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2
Typical Mission Profile
This document guides you through a typical Lunar exploration mission.
Training missions are included to help you gain experience before you attempt
to land on the Moon. Topics include:
Mission Planning
Landing on the Lunar Surface
Abort Procedure
EVA Activities
Return to the LOL
Emergency EVA
Training Missions
Mission Planning
Mission planning includes selecting the landing site, planning EVA routes and
activities, and planning orbital maneuvers.
Select a Landing Site: Possible missions include visiting previous Apollo,
Surveyor, or Luna landing sites, unusual geological features, etc. Map the
vicinity of the primary target using MAPGEN at level 1. Select a smooth cell
near the primary target as the landing site. Enter the coordinates of the
landing site into NEWGAME.
Plan EVA Routes and Activities: Choose EVA routes that minimize the distance
traveled over rough areas. EVA activities may include sampling high-value
geological formations or manmade objects.
Plan Orbital Maneuvers: Note the sequence, timing, and duration of RCS and
main engine burns.
Landing on the Lunar Surface
Landing includes transferring to and checking out the LM, undocking and
separating from the LOL, performing two plane change maneuvers, putting the LM
into a descent orbit, beginning powered descent, and landing on the Moon.
Transfer/Checkout of LM: Set the INS display to "POS-TAR". Begin transfer to
and checkout of the LM about 60° west of the landing site. Transfer and
checkout of the LM reqires about 45 min to complete.
Undocking/Separation from LOL: [Place the LM into an orbit that returns it to
the vicinity of the LOL in about 2 hr if no further action is taken.] Set the
INS display to "POS-TAR" and the RCS throttle to "LOW". UNDOCK after LM
checkout, 155° east of the landing site. Undocking defines MET 00:00 and
imparts a small northward velocity (≈0.1 m/s) to the LM. Set the INS display
to "POS-REL". At 50 m from the LOL, use the RCS DOWN thruster to increase the
separation velocity to 0.3 m/s. Set the RCS throttle to "MEDIUM" and ROLL the
LM so the Face body axis points up. Set the INS display to "POS-TAR". At 105°
east of the landing site, use the RCS FACE thruster to increase the LM upward
velocity by 1 m/s. Turn ON the DSN transponder.
Landing on the Lunar Surface (continued)
Plane Change Maneuvers: [Modify the LM orbit to pass directly over the
landing site.] Set the INS display to "POS-TAR" and the RCS throttle to
"MEDIUM". At 3° east of the landing site, about MET 00:45, use the RCS UP or
DOWN thruster to cancel the north/south velocity component. Next, orient the
LM so the Face body axis points up and the Up body axis points toward the pole
of the hemisphere not containing the landing site. At 87° west of the landing
site, about MET 01:15, set the INS display to "ORB-TAR". If the landing site
is in the southern hemisphere, use the Descent Engine to change the angular
momentum "NORTH" component to 90°. Otherwise, change it to (90-2·L)°, where
"L" is the landing site latitude. During the burn, YAW the LM so the
direction of thrust remains perpendicular to the orbit plane.
Descent Orbit Insertion (DOI): [Change the LM orbit from 100km circular to
20 km by 100 km with a perilune about 15° east of the landing site.] Set the
INS display to "POS-TAR" and the RCS throttle to "MEDIUM". Orient the LM so
the Face body axis points up and the Left Body axis points south. When the LM
is 165° west of the landing site, about MET 01:40, IGNITE the Descent Engine
and switch the INS display to "ORB-TAR". Continue the burn for about 50 s
until the perilune is slightly greater than 20 km. After Descent Engine
cutoff, use the RCS UP thruster to adjust the perilune to 20 km.
Landing on the Lunar Surface (continued)
Powered Descent Initiation (PDI): Set the INS display to "POS-TAR" and the
RCS throttle to "HIGH". Orient the LM so the Face body axis points up and the
Left Body axis points south. At 18° east of the landing site, about MET
02:40, start the Descent Autopilot. The LM will be guided automatically to a
point near the landing site. Turn the Landing Radar ON at an altitude of 12
km and the DSN transponder OFF at 6 km. During descent, use the RCS LEFT and
RIGHT thrusters or YAW control to adjust the crosstrack position and velocity.
Resume manual control at an altitude of 1000 m.
Final Approach and Landing: Reduce horizontal velocity components to less
than 1 m/s while gradually bringing the LM to an upright position. Use RCS
thrusters to cancel the horizontal velocity when the LM is directly over a
smooth lurrain area. Set the RCS throttle to "MEDIUM". Use the Descent
Engine throttle to control the rate of descent. At 200 m, the Landing Radar
display is activated. Land, if possible, with horizontal and vertical
velocity components less than 0.3 m/s and 1 m/s, respectively. A successful
landing is indicated by the "TOUCHDOWN" light. REST immediately after landing
in preparation for the first EVA.
Abort Procedure
Start the Abort sequencer if trouble occurs during final approach and landing,
e.g., the LM runs low on propellant or the rate of descent is too rapid. The
Abort sequencer stops all rotational motion, turns off all RCS translation
thrusters, shuts down the Descent Engine, jettisons the Descent Stage, and
ignites the Ascent Engine. During ascent, the LM is under manual control.
Immediately PITCH forward rapidly until the LM Up body axis is pointing up.
Continue to pitch forward at 1°/s until reaching a "u/r" angle of 60°, heading
west. ROLL rapidly at 5°/s by 180° until the LM Left body axis points north.
Turn OFF the Landing Radar and turn ON the DSN transponder. Use the PITCH
control to bring the LM to an altitude of 20 km with a perilune of slightly
less than 20 km. This orbit may roughly be achieved by pitching back 5° every
40 s during the remainder of the burn. Turn OFF the Ascent Engine after
achieving the proper orbit. Use the RCS UP thruster to put the LM into a 20
km circular orbit. Rendezvous, approach, and dock with the LOL following
standard procedures.
EVA Activities
EVA activities include preparing for EVA, leaving the LM, operating the LRV,
collecting samples, transferring sample boxes from the LRV to the LM,
reentering the LM, and terminating the EVA. The first EVA begins after a rest
period following landing. Subsequent EVAs occur following sleep and rest/meal
periods on successive days while on the Lunar surface.
Preparation and LM Egress: A rest/meal period is recommended following
landing or a sleep period prior to beginning EVA preparation. Put on the
spacesuit and PLSS, evacuate the cabin, and exit the LM. Preparation and
egress requires about 1.5 hr to complete.
LRV Operation: Set the INS display to "POS-ABS". Enter the LRV and drive to
the first sample collection location as defined during mission planning. Set
the LRV throttle to 50-60% while driving over open lurrain. When approaching
rough terrain, reduce throttle to 20-30%. Avoid very rough spots, the LM, and
manmade objects. Park the LRV between 20 m and 40 m of the sampling location.
Make sure the LRV is completely stopped by decreasing the throttle several
times.
EVA Activities (continued)
Sample Collection: Exit the LRV and move to the cell containing the sampling
site. Collect samples and put them into the LRV sample box. The EVA score is
incremented as samples are collected, with higher value samples resulting in
higher scores. When finished, enter the LRV and drive to the next site. Make
sure the PLSS is completely stopped by decreasing the throttle several times.
Sample Box Transfer to the LM: When all sampling sites have been visited or
the LRV sample box is full, set the INS display to "POS-REL" and return to the
LM. Pick up the box from the LRV and transfer it to the LM. The EVA score is
incremented, depending on the total amount of sample collected, and displayed.
Additional boxes may be used if sufficient time remains. EVAs should be
completed between UT 16:30 and 18:30.
LM Ingress and Termination: Reenter the LM at the end of an EVA, pressurize
the cabin, and remove the PLSS and spacesuit. Ingress and termination require
about 1.5 hr to complete. REST once or twice in preparation for the next
sleep period. SLEEP in preparation for the next EVA or liftoff. For maximum
efficiency, begin sleep periods about UT 22:00.
Return to the LOL
Returning to the LOL includes lifting off from the Lunar surface, adjusting
the initial orbit, performing transfer orbit, plane change, and
circularization burns, and approaching, docking, and transferring to the LOL.
Liftoff and Initial Orbital Adjustment: [Put the LM into a 20 km circular
orbit.] Begin liftoff after sleep and rest/meal periods, between UT 09:00 and
11:00. Set the INS display to "POS-REL" and the RCS throttle to "HIGH".
Start the Ascent Autopilot when the LOL is 5° east of the landing site. The
LM will automatically liftoff from the Lunar surface and be placed into an
orbit with an apolune of about 20 km. Immediately after liftoff, switch the
INS display to "POS-TAR" and turn ON the DSN transponder. During ascent, use
the PITCH control if necessary to adjust the rate of ascent. Increase the
burn time, as required, if the LM is carrying a large quantity of Lunar
samples. After Ascent Engine cutoff, set the INS display to "ORB-ABS" and
use the RCS UP thruster to raise the perilune to 20 km.
Transfer Orbit Maneuver: [Put the LM in a 20 km by 100 km orbit that brings
it near to the LOL.] Orient the LM so the Face body axis points up and the
Left body axis points north. Set the INS display to "POS-REL" and the RCS
throttle to "MEDIUM". When the LM is 5.8° east of the LOL, about 15 min after
liftoff, switch the INS display to "ORB-ABS", and use the Ascent Engine to
Return to the LOL (continued)
raise the apolune to slightly less than 100 km. The transfer orbit burn lasts
about 3 s. Use the RCS UP thruster to raise the apolune to 100 km.
Plane Change Maneuver: [Put the LM into an equatorial orbit.] Set the INS
display to "POS-ABS" and the RCS throttle to "HIGH". Orient the LM so the Up
body axis points toward the pole of the hemisphere containing the landing
site. As the LM crosses the Lunar equator, about 30 min after liftoff, use
the Ascent Engine and RCS to set the north component of velocity to 1 m/s.
During the burn, YAW the LM so the direction of thrust remains perpendicular
to the orbit plane.
Circularization Burn: [Put the LM into a 100 km circular orbit.] Set the INS
display to "POS-REL" and the RCS throttle to "MEDIUM". Orient the LM so the
Face body axis points up and the Left body axis points north. As the LM
passes near the LOL, turn ON the LOL transponder. Turn it OFF before the
circularization burn. Near apolune, when the LM is at least 1 km east of the
LOL, about 1 hr after liftoff, IGNITE the Ascent Engine and raise the perilune
to about 100 km by burning for 3 s. The LM should be within 10 km of the LOL.
Turn ON the LOL transponder and turn OFF the DSN transponder. The LOL
transponder must be ON to dock.
Return to the LOL (continued)
LOL Approach: [Bring the LM to within 500 m north of the LOL.] Set the INS
display to "POS-REL" and the RCS throttle to "MEDIUM". Orient the LM so the
Face body axis points up and the Up body axis points south. Use the RCS
translation thrusters to bring the LM to a point approximately 500m north of
the LOL.
LOL Docking and Transfer: Set the RCS throttle to "LOW" and orient the LM so
the Face body axis points up and the Up body axis points south. Use the RCS
translation thrusters to precisely align the LM with the LOL both in altitude
and east/west. Approach the LOL at about 0.5 m/s. At 200 m, the Docking
Radar display is activated. Slow the approach velocity to 0.3 m/s. Align the
LM to center the "ROLL" alignment indicator by executing a clockwise or
counterclockwise ROLL command if the alignment indicator is to the left or
right of the display, respectively. If necessary, align the LM to center the
"PITCH/YAW" alignment indicator. Use the RCS thrusters during final
approach to keep the LM position aligned with the center of the docking port.
Dock, if possible, with an approach velocity between 0.2 and 0.4 m/s. A
successful docking is indicated by the "DOCKING" light. If a docking attempt
fails, the LM bounces off the LOL and the final approach must be repeated.
After successfully docking, transfer to the LOL to complete the mission.
Emergency EVA
The LM and/or LOL may become damaged such that docking is no longer possible.
If LM and LOL damage become severe (50% or more), the Pilot must transfer to
the LOL using an emergency EVA. At a safe distance from the LOL, put on the
spacesuit and evacuate the cabin. Set the INS display to "POS-REL" and the
RCS throttle to "LOW". Move the LM to about 80 m east or west of the LOL and
reduce the relative velocity as low as possible. Execute a "MOVE" command to
transfer to the LOL and complete the mission.
Training Missions
Training missions are suggested, in increasing order of difficulty, that allow
you to become familiar with flying the LM. Try at least one of each variety
before proceeding to the next level of difficulty.
Mission #1: Transfer to and checkout the LM. UNDOCK and perform the first
separation burn. Turn ON the LOL transponder. Practice using the PITCH,
ROLL, and YAW controls and RCS thrusters. After about 1 hr, approach and dock
with the LOL. This mission requires about 2.5 hr to complete.
Mission #2: Same as #1 but add the second separation burn. After one orbit,
approach and dock with the LOL. Use the LOL transponder while the LM is
within 30 km of the LOL, otherwise use the DSN transponder. This mission
requires about 4.5 hr to complete.
Mission #3: Same as #2 but add the two plane change maneuvers so the LM
overflies the landing site. After one full orbit, put the LM into an
equatorial orbit by cancelling the north/south component of velocity as it
crosses the Lunar equator. After one-half orbit, approach and dock with the
LOL. This mission requires about 6.5 hr to complete.
Training Missions (continued)
Mission #4: [This mission is similar to that of Apollo 10.] Same as #3 but
add the DOI maneuver. After returning to the apolune of the descent orbit,
put the LM into a 100 km by 180 km orbit to restore the relative position of
the LM west of the LOL. After another orbit, circularize the LM orbit. Put
the LM into an equatorial orbit, approach, and dock with the LOL. This
mission requires about 8.5 hr to complete.
Other Missions: You are now ready to attempt a landing. Start with targets
located near the Lunar equator. As you gain experience, try to explore
more challenging targets at higher and higher latitudes. To practice parts
of missions, you can copy one of the tutorial save files "*.SAV" to "AMS.SAV"
and start the AMS.
HAPPY LANDINGS !