Note: Only forum leaders may delete posts.
*HTML is ON *UBB Code is ON Smilies Legend
Smilies Legend
Last night at about 5:00 p.m. CDT, NASA Houston FTC (Flight Control Team) received notification of an upcoming "red threshold" conjunction of the ISS with a piece of orbital debris (Object 82618, UNKNOWN), with a TCA (Time of Closest Approach) this morning at 7:08 a.m. CDT — which was too late to begin planning for a DAM (Debris Avoidance Maneuver). Therefore, FTC and crew made preparations for crew sheltering in Soyuz TMA-21 (26S) and TMA-02M (27S). PC (Probability of Collision) at last tracking fix (6:20 a.m.) remained in the Red box, at about 0.003, with a miss distance of 0.25 km radial, 0.375 km downtrack, 0.570 m crosstrack. The necessary reconfiguration procedures (USOS [U.S. Operating Segment] hatches closed, etc.) began 1.5 hrs before TCA (5:38 a.m. CDT), and the six crew members ingressed their Soyuz vehicles. At 7:08 a.m. the object cleared the ISS with no impact, and shortly thereafter the crew was given the Go for returning to the ISS. [The late notification occurred because of the high air resistance (drag) of the object (about 175 times higher than ISS) which made its trajectory very sensitive to small errors in atmospheric density predictions at the current solar flux. Due to the high drag, there is no chance of a recurrence of Object 82618).]
Contact Us | The Source for Space History & Artifacts
Copyright 1999-2024 collectSPACE. All rights reserved.