Exploring the Potential of Fission-Fragment Rocket for High-Speed Space Missions

In summary, the fission-fragment rocket is a promising technology for high-speed space missions, but it is currently at a low Technology Readiness Level and requires further research and investment. Other contenders for nuclear propulsion include the NERVA and Timberwind designs, but all nuclear propulsion presents serious engineering challenges. The estimated speed of the fission-fragment rocket for a 10-year voyage to the gravitational focus at 550 AU is 569,160 mph, which may not be its maximum speed.
  • #1
cjackson
39
0
Fission-fragment rocket

The wiki entry seems to paint this system in a positive light, so is it a workable propulsion system for high speed space missions?

How long would a trip to Pluto take with something like this?

How many years away is this from becoming a reality?
 
Engineering news on Phys.org
  • #2
cjackson said:
Fission-fragment rocket

The wiki entry seems to paint this system in a positive light, so is it a workable propulsion system for high speed space missions?
From the article, emphasis mine: "The design can, in theory, produce very high specific impulses while still being well within the abilities of current technologies." This is pretty much the standard claim made by a proponent of some technology that is at a perpetually low Technology Readiness Level (TRL).

It, along with several other contenders, is a promising technology, so it does merit continued (but smallish) investments of research monies. There's no telling if it is a workable technology. It would be premature to put sizable amounts of monies into this, or any other technology that is at a perpetually low TRL.
 
  • #3
cjackson said:
Fission-fragment rocket

The wiki entry seems to paint this system in a positive light, so is it a workable propulsion system for high speed space missions?

How long would a trip to Pluto take with something like this?

How many years away is this from becoming a reality?
The wiki article doesn't really have any reliable sources/citations. It only has one citation. There is a lot wrong with what is presented, especially in the concepts described by the two figures.

One big problem is that fission fragments in solids have a range of travel on the order of 4 to 7 microns, the heavier particles traveling in the lower range, and the lighter nuclei traveling in the upper range.

Alternative concepts have called for gaseous core reactors, but those have low fission density - fissions per unit volume.

In propulsion, high Isp systems usually have low mass flow rates and low thrusts, and require a lot of power. The trade off is low mass of stored propellant at the expense of thrust. The ultimate goal in propulsion is to maximize specific power or power density, while minimize stored propellant (lower mass to accelerate), but subject to the constraints imposed by the mechanical (physical) limits of materials (tensile strength, creep, fatigue resistance, fracture toughness, melting point) with which we much construct the propulsion system.
 
  • #4
D H said:
From the article, emphasis mine: "The design can, in theory, produce very high specific impulses while still being well within the abilities of current technologies." This is pretty much the standard claim made by a proponent of some technology that is at a perpetually low Technology Readiness Level (TRL).

It, along with several other contenders, is a promising technology, so it does merit continued (but smallish) investments of research monies. There's no telling if it is a workable technology. It would be premature to put sizable amounts of monies into this, or any other technology that is at a perpetually low TRL.

Please name the other contenders.
 
  • #5
Even the simplest nuclear propulsion designs present serious engineering challenges.
While NASA did gas flow tests with the ground bound prototype of the NERVA nuclear rocket in the early 1960s, the more recent (early 1980s) USAF Timberwind design for a nuclear upper stage engine had a serious partial melt (while tested without nuclear materials, just with electric heaters) because the flow of cooling hydrogen was disrupted by a structural defect. High pressure and high temperature together make for very difficult environments for any material. Adding high radiation levels makes it even worse.
 
  • #6
http://rbsp.info/rbs/RbS/PDF/aiaa05.pdf

That says 180 kg of fuel would be required for a 10 year voyage to the gravitational focus at 550 AU.

So that means that it will travel 51,125,693,998.5 miles in 10 years at 569,160 mph = .00085c

Would that be the ships maximum speed?
 
Last edited by a moderator:

What is a Fission Fragment Rocket?

A Fission Fragment Rocket is a type of propulsion system that uses the energy released from nuclear fission to generate thrust, similar to a nuclear reactor. It involves splitting atoms to create smaller, highly energetic particles called fission fragments, which are then expelled out of the back of the rocket to provide thrust.

How does a Fission Fragment Rocket work?

A Fission Fragment Rocket works by using nuclear fission to create a chain reaction, which produces a large amount of energy in the form of heat. This heat is then used to convert a propellant, such as hydrogen, into a high-velocity gas that is expelled out of the back of the rocket. The fission fragments themselves also contribute to the thrust by being directed out of the back of the rocket at high speeds.

What are the advantages of using a Fission Fragment Rocket?

One of the main advantages of a Fission Fragment Rocket is its high efficiency and specific impulse, which refers to the amount of thrust generated per unit of propellant. Fission fragment rockets have the potential to provide much higher specific impulse compared to traditional chemical rockets, meaning they can travel farther and faster with the same amount of propellant. Additionally, fission fragment rockets are powered by nuclear energy, which is much more energy-dense than chemical energy, allowing for longer missions and less fuel storage.

What are the challenges of using a Fission Fragment Rocket?

There are several challenges associated with the use of Fission Fragment Rockets. One of the main challenges is the safety and environmental concerns surrounding the use of nuclear energy. Another challenge is the technical complexity of designing and building a fission fragment rocket, as it requires highly specialized materials and precise control systems to prevent a potential meltdown. Furthermore, the cost of developing and launching a fission fragment rocket is currently much higher compared to traditional rockets, making it less feasible for commercial use.

Are there any current projects or plans for using Fission Fragment Rockets?

There are several ongoing projects and proposals for using fission fragment rockets. NASA has been exploring the use of fission fragment rockets for deep space missions, such as a potential mission to Mars. There are also private companies, such as Interstellar Technologies and SpaceWorks Enterprises, that are actively researching and developing fission fragment rocket technology for potential use in future space missions. However, there are still many technical and regulatory challenges that need to be addressed before fission fragment rockets can be used in practical applications.

Similar threads

Clean lithium fission saltwater rocket
    • Nuclear Engineering
2
Replies
46
Views
12K
I Fission caused by positrons - in a fission fragment rocket?
    • High Energy, Nuclear, Particle Physics
Replies
11
Views
2K
NASA NASA - Bimodal NTP/NEP with a Wave Rotor Topping Cycle
    • Aerospace Engineering
Replies
1
Views
2K
Rocket possible collision with Moon
    • Aerospace Engineering
Replies
19
Views
2K
Exploring Electron Rockets for Interstellar Travel
    • Aerospace Engineering
Replies
5
Views
1K
Some ideas on interstellar space travel
    • Science Fiction and Fantasy Media
Replies
22
Views
3K
The Nuclear Rocket that Could Reach 20% of the Speed of Light
    • Aerospace Engineering
Replies
7
Views
2K
Simulation software for modeling a dusty fission reactor variant.
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
2K
My arXiv preprint on a crewed interstellar spacecraft
    • Science Fiction and Fantasy Media
Replies
15
Views
2K
Other Which pathway should I take for my brilliant dream to come true?
    • STEM Academic Advising
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top