I'm not familiar with the S1000D format, but given it's an XML specification, I can say it's the bread and butter of Asciidoctor. Generating it would be very similar to the DocBook (built-in) and Mallard (https://github.com/asciidoctor/asciidoctor-mallard) converters. And converting to formats such as this are the value add of Asciidoctor.

If you need help getting started, don't hesitate to ask. You may also be interested in join the Asciidoctor channel on gitter at https://gitter.im/asciidoctor/asciidoctor.

Cheers,

-Dan