if (t_state.gps != null) {
AltosLatLon latlon = new AltosLatLon(t_state.gps.lat, t_state.gps.lon);
rocket.set_position(latlon, t_state.received_time);
if (t_state.gps != null) {
AltosLatLon latlon = new AltosLatLon(t_state.gps.lat, t_state.gps.lon);
rocket.set_position(latlon, t_state.received_time);