Apart from fire-based scientific experiment (or fire-ritual, as popularly known), other principal types of yagyas signified in the vedic culture are :
The Seva Yagna -- altruist service of the society is a noble example of Yagya.
The Gyan Yagya, similarly implies the service of people by enlightening their lives in the glow of knowledge and education.
The Prana Yagya implies - the service of saving the lives of people from suffering and agonies and inspiring liveliness and respect for life in them. A v of such Yagyas are described in the Shastras.