[The planetary nebula M 2-9, winds from a dying star. Credit: NASA / ESA / Hubble Legacy Archive / Judy Schmidt]
Something I think you’ll like
You may know Raya Yarbrough’s voice, especially if you watch Outlander — she’s the one who sings in the opening credits. If you don’t know her, do yourself a favor and give that a listen. Her voice is, frankly, amazing.
She’s been producing her own music during the pandemic, and recently released this terrific song, “Holler Down to Your Girl”, which is pretty cool.
I had the pleasure of meeting her at San Diego Comic Con in The Before Times, back in 2019. He husband is Bear McCreary, who composed music for that movie you like; we did a Comic Con panel together years back when he did the music for the movie “Europa Report” and we hit it off. I hung out after his 2019 panel to meet up with him, and Raya was there so I introduced myself and we talked for quite a while. She’s everything you’d hope she’d be: Funny, intelligent, charming, curious about life and science… I do so love it when an artist I admire is also a person I admire. That’s not always the case, but with Raya you can count on it.
What I’ve recently written on the blog, ICYMI
Monday 8 March, 2021: A quasar at the edge of the observable Universe has its radio turned *way* up
Tuesday 9 March, 2021: A new nearby super-Earth’s atmospheric secrets may soon be revealed
Wednesday 10 March, 2021: The Universe is acting funny. Or we’re looking at it wrong.
Thursday 11 March, 2021: Epic Martian cloud forms every summer day around an immense volcano
Friday 12 March, 2021: A second wind — literally — for a scorching super-Earth
Space is big. That’s why we call it “space”
Getting to space means, in general, using a rocket. But once you’re in space, well, the sky’s the limit. Or really, it’s not.
NASA is looking into ways of moving around in space that don’t use chemical rockets. One idea I really like is using a light sail: A big sheet of reflective material (usually Mylar) that’s very lightweight, and uses light from the Sun to accelerate.
This relies on a weird relativistic idea that photons have momentum even if they don’t have mass. But they do! I explain all that on the blog in an article I wrote about an experimental light sail built by The Planetary Society (and which worked quite well). The beauty of them is that they don’t need fuel, and accelerate for long periods of time, making them capable of building up fierce amounts of velocity. Sailing to other stars is possible in a human lifetime!
[Artwork depicting The Planetary Society’s solar sail in space. Credit: Josh Sprading / The Planetary Society]
NASA is putting together a sail prototype called Solar Sail, and contracted with Ball Aerospace to do a lot of testing an integrating of the sail with the spacecraft. I’m all for this. They start off slow, but get moving so rapidly that in the end they can get to the planets faster and more efficiently than chemical rockets.
Another idea is to use nuclear propulsion. A rocket works basically by throwing stuff out the back as hard as it can, and the faster your propellant blows back the more thrust your rocket has. A nuclear reactor can heat propellant (like hydrogen gas, say) to extremely high temperatures, giving a huge amount of thrust, much more than chemical rockets, and can burn for a longer time too. This is called nuclear thermal propulsion.
[Art depicting a nuclear thermal propulsion rocket. Credit: NASA]
A third way is nuclear electric, which uses heat from a nuclear reactor to generate electricity, and that is used to accelerate ionized gas out the back, similar to electric thrusters in use now.
A committee commissioned by NASA looked into these and recommended that nuclear thermal is preferable in getting humans to Mars. Such a rocket could make the trip in three months, half the time of a chemical rocket. It also builds on technology we already have, and could be developed relatively rapidly. Electric thrusters are good too, but the committee felt it wasn’t clear how well they would perform for this task.
Both of these craft — sails and nukes — seem like scifi, but both are on solid theoretical footing, and the sail has already been shown to work in principle. We will still use chemical rockets to get these craft into space, but once there the trips become a whole lot easier. I’d love to see either or both of these be put to use.
Getting to space is hard, and getting around is hard too. But it’s possible that in a few years it’ll be a whole lot easier.
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