Whenever you launch a today's craft, you always face the problem of accuracy of orbit insertion. You simply won't
have enough deltaV to correct even 1 degree deviation by inclination. When you have an autopilot implemented in
your launch vehicle, it's no problem, because it does all the job. However, there are many LVs (for instance, most of
the CVE-lite rockets) which don't have an autopilot. Trying to fly an ascent profile by hand is possible, but challenging.
And also, since the most important parameters of your orbit depend on how you've passed the atmospheric part of
the ascent, there's a big possibility for error here. It's hard to predict the final ApA judging by your current vertical
speed at a given moment (at least, without much practice). This task is ought to be carried out by an automat.
I suggest using the multi-purpose Autopilot addon (currently availavbe version 1.7) which accepts detailed flight plans
in text files. For example, let's assume we want to travel to the ISS from Baikonur cosmodrome using a CVEL Soyuz-
TMA atop the CVEL Soyuz-FG launch vehicle. At the first step, we should reach a 180*180 kilometers chase orbit with
the plane matching with ISS's. Since Soyuz LV has no roll thrusters, we should edit the scenario first, turning it
to the proper launch heading to enter 51.6 deg inclunation in the end of ascent:
Soyuz-FG:soyuz
STATUS Landed Earth
BASE Baikonur:4
HEADING 63.28
FUEL 1.000
CONFIGURATION 0
FAIRING
MANNED
PAYLOAD TMA01 soyuz soyuztma 0 0 29 7220 0 1
ENDYou only will have to do the following: open a Plane Alignment in one MFD and Autopilot in another, setup PA for
tracking for ISS orbital plane, load the flight plan (given below) in the Autopilot and engage it running when you'll find yourself within 200 seconds of the Descending Node (at the North-travelling part of the circuit). During the flight you may enjoy the external view most of the time, but don't foget to control your yaw to stay as close to 0.000 relative
inclination all the time as possible.
If, by occassion, you don't have a live orbital plane marker, such as ISS, to use the PA MFD, just keep the speed ball
you can see on the Surface HUD aligned vertically with the central HUD's marker by applying little yaw correction when needed. It will help precision orbit insertion.
Here's the flight plan:
// -----------------------------------------------------------
// Flightplan for the orbiter space simulation
// for use with the Autopilot MFD
//
// AutopilotMFD (c) 2005 by R. Bumm, Munich
// -----------------------------------------------------------
// flightplan for taking a Soyuz-TMA craft to a circular earth orbit
// 180*180 km, 51.6 deg inclunation using Soyuz-FG launch vehicle
//
// Created by Siberian Tiger (sib_tiger@mail.ru) using a numerical
// launch vehicle model by Kirill Levin
// http://www.geocities.com/levinkirill/SpaceModel/eng/
//
// select home base
select Baikonur
set apcontrol thruster
wait 3
burn main 100
run killrot
// Clearing the tower
wait 5
stop killrot
wait speedmore 39.92
pitch 87.00
wait speedmore 44.34
pitch 84.00
wait speedmore 48.83
pitch 81.00
wait speedmore 53.40
pitch 79.26
wait speedmore 68.01
pitch 78.73
wait speedmore 83.99
pitch 78.12
wait speedmore 101.18
pitch 77.43
wait speedmore 119.54
pitch 76.67
wait speedmore 132.42
pitch 76.14
wait speedmore 145.82
pitch 75.58
wait speedmore 159.75
pitch 75.01
wait speedmore 174.24
pitch 74.43
wait speedmore 189.28
pitch 73.84
wait speedmore 204.90
pitch 73.25
wait speedmore 221.13
pitch 72.66
wait speedmore 237.99
pitch 72.06
wait speedmore 255.50
pitch 71.47
wait speedmore 273.70
pitch 70.88
wait speedmore 292.61
pitch 70.29
wait speedmore 312.29
pitch 69.70
wait speedmore 332.76
pitch 69.11
wait speedmore 354.08
pitch 68.51
wait speedmore 376.29
pitch 67.91
wait speedmore 399.44
pitch 67.30
wait speedmore 423.58
pitch 66.69
wait speedmore 448.76
pitch 66.06
wait speedmore 475.05
pitch 65.42
wait speedmore 502.49
pitch 64.74
wait speedmore 531.02
pitch 64.02
wait speedmore 560.63
pitch 63.27
wait speedmore 591.37
pitch 62.48
wait speedmore 623.28
pitch 61.66
wait speedmore 656.39
pitch 60.80
wait speedmore 690.74
pitch 59.89
wait speedmore 726.36
pitch 58.93
wait speedmore 744.66
pitch 58.42
wait speedmore 763.30
pitch 57.91
wait speedmore 782.26
pitch 57.37
wait speedmore 801.57
pitch 56.82
wait speedmore 821.22
pitch 56.25
wait speedmore 841.22
pitch 55.66
wait speedmore 861.58
pitch 55.05
wait speedmore 882.29
pitch 54.42
wait speedmore 903.36
pitch 53.77
wait speedmore 924.80
pitch 53.09
wait speedmore 946.60
pitch 52.39
wait speedmore 968.78
pitch 51.67
wait speedmore 991.34
pitch 50.92
wait speedmore 1014.28
pitch 50.14
wait speedmore 1037.61
pitch 49.34
wait speedmore 1061.32
pitch 48.50
wait speedmore 1085.43
pitch 47.64
wait speedmore 1109.94
pitch 46.74
wait speedmore 1134.85
pitch 45.81
wait speedmore 1160.16
pitch 44.85
wait speedmore 1185.89
pitch 43.86
wait speedmore 1212.02
pitch 42.83
wait speedmore 1238.58
pitch 41.76
wait speedmore 1265.55
pitch 40.66
wait speedmore 1292.94
pitch 39.51
wait speedmore 1320.75
pitch 38.33
wait speedmore 1348.99
pitch 37.12
wait speedmore 1377.66
pitch 35.86
wait speedmore 1406.76
pitch 34.56
wait speedmore 1436.28
pitch 33.22
wait speedmore 1466.24
pitch 31.83
wait speedmore 1496.62
pitch 30.41
wait speedmore 1527.43
pitch 28.94
wait speedmore 1558.66
pitch 27.44
wait speedmore 1590.32
pitch 25.89
wait speedmore 1622.39
pitch 24.30
wait speedmore 1654.89
pitch 22.67
wait speedmore 1687.79
pitch 21.01
wait speedmore 1721.10
pitch 19.30
// Boosters separation, eliminate rotation for a while
run killrot
wait 5
stop killrot
wait speedmore 1754.81
pitch 17.57
wait speedmore 1788.64
pitch 15.81
wait speedmore 1817.90
pitch 14.19
wait speedmore 2000.0
// Fairing and tower jettison, eliminate rotation for a while
run killrot
wait 5
stop killrot
wait speedmore 2301.55
pitch 14.70
wait speedmore 2623.77
pitch 15.21
wait speedmore 2907.86
// Second stage is running on fumes, shaking wildly!
// Watch your yaw here!
pitch 15.71
wait speedmore 3182.40
pitch 16.23
wait speedmore 3453.06
pitch 16.76
// Second stage separation, eliminate rotation for a while
run killrot
wait 10
stop killrot
wait speedmore 3712.45
pitch 17.29
wait speedmore 3975.78
pitch 17.82
wait speedmore 4106.82
pitch 17.28
wait speedmore 4181.43
pitch 16.73
wait speedmore 4258.94
pitch 16.19
wait speedmore 4339.44
pitch 15.65
wait speedmore 4423.02
pitch 15.11
wait speedmore 4509.79
pitch 14.58
wait speedmore 4599.86
pitch 14.05
wait speedmore 4693.36
pitch 13.53
wait speedmore 4790.44
pitch 13.02
wait speedmore 4891.26
pitch 12.51
wait speedmore 5007.91
pitch 11.96
wait speedmore 5129.70
pitch 11.42
wait speedmore 5256.96
pitch 10.89
wait speedmore 5390.07
pitch 10.37
wait speedmore 5529.46
pitch 9.87
wait speedmore 5690.62
pitch 9.34
wait speedmore 5860.76
pitch 8.83
wait speedmore 6057.66
pitch 8.29
wait speedmore 6285.88
pitch 7.75
wait speedmore 6551.50
pitch 7.22
wait speedmore 6611.41
pitch 4.32
wait speedmore 6693.48
pitch 4.85
wait speedmore 6777.59
pitch 5.39
wait speedmore 6863.86
pitch 5.93
wait speedmore 6952.37
pitch 6.48
wait speedmore 7043.24
pitch 7.04
wait speedmore 7136.60
pitch 7.60
wait speedmore 7232.58
pitch 8.17
wait speedmore 7331.33
pitch 8.75
wait speedmore 7433.02
pitch 9.33
wait speedmore 7510.00
stop apa
stop engines
// Congratulations, you're in orbit!
// Now hit "j" to separate the spacecraft
endA short note of how it has been obtained: I have used a ready Excel spreadsheet with a numercal model which takes
LV parameters, required orbit parameters, and the initial position on Earth as arguments and produces a detailed
flight program taking into account drag and lift aerodinamic forces and a number of restrictions. The model must also be optimized using the Solver add-in which is a standard add-in for Excel. You can find the model and its descriprion
here:
http://www.geocities.com/levinkirill/SpaceModel/eng/. A simple self-written macro helped me to generate a flight plan suitable for the Autopilot from it.
I'm going to utilise it for preparing flight plans for different LV's, for example, I already have a flight plan for the Delta
II carrying a MER.
Any comments, please?
Post Edited ( 12-12-05 06:11 )
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