Discoverer 26 was an earth-orbiting satellite designed to conduct scientific experiments, to test spacecraft engineering techniques, to evaluate the Agena B second-stage launch vehicle, and to attempt deceleration, reentry through the atmosphere, and recovery from the air of an instrument package. The 300-lb reentry capsule contained samples of silicon, iron, bismuth, yttrium, magnesium, nickel, lead, and uranium, which were exposed to the space environment for 50 hr 30 min. The payload also contained infrared sensors, photographic equipment, and other devices planned for use aboard the Midas and SAMOS satellites. The Agena B second stage contained instruments to measure the density and effects of ions and micrometeoroids at orbital altitude. This included an impact detector and a tuned piezoelectric crystal micrometeorite erosion gauge. The capsule successfully reentered the earth's atmosphere after 32 passes, and aerial recovery was accomplished. The Agena B stage remained in orbit and reentered the atmosphere December 5, 1961.