Updating the changing tumble period of the USA 144 decoy

click diagram to enlarge

The diagram above shows the brightness variation of 1999-028C, the USA 144 decoy, as determined on 21 May 2017. It was created from photometry on video records spanning several minutes of a pass using a WATEC 902H with a Samyang 1.4/85 mm lens. The photometry was obtained using a not-yet-public beta-version of TANGRA.

The brightness of the object shows a slow variation between mag +7.2 and invisible. Fitting a sinusoid gives a peak-to-peak period of 43.528 seconds, +/- 0.005.

I have written on this enigmatic object before on this blog. It was launched from Vandenberg 18 years ago, on 22 May 1999, as NROL-9. This launch is widely believed to have launched the second Misty stealth satellite. Following the launch amateurs found this relatively bright object in a (currently) 2668 x 3150 km, 63.4 degree inclined MEO orbit. The object shows a periodic brightness variation.

This object is, however, not Misty 2. A long term analysis by Ted Molczan showed that the object has an unusually large surface-to-mass ratio in the order of 0.09 m²/kg and its orbit is subject to considerable Solar Radiation Pressure (SRP) effects. The surface-to-mass ratio is an order of a magnitude larger than for normal satellites, suggesting this is something large and lightweight - e.g. something inflatable, so large and light that pressure from sunlight has an effect on its orbit.

We have come to believe that it is a decoy, designed to lure attention away from the real, stealthy USA 144 payload when it was launched in 1999.

As the result of SRP influence, the tumble rate is variable over time: in the order of 60-90 seconds 7-8 years ago, 50 seconds 2 years ago (see here), and now 43.5 seconds.

The slow, changing tumble of the USA 144 (Misty 2) decoy

The USA 144 Decoy (1999-028C)
(click image to enlarge)

Yesterday evening I did some observations on the two evening KH-11 Keyholes (USA 186 and USA 245). Following that, I targeted the USA 144 decoy (1999-028C), an enigmatic object from the launch of the stealth satellite Misty 2 in 1999.

Three classified objects and one unclassified: the USA 144 Decoy, NOSS 3-4 A & C,
and an old rocket booster with CAMEO attached
(click image to enlarge)

At left in the image above is a double trail of the classified NOSS 3-4 duo (2007-027 A & C). In the middle is an old Delta 1 rocket booster (78-098B) with CAMEO on top, an earth magnetosphere experiment from 1978. At right, the shortest trail, is the enigmatic classified object we call the USA 144 Decoy.

I have written about this enigmatic object before. It is a bright object in a high 2665 x 3155 km orbit originating from the Misty 2 Stealth satellite launch in 1999.

(click image to enlarge)

From a study of its orbital behaviour, Ted Molczan found that the orbital decay of this object is notably influenced by Solar Radiation Pressure (SRP). This suggests an object that is very "light" relative to its size, i.e. an object with a large area-to-mass ratio. This does not fit a normal payload, so we suspect that this relatively bright object might have been a decoy to attract attention away from the real, stealth payload.

The USA 144 Decoy is slowly tumbling, resulting in a clear brightness variation. Ted already noted that the period of this variation changes over time, sometimes increasing, sometimes decreasing. This is in line with the tumbling behaviour of other known objects subject to SRP (like fragments of the PAGEOS balloon satellites).

click diagram to enlarge

I took a series of images between 20:19:42 UT and 20:26:12 UT (20 Sep 2015) documenting the brightness variability. The curve fits a peak-to-peak period of about 50.5 ± 0.5 seconds (see diagram above). There is clearly much variation in amplitude peak-to-peak.

The period found, is shorter than the periods found during my earlier determinations in 2009 and 2010, a summary of which is given below:

20 Sep 2015:    50.5 seconds (this post)
5 Sep 2010:     60 seconds   (see here)
20 Jul 2010:    61 seconds   (see here)
2-9 Mar 2010:   88 seconds   (unpublished)
19 Nov 2009:    62 seconds   (see here)
25-27 Aug 2009: 71 seconds   (see here)

This variation of the period over time is in line with expectations for an SRP-influenced object like this.

Again the USA 144 (Misty-2) Decoy brightness variability, with another specular glint

Since about a year, I am regularly targetting the enigmatic object (related to what was probably the Misty-2 stealth satellite launch) we call the USA 144 Decoy (99-028C) as part of a long term monitoring of the brightness variability of this object. It shows a slow sinusoid brightness variation with a periodicity of tens of seconds. This period of variation slowly evolves over the course of months.

On the night of September 5-6 I captured a series of images again (between 23:11:22.30 - 23:16:32.35 UTC, Sep 5, 2010) allowing the construction of a curve. Below is the diagram: I find it best fits a periodicity of 60 seconds:

click diagram to enlarge

Earlier period determinations were:

20 Jul 2010: 61 seconds (see here)
2-9 Mar 2010: 88 seconds (unpublished)
19 Nov 2009: 62 seconds (see here)
25-27 Aug 2009: 71 seconds (see here)

I should actually revisit the two determinations (Aug 2009, Mar 2010) that are well off from 60 seconds to see whether I didn't make mistakes there.

As can be seen, I again captured a solitary anomalous glint produced in the "valley"part of he curve. Something very similar happened earlier on July 20th. Both glints happened near a brightness minimum. Below is imagery of the latest glint from September 5 (showing one image before the glint, then the glint image, and an image after the glint), and a comparison diagram of the July 20th and September 5th glints:

click image to enlarge

click diagram to enlarge

These spikes are quite specular in character, and suggest there is a flat mirroring surface attached to the object on (if the slow brightness variation of the object is due to exposure of long versus narrow sides) one of the narrow sides.

Slowly uncovering more clues in the Misty-2/USA144 patch

I have written before about the launch patch of the enigmatic USA 144 launch from Vandenberg on 1999 May 22. This was possibly the Misty-2 stealth satellite (99-028A; while a piece of debris or intentional decoy from the same launch frequently observed by me and other trackers is 99-028C, the "USA 144 Decoy"):


In my earlier post, I wrote that the meaning of the tiger symbol remained a mystery. In this I based myself on noted patch intelligence sleuth Dwayne Day in his discussion of this patch in an overview article in The Space Review, who considered that the tiger was unexplained, although one option was that perhaps it might have "a hidden symbolic meaning for the program (like the dragons)". (the latter comment about dragons points to the use of winged dragon symbolism in launch and mission patches for SIGINT satellites).

I think I now might have come somewhat closer to interpreting the tiger on the patch. I think that, like the half illuminated earth globe with satellite, it designates a unit involved in the launch and mission.

Let me first recapitulate what I wrote earlier here. The black and white gridded globe with revolving satellite clutched in the tiger's claws, appears to be a reference to the 4th Space Launch Squadron (4th SLS), whose patch emblem was this one below:



The 4th SLS had almost exactly a year before the launch fused into the 2nd SLS, which itself is mentioned in the rim text of the USA 144 patch.

Note that the four yellow stars also feature in the 4th SLS patch. The 2nd SLS has only three stars in its emblem, which might explain the difference noted by Dwayne Day: "Another mystery is why the patch contains four stars, whereas the tee-shirt logo contains only three".
(alternatively, and maybe simultaniously, it could refer the 614th Space Operations Flight - see below - which had 3 gold stars in its emblem)


The tiger

But now: the tiger. I found the same symbolism of a tiger with an earth globe between its paws in this patch, which is a patch of the 614th Space Intelligence Squadron.


This unit post-dates the USA 144 launch, as the unit was activated in 2003 (the launch was in 1999). It is however a spawn of the 614th Space Operations Squadron, which was activated (as the 614th Space Operations Flight) in 1996, before the Misty-2 launch. The 614th Space Operations Squadron also featured the tiger symbology, in the form of two tiger eyes in the emblem patch:


The mission of the 614th SOPS was to "provide the component commander for Air Force space forces, COMSPACEAF, the expertise to command and control Aerospace forces in continuous support of global and theater operations".

Both the (related) units had headquarters based at Vandenberg. They have since all gone up in the 614th Air and Space Operations Center, which again has a tiger in its emblem.

Given the connection of this lineage of units to Vandenberg launches and tiger symbolism, I feel the tiger on the USA 144 patch could well represent the 614th Space Operations Squadron or a sibling unit.

In view of the establishment of the 614th SOPS/SOPF relatively shortly before the launch, maybe the text "The Cat's Out of the Bag!" could refer to USA 144 being perhaps the first mission initiated since it's formation. (from what I have found so far, it is not clear when the 614th SOPF became the 614th SOPS, but the transformation seems to have been completed by mid-1999). It is a nice double reference to the tiger of the 614th SOPS and the common meaning of the phrase "to let the cat out of the bag" (disclosing a secret, which basically is what a launch does: you let the thing that remained hidden so far fly out in the open).

Altering tumbling period of the USA 144/Misty-2 decoy (1999-028C)

In August I used a series of photographs to determine the tumbling period of 99-028C, the enigmatic USA 144/Misty-2 "Decoy" (see here).

As the tumbling period of this object is known to alter, I am repeating the experiment. I still need some additional nights to construct a full curve: but the partial curve obtained from the November 19 observations (6 images) already shows a clear change compared to August:

click diagram to enlarge

The sinusoid is for a period of 62 seconds, which compares well to a very similar period visually determined by Ted the same night. It is nice to see the two results coming out so similar.

Back in August the period was 71 seconds. A change of 9 seconds in 3 months time.

In the diagram above, the greyed data points are data from when the trail was very close to both edges of the FOV. Their absolute levels have suffered from lens vignetting, so I scaled them to show that the trend of these points at least is similar to the trend of the period determined from the other four images. The black data points are raw, unaltered data from the latter images.

A Keyhole flaring, a Molniya ELINT and the USA 144 decoy again

The evenings of August 31 and September 1 were clear. On August 31 I targetted two higher objects with the EF 100/2.8 Macro USM: USA 184 (06-027A), an ELINT in a Molniya orbit (see a few posts back), and the USA 144 Decoy again (99-028C). On September 1st, two LEO objects were the target: the KH-12 Keyholes USA 129 (96-072A) and USA 186 (05-042A).

USA 129 brightly flared to mag. -1 at 20:34:11.1 UTC (Sep 1st). The camera was open when it did:

Click image to enlarge

The series of images of the USA 144 Decoy yielded information again about the periodicity of it's brightness (indicating the tumbling period). Like the data of August 25 and 27, it fits a sinusoid with a period of 71 second.

Click diagram to enlarge

The tumbling period of the USA 144/Misty-2 Decoy (99-028C)

On August 25 and August 27, I obtained a series of photographs of the USA 144/Misty-2 decoy (see here and especially here). On the request of Pierre Neirinck, I did some simple photometry on the image series, to see whether I could retrieve information out of this on the current tumbling period of the object.

It concerns the following two image series. In both cases, the object is moving from right to left, and the image series has to be "read" from right to left (i.e., the most right image is the earliest in time, the most left the latest). Some clear brightness variation from image to image is already apparent.

Click images to enlarge

From these images, the following two partial photometric curves were obtained, both suggesting a period near ~70 seconds:

Click images to enlarge

Next I combined these two partial curves (from two separate nights) into one amalgamated curve (this included of course some data normalization/scaling), shown below:

Click image to enlarge

The result is a curve that can be approximated by a sinusoid with a period of 71 seconds. This suggests the object's current tumbling period is 2 * 71 = 142 seconds.

(in the curve above, the dark dots are (normalized) data points, the grey line is a 20-point running average, and the black line a sinusoid with a period of 71 seconds)