In 2000, Chawla was selected for her second flight as part of the crew of STS-107. This mission was repeatedly delayed due to scheduling conflicts and technical problems such as the July 2002 discovery of cracks in the shuttle engine flow liners. On January 16, 2003, Chawla finally returned to space aboard Space Shuttle Columbia on the ill-fated STS-107 mission. The crew performed nearly 80 experiments studying earth and space science, advanced technology development, and astronaut health and safety. During the launch of STS-107, Columbia's 28th mission, a piece of foam insulation broke off from the Space Shuttle external tank and struck the left wing of the orbiter. Previous shuttle launches had seen minor damage from foam shedding,^[16] but some engineers suspected that the damage to Columbia was more serious. NASA managers limited the investigation, reasoning that the crew could not have fixed the problem if it had been confirmed.^[17] When Columbia re-entered the atmosphere of Earth, the damage allowed hot atmospheric gases to penetrate and destroy the internal wing structure, which caused the spacecraft to become unstable and break apart.^[18] After the disaster, Space Shuttle flight operations were suspended for more than two years, similar to the aftermath of the Challenger disaster. Construction of the International Space Station (ISS) was put on hold; the station relied entirely on the Russian Roscosmos State Corporation for resupply for 29 months until Shuttle flights resumed with STS-114 and 41 months for crew rotation.