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hc03 - Payloads to the moon.
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<<EmbedObject(hc03.swf,play=true,loop=true,width=1024,height=768)>>
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[[ attachment:hc03.c | Here is the source ]], [[ attachment:hc03.cmd | Here is the command file, ]], and you will need [[ http://www.gnuplot.info/ | gnuplot ]] and [[ http://www.swftools.org/ | swftools ]]
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== 5 ton payloads to 10800 m/s, 30 m/s2, burst launch 15 payloads 24 seconds apart ==
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hc04 - Burst payloads to the moon, perhaps to slingshot into lower orbits. you will need [[ http://www.gnuplot.info/ | gnuplot ]] and [[ http://www.swftools.org/ | swftools ]]
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<<EmbedObject(hc04.swf,play=true,loop=true,width=1024,height=768)>>
==== 5 ton payloads to 10800 m/s, 30 m/s2, burst launch 15 payloads 24 seconds apart ====

[[ attachment:hc04.swf | hc04.swf ]] - Burst payloads to the moon, perhaps to slingshot into lower orbits.
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== 1.6 ton payloads to 8600 m/s, 20 m/s2, continuous, 10 seconds apart == ==== 1.6 ton payloads to 8600 m/s, 20 m/s2, continuous, 10 seconds apart ====
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hc05 - Smaller payloads into m288. 8640 payloads, 13,800 tons per day.

<<EmbedObject(hc05.swf,play=true,loop=true,width=1024,height=768)>>
[[ attachment:hc04.swf | hc05.swf ]] - Smaller payloads into m288. 8640 payloads, 13,800 tons per day.

Launch Loop Rotor Heating During Launch

The vehicle is accelerated by magnetic drag on the rotor. This adds kinetic energy to the vehicle, but subtracts more kinetic energy from the rotor. The difference is turned into heat, which is carried away by the rotor moving ahead of the vehicle. The heating is proportional to the force on the vehicle. A 5000 kg vehicle accelerating at 30 meters per second will heat the rotor by 85C (or 85K). Since the rotor does not make physical contact, the heat is removed by black body radiation. Since this is proportional to the 4th power of the temperature, the rotor on an active launch loop will be very hot. This limits the maximum launch rate - the rotor must stay below its Curie temperature (1000K ?).

The rotor slows down, more when the vehicle is moving faster and the relative velocities are smaller. Since the mass flow rate (on average) must be constant, this will be compensated (in the long term) by rotor stretching. The rotor's thermal expansion may help.

simulations

These are a few simulations of the heating of the launch loop rotor for the first hour after the beginning of launch operations, under different conditions. At 12 frames per second, the animated graphs should repeat every 60 seconds, simulating one hour of operation.

The rotor is simulated as 5600 1km long elements in a 14km/sec moving frame of reference. The viewing window (2000 km launch path, and 200 km of the inclines to each side) is rotated around this frame, as are the payloads. There is some numerical noise, probably resulting from inadequate assignment of heat impulses to rotor elements. But this can be used to get some estimate of the heating of the rotor under various conditions. Modify the #defines in the source - the code should be rewritten with an input file instead. (Note - the simulations below are for 5180km - these need to be updated).

5 ton payloads to 10800 m/s, 30 m/s2, continuous, 45 seconds apart

you will need gnuplot and swftools

5 ton payloads to 10800 m/s, 30 m/s2, burst launch 15 payloads 24 seconds apart

hc04.swf - Burst payloads to the moon, perhaps to slingshot into lower orbits.

Here is the source, Here is the command file,, and you will need gnuplot and swftools

1.6 ton payloads to 8600 m/s, 20 m/s2, continuous, 10 seconds apart

hc05.swf - Smaller payloads into m288. 8640 payloads, 13,800 tons per day.

Here is the source, Here is the command file,, and you will need gnuplot and swftools

LaunchLoopHeating (last edited 2021-06-20 01:12:26 by KeithLofstrom)