A new space-based solar power concept enters the chat. Let's take a look at @AetherfluxUSA 's proposal.

As with so many things in space, the focus is often on the tech, but the thing that is make-or-break for SBSP isn't technical; it's economic. Let's dive in.

https://twitter.com/BaijuBhatt/status/1844063967020458425

After running numbers on *hundreds* of combinations of SBSP ideas, I can say that the economic feasibility of an SBSP idea boils down to three numbers:

1) The $/W of setting up the panels
2) The $/Wh you can charge to customers
3) The operational lifetime of the system

I encountered a delightful little astrodynamics proof last week when an astronaut casually stated it as a fact, and when I looked skeptical, he just smiled and said, "Check it yourself."

Here's the statement:

"It takes 2 hours to orbit at the surface of any object made of rock" My first thought was that it couldn't be right since Low Earth Orbit period isn't 2 hours; it's 1.5. But of course,🌎isn't a rock; 🌎has an iron core that bumps our density up to ~twice that of rock, (and actually makes Earth the densest planet in the solar system)

I am where I am in my career today because of hard work, support from friends and family, and luck. But today, I ran into a former SpaceX colleague who reminded me of a factor I often forget: I am where I am today because I did theater in school to fulfill a sports credit.🧵 The first space job I ever had was in '10 where I was fortunate to be one of 14 students from a pool of +1000 candidates for the @NASAAmesAcademy. I worked in the @NASAAmes director’s office with Gen. Pete Worden. Still the most insightful 3 months I’ve had into how NASA works.

Oh! I am *so* glad you asked that question! Thread incoming:

https://twitter.com/WWIPhD/status/1167655616829165570

1/ If you want to make an experimental astronomer cringe, here are two good ways to do it:

1) Touch an eyepiece with your bare finger.

2) Say the words "flat field".

Hey! It's been weeks since I raved about how awesome #SpaceElevators are. That's too long. Here is my take on 5 portrayals of space elevators that I've seen in science fiction (Not definitive, and limiting myself to visual media). #5) The planet Drill from Star Trek 2009. Completely impractical, and only exists because it's a fun setting for a 23rd-century sword fight. But not a complete loss because it correctly shows how space elevators are deployed (lowered down from orbit, not built up from the ground)

3... 2... 1... 22:23 GMT! Happy #WinterSoltice Earth!

I'm going to let you in on a little trade secret: There is script astronomers are supposed to follow today when explaining what the solstice is, and that script goes something like this: 1) Construct a strawman who mistakenly thinks winter is because Earth has gotten further from the sun.

2) Ask the strawman "Ah! But if that *were* the cause of winter, then why is it summer in the southern hemisphere right now?"

November is here, and that means a massive shift is coming. And by "massive" I am of course referring to the redefinition of the kilogram unit of mass that the world has been building up to for more than 100 years. Let me explain: 1/ I've had an unhealthy fascination with metrology (the study of measurement) ever since my 2nd year as a physics major when I took a class devoted to duplicating historic physics experiments, so please indulge me for going into heavy detail (get it?) about the kilogram.