Monday 25 May 2009

Clear nights, and the NOSS 3-4 rocket brightness behaviour

A series of clear nights the past week, allowing a series of observations of the STSS-ATRR rocket (09-023B) and two Keyholes, USA 186 (05-042A) and USA 161 (01-044A). 09-023B keeps being an interesting target, as its orbital evolution is that quick that it necessitates continuous coverage. The current orbit projects decay around mid-August.

About a week ago, on May 19-20th (see here), I obtained images on the NOSS 3-4 r (07-027B). This spent Centaur rocket of the NOSS 3-4 launch shows a slow brightness cycle. I obtained some partial brightness profiles from the trail photographs, including an interesting one covering one of the brightness peaks:

(click diagram to enlarge)

It can be clearly sees that this (10.05 s) part of the cycle consists of two components, a slow modestly exponential brightness development with a short narrow peak superimposed on it.

Wednesday 20 May 2009

Flare evening

Yesterday evening 19-20 May was an evening of unpredicted flares.

It started with the International Space Station (ISS) in deep twilight. After a splendid zenith pass, while at 40 degrees altitude descending to the East, it shortly brightened to a dazzling mag. -8.

Somewhat later, still in twilight, it was the Keyhole USA 129 (96-072A) flaring to mag. 0. I caught one of the flares on photograph, just south-east of Regulus against a bright blue twilight background. Below the image ( plus a detail) and the brightness profile:

(click images to enlarge)

Somewhat later in the evening, I was next treated to a spectacular mag. -7 flare of IGS 1B (03-009B) while it was passing through the zenith, alas just after the camera shutter closed. The flare was a bright orange-yellow and lasted maybe a second (approximate time, not too accurate: 21:25:00 UTC).

Apart from these flaring objects, observations were also obtained of the NOSS 3-4 rocket (07-027B), showing its regular slow brightness variation; the keyhole USA 186 (05-042A), the SAR satellite Lacrosse 3 (97-064A) and the STSS-ATRR rocket (09-023B).

I also visually observed the STSS-ATRR itself (09-023A), but due to pressing a wrong button of the stopwatch lost my two points on it alas.

In all, a very fruitful night!

Monday 18 May 2009

STSS-ATRR rocket again

Yesterday evening it cleared, and I observed the STSS-ATRR (09-023A) through the ETX-70, and photographically also its rocket (09-023B). In addition, I captured the KeyHole satellite USA 186 (05-042A).

The pass of the STSS-ATRR rocket (09-023B) provided the nice image below, showing it while crossing Lyra.

(click image to enlarge)

Tuesday 12 May 2009

STSS-ATRR and it's rocket, and Progress-M66 (with photographs)

On May 5, the US military launched a Delta 2 rocket from Vandenberg AFB with the new experimental STSS-ATRR - which stands for Space Tracking and Surveillance System Advanced Technology Risk Reduction satellite. They are also known by the international designation 09-023A, and (for the rocket booster still circling earth) 09-023B.

European observers saw the satellite and the rocket as a thight pair shortly after launch, during their first pass over Europe (see e.g. here and here and here). While the payload was subsequently observed over more passes, the rocket initially got temporarily lost.

Ted Molczan suggested an alternative search orbit (here) and based on that I made an area search with the Meade ETX-70 on the evening of May 8-9, during 20 minutes (between 20:49 and 21:10 UTC) around the nominal pass time from that estimated orbit, covering a 4 degree wide area centered just south of gamma Umi and 11 Umi. During this search I observed an object of around magnitude +6 passing about 2 degrees south of the predicted trajectory, some 4 minutes late.

This indeed turned out to be the rocket. Independant from me, Bram Dorreman also observed it from Belgium that evening on the same pass, bumping into it by chance during his flash observations. With these observations as the basis for an orbital update, it was found and observed by several observers the following nights. Yesterday, in the evening of May 11-12, I photographed it (see below). During a fine zenith pass near 21:50 UTC it appeared as an easy naked-eye object, reaching mag. +2.5 in the zenith.

In below two (out of a total of 3) images it can be seen ascending in the south-southeast in Virgo, and then crossing Bootes in the second image.

(click images to enlarge)

That same night I observed the payload, STSS-ATRR itself, much fainter, with the ETX-70. In addition, I saw Progress-M66 (09-006A), recently released from the ISS, and ISS itself. below is one of the images of Progress-M66, here seen crossing through Leo.

(click image to enlarge)