It is possible. By using a custom voice command, however, do take note that your voice command will need to be approved if you would like to launch your Glassware in MyGlass. For development purposes, it should be fine.
After you've found or set up the appropriate voice command, you can look at this on how to create the intent-filter and trigger that will start this voice-activated activity. The link has instructions on how to add prompts to your voice commands (i.e. when you want to go to different URLs for different prompts).
Then you can immediately start an activity that starts the browser from the voice-triggered activity.