U.S. space capabilities—long a bastion of strength—have become an Achilles’ heel to America’s national security. The space domain has fundamentally transformed, and the establishment of the United States Space Force is a testament to that. A new methodology is needed to rise to the challenge of this moment. The nimble capability development methodology known as Designing for Principles (DfP) can help the USSF act with unprecedented velocity to fundamentally revector its current capability development trajectory. DfP is tailor-made for a small, bold service that prioritizes innovation and is committed to more quickly develop and field agile capabilities in an uncertain environment.