As advanced in-space propulsion moves from science fiction to reality, the Variable Specific Impulse Magnetoplasma Rocket, or VASIMR® engine, is a leading contender for making 'Mars in a month' a possibility. A paradigm shift in space transportation, this book is an in-depth and compelling story co-written by its inventor. It traces the riveting history of the development of the VASIMR® engine. This landmark technology is grounded in concepts of advanced plasma physics. It cross-pollinates ideas and disciplines to offer a new, practical, and sustainable solution for in-space transportation beyond low Earth orbit in the decades to come. Invented by the co-holder of the world's spaceflight record, astronaut Franklin Chang Díaz, the VASIMR®  engine is developed by Ad Astra Rocket Company in its Texas facilities with NASA as part of the NextSTEP VASIMR® partnership. With adequate funding, the first spaceflight of the VASIMR® engine is imminent. Plasma rockets feature exhaust velocities far above those achievable by conventional chemical rockets. The VASIMR® engine is the most advanced high-power plasma propulsion system operating in the world today and it may place long, fast interplanetary journeys withinour reach in the near future.