Last week the Chinese launched the first module for their new Tianhe space station. The rocket that lifted it to orbit, a CZ-5B Long March 5, is headed for an uncontrolled reentry this weekend. Some portions of the rocket body are expected to survive reentry and make it to the surface.
Space-Track.org is releasing Tracking and Impact Prediction (TIP) messages for this event. These messages list the estimated location of the rocket body at the midpoint of a reentry window. It is important to note that any location within the reentry window has the potential for debris fall. As the reentry gets closer the window will get smaller and as a result the reentry location will become more defined.
The TIP messages are displayed at the top of the graphic below with the most recent on top. You can see the reentry windows have been getting smaller. The first window was +/- 1260 minutes (42 hours), the second window was +/- 900 minutes (30 hours), and the most recent window is +/- 540 minutes (18 hours) which spans from May 8th at 10:13 AM EDT until May 9th at 4:13 AM EDT. The location of the rocket body at the midpoint of the most recent TIP is shown below.
click any image to enlarge
Using the latest TLE (two-line element) I have been plotting any passes within the reentry windows that are visible from Harris County. The good news is we are safe from any debris fall as none of the passes are directly overhead.
For the 30-hour window there were four potential passes:
For the most recent 18-hour window there are only two passes. Notice these are the same as the first two passes from the 30-hour window but they are seven minutes earlier:
These pass predictions will continue to change as the rocket body descends lower into the atmosphere and speeds up. I will be posting updates as new TIPs and TLEs are released.