TAE Technologies has also looked at building a nuclear fusion rocket. Nextbigfuture had covered TAE Technologies recent announcement that they will have a commercial nuclear fusion rocketby 2023.
The design is from an older 2004 paper. Any new system that is built after TAE Technologies actually achieves commercial power generation with fusion would be vastly better than what is in the 2004 paper.
Nuclear fusion rockets are simpler and less challenging than creating commercial energy that is nearly as cheap as coal. A commercial nuclear reactor needs to be generating power for an average of 70-90% of a year. A nuclear fusion rocket just has to be better than ion drive or more useful than chemical rockets in some situations.
UPDATE – TAE Technologies emailed about how they are not working on the fusion rocket. I knew they were not working on a nuclear fusion rocket but wanted to publish the 2004 paper. I expect and agree that the handful of companies that are funded and focused on nuclear fusion rockets are ahead. I will cover those other nuclear fusion and advanced propulsion projects again.