Author Archives: Chris Stelter

Fundamental cost of putting stuff in orbit: theoretical minimum vs RLV

What is the minimum energy of orbit, and how does that compare to the energy in a chemical rocket’s propellant? Accessing a 150km LEO orbit requires first the energy to get to 150km. That’s roughly (in Energy/mass, or J/kg, aka … Continue reading

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New (?) ideas for utilizing space for business: hypergravity for athletic training

(Note, I had previously written this along with the isotope separation, but wanted to give that idea a chance for discussion first.) Another possible use for hypergravity is for training humans. A big 2-gee facility on Earth would be expensive … Continue reading

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New (?) ideas for utilizing space for business: hypergravity for isotopic enrichment

One night, as I was putting my daughter to bed and waiting for her to fall asleep, I tried to think of some new markets for space utilization. We often hear about attempts to find industrial uses for microgravity for … Continue reading

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SBSP for electric aircraft, cont.

Chris speaking. Along with Jon, I’ve given a lot of thought to this specific application of space-based solar power (SBSP). Yes, there are thousands of aircraft in the air at any one time, but I find this to be one … Continue reading

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Anti-radiation Biological Countermeasures: Amifostine

Whenever human spaceflight comes up, inevitably someone mentions radiation. Personally, I think the radiation risk is WAY overblown. “Compound conservatism” is rampant, I believe, and gets worse as time goes on and people keep recycling the same sources, adding some … Continue reading

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Mars surface shielding from radiation

I want a short little aside here to talk about a little pet peeve of mine: People talk as if Mars’ atmosphere does basically nothing to reduce the radiation dose as compared to free space. This is definitely not true, … Continue reading

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Minimum viable microwave-based space-based solar power system

The Solomon Islands pay almost $1/kWh for electricity. You could provide beamed solar power to them on a demonstration basis for a fraction of that price. Unfortunately, being in the ocean is one of the worst places for beamed power, … Continue reading

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Power beaming

Power beaming is clearly central to space-based solar power concepts. Here I will provide a quick overview of my understanding of power beaming, the various equations involved, typical example calculations. If power beaming were efficient and cheap, I believe space-based … Continue reading

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Space-based solar power preview

I will start out with a look at space-based solar power, including both microwave and laser based beaming approaches as well as seeing if there’s some use that can be had for that power that doesn’t involve beaming it. This … Continue reading

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Why we won’t run out of fossil fuels and why that’s a problem

This is my first post… I guess started because of a comment on the previous post by Jon. I was in the middle of writing a long comment, then decided to flesh it out and add some references. I used … Continue reading

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