Theoretical and experimental results are presented for ultrafast, chirped-pulse amplifier compressors that contain only the final, high-peak power grating in vacuum. The designs are compact and the adjustments of the compressor gratings are at atmosphere. The optical aberrations and dispersion of the system are found to be negligible for the compression of 25-fs pulses. The application of the hybrid vacuum-atmosphere compressor is robust with respect to a broad range of wavelengths and optical configurations.