Flight to Mars: non-Hohmann transfer orbit, aerotormozhenie complexity and landing in the rarefied atmosphere
Autumn, sadness, nostalgia. It's time to unwind, to give himself an educational quest mission to Mars. Virtually, of course, in Orbiter'e. And that was interesting, brake Mars we will not motors, and friction of the atmosphere.
flight plan For maximum clarity and convenience, our flight will be broken down into simple steps:
Start with the Earth. Sovmescheschenie orbital planes. Acceleration to Mars. trajectory correction on the way to Mars. The corridor entrance. Sedation in the atmosphere. Prepare for landing. The flight in the atmosphere and landing Preparing to fly addition of Orbiter'a we need only AerobrakeMFD (archive simply unzip the folder specified in the simulator).
definitions used If you have not read the previous publication of the series, it is worth to deploy. Apoapsis
Periapsis
The orbital inclination
Ascending node
Descending node
For example, if we talk about the orbit of the Moon around the Earth, the picture is as follows:
Step 1: Start with the Earth The first thing you want to include in the "Settings" mode "infinite fuel 'uncheck:
The required script - «DG-S ready for takeoff» folder Delta-glider. In it, our ship is already on the runway at Cape Canaveral, ready for takeoff.
Delta-glider - a workhorse Orbiter'a
By clicking F1 F8
Left and right are multifunctional displays (MFD, MFD). On these screens, we will display various instruments that we will need in flight. Hotkeys work with MFD used with pre-pressed left and right Shift Shift-F1 MNU Shift - F1 Shift - S Shift - O Shift - P Shift - D
Recommend to remember one key combination - Ctrl - P
The second is a very useful set of keyboard shortcuts controls the time - R T
Before takeoff must still include engines orientation system ( Ctrl - / Trimmer to lock up while holding down the Delete
Turn and fix the boosters (click Num + Ctrl Num + Ctrl
Retractable landing gear (the button G Insert Delete Num 5
Starting with a height of ~ 30 km and trimmers mode KillRot no longer cope. You can not interfere in the management (in this case, the land will be a slight reduction), you can switch to the 2D cockpit (by pressing F8 change the thrust vector propulsion engines , enter orbit it does not hurt. Accelerate to until apoapsis reaches 200 km.
Turn off the main engine-click Num * [
So, we have a circular reference orbit of ~ 200 km. For further convenience, the flight will open sash brake motors ( Ctrl - Space H
Phase 1 completed successfully. Save by pressing Ctlr-S
I do not know about you, but I think that psy-ambient is perfect for such flights:
Step 2. Combining orbital planes In order that we may normally be dispersed to Mars, it is necessary to combine our orbit plane with the plane of the orbit of Mars. For this we need a MFD "The combination of orbital planes» ( Shift - A Shift - T
Next ascending node (Ascend Node, AN), so you need to take a position "down" from the plane of the orbit. For this, there is a mode NML- (button '
Why do half the time to host? The fact that the line of nodes shifting maneuver, however if start correction of the orbit for a time equal to the time the maneuver at a node, the node "leave". This same shift of the line of nodes is the criterion for stopping the engine. When the line of nodes is almost perpendicular to the green line further correction does not make sense.
With this simple formula, we almost have combined orbital planes with one maneuver. But it is necessary to repeat the maneuver to maximize the alignment of planes:
We finished the second stage. Remember to save.
Step 3. Acceleration to Mars
To prepare for the maneuver will include MFD "Transition» ( Shift - X Shift - R Shift - S Shift - T
Including the mode of planning maneuver (the button HTO Shift - & lt; & gt; Shift - - +
Note that the point of interception of Mars is not on the opposite side of the orbit. This means that our path will not Гомановской, We spent fuel, but could reach faster.
IDF says that we need to accelerate at 2, 8 km / s. Our current orbital speed of 7, 6 km / s. It seems to be simple: 7, 6 + 2, 8 = 10, 4 km / s. But this is not true! Our ship is orbiting the Earth. A Land in turn revolves around the sun. It turns out this interesting picture:
2, 8 km / s, which offers us the MFD, it is necessary to add to the orbital velocity of the Earth, not us. The situation is even more complicate the following factors:
To leave the Earth's orbit must accelerate to escape velocity (11, 2 km / s). The orbital velocity of non-linearly dependent on the height of the orbit . When you remove from the Earth, our speed will drop because of the conversion of kinetic energy into potential energy. Acceleration is produced is not instantaneous, during acceleration, speed will already be lost on the transition to the potential energy.
Monitored parameters of the orbit on the right MFD "Orbit»:
There is a second space! Note that the speed is not yet 11, 2 km / s. Stop acceleration at a speed near 11 5 km / s, so as not to accelerate too much.
Stabilize the ship in space, including the mode KillRot. Accelerating time to waste it until the moment when the gravitational influence of the Earth almost come to naught. Select yourself from the body as the source ( Shift - S GL-01S
Now our task - to adjust the orbit so that we took aim at about the point of meeting with Mars. Visually, it can be represented as:
In precise targeting will help us sync orbit MFD ( Shift - Y Shift - T
Common sense dictates that when the correction necessary to give impulses to the right. Occupies a position of 90 ° to the right and hold it manually (no automatic mode) include boosters. Markedly decrease DTmin:
The algorithm further action is simple. When DTmin ceases to decrease, reaching near-zero values, change the axis - check whether it will reduce the displacement of up / down or forward / backward. If we have combined the orbit in step 2 of this likely will not. Result right action:
Stage 3 is completed. Remember to save.
Step 4. trajectory correction on the way to Mars Mars - relatively easy planet. This is not Jupiter, which not require intermediate corrections in flight. Therefore, we have several times will adjust our trajectory, not to fly past. The first step is a complete combination of the orbital plane and the first correction of the trajectory. If you look at the MFD sync orbit, it shows the angle of the plane of the orbits nearly two degrees. It needs to be corrected, because the IDF can not work properly under such conditions. Therefore, switch the left MFD mode of combining the orbital plane. It "remembers" previous body treatment - Earth, so we need to switch it to the Sun ( Shift - R
Combine orbital planes:
Then decreases DTmin. Recommended to change its acceleration / braking, and in any case does not move up / down - the plane of the orbits we already compatible. When DTmin will be close to zero, the small displacement is better not to perform mid-flight, and thrusters:
After precise aiming DTmin is almost zero:
Prior to the meeting point of 9, 5 megasekund. I propose to make the correction method of dichotomy - five, two and one-half megasekundu.
Stage 4 is considered ended 1 megasekundu from the collision point. Remember to save.
Step 5. The corridor entrance. What is the "entrance hall"? We need to go to Mars, so that, on the one hand, does not crash into it, and on the other hand - not to miss. Our goal - periapsis 20 km, so we firmly entered the atmosphere and could slow down. Switch the left MFD mode "Orbit» ( Shift - O Shift - T
Apoapsis negative, we will have to crash into Mars. Apocentre need to raise up to 20 km. To do this, expand the nose to the planet Mars will increase (the button Z X
I choose the braking on the dayside. At night, under time pressure can lose orientation in space that is potentially dangerous.
Periapsis 20 km. Stage 5 is completed. Be sure to save!
Step 6. Inhibition in the atmosphere. mounted on the right MFD mode "Surface", or rather the normal field of view, expand the ship in the direction of motion and mentally prepare ourselves for the difficult stage.
Our main controls are trimmer, which we have used to take off from the earth, and air brakes (produced and removed by pressing Ctrl - B H
Reaching pericenter, manage roll so as to keep near-zero vertical velocity and continue braking:
At an altitude of 1000 km below apocentre remove air brakes and start to get out of the atmosphere:
Upon reaching apocentre raise periapsis above 100 km:
Everything we have on a stable orbit around Mars. Be sure to save.
In theory, one can construct a set so as to come in to land at once with this step. But it is firstly difficult, and secondly requires very fast operation with multiple MFD parallel piloting the ship, which increases the chances of error. I prefer to go longer, but a simple and safe way.
Historically used aerotormozhenie Martian machines. For example, the device MRO on aerodynamic deceleration saved about half of the fuel that would be required for normal braking. Of course, the machine is not impeded by so-Hussar, as we are. MRO apoapsis distance gradually decreased repeatedly braking in the upper atmosphere.
Step 7. Prepare for landing Our goal - base Olympus, which, as the name implies, is located close to Mount Olympus, the highest mountain on Mars and the second highest in the Solar System:
This phase consists of several parts.
Preparing MFD card. Open MFD card ( Shift - M Shift - T
Preparing MFD Aerobrake. Open the MFD ( Shift - E Shift - T
Preparing MFD connection. Open the MFD ( Shift - C Ctlr - I
Then you need to plan the landing. Our nonzero orbital inclination means that our path will move over the surface. Also now base "Olympus" is on the night side. Therefore, while in orbit, waiting for the coincidence of two factors - the database on the day side and our trajectory passes near her. If necessary, you can change a little inclination of the orbit. In my case I had to wait for long, turns ten:
When the database remains up 4-5 thousand kilometers braking maneuver so that the database remains up to two thousand kilometers undershooting and orient the ship nosed ahead:
Stage is completed, be sure to save!
Step 7. Flying in the air and landing
MFD card can be switched to centering on the ship (the button TRK
We continue to actively manage.
The problem of the Martian atmosphere is that it is too weak. She is not able to quickly and efficiently inhibit us. Therefore, you are sure to fly over the base:
This is nothing to worry about. Because of the atmosphere we in any case, will not be able to turn and brake boosters, as the moon , so will have to dump the remains of speed in turn. Follow height - not to slide into Mars. In turn, you can help yourself lift engines ( Num 0 Num. - reduced):
Turned towards the base until it has ~ 50 km. By maintaining the ship in the air lift engines continue rapprochement
Turn on automatic maintenance of a horizontal orientation ( L Shift - L
Brake motors are very weak. Try to stick to the rules: the horizontal velocity in the hundreds of meters per second should not be over distances of tens of kilometers. Otherwise there is a risk to fly the base for the second time: