# Atmosphere Table

In order to compute launch drag and heating, I will eventually need a table of atmospheric model data near the equator, over the year, and hour by hour. The only tables I have now are from the US Standard Atmosphere 1976, which are computed for a reference latitude ( 45° 32' 33" = 45.5425 North ) using geopotential altitudes rather than geometric altitudes. I will also need variance and turbulence estimates, to determine how much post-launch velocity adjustment will be necessary.

For now, I would rather be vaguely right than exactly wrong. Below is a table of relevant parameters at 1 km vertical altitude steps. Vehicles will accelerate on the launch loop between 40 and 80 km altitude, and exit the remaining atmosphere following Kepler orbit elliptical trajectories.

Vehicles following those ellipses will seem to accelerate vertically, and climb out of the dense, trajectory-modifying portion of the atmosphere in minutes. Hence, the upper altitude numbers are not as important, but will be added to the table to make calculation easier. Calculations will truncate the kilometer value to an integer index value, and use the fractional part to interpolate to the next index value.

There are more sophisticated ways to do this, involving interpolations within complicated functions between "standard" geopotential altitudes, and those will be used by professionals, when launchloops are designed and built.

Parameters like undisturbed mean free path, viscosity, and composition will also matter, but will change radically during hypersonic vehicle passage. Those will be ignored for now.

## Tables

Molecular weight MW=28.964 unless noted

 index temp. pressure density sound km K Pascals kg/m³ m/s 0 288.150 1.0133e+5 1.2250e+0 340.29 mean free path MFP=67nm, 7e9Hz collisions/sec 1 281.651 8.9876e+4 1.1117e+0 336.43 2 275.154 7.9501e+4 1.0066e+0 332.53 3 268.659 7.0121e+4 9.0925e-1 328.58 4 262.150 6.1660e+4 8.1935e-1 324.59 5 255.676 5.4048e+4 7.3643e-1 320.55 6 249.187 4.7217e+4 6.6011e-1 316.45 7 242.700 4.1105e+4 5.9002e-1 312.31 8 236.215 3.5651e+4 5.2579e-1 308.11 9 229.733 3.0800e+4 4.6706e-1 303.85 10 223.252 2.6499e+4 4.1351e-1 299.53 11 216.774 2.2699e+4 3.6480e-1 295.15 12 216.650 1.9399e+4 3.1194e-1 295.07 13 216.650 1.6579e+4 2.6660e-1 295.07 14 216.650 1.4170e+4 2.2786e-1 295.07 15 216.650 1.2111e+4 1.9476e-1 295.07 16 216.650 1.0352e+4 1.6647e-1 295.07 17 216.650 8.8497e+3 1.4230e-1 295.07 18 216.650 7.5652e+3 1.2165e-1 295.07 19 216.650 6.4674e+3 1.0400e-1 295.07 20 216.650 5.5293e+3 8.8910e-2 295.07 21 217.581 4.7289e+3 7.5715e-2 295.70 22 218.574 4.0475e+3 6.4510e-2 296.38 23 219.567 3.4668e+3 5.5006e-2 297.05 24 220.560 2.9717e+3 4.6938e-2 297.72 25 221.522 2.5492e+3 4.0084e-2 298.39 26 222.554 2.1883e+3 3.4257e-2 299.06 27 223.536 1.8799e+3 2.9298e-2 299.72 28 224.527 1.6161e+3 2.5076e-2 300.39 29 225.518 1.3904e+3 2.1478e-2 301.05 30 226.509 1.1970e+3 1.8410e-2 301.71 31 227.500 1.0312e+3 1.5792e-2 302.37 32 228.490 8.8906e+2 1.3555e-2 303.02 33 230.973 7.6730e+2 1.1573e-2 304.67 34 233.743 6.6341e+2 9.8874e-3 306.49 35 236.513 5.7459e+2 8.4634e-3 308.30 36 239.282 4.9852e+2 7.2579e-3 310.10 37 242.050 4.3324e+2 6.2355e-3 311.89 38 244.818 3.7713e+2 5.3666e-3 313.67 39 247.584 3.2282e+2 4.6268e-3 315.43 40 250.350 2.8714e+2 3.9957e-3 317.19 41 253.114 2.5113e+2 3.4564e-3 318.94 42 255.878 2.1996e+2 2.9948e-3 320.67 43 258.641 1.9295e+2 2.5989e-3 322.40 44 261.403 1.6949e+2 2.2589e-3 324.12 45 264.164 1.4910e+2 1.9663e-3 325.82 46 266.925 1.3134e+2 1.7142e-3 327.52 47 269.684 1.1585e+2 1.4965e-3 329.21 48 270.650 1.0229e+2 1.3167e-3 329.80 49 270.650 9.0336e+1 1.1628e-3 329.80 50 270.650 7.9779e+1 1.0269e-3 329.80 51 270.650 7.0458e+1 9.0690e-4 329.80 52 269.031 6.2214e+1 8.0562e-4 328.81 53 266.277 5.4873e+1 7.1791e-4 327.12 54 263.524 4.8337e+1 6.3901e-4 325.43 55 260.771 4.2525e+1 5.6810e-4 323.72 56 258.019 3.7362e+1 5.0445e-4 322.01 57 255.268 3.2782e+1 4.4738e-4 320.29 58 252.518 2.8723e+1 3.9627e-4 318.56 59 249.769 2.5132e+1 3.5054e-4 316.82 60 247.021 2.1958e+1 3.0968e-4 315.07 61 244.274 1.9157e+1 2.7321e-4 313.32 62 241.527 1.6688e+1 2.4071e-4 311.55 63 238.781 1.4515e+1 2.1178e-4 309.77 64 236.036 1.2605e+1 1.8605e-4 307.99 65 233.292 1.0929e+1 1.6321e-4 306.19 66 230.549 9.4609e+0 1.4296e-4 304.39 67 226.436 8.1757e+0 1.2503e-4 302.57 68 223.695 7.0529e+0 1.0917e-4 300.75 69 222.325 6.0736e+0 9.5171e-5 298.91 70 219.585 5.2209e+0 8.2829e-5 297.06 71 216.846 4.4795e+0 7.1966e-5 295.20 72 214.263 3.8362e+0 6.2374e-5 293.44 73 212.308 3.2802e+0 5.3824e-5 292.10 74 210.353 2.8008e+0 4.6386e-5 290.75 75 208.399 2.3881e+0 3.9921e-5 289.40 76 206.446 2.0333e+0 3.4311e-5 288.04 77 204.493 1.7286e+0 2.9448e-5 286.67 78 202.541 1.4673e+0 2.5239e-5 285.30 79 200.590 1.2437e-0 2.1600e-5 283.92 80 198.639 1.0524e-0 1.8458e-5 282.54 81 196.688 8.8923e-1 1.5750e-5 281.15 82 194.739 7.5009e-1 1.3418e-5 279.75 83 192.790 6.3167e-1 1.1414e-5 278.35 84 190.481 5.3105e-1 9.6940e-6 276.94 85 188.893 4.4568e-1 8.2196e-6 275.52 MFP=1cm, 38KHz 86 186.87 3.7338e-1 6.958e-6 274.04 est 88 186.87 2.6173e-1 4.875e-6 274.04 est 89 186.87 2.1919e-1 4.801e-6 274.04 est 90 186.87 1.8359e-1 3.416e-6 274.04 est 91 186.87 1.5381e-1 2.860e-6 274.04 est 92 186.96 1.2887e-1 2.393e-6 274.11 est 93 187.25 1.0801e-1 2.000e-6 274.32 est 94 187.74 9.0560e-2 1.670e-6 274.68 est 95 188.42 7.5966e-2 1.393e-6 275.18 est 96 189.31 6.3765e-2 1.162e-7 275.82 est 97 190.40 5.3571e-2 9.685e-7 276.62 est 98 191.72 4.5057e-2 8.071e-7 277.57 est 99 193.28 3.7948e-2 6.725e-7 278.70 est 100 195.08 3.2011e-2 5.604e-7 280.00 est MFP=14cm, 2.68KHz, MW=28.40 101 197.16 2.7192e-2 4.695e-7 281.48 est 102 199.53 2.3144e-2 3.935e-7 283.17 est 103 202.23 1.9742e-2 3.300e-7 285.08 est 104 205.31 1.6882e-2 2.769e-7 287.24 est 105 208.84 1.4477e-2 2.325e-7 289.70 est 106 212.89 1.2454e-2 1.954e-7 292.50 est 107 217.63 1.0751e-2 1.643e-7 295.74 est 108 223.29 9.3188e-3 1.381e-7 299.56 est 109 230.33 8.1142e-3 1.161e-7 304.24 est 110 240.00 7.1042e-3 9.708e-8 310.56 est 111 252.00 6.2614e-3 8.111e-8 318.23 est 112 264.00 5.5547e-3 6.838e-8 325.72 est 113 276.00 4.9570e-3 5.811e-8 333.04 est 114 288.00 4.4473e-3 4.975e-8 340.20 est 115 300.00 4.0096e-3 4.289e-8 347.22 est 116 312.00 3.6312e-3 3.720e-8 354.10 est 117 324.00 3.3022e-3 3.246e-8 360.84 est 118 336.00 3.0144e-3 2.847e-8 367.46 est 119 348.00 2.7615e-3 2.509e-8 373.97 est 120 360.00 2.5382e-3 2.222e-8 380.36 est 121 371.89 2.3401e-3 1.977e-8 386.59 est 122 383.55 2.1635e-3 1.767e-8 392.61 est 123 394.99 2.0055e-3 1.585e-8 398.42 est 124 406.22 1.8635e-3 1.428e-8 404.04 est 125 417.23 1.7354e-3 1.291e-8 409.48 est 126 428.04 1.6194e-3 1.171e-8 414.75 est 127 438.64 1.5141e-3 1.065e-8 419.86 est 128 449.04 1.4183e-3 9.717e-9 424.80 est 129 459.25 1.3307e-3 8.889e-9 429.61 est 130 469.27 1.2505e-3 8.152e-9 434.27 est 131 479.09 1.1769e-3 7.494e-9 438.79 est 132 488.74 1.1092e-3 6.904e-9 441.37 est 133 498.20 1.0468e-3 6.374e-9 447.45 est 134 507.48 9.8907e-4 5.897e-9 451.60 est 135 516.59 9.3568e-4 5.465e-9 455.64 est 136 525.53 8.8617e-4 5.074e-9 459.56 est 137 534.29 8.4018e-4 4.719e-9 463.38 est 138 542.80 7.9739e-4 4.396e-9 467.05 est 139 551.34 7.5751e-4 4.101e-9 470.71 est 140 559.63 7.2028e-4 3.831e-9 474.24 est 141 567.76 6.8550e-4 3.584e-9 477.67 est 142 575.73 6.5294e-4 3.358e-9 481.01 est 143 583.56 6.2243e-4 3.150e-9 484.27 est 144 591.24 5.9380e-4 2.958e-9 487.45 est 145 598.78 5.6691e-4 2.781e-9 490.55 est 146 606.17 5.4162e-4 2.618e-9 493.56 est 147 613.43 5.1781e-4 2.466e-9 496.51 est 148 620.55 4.9538e-4 2.326e-9 499.38 est 149 627.54 4.7421e-4 2.196e-9 502.19 est 150 634.39 4.5422e-4 2.076e-9 504.92 est MFP 33m, 33Hz, MW=24.1 151 641.12 4.3533e-4 1.963e-9 507.59 est 152 647.72 4.1746e-4 1.859e-9 510.20 est 153 654.20 4.0054e-4 1.761e-9 512.74 est 154 660.56 3.8451e-4 1.670e-9 515.23 est 155 666.80 3.6930e-4 1.585e-9 517.66 est 156 672.92 3.5487e-4 1.505e-9 520.03 est 157 678.93 3.4116e-4 1.431e-9 523.35 est 158 684.83 3.2813e-4 1.361e-9 524.61 est 159 690.61 3.1574e-4 1.295e-9 526.82 est 160 696.29 3.0395e-4 1.233e-9 528.98 est 161 701.86 2.9272e-4 1.175e-9 531.09 est 162 707.33 2.8201e-4 1.121e-9 533.16 est 163 712.70 2.7181e-4 1.069e-9 535.18 est 164 717.96 2.6207e-4 1.021e-9 537.15 est 165 723.13 2.5278e-4 9.750e-10 539.08 est 166 728.20 2.4390e-4 9.319e-10 540.97 est 167 733.18 2.3541e-4 8.911e-10 542.81 est 168 738.07 2.2730e-4 8.525e-10 544.62 est 169 742.86 2.1953e-4 8.161e-10 546.39 est 170 747.57 2.1210e-4 7.815e-10 548.11 est 171 752.18 2.0499e-4 7.488e-10 549.80 est 172 756.71 1.9817e-4 7.178e-10 551.46 est 173 761.16 1.9164e-4 6.883e-10 553.07 est 174 765.53 1.8537e-4 6.604e-10 554.66 est 175 769.81 1.7936e-4 6.339e-10 556.21 est 176 774.01 1.7360e-4 6.086e-10 557.72 est 177 778.14 1.6806e-4 5.846e-10 559.21 est 178 782.19 1.6274e-4 5.618e-10 560.66 est 179 786.17 1.5763e-4 5.401e-10 562.09 est 180 790.07 1.5271e-4 5.194e-10 563.48 est 181 793.89 1.4799e-4 4.997e-10 564.84 est 182 797.65 1.5345e-4 4.809e-10 566.18 est 183 801.34 1.3907e-4 4.630e-10 567.48 est 184 804.96 1.3487e-4 4.459e-10 568.76 est 185 808.51 1.3081e-4 4.295e-10 570.02 est 186 812.00 1.2691e-4 4.139e-10 571.25 est 187 815.42 1.2315e-4 3.990e-10 572.45 est 188 818.78 1.1952e-4 3.847e-10 573.63 est 189 822.08 1.1603e-4 3.711e-10 574.78 est 190 825.31 1.1266e-4 3.581e-10 575.91 est 191 828.49 1.0940e-4 3.456e-10 577.02 est 192 831.61 1.0627e-4 3.336e-10 578.10 est 193 834.67 1.0324e-4 3.222e-10 579.17 est 194 837.67 1.0031e-4 3.112e-10 580.21 est 195 840.62 9.7491e-5 3.006e-10 581.23 est 196 843.51 9.4763e-5 2.905e-10 582.22 est 197 846.35 9.2127e-5 2.809e-10 583.20 est 198 849.14 8.9580e-5 2.626e-10 584.16 est 199 851.87 8.7117e-5 2.626e-10 585.10 est 200 854.56 8.4736e-5 2.541e-10 586.03 est MFP=240m, 3.9Hz, MW=21.3 300 976.01 8.7704e-6 1.916e-11 626.29 est MFP=2.6km, 0.42Hz, MW=17.7 400 995.83 1.4518e-6 2.803e-12 632.61 est MFP=16km, 72mHz, MW=16.0 500 999.24 3.0236e-7 5.215e-13 633.70 est MFP=77km, 16mHz, MW=14.3 600 999.85 8.2130e-8 1.137e-13 633.89 est MFP=280km, 4.8mHz, MW=11.5 700 999.97 3.1908e-8 3.070e-14 633.93 est MFP=730km, 2.2mHz, MW=8.0 800 999.99 1.7036e-8 1.136e-14 633.93 est MFP=1.4Mm, 1.4mHz, MW=5.5 900 1000.00 1.0873e-8 5.759e-15 633.94 est MFP=2.1Mm, 1.0mHz, MW=4.4 1000 1000.00 7.5138e-9 3.561e-15 633.94 est MFP=3.1Mm, 0.7mHz, MW=3.9 index temp. pressure density sound km K Pascals kg/m³ m/s

est sound speed = sqrt( 401.875 * K )

AtmosphereTable (last edited 2020-12-22 05:12:52 by KeithLofstrom)