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 h4> For maximum clarity and convenience, our flight will be broken down into simple steps:

1. Start with the Earth.
2. Sovmescheschenie orbital planes.
3. Acceleration to Mars.
4. trajectory correction on the way to Mars.
5. The corridor entrance.
6. Sedation in the atmosphere.
7. Prepare for landing.
8. The flight in the atmosphere and landing

   Preparing to fly h4> addition of Orbiter'a we need only AerobrakeMFD (archive simply unzip the folder specified in the simulator).
   
   

   definitions used h4> If you have not read the previous publication of the series, it is worth to deploy. B> Apoapsis - the highest point of the orbit. To orbit around the Earth also used the name "Apogee».
   Periapsis - the lowest point of the orbit. To orbit around the Earth also used the name "perigee».
   The orbital inclination - the angle between the plane of the orbit and the other plane (the plane passing through the equator of the Earth's orbital plane, or other body)
   Ascending node - the point at which the orbit crosses the equatorial plane of the Earth's orbital plane, or other body, they find themselves "above" it. "Above" and "below" are defined conditional north and south poles.
   Descending node - the point at which the orbit crosses the equatorial plane of the Earth's orbital plane, or another body, appearing "below" it. "Above" and "below" are defined conditional north and south poles.
   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 h4> 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 i>
   
   By clicking F1 Switch to "view from the cockpit." Press the F8 to switch the view mode "glass cockpit».
   
   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 for the left and right MFD respectively. Selection menu is called by pressing the MFD Shift-F1 or mouse click on the button MNU under the MFD. Cockpit interactive, if you are too lazy to remember the hotkeys, you can press a button mouse clicks. Switch the left MFD mode "Surface" by pressing Shift - F1 , Shift - S , and right into the "Orbit" by pressing Shift - O Shift - P (MFD replace ECL on SHP in his right upper part) and regime change frame height from the center of a celestial body at the height of the surface of the combination Shift - D (MFD replaces distance pericenter and apocenter PeR and ApR at periapsis and apocentre PeA and ApA).
   Recommend to remember one key combination - Ctrl - P The second is a very useful set of keyboard shortcuts controls the time - R - slows down time by 10 times, T - 10 times faster.
   Before takeoff must still include engines orientation system ( Ctrl - / on the numeric keypad) and set Trimmer abbr> to lock up while holding down the Delete on the block cursor keys.
   Turn and fix the boosters (click Num + , then Ctrl , let Num + , let Ctrl ). Getting run. When properly installed trimmer ship starts to break away from the band themselves:
   
   Retractable landing gear (the button G ), and driving with a numeric keypad, expand the ship on course 90 °. Driving trimmer ( Insert down, Delete up) mode and stop the rotation KillRot ( Num 5 ) starts acceleration, keeping the pitch angle 20-30 °.
   
   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 ) and 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 * [) and wait apocenter. In the area again apocentre include boosters and raise periapsis to ~ 200 km.
   
   So, we have a circular reference orbit of ~ 200 km. For further convenience, the flight will open sash brake motors ( Ctrl - Space , Retro Doors - Open). Translate the display on the windshield (HUD) in the orbital mode by pressing 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 h4> 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 ). We choose the purpose of Mars ( Shift - T , in the menu select Celestial Bodies - Mars):
   
   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 ' or click on the button at the bottom of the screen NML-). Let's wait for the point at which the time until a node (Tn on MFD) will be about half the time of maneuver in the node (Est Thrust T), and include it in the main engine:
   
   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 h4>
    To prepare for the maneuver will include MFD "Transition» ( Shift - X ). Our goal - Mars, which revolves around the Sun, so as central body shall indicate the Sun ( Shift - R , select the Sun in the menu). We turn around the Earth, so we indicate the Earth as the original body ( Shift - S , select the Earth in the menu). We choose Mars purpose ( Shift - T , select Mars in the menu). MFD will look like (added explanations for clarity):
   
   Including the mode of planning maneuver (the button HTO on the MFD). Appears dotted range start point maneuver. It can be moved by pressing the Shift - & lt; and & gt; Shift - - and +
   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:
   

9. 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 , type in the text field the name of our GL-01S ). Nice overclock:

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 , select Mars as a goal by Shift - T ). Our task - pulses to the right, left, up, down, forward, backward, to reduce the value DTmin:

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 h4> 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 , select the Sun in the menu). Next node upward, until it almost five megasekund (brings to mind "The depth in the sky" Vinge, where time is measured by such units):

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. H4> 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 ) and choose as the body circulation Mars ( Shift - T , select Mars in the menu). To squander time until gravity of Mars begins to be felt (20-30 kilosekund to the point of the meeting):

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 reduces the field of view, the button X - increases).

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. H4> 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 ). The trims all the way up and release the brakes. Switch the HUD mode "surface" by pressing H and borrowings position with a roll of 90 °:

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 h4> 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 ) and choose our goal Martian base Olympus ( Shift - T , select Spaceports - Olympus)
Preparing MFD Aerobrake. Open the MFD ( Shift - E ), establish the purpose of the base Olympus ( Shift - T , enter Olympus keyboard), switch the MFD mode card clicks PG and PRJ.

Preparing MFD connection. Open the MFD ( Shift - C ). Open the menu with these beacons ( Ctlr - I ). Base Olympus has three landing sites (alas, no runways), the first of which has a lighthouse, clocked at 129.70 MHz. We establish that the frequency of clicks in the MFD MFD & lt ;, & lt; & lt ;, & gt ;, & gt; & gt ;.

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 h4>
 MFD card can be switched to centering on the ship (the button TRK on the MFD). Our main management bodies will again be trimmer and air brakes. Driving them to support the path to the base area Aerobrake MFD.

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 to increase traction, Num. B> - 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 ). Switch to the MFD landing ( Shift - L ). It is good because it shows the direction and distance accurately enough.
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:






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