Dead Space 3 secrets in chapter 8: Off the Grid.
S.C.A.F. Artifacts (1)
Text Logs (2)
Audio Logs (2)
Weapon Parts (3)
Upgrade Circuits (2)
Weapon Parts 1/3
After starting the chapter move forwards, keeping on the left. The weapon part is located near the firs crate you'll come across.
Upgrade Circuits 1/2
After falling down from the cliff, walk around burning parts of the shuttle on the right - you should see a circuit.
Text Logs 1/2
In the first room with a generator, on the table left from the entrance.
Audio Logs 1/2
In the first room with a generator. When you start it, an audio log panel will activate.
In the room with colorful lights on the wall, in the dark side - right after passing by mentioned lights, on the table.
Upgrade Circuits 2/2
After exiting the cargo elevator and reaching the part looking like a huge pipe, turn right - the circuit is on the nearby catwalk.
Weapon Parts 2/3
After leaving the collapsed "pipe", go to the right - you'll reach a room with a generator. The weapon part lies on the bed, right from the entrance.
S.C.A.F. Artifacts 1/1
On the catwalk, where you can climb with a ladder located in front of the initially inaccessible gate.
Audio Logs 2/2
After walking past the large gate, initially inaccessible, you'll get to the room with a generator. Once you start it, an audio log will be played.
Text Logs 2/2
After walking past the large gate, initially inaccessible, you'll get to another room with a generator. Log can be found on the ground, near the bed and the second exit.
Weapon Parts 3/3
Inside the cave on the right. If you walk along the hill, you should see the entrance without problems.