Direct Fusion Drive, is a unique fusion engine concept based on the Princeton Field-Reversed Configuration (PFRC) fusion reactor under development at the Princeton Plasma Physics Laboratory. The truly game-changing levels of thrust and power in a modestly sized package could integrate with our current launch infrastructure while radically expanding the science capability of these missions. NIAC grants require that a technology be studied in the context of a specific mission. The mission context is the delivery of a Pluto orbiter with a lander, which cannot be done with any other technology. Direct Fusion Drive (DFD) provides moderate thrust to allow for reasonable transit times to Pluto while delivering substantial mass to orbit: 1000 kg delivered in four years using 5 N constant thrust.
Source: Game Changing Direct Drive Fusion Propulsion Progress – NextBigFuture.com
We should have R&D facilities in space, so we can test new propulsion systems sooner.
SINCE THE BIRTH of the space age, the dream of catching a ride to another solar system has been hobbled by the “tyranny of the rocket equation,” which sets hard limits on the speed and size of the spacecraft we sling into the cosmos. Even with today’s most powerful rocket engines, scientists estimate it would take 50,000 years to reach our closest interstellar neighbor, Alpha Centauri. If humans ever hope to see an alien sunrise, transit times will have to drop significantly.
Of the advanced propulsion concepts that could theoretically pull that off, few have generated as much excitement—and controversy—as the EmDrive. First described nearly two decades ago, the EmDrive works by converting electricity into microwaves and channeling this electromagnetic radiation through a conical chamber. In theory, the microwaves can exert force against the walls of the chamber to produce enough thrust to propel a spacecraft once it’s in space. At this point, however, the EmDrive exists only as a laboratory prototype, and it’s still unclear whether it’s able to produce thrust at all. If it does, the forces it generates aren’t strong enough to be registered by the naked eye, much less propel a spacecraft.
Over the past few years, however, a handful of research teams, including one from NASA, claim to have successfully produced thrust with an EmDrive. If true, it would amount to one of the biggest breakthroughs in the history of space exploration. The problem is that the thrust observed in these experiments is so small that it’s hard to tell if it’s real.
Source: A Mythical Form of Space Propulsion Finally Gets a Real Test | WIRED
If the citizens of the United States want to remain the preeminent world power, we can only do that through space exploration, research, mining, and colonization.
In the near future, when a free person thinks of low cost, reliable, and open access to low Earth orbit and beyond, they should think of America and American free enterprise.