The book begins after Earth has been attacked several times, already. These alien vessels are being sent into the system and attacking the planet.
An elite team of humans from all over the world (iirc) called the “Angels” are sent up on what is almost always a suicide mission to stop the ship and prevent if from wreaking destruction on the planet. As I recall it, only one person has ever survived one of these and that person is in pretty bad shape. Their actions are guided by a crowdsourcing effort, where anyone on the planet can suggest an action, which I think were voted on before the Angels would carry them out.
The one I read was a paperback, I don't think it made it to hardback.
I read the book sometime between 2000 and 2010. It was in English and it was pretty new. It was an uncatalogued paperback from a library. I think the cover art was a space ship of some kind, but I'm not completely sure.