Source: Radical Idea Shows Laser Propulsion Could Rapidly Accelerate Trips to Mars . . . a team of researchers from Montreal's McGill University assessed the potential of a laser-thermal propulsion system. According to their study, a spacecraft that relies on a novel propulsion system – where lasers are used to heat hydrogen fuel . . . Referencing hydrogen normally makes me 'turn the page' as we've seen so many hydrogen frauds but what the heck, I scanned the rest only to find: . . . While much of the technology in this proposed mission architecture – and other similar proposals – is still in the theory and development phase, there is no doubt about their potential. Reducing the time it takes to get to Mars to a matter of weeks instead of months will address two of the biggest challenges for Mars missions – logistical and health considerations. Furthermore, establishing a rapid-transit system between Earth and Mars will speed the creation of infrastructure between Earth and Mars. This could include a Gateway-like space station in orbit of Mars, like the Mars Base Camp proposed by Lockheed Martin, as well as a laser array to decelerate incoming spacecraft. . . . Then I realized this is science fiction like earlier articles that predated: aviation; spaceflight; nuclear, and; bioengineering. Science fiction is aspirational and can inspire breakthrough work. But it can also lead to shady characters selling 'snake oil' (which is a thing.) Bob Wilson
We should be getting to Mars before any of this aspirational stuff is ready, so it would be for future mass transit and tourism, not initial exploration. I also can't yet take it seriously when the project doesn't have enough oversight and review resources to catch "break" vs "brake" mistakes: "... development of high-temperature materials that allow the spacecraft to break against the Martian atmosphere upon arrival.”"
I should also point out that this is not a hydrogen "fusion" proposal. There is no nuclear fusion here. Instead, it is laser-thermal, using captured laser energy, directed from a distant external source, to heat hydrogen propellant to a much higher temperature than is possible from chemical combustion. This is used to achieve a higher exhaust velocity and specific impulse, allowing the job to be done with a lighter load of propellant. For comparison, the Space Shuttle Main Engines had a specific impulse of about 450, or exhaust velocity of about 4400 m/s. This proposal is aiming for a specific impulse in the range of 3000, corresponding to rocket chamber temperature of about 10,000 K, and apparently an exhaust velocity around 30,000 m/s.
For most of Ben Bova's "Grand Tour" series of books, there's a "fusion torch drive" for high-speed, but slower-than-light, travel. Not much detail on how it works, though.
I was on Gumtree this week, looking for a desk. (Do they have Gumtree in America? It's like Craigslist without the drugs and prostitution.) The number of people who said their desks had "three draws" or "built-in draws". I honestly think more people wrote "draws" than "drawers". It was a disgrace. And car sales websites are full of cars with "good breaks" or that "need new breaks". What, are we talking about cars that are good for surfing on?
I'm finding 0 ads within 100 miles of my zip code. Expanding the search to Nationwide, I see all prices shown in £, no $. Displayed Nearby locations are all in the UK. My own informal writings are getting sloppier with age, and with increasing exposure to even worse material from very many others. Some gets caught and corrected before edit windows expire, but I keep wondering how much has become mentally baked in such that I can't notice anymore. But I still expect much better than 'breaks' vs 'brakes' in formal materials from universities and news and technical media. I didn't read any of it, but it sounds like a sufficiently plausible sci-fi idea to leave at just that, without enough technical detail to draw naysayers and factcheckers. Some time long after ground-based fusion power plants starting operating -- six decades ago they were just two decades away, now maybe three for four decades away -- it eventually ought to reach space propulsion too. The theoretical potential should be far higher than this laser-thermal concept, with direct drive hydrogen fusion expelling its exhaust products at velocities a good fraction of light speed. The biggest challenge will be in not exterminating our own evolutionary branch before we can reach that technology.
Considering the very many abuses by that institution that keep getting revealed nearly everywhere it has been, I'll pass on that option.
I've worked with several parochial school survivors in the past. It's not pretty. We'd need to refine beryllium into superberyllium before it will help get us to the stars. think flexfuel like oxygen + hydrogen from the early years.
