We demonstrate the end-to-end functional operation of the GTM system designed to detect Gamma-Ray Bursts (GRBs) associated with LIGO (Laser Interferometer Gravitational Wave Observatory) gravitational wave (GW) events. The GTM can furthermore trigger on GRB’s that were not otherwise detected. We have designed and implemented a GTM laboratory model and further research will include testing, fabricating and calibrating the GTM at high space-qualification standards. ISS-Lobster’s main goal is to detect electromagnetic (EM) counterparts of GWs. Lobster’s X-ray Wide Field Imager (WFI) will re-point toward GW events within ten minutes, and cover the LIGO error box of ∼1000 deg2  in a single pointing. Observation of both GW and the EM counterpart will achieve several astrophysical goals.   This combined observation of the WFI and GTM will increase the statistical significance of the GW detection, by increasing LIGO sensitivity to these events, and indicate the GW are associated with a GRB.