Tuesday, 18 June 2019

Two-and-a-half months after the Indian ASAT test: What's Up?

On 27 March 2019, India conducted it's first succesful Anti-Satellite (ASAT) test, destroying Microsat-R on orbit. I have blogged on this before here, here, here and here; and published a detailed OSINT analysis of this test in The Diplomat, in which I have shown that the Indian version of events concerning this ASAT test is not entirely correct.

So what is the current situation? The Indian government claimed right after the test that 45 days after the test, the space debris generated by the ASAT test would be gone. We are now a month after that deadline. Is everything gone indeed? Far from it.

Some 92 larger debris pieces resulting from the test have been catalogued by CSpOC. Of these, 56,  i.e. some 60% were still on orbit 45 days after the ASAT test. And 46 (that is 50%) were still in orbit on June 15, one full month after all should have been gone according to the Indian Defence Research and Development Organisation (DRDO). These numbers are in line with my earlier forecast here.

The diagrams below visualize these data, including (grey lines) a new forecast for the remainder of the debris still orbiting. The top diagram is the cumulative percentage of reentered debris from the test, the lower diagram gives the number of objects reentering per week.

click diagram to enlarge
click diagram to enlarge

Many of these objects still on-orbit have apogees still well into the range of operational satellites, i.e. they remain a threat to other objects in space. In my current forecast for these remaining objects, at least 5 objects will stay in orbit for at least a year to come, and the last one might not reenter until mid-2021. So clearly, Indian DRDO estimates were much too optimistic.

click diagram to enlarge

Saturday, 1 June 2019

[UPDATED] Erratic orbital evolution of four Starlink objects

Edit 5 June 2019: updated at end of post with new data

During a talk at MIT on May 29, SpaceX President Gwynne Shotwell reportedly mentioned that four of the 60 Starlink objects launched on May 24 are having issues (but she reportedly also said that these four are in contact with SpaceX  ground control: i.e. it is too early to consider these four objects a failure).

These four objects are probably object J, AA, AG and AQ. Their orbital evolution so far stands out from the rest of the objects: while 56 objects have gone up, these four either stayed near the altitude of orbit insertion, or are in fact going down.

This can be cleearly seen in these two diagrams I made today, showing the total amount of altitude gained for each object. Objects J, AA, AG and AQ (red) clearly stand out form the rest (black).

click to enlarge

click to enlarge

The other four objects (blue) that did not raise their orbit, are the 'FALCON 9 DEB' objects (with DEB standing for 'debris'. These are four support bars that held the satellite stack together untill deployment. Our observations show that these four are tumbling, as they can be seen flashing in a regular pattern.

Two of these support bars can be seen as fainter flashing objects at about 25 seconds into my video from May 24th (the other two were filmed as well, moving somewhat in front of the "train", but are not in the video I posted):

UPDATE 5 June 2019:

 One of the four objects, object AA, has come to life and is raising orbit now. Objects AG, AQ and J have not changed: