We describe the architecture of the Spoken Language Translator (SLT), a prototype speech translation system which can translate queries from spoken English to spoken Swedish in the domain of air travel information systems. Though the performance given the level of effort so far has been extremely encouraging, more work is needed to provide a technology that will support widespread applications. With this goal, we have developed techniques for rapid development and for evaluation. These techniques allow us to estimate the level of effort required to achieve higher levels of performance.