: 363 The orbiter was a reusable, winged vehicle that launched vertically and landed as a glider. : III–148 At launch, it consisted of the orbiter, which contained the crew and payload, the external tank (ET), and the two solid rocket boosters (SRBs). : 5, 195 It flew for the first time in April 1981, : III–24 and was used to conduct in-orbit research, : III–188 and deploy commercial, : III–66 military, : III–68 and scientific payloads. National Aeronautics and Space Administration (NASA). The Space Shuttle was a partially-reusable spacecraft operated by the U.S. Later Space Shuttle missions launched with redesigned SRBs, and crews wore pressure suits during ascent and reentry. To replace Challenger, construction of Endeavour was approved in 1987, and the new orbiter first flew in 1992. As a result of the disaster, NASA established the Office of Safety, Reliability and Quality Assurance to better address safety concerns, and commercial satellites would be launched on expendable launch vehicles rather than deployed from the crewed orbiter. NASA managers also disregarded warnings from engineers about the dangers of launching in cold temperatures and did not report these technical concerns to their superiors. Neither NASA, nor Morton Thiokol (the SRB manufacturer), addressed or corrected the issue. Test data from as early as 1977 had revealed a potentially catastrophic flaw in the SRBs' O-rings. The commission criticized NASA's organizational culture and decision-making processes that had contributed to the accident. President Ronald Reagan created the Rogers Commission to investigate the accident. The disaster resulted in a 32-month hiatus in the Space Shuttle program. By design, the orbiter had no escape system, and the impact of the crew compartment at terminal velocity with the ocean surface was too violent to be survivable. The exact timing of the deaths of the crew is unknown several crew members are known to have survived the initial breakup of the spacecraft. The crew compartment and many other vehicle fragments were recovered from the ocean floor after a three-month search and recovery operation. Following the explosion, the orbiter, which included the crew compartment, was broken up by aerodynamic forces. This led to the separation of the right-hand SRB's aft attachment and the structural failure of the external tank. The broken seals caused a breach in the joint shortly after liftoff, which allowed pressurized gas from within the SRB to burn through the wall to the adjacent external fuel tank. The record-low temperatures of the launch reduced the elasticity of the rubber O-rings, reducing their ability to seal the joints. The disaster was caused by the failure of the two redundant O-ring seals in a joint in the Space Shuttle's right solid rocket booster (SRB). The spacecraft disintegrated over the Atlantic Ocean, off the coast of Cape Canaveral, Florida, at 11:39 a.m. The crew was scheduled to deploy a communications satellite and study Halley's Comet while they were in orbit. The mission carried the designation STS-51-L and was the tenth flight for the Challenger orbiter and twenty-fifth flight of the Space Shuttle fleet. The Space Shuttle Challenger disaster was a fatal accident in the United States' space program that occurred on January 28, 1986, when the Space Shuttle Challenger (OV-099) broke apart 73 seconds into its flight, killing all seven crew members aboard. Christa McAuliffe, Payload Specialist, teacher.Your modified CAD detail can also be added to your library for future use click on the CAD block to select it, then click the Add to Library edit button to add the block to the User Catalog section located in the Library Browser.In X12 and prior versions, create a selection marquee using the Select Objects tool, then use the Make CAD Block edit button to block it back together. You may be prompted with a Question dialog asking if you'd like to replace all instances of the block with the copy you have modified. When your CAD detail is edited to suit your needs, select Tools> Active View> Save Active View in X13 and newer versions.If you find this button, click on it and continue editing. If, after clicking Edit CAD Block or Explode CAD Block tool, you find an object that you cannot edit as expected, click on it to select and then check the Edit toolbar for the Explode CAD Block edit button. It is possible to nest a CAD block within another CAD block.