Monday, 8 February 2021

A possible (now CONFIRMED) Trident-II SLBM test launch between February 9 and 14, 2021 [UPDATED]

click map to enlarge

A Navigational Warning, NAVAREA IV 117/21, appeared yesterday, and is suggestive of an upcoming Trident-II SLBM test in the Atlantic. I have posted on such test launches before.

This is the text of the Navigational Warning:

 071431Z FEB 21
 NAVAREA IV 117/21(GEN).
 ATLANTIC OCEAN.

 1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING
    091340Z TO 140226Z FEB IN AREAS BOUND BY:
    A. 28-56N 76-17W, 28-56N 75-34W,
       28-36N 75-34W, 28-43N 76-17W.
    B. 28-02N 73-18W, 28-17N 73-13W,
       27-47N 71-11W, 27-34N 71-17W,
       27-44N 72-10W.
    C. 26-25N 67-23W, 26-47N 67-10W,
       25-44N 63-47W, 25-06N 63-57W,
       25-32N 65-52W.
    D. 17-10N 45-30W, 17-37N 45-11W,
       16-53N 43-06W, 15-23N 41-22W,
       14-46N 41-42W, 16-11N 44-26W.
    E. 06-00S 09-39W, 05-13S 09-08W,
       06-37S 06-56W, 07-17S 07-22W,
       06-55S 07-57W, 07-00S 08-05W.
 2. CANCEL THIS MSG 140326Z FEB 21.


The map in top of this post shows the hazard areas A to E from this Navigational Warning plotted, and a fitted ballistic trajectory. Together they define what strongly looks like a Trident-II Submarine Launched Ballistic Missile (SLBM) trajectory. 

Area 'A' is the launch area where the submarine is located; areas 'B', 'C' and 'D' is where respectively the first, second and third stages of the missile splash down; area 'E' is the target area of the warhead(s).

The indicated range, from the distance between area's A and E, is about 8400 km. That is somewhat shorter than most earlier Trident-II tests in the Atlantic.

Earlier tests in the Atlantic typically had a range near  9800 km, in one case even 10 600 km (see my overview here). So this test falls short from a  typical test by about 1500 km. 

An earlier clearly shorter range was however indicated for the infamous June 2016 Royal British Navy Trident-II test, which would have had a 8900 km range with a target area west of Ascension Island if it had not failed. The range of the upcoming February 2021 test is 500 km shorter than that of this June 2016 test, with a target area slightly more north and the launch area further out of the Florida coast. 

The launch area is nevertheless a familiar one: one of two areas regularly used for Atlantic Trident test launches. 

It is the same as that for the 10 Sep 2013, March 2016 and June 2018 Trident tests. It is the area labelled 'launch area B' in the map below, which plots the launch areas of several previous Trident tests. The figure comes from this previous post and is discussed there (including a suggestion for why there might be two distinct launch areas).

click map to enlarge
 

The target area near Ascension Island and shorter range might perhaps indicate that this will be a British Royal Navy test with the SLBM launched from a Vanguard-class submarine rather than a US Navy test, but this is by no means certain. It could also mean a US Navy test with new hardware, e.g. a more heavy dummy warhead or a new stage engine.

US Navy tests are usually acknowledged after the test, so it will be interesting to see whether such an acknowledgement will appear from either the US or British Navy.


UPDATE  10 Feb 2021 10:50 UT

Overnight, images and footage have appeared from Florida and Bahama residents that show an exhaust plume, indicating that the test indeed took place, near 23:30 UT on Feb 9. These are a few of them:


 

The imagery shows the sun-illuminated exhaust plume of the missile. The missile itself is in space by that time, ascending towards its ~1200-1800 km apogee.

I did a quick calculation: for a launch at 23:30 UT on 9 February 2021, the missile (and its expanding exhaust plume) should break into sunlight about a minute after launch once above ~147 km altitude. I have indicated the sunlit part of the trajectory in the map below in yellow. This means that the exhaust plume on the imagery is from either the second or third stage of the missile.

click map to enlarge

UPDATE 16 Feb 2021:

The Drive reports that the US Navy has now confirmed that this was a Trident test. The name of the submarine from which the missile was launched has not been released.

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