Pyro Actuated Devices are widely used for carrying out separation of structural
components as well as to deploy or release appendages. These Pyro Cartridges, upon
initiation of the explosive charge generates high pressure gas which in turn initiates
the mechanism. Pyro cartridges are highly compact, lightweight and highly reliable
systems for attaining on-command separation. Pyro initiated separation bolts or Pyro
Bolts are generally used for stage separation of launch vehicle systems. These pyro
cartridges generate high levels of shock waves, which leads to failure of many critical
components like avionics and electronic packages in the vicinity of the pyro shock
source. Anecdotal evidence suggests that the shock can only be reduced, if the pyro
initiation is replaced by non-pyro initiation methods like electrical initiation of
unlocking mechanism, pneumatic initiation or initiation by gas generator. The
electrical / electro-mechanical and pneumatic initiation comes with a penalty of bulky
sub structures. In this work, studies have been carried out for reduction of shock by
various means like shock absorbers, dampers and by shock load path isolation. There
is a drastic reduction of shock only by either initiating with pneumatic pressure or by
implementing Gas Generator (GG) based cartridge in place of Pyro Cartridges. The
GG cartridge generates the required minimum pressure for initiating the release
mechanism of the separation bolt. Separation bolt ejection test has been carried out
with pyro cartridge as well as with gas generator based cartridge and the shock
generated has been monitored. It is found that there is an order reduction of shock
with the use of gas generator cartridge as compared to that of a pyro cartridge. This
work describes the developmental work carried out for design, realization and testing
of GG cartridge and its prospective application for a low shock stage separation
mechanism.