The actual number of pulse units is more difficult to answer, as their decided size is a bit arbitrary. As bigger nuclear charges are more effective, I choose pulse units giving your stated g of acceleration. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
Create a free Team What is Teams? Learn more. Ask Question. Asked 5 years, 10 months ago. Active 5 years, 9 months ago. Viewed times. Improve this question. Jerard Puckett 7, 2 2 gold badges 32 32 silver badges 78 78 bronze badges. John John 1 1 silver badge 6 6 bronze badges. That is neglecting the rocket equation - fuel needed to accelerate the fuel; just the payload.
As you want to increase craft speed using a certain propellant, you need to add exponentially more of the propellant to achieve linear growth of delta-V. The magnetic field then directs the energy as rocket exhaust, thereby accelerating the vessel. In deep space, there is only one hydrogen atom for every 10 cubic centimeters of space.
This means that the frontal scoop would need to be hundreds of kilometers across to scoop enough hydrogen atoms to funnel through to the reactor. Also, at ship speeds close to the speed of light, these atoms are traveling at the same relativistic speeds; the resulting cosmic rays would effectively fry the ship's passengers.
To counter this, Bussard proposed ionizing these atoms at a safe distance using a laser beam, and using a powerful magnetic field to funnel the ionized atoms into the ship, bypassing the ship's hull. There is an amazing characteristic of such a ship, assuming the highly advanced engineering and construction can someday be accomplished and the proposed fusion drive can be brought into existence. Let's assume a constant acceleration of 1g during the first half of the ship's journey, whereupon the ship decelerates to its destination at the same 1g for the comfort of all aboard.
The resulting velocity of the ship for most of the journey would be very close to the speed of light. This would mean that the relativistic effects of time dilation come into play for the passengers. For such a hypothetical voyage, Barnard's Star-six light-years away-could be reached in a little under eight years, ship time.
For longer voyages, even the center of our Milky Way galaxy could be reached in just 21 years. As Sagan said, traveling fast into space means traveling fast into the future-because those left behind on earth during such a hypothetical journey would perceive things very much differently.
For them, millions of years would have passed. Relativistic travels make distant interstellar space travel feasible-but only for those on board the voyage. In subsequent installments in this series, the history, science, and technology of these and other space nuclear propulsion projects will be explored in depth.
Stay tuned. Stan Tackett holds undergraduate degrees in mathematics and computer science, and is currently pursuing a Master's degree in computer science with specializations in uses of artificial intelligence in the nuclear industry. His interests in nuclear engineering include nuclear propulsion for space travel, fusion, computational fluid dynamics and reactor physics.
In his spare time he reads Piers Anthony as much as possible, and enjoys writing and editing crossover science fiction stories. Trump leaves space nuclear policy executive order for Biden team. New U. NASA work on lattice confinement fusion grabs attention. While lattice confinement fusion is not One small step for fission—on the Moon and beyond.
A reliable energy source is critical for long-duration space exploration. Nuclear energy has played a key supporting role in historic missions to Mars, Pluto, and across the Solar System for the last 50 years. On January 1 , the nuclear-powered New Horizons flew Are the Tides Turning for Advanced U. Other inertial confinement fusion-based projects have been proposed since Daedalus e.
Project Longshot but most have followed the same general design and hence have similar performance characteristics. In , a form of nuclear pulse propulsion based on mini-fission-fusion devices mini-nukes was proposed.
These would consist of a fissile core surrounded by a deuterium-tritium D-T layer as shown. On ignition, the high explosive would accelerate the aluminium and pusher layers and the D-T layer would heat up sufficiently for fusion to take place. The critical mass of the fission explosive is greatly reduced as neutrons from the fusion reaction will increase the rate of fission.
Because the critical mass of the fissile material can be reduced, the resulting explosion will also be smaller and can be more easily contained in a combustion chamber. This improves efficiency when compared to the Orion design.
While no designs have been created which employ mini-nukes as their form of propulsion, if practical tests are successful and the system cost is comparable to pure fission or fusion systems, we believe mini-nukes will be the way forward for nuclear pulse propulsion. Nuclear pulse drives have much higher specific impulses than chemical rockets and this allows a spacecraft to accelerate extremely quickly and reach their destinations in a much shorter time.
However, even though most of the technology required to implement such a drive has been actualised, implementation remains difficult. The stumbling blocks have been mainly political—nuclear test ban treaties make it impossible to carry out practical development and politicians are worried about angering nuclear-weary populations.
Also, the lack of a strong mission requirement makes funding for such projects scarce. Despite this, when space agencies begin to plan for manned missions beyond Mars, it is almost certain that they will look hard at this form of propulsion because it makes it possible to travel further, faster. Fission-based Configuration of Orion vehicle. Project Daedalus schematic with present-day space shuttle for comparison.
0コメント