Onufrienko and Bursch perform IFM on SM Potok air purification unit during Expedition Four

ISS004-E-5387 (January 2002) --- Cosmonaut Yuri I. Onufrienko (right), Expedition Four mission commander, and astronaut Daniel W. Bursch, flight engineer, perform maintenance on equipment in the Zvezda Service Module on the International Space Station (ISS). Onufrienko represents Rosaviakosmos. The image was taken with a digital still camera.