Re: skyhooks again

From: Doug Jones (
Date: Tue Mar 21 2000 - 00:43:22 MST

Spike Jones wrote:

> I calculated, assuming a minimal orbit ignoring the atmosphere,
> one needs to be about 30,000 km from the center of the
> earth, or 23450 km from the surface in order to fall into a
> minimal orbit.
> Since there is an atmosphere, and one needs to be at least
> about 300 km up before that orbit will last any time at all,
> one needs to climb to 23750 km from the earth surface in
> order to jump off and fall into orbit.
> I wrote a spreadsheet to calc this, and will send it offlist
> if anyone wants it. spike

Sure, I'll take one... I started to write a spreadsheet a week or two
ago, but ran out of time & energy.

I've been kinda busy with engine controls and cooling systems, but we're
doing calorimetry finally. Fifteen second sustained runs are a lot more
fun than one second blips on a heatsink chamber. I have a large test
matrix to work through this week, turning up the thrust and reducing the
coolant flow until we deliberately slag a chamber (cooling with
subcritical fluids has wierd phase change problems). Then we'll set the
minimum flow at 2x the level that failed :)

This little engine is a helluva water heater- makes about 4
gallons/minute of nice toasty water, too hot to touch...

Doug Jones
Rocket Plumber, XCOR Aerospace

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