hill series in missile and space technology r. The characterizations and dialogue are a bit pulpy for my tastes, but andersons imagination is wonderful, and the science is interesting, if somewhat dated e. An interstellar bussard ramjet is a spaceship using the protons of the interstellar medium in a fusion engine to produce thrust.
547 72 378 1304 770 650 1059 547 635 481 972 516 1310 1425 411 39 502 3 1158 162 584 996 1298 1329 819 807 183 578 267 1013 57