Author Archives: Chris Stelter

How brute-efficiency enables practical electric flight

Anytime the topic of electric aircraft comes up, the immediate response by the middle-brow (and some high-brow) is that it’s obviously impractical due to the mass-sensitivity of flight and the obvious energy density (or they usually intend “specific energy”) advantage … Continue reading

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The Unreasonable Energy Efficiency of Conventional Orbital Rockets, Part One: Versus the F-150

Orbital rockets do not *seem* efficient. They take off in what amounts to a mushroom cloud, using extravagant amounts of propellant to rise even the first 100 meters into the air to clear the tower. Yet, their efficiency rivals that … Continue reading

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How much mass can we put in orbit before running into atmospheric constraints?

In January, Elon Musk mused that the design goal for Starship was 3 flights per day, for about 1000 flights per year per Starship (assuming for the sake of simplicity he’s talking about a whole stack) with a payload of … Continue reading

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Adding an Earth-sized magnetic field to Mars

Mars has only the ancient remnants of a magnetic field. What little chunks of field it does have (imprinted into magnetic rocks) are regional in scale and do nothing at all for radiation shielding (I once calculated this). Additionally, over … Continue reading

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A human tribe is a Von Neumann probe

After thinking a while about why self-replicating robots do not exist (thanks, Casey: ), we’re reminded that living things do this regularly. I’m tempted to write “a human is a von Neumann probe,” but that wouldn’t be accurate. A … Continue reading

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Modeling COVID-19: When will the peak occur in the US?

So, given that the CDC recently confirmed the first possible instance of community transmission of COVID-19 (Novel Coronavirus) in the US, I thought I’d guesstimate roughly when the peak of the epidemic would occur in the US with some (extremely) … Continue reading

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SpaceX is great. But Mars needs more than SpaceX.

With the death of Mars One, there are no high-profile companies looking to settle Mars besides SpaceX. Mars settlement future is currently single-string. Reliant on a single company. What can we do to change that? Am I missing someone? On … Continue reading

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Initial BFR (Starship) is not much more powerful than Falcon Heavy

In 2016 when Elon Musk unveiled ITS, everyone thought it was ridiculous and huge. It dwarfed the Saturn V. People were scratching their heads as to how it could possibly launch from LC-39A as pictured, since the 42 Raptors were … Continue reading

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Disabilities as enabling for space travel

So, the other day I listened to a presentation from the FISO (Future In-Space Operations) working group. They have regular online telecons which anyone can listen to and follow along after the fact on their web archive: It was … Continue reading

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Amistics of Human Spaceflight, or How Autonomy and Miniaturization can be the Enemies of Human Spaceflight (Part 1)

Neal Stephenson in his novel Seveneves coined the term “Amistics”, deriving from how some Amish people have strong preferences for certain technological paths to achieve the same goal. For instance, these Amish folk swear off modern technology, which for them … Continue reading

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