| RENDEZVOUS |
Is your head spinning, Cadet?
Space is not easy. But it IS rewarding.
Would it help if I told you that by the end of this section you'll be able to hit the space station
with a rock?
You are very close now. You are in the same orbital plane as the ISS. You and the ISS are
even passing through virtually the same exact spot in space--Your shared periapsis. Now all we
have to do is get you and the ISS to pass thru that spot at the same time.
Don't flag now, Cadet. Glory beckons!
==
Ensure you are in cockpit view and that the sim is not paused.
69 - Set your right MFD to 'sync orbit'
70 - Click on 'TGT' and assign the ISS as your target. (Use arrow keys)
71 - Click on 'MOD' until 'ref' reads as 'Tgt Periapsis'.
72 - Click on 'LEN' and enter '10'. This will increase the list length on the right of the MFD.
The left hand column (01 Sh-ToR) shows times in the future that your ship will arrive at
periapsis. The right hand column is the same information for the ISS.
The goal is to get one set of values from both columns to match up. When they do, your ship
and the ISS will arrive at the same place (periapsis) at the same time.
The most important number on this MFD is DTmin. It needs to be adjusted to as close to zero
as possible.
Here is another graph to further explain the Sync Orbit MFD:
Note: Your MFD may not look exactly like this but yours can be read correctly using the notes
in the above graphic.
There are two ways to get your ship to the ISS:
One is to catch up to the ISS. That means making your orbit smaller than the ISS's which
makes you go faster and after several orbits, you catch up. This is an option that you can
explore later but we will not use it now. The primary reason is because to reduce your orbit, you
would have to lower your Apoapsis below your current periapsis. This causes them to swap out
in the MFDs and causes no end of confusion. Once you have a few dockings and a moon shot
under your belt, you can go that route.
Two is to slow down and let the ISS catch up with you. This will require a prograde burn at
periapsis to increase the size of your orbit. Burning prograde will not cause a
Apoapsis/Periapsis switch. Furthermore, you have all of space to expand into so you can often
force a merge in 1-3 orbits.
Pause the sim and read through steps 73 - 76. These are complex steps that need to be
performed quickly.
73 - As you approach Periapsis, point your ship prograde.
74 - At approx 15-20 seconds prior to PeT, fire main engines using 'control' + 'num pad +'.
75 - Monitor the left hand column on the right MFD (sh-ToR). You will see highlighted values
jump around. In general the highlights should move up the list but they can also jump around.
When you get a highlighted value in any of the top three rows, disengage main engines.
76 - Monitor the DTmin value. Engage linear thrusters 'num pad 6' or 'num pad 9'. If DTmin
increases, switch to the other thruster. Continue to burn thruster until DTmin is as close to zero
as you can get it. Use 'control' plus num pad 6 or 9 to fine tune.
Notice that your orbit (green) has been expanded. You must now travel a further distance than
the ISS on each orbit. Also the further you are from Earth, the slower you travel. Both of these
facts will allow the ISS to catch you.
Now you simply want to ride it out. On each orbit, the highlighted values on the sync orbit MFD
should move up one slot. It should be noticeable on the MFD graph that the ISS is catching up
to you on each orbit. On the final orbit as you cross your periapsis your position should be
merged with that of the ISS.
If merge is not going to happen for 2 or 3 orbits you can fine tune DTmin as you cross your
periapsis. Sometimes it varies a bit. Also if PeR does not match for both orbits you can alter it
at Apoapsis per procedures in steps 60.5 - 65. Be advised this will alter DTmin in the Sync
MFD which will need to be re-adjusted at the next Periapsis crossing.
NOTE: All correction burns should be made strictly at Apoapsis or Periapsis. Small variances
should be ignored if possible. If adjustments are made, ensure DTmin is adjusted to zero on all
possible Periapsis crossings.
==
76.5 - While waiting for your final orbit, we can do a quick step that will help us when we
rendezvous with the ISS. We can set up the Com system with the Transponder and Dock
frequencies of the ISS.
Hit 'F4' on keyboard. Click on 'object' info. In the first pulldown select 'vessel' In the second pull
down select 'ISS'. Reference frequencies for XPDR and Docking Port IDS values. Write them
all down. Close the two windows.
76.75 - Change your left hand MFD to 'COM/NAV'. Using the side arrow buttons, change
frequency Nav1 to the ISS XPDR value that you wrote down in the last step. Add as many
docking ports in the remaining NAV frequencies slots as it will allow. Double check your
numbers.
76.9 - Change the left MFD back to 'orbit'. The ISS should still be selected as your target.
==
76.95 - If desired, accelerate time. As you orbit to merge, monitor 'DTmin' on 'sync MFD'. Also
monitor that 'PeR' matches for both craft on the 'orbit' MFD. If required, reduce time to normal
prior to Apoapsis or Periapsis to make slight adjustments to these values as outlined previously.
If all goes well, you should see your ship and the ISS snuggling up nice on the MFDs coming
into Periapsis on the final orbit per the Sync MFD.
76.96 - Approx 1/2 orbit from merge, pause the sim and read through steps 77 - 80. They are
complex and will need to be performed quickly.
77 - Reference the ISS Ecc on the left hand 'orbit' MFD. Write it down.
77.5 - Turn your ship to 'retro grade'.
78 - Estimate burn time to bring your orbit path down to match the ISS. This will have to be your
best guess. If you remember approximately how long it took to push your orbit out in steps
74-76 then you have a good estimate. Divide your burn estimate by two. When PeT counts
down to that number, initiate main engine burn.
79 - While burning, monitor your Ecc as it descends in value. Anticipate when to shut down
burn to match your Ecc with the ISS Ecc that you wrote down in step 77. Fine tune the burn with
linear thrusters.
When both Ecc's match, you should now share an orbit that is virtually identical with the ISS.
80 - Cycle HUD to 'dock' mode with the 'h' key.
81 - Ensure the HUD is slaved to frequency Nav1. If not hit 'control + r' until it is.
81.5 - If the ISS is not already in your field of view, you should see an arrow that points towards
it. Use rotational thrusters to rotate your ship in the direction of the arrow. Follow the ISS
arrow not the V(ISS) arrow.
THE ISS SHOULD COME INTO VIEW! When it gets close to the center of your screen kill
rotation with 'num pad 5'.
82 - SAVE!
Excellent!
The final steps are complex but a lot of fun!
Onward to Docking!
Space is not easy. But it IS rewarding.
Would it help if I told you that by the end of this section you'll be able to hit the space station
with a rock?
You are very close now. You are in the same orbital plane as the ISS. You and the ISS are
even passing through virtually the same exact spot in space--Your shared periapsis. Now all we
have to do is get you and the ISS to pass thru that spot at the same time.
Don't flag now, Cadet. Glory beckons!
==
Ensure you are in cockpit view and that the sim is not paused.
69 - Set your right MFD to 'sync orbit'
70 - Click on 'TGT' and assign the ISS as your target. (Use arrow keys)
71 - Click on 'MOD' until 'ref' reads as 'Tgt Periapsis'.
72 - Click on 'LEN' and enter '10'. This will increase the list length on the right of the MFD.
The left hand column (01 Sh-ToR) shows times in the future that your ship will arrive at
periapsis. The right hand column is the same information for the ISS.
The goal is to get one set of values from both columns to match up. When they do, your ship
and the ISS will arrive at the same place (periapsis) at the same time.
The most important number on this MFD is DTmin. It needs to be adjusted to as close to zero
as possible.
Here is another graph to further explain the Sync Orbit MFD:
Note: Your MFD may not look exactly like this but yours can be read correctly using the notes
in the above graphic.
There are two ways to get your ship to the ISS:
One is to catch up to the ISS. That means making your orbit smaller than the ISS's which
makes you go faster and after several orbits, you catch up. This is an option that you can
explore later but we will not use it now. The primary reason is because to reduce your orbit, you
would have to lower your Apoapsis below your current periapsis. This causes them to swap out
in the MFDs and causes no end of confusion. Once you have a few dockings and a moon shot
under your belt, you can go that route.
Two is to slow down and let the ISS catch up with you. This will require a prograde burn at
periapsis to increase the size of your orbit. Burning prograde will not cause a
Apoapsis/Periapsis switch. Furthermore, you have all of space to expand into so you can often
force a merge in 1-3 orbits.
Pause the sim and read through steps 73 - 76. These are complex steps that need to be
performed quickly.
73 - As you approach Periapsis, point your ship prograde.
74 - At approx 15-20 seconds prior to PeT, fire main engines using 'control' + 'num pad +'.
75 - Monitor the left hand column on the right MFD (sh-ToR). You will see highlighted values
jump around. In general the highlights should move up the list but they can also jump around.
When you get a highlighted value in any of the top three rows, disengage main engines.
76 - Monitor the DTmin value. Engage linear thrusters 'num pad 6' or 'num pad 9'. If DTmin
increases, switch to the other thruster. Continue to burn thruster until DTmin is as close to zero
as you can get it. Use 'control' plus num pad 6 or 9 to fine tune.
Notice that your orbit (green) has been expanded. You must now travel a further distance than
the ISS on each orbit. Also the further you are from Earth, the slower you travel. Both of these
facts will allow the ISS to catch you.
Now you simply want to ride it out. On each orbit, the highlighted values on the sync orbit MFD
should move up one slot. It should be noticeable on the MFD graph that the ISS is catching up
to you on each orbit. On the final orbit as you cross your periapsis your position should be
merged with that of the ISS.
If merge is not going to happen for 2 or 3 orbits you can fine tune DTmin as you cross your
periapsis. Sometimes it varies a bit. Also if PeR does not match for both orbits you can alter it
at Apoapsis per procedures in steps 60.5 - 65. Be advised this will alter DTmin in the Sync
MFD which will need to be re-adjusted at the next Periapsis crossing.
NOTE: All correction burns should be made strictly at Apoapsis or Periapsis. Small variances
should be ignored if possible. If adjustments are made, ensure DTmin is adjusted to zero on all
possible Periapsis crossings.
==
76.5 - While waiting for your final orbit, we can do a quick step that will help us when we
rendezvous with the ISS. We can set up the Com system with the Transponder and Dock
frequencies of the ISS.
Hit 'F4' on keyboard. Click on 'object' info. In the first pulldown select 'vessel' In the second pull
down select 'ISS'. Reference frequencies for XPDR and Docking Port IDS values. Write them
all down. Close the two windows.
76.75 - Change your left hand MFD to 'COM/NAV'. Using the side arrow buttons, change
frequency Nav1 to the ISS XPDR value that you wrote down in the last step. Add as many
docking ports in the remaining NAV frequencies slots as it will allow. Double check your
numbers.
76.9 - Change the left MFD back to 'orbit'. The ISS should still be selected as your target.
==
76.95 - If desired, accelerate time. As you orbit to merge, monitor 'DTmin' on 'sync MFD'. Also
monitor that 'PeR' matches for both craft on the 'orbit' MFD. If required, reduce time to normal
prior to Apoapsis or Periapsis to make slight adjustments to these values as outlined previously.
If all goes well, you should see your ship and the ISS snuggling up nice on the MFDs coming
into Periapsis on the final orbit per the Sync MFD.
76.96 - Approx 1/2 orbit from merge, pause the sim and read through steps 77 - 80. They are
complex and will need to be performed quickly.
77 - Reference the ISS Ecc on the left hand 'orbit' MFD. Write it down.
77.5 - Turn your ship to 'retro grade'.
78 - Estimate burn time to bring your orbit path down to match the ISS. This will have to be your
best guess. If you remember approximately how long it took to push your orbit out in steps
74-76 then you have a good estimate. Divide your burn estimate by two. When PeT counts
down to that number, initiate main engine burn.
79 - While burning, monitor your Ecc as it descends in value. Anticipate when to shut down
burn to match your Ecc with the ISS Ecc that you wrote down in step 77. Fine tune the burn with
linear thrusters.
When both Ecc's match, you should now share an orbit that is virtually identical with the ISS.
80 - Cycle HUD to 'dock' mode with the 'h' key.
81 - Ensure the HUD is slaved to frequency Nav1. If not hit 'control + r' until it is.
81.5 - If the ISS is not already in your field of view, you should see an arrow that points towards
it. Use rotational thrusters to rotate your ship in the direction of the arrow. Follow the ISS
arrow not the V(ISS) arrow.
THE ISS SHOULD COME INTO VIEW! When it gets close to the center of your screen kill
rotation with 'num pad 5'.
82 - SAVE!
Excellent!
The final steps are complex but a lot of fun!
Onward to Docking!
