In addition, as occurred in the Challenger investigation, he said, the search will need to be extended "to identify all other potential failure modes and design weaknesses everywhere in the orbiter system, and engineer fixes for them".
Since its arrival, engineers have been checking out the orbiter's systems and gear.
But another of the modest-sized orbiters, dubbed cube satellites, marks an important step toward an orbiting system dedicated to tracking large-scale movements of animals small enough to hold in an adult hand.
Examples of a large sculpture located outside of the Canadian Museum of Civilisation in Hull, Canada and the Orbiter Docking System (ODS) located at the Kennedy Space Center in Florida, are presented.
The day's schedule also included the installation and alignment of the centerline camera in the centre of the Orbiter Docking System.
On flight day 3, the STS-74 crew members successfully mated the 15-foot Russian built docking module with the shuttle's Orbiter Docking System.
Once the two spacecraft were locked together, the docking ring on the Orbiter Docking System retracted, and a series of hooks and latches were engaged to ensure an airtight seal between the two spacecraft.
Chris Hadfield, a Canadian Space Agency astronaut and STS-74 mission specialist, used the shuttle's robot arm to hoist the docking module out of the aft portion of the payload bay, rotated it to a vertical position, and moved it to within five inches of the Orbiter Docking System.
Although these errors are reduced by adding two Mars orbiters, the system is only barely observable.
The astronauts will test the orbiter's flight systems today in preparation for a scheduled landing tomorrow at Cape Canaveral, Fla., weather permitting; otherwise, the shuttle will remain in orbit another day.
