The current leads proposed are of direct use to NASA X-ray telescopes; in particular the XRS-type cryostat. The techniques proposed may be applicable to other low-temperature detectors used by NASA and even in cryogenic rocket fuel instrumentation and management. All superconducting magnets operating at 4 degrees Kelvin e.g. NMR, MRI, magnetic separation, use current leads running from room temperature to 4K. HTS leads are of potential benefit in reduction of helium consumption in all these applications. Helium is becoming an increasingly scarce commodity, and the financial benefits of saving helium boil-off are increasing for many commercial users of these superconducting magnet technologies. Superconducting electronics is being proposed as the foundation of energy-efficient supercomputers operating at 4 degrees Kelvin. Such systems would need HTS leads similar to those proposed here to maintain energy efficiency.