Ignition Ring
To insure that the motor starts under the high velocity flow of oxygen at Tminus 0 seconds, a solid propellant ring is lit 2 seconds prior to the initiation of oxygen flow.
The solid propellant ignition ring is made from a commercially available solid propellant AP/HTPB hobby rocket motor reload kit.
The fuel grain is cut into 0.25" disks and then embedded into the paraffin fuel grain at the oxygen injector side.
View movie of ignition ring test
Additional Information