Pneumatisch ists.
Steht im Handbuch. Mehrfach.
http://www.spacex.com/sites/spacex/files/falcon_9_users_guide_rev_2.0.pdf"Non explosive, pneumatic release and separation systems
Zero debris separation systems significantly reduce orbital debris signature, can be repeatedly tested during the manufacturing process, and eliminate hazardouspyrotechnic devices"
"The Falcon second-stage restraint, release and separation systems use pneumatic devices that provide low-shock release and positive force separation over a comparatively long stroke. The pneumatic system allows for acceptance and functional testing of the actual flight hardware,
which is not possible with a traditional explosives-based separation system."
"The stage separation system is located at the forward end of the interstage and interfaces to the second-stage."
"After the first-stage engine shut down, a high-pressure helium circuit is used to release the latches via redundant actuators. The helium system also preloads three pneumatic pushers, which provide positive-force stage separation after latch release. For added reliability, a redundant center pusher attached to the first stage is designed to dramatically decrease the probability of re-contact between the stages following separation. The two halves of the fairing are fastened by mechanical latches along the fairing vertical seam. To deploy the fairing, a high-pressure helium circuit releases the latches, and four pneumatic pushers facilitate positive-force deployment of the two halves."
So, RTFM. Oder sich mal auf die Vorposter verlassen.
Axel
