The expedition

 is an optional side mission featured in S.T.A.L.K.E.R.: Lost Alpha (v1.4000 onwards).

"You can look everywhere. There are lots of facilities and laboratories. Let's do it that way, I'll send a group of researchers with you to explore the places where the documents may've been left. Besides it you'd have to take all the electronics you find: recording, measurement devices and etc. And when you return, I'll make the copies of the papers I have for you."

- Sakharov

Overview
The mission is given by Sakharov.

The Find The Item side mission consists of numerous steps. After the completion of certain steps a new mission with the same name is created in the Tasks list.

In v1.4002 the mission is seriously bugged and very fragile in terms of breaking the mission by doing things in the wrong order.

Initial mission

 * 1) Talk to Professor Pirozhenko.
 * 2) Talk to Professor Kuleshov.
 * 3) Talk to assistant.
 * 4) Get going to the first checkpoint.

Talk to Professor Pirozhenko

 * The professor usually is waiting somewhere on the compound.
 * The "final mission" will appear

Talk to Professor Kuleshov

 * This professor usually is waiting in one of the huts on the compound.

Talk to assistant

 * The assistant is waiting in the frame used to airdrop the BTR on the compound.

Get going to the first checkpoint

 * The three members of the expedition are waiting at the compound gate, talk to Professor Pirozhenko.
 * The "initial mission" finishes and the "first checkpoint" mission will appear

The "first checkpoint" mission

 * 1) Get to the first checkpoint.
 * 2) Examine the first checkpoint.

Get to the first checkpoint

 * The first checkpoint is the small, hidden bunker just south of the Dead City entrance.

Examine the first checkpoint

 * Talk to the other three until Professor Pirozhenko tells you that there is something on the shelf.
 * Equip yourself with the Elite anomaly detector and as much psy protection as you have.
 * Find your way to the shelf on the left side of the bunker. The easiest way is through the right entrance to the back of the room and then along the wall to the shelf.
 * On the shelf is, beside some notable loot, an Old device.
 * The Experiment journal, an element of the Find the documents (Yantar) mission, will be nearby.
 * Talking to Professor Pirozhenko again will start the "second checkpoint" mission

The "second checkpoint" mission

 * 1) Get to the second checkpoint.
 * 2) Investigate the situation.
 * 3) Examine the second checkpoint.
 * 4) Report to professor.

Get to the second checkpoint

 * The second checkpoint is the old hangar at Yantar Military Stores.

Investigate the situation

 * The purpose of this task is unclear.

Examine the second checkpoint

 * Talk to Professor Pirozhenko and check the house in the northeastern part of the compound.
 * Talk to Professor Pirozhenko again and check the hangar.
 * In the hangar you will find two important items:
 * another Old device a little concealed in the lower part of one of the lathes.
 * the third Old device sitting on the workbench.
 * While in the hangar you can also pick up two items for the Find the documents (Yantar) side mission:
 * the Report, item 4 in the side mission, lying on an old fuel tank.
 * the Papers, item 3 in the side mission, in the inventory of the dead scientist.

Report to professor

 * Just do that and he will tell you some details for the next checkpoint.

The "third checkpoint" mission

 * 1) Get to the third checkpoint.
 * 2) Examine the old warehouse.
 * 3) Get to a big hall.
 * 4) Examine the hall.
 * 5) Examine the third checkpoint.
 * 6) Return to the base. (1.4005+ only)

Get to the third checkpoint

 * The third checkpoint is storage room and a hangar below the Yantar Military Stores, reachable only through Yantar underground.

Examine the old warehouse

 * After the other members of the expedition have left you alone, go the upper floor of the Radar Station.
 * Here you can pick up the Document case, item 8 in the Find the documents (Yantar) side mission.
 * Find the elevator shaft, head downwards and continue to a chamber with wooden storage racks. On one of the racks, near the blue chest of the Chest within the old lab stash, is the fourth Old device.
 * v1.4002 only: due to a bug in this version the Old device is not in the chamber but at the surface.
 * It is lying on the ground between the nearby works car, the anomaly infested buildings above the (closed) entrance to the underground, and the outer wall of the Radar Station.
 * No need to pick it up immediately, just continue with the mission and remember to get it before you return to Sakharov. This will leave the task uncompleted but will not break the mission.
 * If you pick it up right at the beginning of this subtask, after the other members of the expedition have left you alone, before going to the upper floor of the Radar Station, things may go a bit more smoothly (see below). This will complete this subtask and start "Get to a big hall".
 * In the same chamber you can find two items for other missions:
 * the Calculations, item 2 in the Find the documents (Yantar) side mission.
 * the PDA wires for the Get wire for the scientist storyline mission.

Get to a big hall

 * Follow the pipes through the southern exit of the chamber into the tunnel until you come to the hangar or hall with a parked BTR.
 * In v1.4002 you will see this subtask only if you have already picked up the fourth Old device (see above).

Examine the hall

 * Take care of the zombies and you will find the fifth Old device.
 * Beside it on the table is the Order №316, item 6 in the Find the documents (Yantar) side mission.

Examine the third checkpoint

 * In v1.4002 this task will complete only if you have already picked up the fourth Old device (see above).
 * Otherwise on the map the area of Sakharov's Bunker is highlighted and marked with "Return to the base". Before returning to the base remember to pick up the fourth Old device as described in Examine the old warehouse.
 * In v1.4005 this subtask completes together with it's predecessor, Examine the hall.

Return to the base

 * In v1.4002 you will see this subtask only if you have already picked up the fourth Old device (see above).
 * On the map the area of Sakharov's Bunker is highlighted and marked with "Return to the base".
 * There is one document to be retrieved for the the Find the documents (Yantar) side mission from the rear of the Motor Pool, the Transport invoices ("yan_docs_part1_name"), which should not pose any problems as the local occupants are also observing the ceasefire that has been negotiated for the mission.
 * Back at Sakharov's Bunker talk to Professor Pirozhenko first, then to Sakharov.

The "final" mission

 * 1) Finish the expedition.
 * 2) Talk to Sakharov.

Finish the expedition

 * Go and find Sakharov.

Talk to Sakharov

 * Sakharov should then conclude the mission by taking the five pieces of hardware (the "devices") from the player, provide copies of the eight discovered Documents, and give the player a copy of his own files, Sakharov's documents ("yan_docs_part9_name") to complete the set required by Petrenko.
 * v1.4002 only: Sakharov considers the mission as not completed... and has no dialogue available. Workaround: (Hat-tip to ElMachor)
 * Kill one of The expedition party...
 * Clearly, this will have consequences detrimental to the player's standing.
 * (If effected from outside of Sakharov's Bunker perimeter these negative factors may be mitigated)
 * The mission "fails" and Sakharov has a dialogue to deal with this eventuality.
 * He also relieves the player of the "Old devices", provides the ninth document (Sakharov's documents) which completes the parallel Find the documents (Yantar) mission for Petrenko.
 * Otherwise implement the bug fix to get the dialog working.

Trivia

 * The expedition party take routes that may lead them into harms way (like Nimble) and it may play to the player's advantage to trim the local wildlife down to size between accepting the mission from Sakharov and rounding up the expedition proper.
 * Notable "easy kills" are the Fleshes by the first CP, the quiescent Zombies outside of the same location, the Boars to the south, the Blind Dog pack that the party will try to run through first; the Zombified Stalkers near to the Radar Station (along with any snork infestation)
 * The Zombie group that are the target of the Kill radar zombies. sidemission should be left alone where possible (if extant)