The context would help to fine tune an answer, as there are many way s to do this.

There are airborne environmental spore collection methods, and tests for bulk items, such as foods, etc, that can use incubation, and DNA based markers, etc, to establish the presence and identity of bacillus spores.

This would be an example of a food media based test:

http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm070875.htm

If you have a known bacillus population and just need to know if there are airborne propagules (IE: Any airborne particle can be attributed to the bacillus), particle counting techniques (Laser scatter, etc) can be used.

If you have a potentially mixed airborne particle environment, there are commercially available spore traps (Anderson, Bio-Test, etc) that can collect spores for analysis.

There are electron microscopy methods, incubation methods, DNA methods, etc, for the actual analysis of the collected spores, and the morphology-based methods can be used to evaluate the presence in a sample as well, depending upon the context.

And so forth.

What is the context for your project?

If you are working with a pure culture, you can use heat. Bacillus endospores survive 20 minutes at 80 degrees C.  Vegetative cells do not.  Heat shock and plate count.

Heat shock, ethanol shock and chloroform treatment are all common ways of eliminating vegetative cells and do generally not kill spores. In a research setting, these methods are frequently used.

Use a heat treatment and plate the heat-treated culture on agar such as TSA medium. Shall you need visualization on microscope, IF protocols are available, but you can just use a simple gram staining. Hope it helps