Project Vela was a project by the United States to develop and implement methods to monitor compliance with the 1963 Partial Test Ban Treaty. The development work was primarily performed by the Advanced Research Projects Agency and was overseen by the United States Air Force. Project Vela consisted of three elements: Vela Uniform to monitor seismic signals to detect underground nuclear testing, Vela Sierra to detect atmospheric nuclear testing and Vela Hotel to detect nuclear testing from space.