A new era of spaceflight? Promising advances in rocket propulsion

The US Defense Advanced Research Projects Agency (Darpa) has recently commissioned three private companies, Blue Origin, Lockheed Martin and General Atomics, to develop nuclear fission thermal rockets for use in lunar orbit.

Such a development, if flown, could usher in a new era of spaceflight. That said, it is only one of several exciting avenues in rocket propulsion. Here are some others.

more…

continuing the old era of polluting the fuck out of the area

Tau.Neutrino said:

A new era of spaceflight? Promising advances in rocket propulsion

The US Defense Advanced Research Projects Agency (Darpa) has recently commissioned three private companies, Blue Origin, Lockheed Martin and General Atomics, to develop nuclear fission thermal rockets for use in lunar orbit.

Such a development, if flown, could usher in a new era of spaceflight. That said, it is only one of several exciting avenues in rocket propulsion. Here are some others.

more…

Already done in the 60’s, with the NERVA rocket (& other) tests.

Tau.Neutrino said:

A new era of spaceflight? Promising advances in rocket propulsion

The US Defense Advanced Research Projects Agency (Darpa) has recently commissioned three private companies, Blue Origin, Lockheed Martin and General Atomics, to develop nuclear fission thermal rockets for use in lunar orbit.

Such a development, if flown, could usher in a new era of spaceflight. That said, it is only one of several exciting avenues in rocket propulsion. Here are some others.

more…

> to develop nuclear fission thermal rockets for use in lunar orbit

Um, what? Better look up the link.

> In a nuclear fission thermal rocket, a propellant gas, such as hydrogen, is heated by nuclear fission to high temperatures, creating a high pressure gas within the reactor chamber. Like with chemical rockets, this can only escape via the rocket nozzle, again producing thrust. Nuclear fission rockets are not envisaged to produce the kind of thrust necessary to lift large payloads from the surface of the Earth into space. Once in space though, they are much more efficient than chemical rockets – for a given mass of propellant, they can accelerate a spacecraft to much higher speeds.

mollwollfumble said:

Tau.Neutrino said:

A new era of spaceflight? Promising advances in rocket propulsion

The US Defense Advanced Research Projects Agency (Darpa) has recently commissioned three private companies, Blue Origin, Lockheed Martin and General Atomics, to develop nuclear fission thermal rockets for use in lunar orbit.

Such a development, if flown, could usher in a new era of spaceflight. That said, it is only one of several exciting avenues in rocket propulsion. Here are some others.

more…

> to develop nuclear fission thermal rockets for use in lunar orbit

Um, what? Better look up the link.

> In a nuclear fission thermal rocket, a propellant gas, such as hydrogen, is heated by nuclear fission to high temperatures, creating a high pressure gas within the reactor chamber. Like with chemical rockets, this can only escape via the rocket nozzle, again producing thrust. Nuclear fission rockets are not envisaged to produce the kind of thrust necessary to lift large payloads from the surface of the Earth into space. Once in space though, they are much more efficient than chemical rockets – for a given mass of propellant, they can accelerate a spacecraft to much higher speeds.

Yep their ISP is up around 900 or perhaps better.

Spiny Norman said:

mollwollfumble said:

Tau.Neutrino said:

A new era of spaceflight? Promising advances in rocket propulsion

The US Defense Advanced Research Projects Agency (Darpa) has recently commissioned three private companies, Blue Origin, Lockheed Martin and General Atomics, to develop nuclear fission thermal rockets for use in lunar orbit.

Such a development, if flown, could usher in a new era of spaceflight. That said, it is only one of several exciting avenues in rocket propulsion. Here are some others.

more…

> to develop nuclear fission thermal rockets for use in lunar orbit

Um, what? Better look up the link.

> In a nuclear fission thermal rocket, a propellant gas, such as hydrogen, is heated by nuclear fission to high temperatures, creating a high pressure gas within the reactor chamber. Like with chemical rockets, this can only escape via the rocket nozzle, again producing thrust. Nuclear fission rockets are not envisaged to produce the kind of thrust necessary to lift large payloads from the surface of the Earth into space. Once in space though, they are much more efficient than chemical rockets – for a given mass of propellant, they can accelerate a spacecraft to much higher speeds.

Yep their ISP is up around 900 or perhaps better.

Ta. Are they getting that because they have exceedingly high temperatures or because the fuel being hydrogen is so light?

> A major engineering challenge is to sufficiently miniaturise a reactor so that it will fit on a spacecraft. There is already a burgeoning industry in the production of compact fission reactors, including the development of a fission reactor which is smaller than an adult human.

I’ve several times posted here a full scale nuclear reactor the size of a basketball that was built in the 1960s. The only real problem there is that the radiation requires a lot of shielding. But in space if the electonics are hardened then much less shielding would suffice.

There have been other small nuclear reactors. The ones on Russian subs were about twice the size of a human, and there have been much smaller ones since.

mollwollfumble said:

Ta. Are they getting that because they have exceedingly high temperatures or because the fuel being hydrogen is so light?

A bit of both I think.
There was a series study done on using a nuclear rocket for the 2nd stage in the Saturn 5 assembly, but of course it never eventuated.