I am trying to access a certain value from a JSON object. The value I am trying to access is launches->rocket->agencies->abbrev from a JSON object that has a lot of nested objects and arrays. I can't access values below a certain nested level for some reason. Here is a screenshot of the JSON object logged in the console.
JSON Object screenshot http://prntscr.com/c6ym11 Edit: Link to the image, since embedding didn't work
Here is a link to an example of the JSON formatting in the returned data
These are the ways I have tried:
data = JSON.parse(data);
var agency = [];
var names = [];
var configuration = [];
for(i = 0; i < data.launches.length; i++){
    //This works just fine
    names.push(data.launches[i].name);
    //This also works
    configuration.push(data.launches[i].rocket.configuration);
    //This returns undefined
    agency.push(data.launches[i].rocket.agencies.abbrev); 
    //This generates Uncaught TypeError: Cannot read property 'abbrev' of undefined
    agency.push(data.launches[i].rocket.agencies[0].abbrev); 
}
I can access key:value pairs on the "rocket" level, but I cannot access anything nested below that level. Is there something wrong with how I am calling the data?