In a little over four years, NASA’s Dragonflymission will launch into space and begin its long journey towards Titan, Saturn’s largest moon. As part of the New Frontiers program, this quadcopter will explore Titan’s atmosphere, surface, and methane lakes for possible indications of life (aka. biosignatures). This will commence in 2034, with a science phase lasting for three years and three and a half months. The robotic explorer will rely on a nuclear battery – a Multi-Mission Radioisotope Thermal Generator (MMRTG) – to ensure its longevity.
But what if Dragonfly were equipped with a next-generation fusion power system? In a recent paper, a team of researchers from Princeton Satellite Systems proposed how a Direct Fusion Drive (DFD) could greatly enhance a mission to Titan. This New Jersey-based aerospace company is developing fusion systems that rely on the Princeton Field-Reversed Configuration (PFRC). This research could lead to compact fusion reactors that could lead to rapid spacecraft, longer-duration missions, and miniature nuclear reactors here on Earth.
The research team was led by Michael Paluszek, the president of Princeton Satellite Systems (PSS) and an aeronautic and astrological engineer with a long history of experience in space systems and the commercial space industry. He was joined by multiple colleagues from PSS, the Princeton Plasma Physics Laboratory (PPPL), the Air Force Institute of Technology at Wright-Patterson AFB, and Princeton and Stanford University. Their proposal, “Nuclear fusion powered Titan aircraft,” recently appeared in Astra Astronautica.
Artist’s concept of a Bimodal Nuclear-Thermal/Nuclear-Electric spacecraft in Low Earth Orbit. Credit: NASA
The concept of nuclear propulsion goes back to the early Space Age when NASA and the Soviet space program sought to develop reactors to power future missions beyond the Earth-Moon system. Between 1964 and 1969, their efforts led to the Nuclear Engine for Rocket Vehicle Application (NERVA), a slow-fission reactor that would power a Nuclear-Thermal and Nuclear-Electric Propulsion (NTP/NEP) system. The former relies on heat generated by a reactor to turn hydrogen propellant into plasma (which is directed through nozzles to generate thrust). The latter involves a reactor providing electricity to a Hall-Effect thruster (aka. ion engine).
On the other hand, the Direct Fusion Drive (DFD) calls for a nuclear-fusion rocket engine that would produce both thrust and electric power for an interplanetary spacecraft. In a previous study, an international research team proposed how a spacecraft equipped with a 2-megawatt (MW) DFD could transport a 1000 kg (2200 lbs) payload to Titan in less than 2.6 years (~31 months). This is over twice the mass of the Dragonfly mission, which is (relatively speaking) a featherweight by comparison – 450 kg (990 lbs). A transit time of 2.6 years is also significantly less than the seven years the Dragonfly’s spacecraft will take to reach Titan.
In their paper, Palusek and his colleagues extended this work to include an aircraft (similar in concept to NASA’s Dragonfly) as the payload, which would explore Titan’s atmosphere and surface for years. As Paluszek told Universe Today via email, the key to this spacecraft concept is the PFRC process developed by researchers at the PPPL:
“The Princeton Field Reversed Configuration is a magnetic topology in which fields, produced by antennas, close the field lines in magnetic mirrors. The antennas produce what is called a rotating magnetic field (RMF). Fusion takes place in this closed field region. Additional lower-temperature plasma streams around the fusion region produce an exhaust stream with the best exhaust velocity and thrust for a given mission.”
Did you miss our previous article…
https://mansbrand.com/webb-examined-an-asteroid-belt-and-found-more-than-it-bargained-for/
Starship gave us quite a show during the first flight test of a fully integrated Starship (S24) and Super Heavy rocket (B7) from Starbase in Texas.
On April 20, 2023 at 8:33 a.m. CT, Starship successfully lifted off from the orbital launch pad for the first time. The vehicle cleared the pad and beach as Starship climbed to an apogee of ~39 km over the Gulf of Mexico – the highest of any Starship to-date.
With a test like this, success comes from what we learn, and we learned a tremendous amount about the vehicle and ground systems today that will help us improve on future flights of Starship.
Did you miss our previous article…
https://mansbrand.com/arabsat-badr-8-mission-control-audio/
This is the vehicle trajectory and mission control audio without any additional commentary. There may be very long periods of silence. For our full hosted webcast, visit
Did you miss our previous article…
https://mansbrand.com/when-black-holes-merge-theyll-ring-like-a-bell/
When two black holes collide, they don’t smash into each other the way two stars might. A black hole is an intensely curved region of space that can be described by only its mass, rotation, and electric charge, so two black holes release violent gravitational ripples as merge into a single black hole. The new black hole continues to emit gravitational waves until it settles down into a simple rotating black hole. That settling down period is known as the ring down, and its pattern holds clues to some of the deepest mysteries of gravitational physics.
Gravitational wave observatories such as the Laser Interferometry Gravitational-Wave Observatory (LIGO) have mostly focused on the inspiral period of black hole mergers. This is the period where the two black holes orbit ever closer to each other, creating a rhythmic stream of strong gravitational waves. From this astronomers can determine the mass and rotation of the original black holes, as well as the mass and rotation of the merged black hole. The pattern of gravitational waves we observe is governed by Einstein’s general relativity equations, and by matching observation to theory we learn about black holes.
General relativity describes gravity extremely well. Of all the gravitational tests we’ve done, they all agree with general relativity. But Einstein’s theory doesn’t play well with the other extremely accurate physical theory, quantum mechanics. Because of this, physicists have proposed modifications to general relativity that are more compatible with quantum theory. Under these modified theories, there are subtle differences in the way merged black holes ring down, but observing those differences hasn’t been possible. But a couple of new studies show how we might be able to observe them in the next LIGO run.
The modified Teukolsky equation. Credit: Li, Dongjun, et al
In the first work, the team focused on what is known as the Teukolsky Equation. First proposed by Saul Teukolsky, the equations are an efficient way of analyzing gravitational waves. The equations only apply to classical general relativity, so the team developed a way to modify the equations for modified general relativity models. Since the solutions to both the Teukolsky and modified Teukolsky equations don’t require a massive supercomputer to solve, the team can compare black hole ring downs in various gravitational models.
The second work looks at how this would be done with LIGO data. Rather than focusing on general differences, this work focuses on what is known as the no-hair theorem. General relativity predicts that no matter how two black holes merge, the final merged black hole must be described by only mass, rotation, and charge. It can’t have any “hair”, or remnant features of the collision. In some modified versions of general relativity, black holes can have certain features, which would violate the no-hair theorem. In this second work, the authors show how this could be used to test general relativity against certain modified theories.
LIGO has just begun its latest observation run, so it will be a while before there is enough data to test. But we may soon have a new observational test of Einstein’s old theory, and we might just prove it isn’t the final theory of gravity after all.
Reference: Li, Dongjun, et al. “Perturbations of spinning black holes beyond General Relativity: Modified Teukolsky equation.” Physical Review X 13.2 (2022): 021029.
Reference: Ma, Sizheng, Ling Sun, and Yanbei Chen. “Black hole spectroscopy by mode cleaning.” Physical Review Letters 130.2 (2023): 141401.
The post When Black Holes Merge, They’ll Ring Like a Bell appeared first on Universe Today.
Did you miss our previous article…
https://mansbrand.com/theres-a-polar-cyclone-on-uranus-north-pole/
-
Mens Health3 years ago8 Things I Do Before 8 Am: My Morning Routine
-
Fashion2 years ago
Best Timepieces To Buy For The Holiday Season
-
Fashion3 years ago
Steampunk Clothing & Jewelry
-
Sports2 years ago
Best Christmas Gift For Your Golfer Co-Worker
-
Trending Stories2 years ago
Dior Homme Cologne Men’s Fragrance Review
-
Motor2 years ago
2022 Infiniti QX55 Carigami Can Be Yours
-
Uncategorized3 years ago
How To Attract Women Easily (Without Talking)
-
Grooming3 years ago
5 Men’s Hairstyles For Thin Hair – Haircuts For Receding Hairlines