USA 193 lost in clouds, and a visit from a TV crew

As I feared in my previous post, I lost this evenings USA 193 pass. It did seem to turn clear in the afternoon at first, and in early twilight I had real hope. But eventually, at the 18:42 UTC pass the sky had filled with thin clouds. Naked eye, I could barely make out Aldebaran. Tried to find the relevant star-field in the telescope but failed. Oh well....

Earlier this evening, and after several phone calls in the daytime, I got a visit by a reporter and camera-man of the NOS (the Dutch "BBC"). They shortly interviewed me and shot some pictures of me doing mock observations behind the telescope. It is going to be broadcast in the TV News on the Dutch channel 2 at 22:00 CET.

With the current weather conditions, I have little hope for tonight's total lunar eclipse.

Defeated by the weather?

Just as the, perhaps last, visibility window of the by now world-famous USA 193 (06-057A) is starting here, weather has turned bad. Yesterday evening I could still observe the Keyhole USA 129 (96-072A) and the spent rocket boosters Lacrosse 5r (05-016B) and NOSS 3-4r (07-027B) under already hazy conditions: but now, heavy fog is hiding the skies and all what moves along it.

The USA 193 craziness is still continuing. Following the news that it will be shot with a missile somewhere next week - perhaps Wednesday/Thursday night, see also my ongoing updates here - this weblog is attracting an enormous amount of traffic again. Even more than the previous time USA 193 was in the news, late January.



Yesterday I was called by a journalist from the NRC, one of the "quality" newspapers of my country. This resulted in a short piece on USA 193, with some mention of our amateur observing work and me, in today's scientific pages.

This evening the NOS (our Dutch "BBC") called for a short informative chat, as they might do an item on it the coming days.

With all this, I should almost forget to report that I have been observing a lot the past days, taking advantage of three consecutive days of nice clear skies. Targets on these nights were the satellites and rocket bodies mentioned above, especially USA 129.

I also experimented further with photographing the moon through my ETX-70, in preparation for the lunar eclipse of coming Wednesday-Thursday night (that I am affraid I am going to lose to fog and/or clouds). With the help of a few euro of hardware I bought at a hardware store on Saturday, I made an extension to my telescope to firmly attach the camera to the eyepiece.

Below is one of the results. It is a mosaic composite of three images taken in the evening of February 17th. It is 2600 x 2600 pixels wide, 880 kB (click it to see it in full detail).

(click image to enlarge)

Here's a part-image of the southern highgland with a.o. the craters Tycho, Clavius and Schiller:

(click image to enlarge)

ISS and the Moon

Another clear evening yesterday. The moon is now becoming more and more prominent in the sky. The International Space Station (ISS) made a pass that brought it close to it in twilight at 18:44 local time (17:44 UTC). I made the photograph below with my Canon Ixus on maximum zoom and 2s exposure:

(click image to enlarge)

I also made another moon shot through my ETX-70 telescope:

(click image to enlarge)

Later that evening, telescopic points were obtained on the ELINT sat USA 32 and Keyhole sat USA 129.

Lacrosse 5 "disappearance trick" over the Pleiades, UARS and ISS again

The sky keeps being clear, so last evening I had another observing session.

In twilight I observed ISS again, and filmed it again as it passed Mars and descended to the eastern horizon. Below short movie (shot with my Ixus camera in "movie"-mode) shows it (Mars can occasionally be seen in the upper right corner):



I observed UARS in twilight too, on the request of John Locker. It was about mag. +2 in the brightest part of the pass.

Lacrosse 5 (05-016A) made an initially nice & bright pass that brought it very close to the Pleiades. As I was photographing it, it did it's infamous "disappearance trick" right above the star cluster:

(click image to enlarge)

Other objects observed (telescopically) this evening were USA 129 and the NOSS 3-2 duo.

Last but not least, I imaged the moon again through my Meade ETX-70:

(click image to enlarge)

Twice the ISS, and a bag of other objects

Yesterday I observed the International Space Station (ISS) twice. The first observation was in deep twilight, 20 minutes after sunset with the sun at only 4 degrees below the horizon.

I filmed this pass, using the "movie"-mode of my Canon Digital Ixus photo camera. The resulting short movie is below: it shows the ISS descending towards the east.



Later that evening, one pass later, I shot this photograph, which shows the ISS crossing Taurus just before entering earth shadow:

(click image to enlarge)

Both this evening and the morning of today (the 11th) I telescopically observed a number of other objects; the keyhole USA 129 (96-072A), the ELINT USA 32 (88-078A), the SAR satellites Lacrosse 5 (05-016A) and Lacrosse 3 (97-064A), and the NOSS 3-2 duo (03-054A & C) and, as a stray while waiting for USA 32, the old NOSS 6F (84-012F).

In addition, I shot this photograph of the crescent moon through my Meade ETX-70 in the late afternoon/early evening:

(click image to enlarge)

ISS in daylight, and Progress-M62

Inspired by similar observations on Friday by Bram Dorreman, I tried to observe the ISS and the Shuttle just before docking when they made a daylight pass yesterday at 17:43 local time (16:43 UTC). The sun was barely 1 degree under the horizon at that moment.

There was some thin cirrus in the sky, but to my surprise the ISS was ridiculously easy to see with the naked eye! It had a distinct yellow-orange colour, perhaps boosted by the bright blue sky background.

I couldn't see the Shuttle: it was either too faint, to close to the ISS, or the cirrus interfered too much to see it naked eye.

The next ISS pass took place in darkness. ISS was bright, at least -3 if not more. In addition, I observed Progress-M62 again some 10 minutes later. It was fainter than the previous evening, at mag. +1.5. below image shows it passing through the Perseus-Taurus-Auriga area:

(click image to enlarge)

I also observed the NOSS 3-2 duo (03-054A & C) through the telescope, and did so as well with Lacrosse 5 (05-016A) and the Keyhole satellite USA 129 (96-072A). The latter by now is two minutes late and almost a degree off-track with respect to a week old elements.

In spired by recent similar graphs by Bob Christy, I made a lightcurve diagram of Friday's bright flare by Progress-M62:

(click diagram to enlarge)

Here's a similar lightcurve for one of my Space Shuttle STS-122 images of that same evening:

(click diagram to enlarge)

Space Shuttle Atlantis STS-122, Progress-M62 flaring, and the ISS

After a sunny day, but with cirrus in the sky, the evening of February 8 was clear. This was the only evening that I had a chance to observe the Space Shuttle Atlantis STS-122 before it docks to the International Space Station. The sequence was for ISS to make a near-zenith pass in twilight around 18:55 local time, followed by Progress-M62 on a similar trajectory ten minutes later, and finally the Space Shuttle STS-122 a quarter of an hour after that, entering shadow just below the zenith.

First the ISS passed, reaching magnitude -3 in the zenith:

(click images to enlarge)

Next the Progress-M62 spacecraft leaving ISS filled with garbage made a pass. It spectacularly flared to mag. -2 in Andromeda (in the image below, M31 the Andromeda galaxy is just to the right of the trail), while the camera was open. The result is this very nice image:

(click image to enlarge)

In this second image, it is back to it's normal brightness of mag. +1 again:

(click image to enlarge)

15 minutes later the Space Shuttle Atlantis STS-122 on its way to the ISS passed, reaching mag. -1 before going into eclips just below the zenith:

(click images to enlarge)

A fine evening altogether! And although I have seen Space Shuttles pass before, this is the first time I catched one on photograph. The spectacular flare of Progress-M62 really made the evening though.

Observing ISS and two of its Progress cargo spacecraft

Yesterday evening was very clear, and provided the rather unique opportunity to see the International Space Station (ISS) pass in twilight, followed several minutes later by two of its cargo Spacecraft: Progress-M62 (07-064A) decoupled from ISS on Wednesday and now moving away from it carrying garbage, and Progress-M63 (08-004A) launched from Baikonur in Kazachstan on Wednesday and on its way to the ISS with fresh cargo. Seeing two Progress spacecraft in free flight on the same evening is unique.

ISS was the first to pass, still in deep twilight, at 18:15 local time, being around mag. -3. Five minutes later Progress-M62 followed on a trajectory a few degrees higher, grazing the Hyades cluster, and being about mag. +1. And twelve minutes after that, the newly launched Progress-M63 followed in a very similar trajectory. By that time, although the sky was still bright due to twilight, it was dark enough to try to photograph it. The resulting photograph has a very bright background drowning the trail, but after some image manipulation for brightness and contrast it is visible:

(click image to enlarge)

I logged a point for Progress-M63 through the telescope, and the endpoint of the trail on the image above provided a second point.

Later in the evening I observed Lacrosse 2 (91-017A), which by now was 34.6 seconds early, the USA 32 ELINT sat (88-078A), Lacrosse 5 (05-016A) and the NOSS 3-2 duo (03-054A & C), the latter duo on two consecutive passes.

Like previous days it was again clouded in the morning, so no chance to observe USA 193.

Tomorrow evening is going to prove very interesting, I hope. The weather prospects are good, and if the launch isn't postponed this evening, I will have a very good 80 degree post-twilight pass of Space Shuttle Atlantis STS-122. In addition, the ISS and the two Progresses can be observed again. Plus, the Soyuz rocket booster (08-004B) from the Progress-M63 launch could prove very interesting, as it will make two passes (one visible and one in shadow) while close to decay.

Lacrosse 2 manoeuvred again (updated)

Yesterday evening was very clear. While looking up some deep-sky objects and while waiting for target satellites to appear, I saw several faint strays.

Lacrosse 2 (91-017A) was 21.6s early and 0.16 degree off-track relative to a week old elset 08027.82795435. Hence, just like early January, it appears to have manoeuvred again.

Update: Russell Eberst's data of the same pass confirm my observation. From a very preliminary analysis I did, it seems that the manoeuvre entails a similar mean motion change by about +0.0005 as was the case early last month.

Other objects observed this evening were the ELINT sat USA 32 (88-078A) and the NOSS 3-2 duo (03-054A & C). In addition, I observed the International Space Station making a pass through Taurus just beneath the Hyades and Pleiades. I had not realised the decoupled Progress M-62 would be following it closely, so I missed that one (it also was just too far behind ISS to show up on the photograph I shot, see below).

(click image to enlarge)

It was overcast this morning so again no chance to observe USA 193. It is still overcast, so I am going to miss both the old and new Progress (the latter launched today) tonight. I hope it clears in time to observe them and the Space Shuttle STS-122 that is scheduled to launch next Thursday.

How USA 193 rocked this blog

Last week has been an amazing week for this blog. While normally only some 10 geeks a day follow my reports in this rather esoteric journal blog, the web traffic sky-rocketed after the imminent USA 193 spy satellite decay became a hot news item, and my post with backgrounds on the satellite became an often consulted link. These graphics of my web traffic the past week show the surge in readers:



It all started when I privately answered a question about the decay that was posted by someone in the Satobs mailing list of satellite observers. My answer was then integrally quoted in one of the comments to the story on Slashdot, mentioning my name as the source. As a result, people started to Google for me. So I put up some pertinent info on this blog, to satisfy their curiosity. Next this blog post of mine was linked by someone as a primary external link in the Wikipedia entry on USA 193. All kinds of internet fora picked up the URL too (both serious fora as well as those of the tin foil hat brigade). The result was a peak in activity that is unique in the history of my blog.

The web statistics for these days contain some interesting hits, from interesting IP's. For example:

* The NSA ended up on my blog, apparently after Googling for info on their own satellite;

* An IP from the US Department of State repeatedly visited over the course of several days;

* An IP from the Sergeant at Arms of the US Senate;

* Various IP's of the US DoD and other US military related IP's, as well as various IP's from the defense industry.

After that NSA visit, I sent a joking e-mail to some friends that I was on the watch for black helicopters, and that in case they should suddenly lose contact with me, they should send some clean underwear to Guantanamo.... :-p

On Monday the 28th of January I was interviewed (together with Prof. Ambrosius of the TU Delft) about the decay by the science program "Hoe?Zo!" of the Dutch educational broadcaster TELEAC on the Dutch national Radio 5 channel. For those who master the Dutch language, an MP3 recording (58 Mb) of the broadcast can be found here. The 8-minute item on USA 193 starts at 9m15s in the broadcast.

NOSS 3-4, Lacrosse 5 oddity, and not every DCF-77 clock is the same... (updated)

This morning, unlike yesterday evening, it was reasonably clear. There was some haze in the sky, but conditions were good enough for decent observations. Targets were the ELINT sat USA 32 (88-078A), two of the NOSS 2-3 components (96-029C & E) and the NOSS 3-4 duo (07-027A & C). USA 193 (060-57A) stayed too low in the sky for my location this morning.

The NOSS 3-4 duo (07-027A & C) is still actively manoeuvering. I observed them on two consecutive passes this morning. Compared to their 08031.475 elsets they were 46-50 seconds late, indicating that they have moved up again between Jan 31 and early Feb 3.

The reason for this manoeuvering is that during their launch last year, the final stage of their rocket booster quit too early, and the payloads as a result entered into a too low orbit. Since that moment, they are gradually working themselves upward to their intended orbits, using their own onboard engines.

In my previous post I noted the purchase of a new DCF-77 clock, following the failure of my old trusted Oregon Scientific DCF-77 clock. Careful comparison to several other DCF-77 clocks however, reveiled that the new clock is 0.40 seconds early to other DCF-77 clocks. That was an unpleasant surprise. I ditched the clock and purchased yet a new one, which runs synchronous with other DCF-77 clocks I compared it too. Interestingly, this new clock was a cheap 7 euro one purchased in a large store chain here in Leiden (HEMA: clock name is "Portland"). The clock that runs 0.40s early (brand: Cresta) was much more expensive. So more expensive evidently not always translates to "more reliable".

As a result, my observations on the evening of Feb 1 need to be corrected by 0.40 seconds.

Those observations concern USA 32 again, and Lacrosse 5 (05-016A). I have the latter 2 seconds early and 0.6 degree off-track compared to elset 08027.73865531. However, this was a difficult observation during a short clearing, with clouds moving into the FOV almost right after the sat passed it, so I cannot rule out I made a mistake in the reference stars used.

Update: an 05-016A observation I made on the evening of Feb 3rd is in-line with elset 08027.73865531 again (delta T only 0.07s, x-track 4 arcminutes), so the Feb 1st result indeed must be the result of a mistake in reference stars used.

Peeping through holes in the cloud cover

The past two days the atmosphere has been very dynamic here. We had a gale yesterday, and both yesterday night and the night previous to that cloud cover and short but bright clearings followed each other up unpredictably.

I did try to do some observing, but as a result of these dynamic weather conditions I lost most selected objects to untimely cloud fields: apart from the NOSS 3-2 duo (03-054 A & C) on Wednesday night the 30th Jan.

When observing through the telescope, these NOSS duo's are very attractive targets. They operate in thight couples (the older ones even in trio's), crossing the same field of view with usually only a few seconds between them. It is very cool to see two bright yellow sparks chase each other through the FOV.

NOSS-es are operated by the US Navy, the acronym meaning Naval Ocean Surveillance System. They intercept radio traffic from ships and use it to pinpoint the locations of enemy shipping.

My trusted Oregon Scientific DCF-77 clock (a radio controlled clock getting its time signal from an atomic clock in Frankfurt) died last Wednesday after years of faithful service. Wednesday evening I temporarily used the clock on my weather station, which is also DCF-77 controlled, as a back-up, but I do not completely trust it so I ordered a new DCF-77 as a replacement for the failed one. It arrived today.

USA 193: life and death of a spy sat (twice updated 29 Feb)

UPDATE 29/02/08 (II): New NOTAM warns aircraft for decaying USA 193 debris between now and March 9th. See my post here.
UPDATE 29/02/08 (I): NROL-28 launch delayed because of USA 193 debris risk. See my post here
UPDATE 27/02/08: Fragments of USA 193 still in orbit and observable: see my post here

21/02/08: THEY DID IT! more below.

UPDATE 20/02/08: Sources say rough seas in the Pacific might prevent taking a shot at USA 193 on Wednesday/Thursday night.
UPDATE 19/02/08: John Locker has drawn attention to a second NOTAM for the same area, one day later. This is probably for a possible second attempt if the first one fails.
UPDATE 18/02/08: Ted Molczan has drawn attention to a NOTAM issued by the US Government that might point to a possible ASAT attempt on USA 193 on Feb 21, 3:30 UTC as USA 193 passes near Hawaii. See below for more.
UPDATE 17/02/08: Russia has now accused the USA that it is all a cover-up for an ASAT test..
UPDATE 14/02/08: News reports today suggest the US military has serious plans to shoot the satellite from orbit before the time of the expected decay, and are now confirmed by the US military. See the note at the end of this post.


Latest (21/02): USA 193 destroyed with a missile! News comes in that the American Navy last night (20/21 Feb) made a successful attack on USA 193, destroying it into multiple pieces with a SM-3 missile shot at 3:26 am GMT from the USS Lake Erie.

Link: Missile Intercept. Video released by the Pentagon

Amateur observers on the Canadian west coast report observing a spectacular shower of fragments re-entering in the atmosphere over Canada within 10 minutes after the successful attack. More fragments might come down today elsewhere along the former satellite's flight path.

***

Main background story

The weekend of 25 January, after what appeared to be an "organized leak" by a US government agency, the imminent decay of the failed reconnaisance satellite USA 193 (06-057A) gathered press attention.

USA 193 was launched on 14 December 2006 as NROL-21 with a Delta II rocket from Vandenberg Air Force Base in California. It somehow failed and went "dead" shortly after launch. There is no sign that its orbit has been under control since, and amateur satellite trackers were already long aware that the satellite orbit was decaying and the satellite doomed due to this.

Some sources suggest failure of an onboard computer as the problem with the satellite. Imaging by John Locker shows no sign of solar panels, which brings in the option of a power failure due to a failure to deploy the panels. Ted Molczan has suggested that an onboard computer boot failure prevented the panels from deploying, causing a loss of power when the batteries ran down, and notes that this tallies with the fact that radio signals from the satellite were logged by amateur radio trackers for 1.5 days after launch but then died down.

Orbital plane of USA 193 (06-057A)

The orbital inclination of the satellite was 58.5 degrees meaning it roughly covered all locations between 60 degrees north and south latitude. It was probably intended as a test platform for a new generation reconnaisance sats about the purpose and construction of which little is known. Sources differ on whether it could have been an optic or radar reco platform, or maybe both. According to the usually knowledgeable globalsecurity.org, it was a radar reco sat intended to replace the Lacrosse system and probably weighing about 3300 kg (which is only 1/3rd of the 9000 kg reported in the press for the object). Imaging by John Locker from September 2007 suggests the satellite was about 4 meters large. The official NRO press release at the time of the launch only stated that "the satellite launched will provide invaluable intelligence data to support the war on terrorism".

USA 193 was a satellite which was part of my regular observing program, observed and imaged by me several times. It was a bright naked eye target, reaching magnitude +1 under favourable illumination conditions, zipping across the sky at a spectacular high speed due to it's low orbital altitude. At the end of it's one year "life", it's perigeum was already below 250 km above earth surface and in its last weeks it was coming down fast (see diagram below).

Below diagram shows the altitude decay of the perigee (and apogee) of the orbit over time, and how the decay rate was accelerating. The final rate of decay was over 1 km/day.

(data in the diagram are derived from published orbits
based on amateur observations including mine,
calculated by McCants and Molczan:
last updated 23/02 with final epoch 08052 orbit)

The last orbit calculated by Molczan (08052.017 epoch) measured 242 x 257 km and provided a nominal value of the expected decay date of March 12th, but this value has an uncertainty of many days. On February 21st at 3:29 GMT, the satellite was destroyed by an SM-3 missile, making the subject of the expected decay date moot.

The large media attention to the imminent satellite decay was somewhat surprising, and the same goes for the fact that the US government itself has brought the imminent decay to the attention. We failed to see the reason for this. Among (amateur) satellite observers it was already known for a long time that this decay was about to happen. Moreover, the question is how much of an extra risk this decay really posed compared to other decays happening several times a year. Chances that the impact of remains, if any, posed damage to property or persons are minimal. Only if someone comes into direct contact with hydrazine fuel remnants, risks are involved. With several earlier occasions of satellite or rocket fuel tanks reaching earth surface intact in the past, this so far never has happened. In fact, the chances that a random passenger aircraft with fuel tanks will drop on your head today, are considerably bigger than the chance that USA 193's fuel tank would have done.

The whole situation as to the "why?" of bringing the satellite decay (and later the ASAT-attack on it) so prominently into the news definitely has open questions.

Some wild speculation about the potential presence of a nuclear (Plutonium based) power system on board has been popping up here and there, e.g. in the discussion on Slashdot, in The Observer and here. There is no reason to think the latter is really likely according to several specialists.

*** "Shooting it down" ***

On February 14th, the US military announced that they had plans to shoot the satellite down with a missile, "to reduce the danger to human beings". This gives a new twist to the story.

Official sources state that here is about 450 kg of hydrazine fuel (a very toxic substance) on board, and an expected 1100 kg (about one tonne) of debris of the satellite itself might reach earth surface intact.

The plan was (and we now know they did it too) to intercept the satellite in the week following February 20, using one or more SM-3 intercept missiles fired from naval vessels in the North Pacific. The SM-3 missiles need to be modified for this task as they normally target object at lower altitude on a ballistic trajectory instead of a true orbit.

The term "shooting it down" is, by the way, a bit misleading here. In reality, what happened is that the impact of the ASAT weapon broke up the satellite in many pieces, which will continue their orbit around the earth as a debris cloud. Due to their higher surface-to-mass ratio, smaller debris pieces will experience increased drag, which will make them decay earlier than the intact satellite would have.

On Feb 18th Ted Molczan has drawn attention to a NOTAM, issued by the US Government, that pointed to a possible ASAT attempt on USA 193 on Feb 21, 3:30 GMT.

PHZH   HONOLULU CONTROL FACILITY

02/062 (A0038/08) - AIRSPACE CARF NR. 90 ON EVELYN STATIONARY RESERVATION WITHIN
AN AREA BNDD BY 3145N 17012W 2824N 16642W 2352N 16317W 1909N 16129W 1241N 16129W
1239N 16532W 1842N 17057W 2031N 17230W 2703N 17206W SFC-UNL. 21 FEB 02:30 2008
UNTIL 21 FEB 05:00 2008. CREATED: 18 FEB 12:51 2008

The NOTAM excluded an area just west of Hawaii over which USA 193 would pass near the time above (see below map, showing USA 193's approximate position at 21 Feb 3:30 UTC):

(click map to enlarge)

An ASAT attack at this moment in this ground track would mean that within minutes the resulting debris cloud would come into range of ground tracking stations at the US West coast, where twilight would just have ended (and with the full moon being in eclipse at that moment (!) and low in the sky anyway, it woild be no hindrance to optical tracking facilities for tracking faint fragments). Next the debris cloud would pass over the arctic region of North America, where several radar tracking facilities exist.

Also, any quickly re-entering fragments would come down over the barren Canadian Arctic, rather than pass over highly populated areas. For a full orbit following an attack at this location, debris will not pass over significant inhabited land, as can be seen in the map below showing the trajectory of the satellite.

The marked position in the map below near Hawaii is for 3:30 GMT (Feb 21st), the moment of intercept, and the satellite (and its fragments after intercept) moves "up" along the marked line in the map, towards North America, over the Canadian arctic and then the Atlantic Ocean:

(click image to enlarge)

Hawaii itself would provide valuable tracking facilities prior and after the intercept.

On February 21st 2008 at 3:29 GMT (and quite along the anticipation described above), the satellite was indeed successfully destroyed with a SM-3 missile shot at 3:26 am GMT from the USS Lake Erie.

Link: Missile Intercept. Video released by the Pentagon

Amateur observers on the Canadian west coast report observing a spectacular shower of fragments re-entering in the atmosphere over Canada within 10 minutes after the successful attack. More fragments might come down today elsewhere along the former satellite's flight path.

As mentioned, there are questions as to the "why?" of the high profile media publicity of this all. Some observers have started to wonder whether it might all be a very cleverly orchestrated setup by the US Government, designed to get maximum global attention to an ASAT demonstration. Indeed, Russia has publicly accused the USA of covering-up a true ASAT-test with this.

If we entertain that notion for a moment: with this ASAT demonstration, they would hit three birds with one stone:

a) They send a high profile geopolitical message to China, and to the homefront, in answer to last year's Chinese ASAT test on Fengyun 1C. Basically, this message says: "you/they can shoot satellites out of the sky, okay. But remember we can too, so don't even dare to try ours or we will do the same to yours/theirs..."

b) They give some rendement to an otherwise worthless assemblage of several millions of Dollars worth of inoperative scrap metal now uselessly orbiting this planet.

c) it is an ideal opportunity to test their anti-satellite and anti-ICBM weaponry

I can't really comment on the value of this speculation, as I am not an expert on military geopolitics. A valid argument against (a) raised by some is however, that shooting down USA 193 at 250 km altitude is not quite the typical situation for an ASAT attack as this is much lower than the normal operational altitude of satellites. It is known from the succesfull ASAT test on the Solwind satellite (which orbitted at 550 km altitude) which the USA carried out in September 1985 however, that the USA does possess the capability to reach higher altitudes. The problem with ASAT attacks is moreover not so much the altitude to reach, but rather to hit the (small, fast moving) target.

As a reminder that the USA is capable of this, the demonstration would suffice, and USA 193 is the ideal target for it. Because of its low orbit, the formation of a debris cloud such as happened with the Chinese ASAT demonstration early last year isn't such a concern. Because of the low altitude, and unlike with the Chinese ASAT test, most if not all debris pieces would re-enter into the earth atmosphere within days after the ASAT attack, and therefore will not propose a real hazard to other satellites. This means the USA can use this object as a target without fear of being called hypocrits after their fierce criticism of the Chinese ASAT test last year, which created a high altitude, long lasting debris field which does provide a threath to other satellites.

Here's an archive picture of a USA 193 pass over Cospar 4353, which I shot on April 3 2007:

(note: all images in this post may be used for informational purpose, provided the source is acknowledged)

(click image to enlarge)

Thin clouds spoiled the sats, but nice Moon this morning

When I came back from diner with friends around midnight, it was nicely clear. So I set the alarm-clock to see if I could catch the NOSS 3-4 duo in morning twilight.

Alas, when the alarm clock went off it turned out to be thinly veiled and impossible to observe satellites. So instead I took photographs of the waning moon. The best one is shown below. Like a few days ago, this one was made by just holding the Canon Ixus compact camera with its front lens on the eyepiece of the Meade ETX-70.

(click image to enlarge)

Of NOSS-es, strays and neighbours

Yesterday the 22nd of January started clear and ended clear, albeit with a near full moon. I did an observing session with the ETX-70 telescope in morning twilight as well as in the evening.

The result: positions on the NOSS 3-4 pair (07-027A & C), the NOSS 3-3 pair (05-004A & C) and the NOSS 3-2 pair (03-054A & C), plus stray observations of the ELINT sat USA 32 (88-078A) and the spent Russian rocket Kosmos 1171r (80-026B). I also observed the NOSS 2-2 C & D pair, but couldn't log points (There was only a short time to re-aim the telescope between this pass and the NOSS 3-3 pass, and it then took me just too long to verify I had the correct star field. I saw them pass the FOV but couldn't get to clock them in time.).

During the morning session I unintendedly startled one of my neighbours when she came out of her house and saw me on the courtyard with my telescope. She went into a panicky fit as a result. This was just as I was about to catch 07-027A. The resulting melée and the added unexpected appearance of 88-078A as a "stray" only 11 seconds before 07-027A make me suggest to use the 07-027A point with some caution (by the time of 07-027C I should have regained my composure).

Some time after the end of the evening session, I portrayed the nearly full Moon. Below image is a quick shot made by simply pressing the (non-removable) objective lens of my Canon Ixus compact on the eyepiece of my ETX-70 telescope. Some after-editing has been done to the image to bring out detail.

(click image to enlarge)

Lacrosse 2 manoeuvre, and bad luck with a stopwatch

Yesterday was a very clear day, so in twilight I set up the ETX-70 to gather positional data on Lacrosse 2 (91-017A), the NOSS 3-3 (05-004 A & C) duo and the NOSS 3-4 (07-024A & C) duo.

I had adapted the home-made piggyback camera adapter slightly, so it can also funtion as a rest for my 5 mw green laserpointer. The drawback of the ETX-70 is that it doesn't come with a finderscope, so I use the laser to point the telescope. A 5 mw green laser gives a tens of meters long visible beam at night pointing to where you point the scope if you shine it parallel to the scope tube. Simple, and works like a charm.

Unfortunately, after succesfully observing passes of NOSS 3-3 A & C and Lacrosse 2 I must have hit a wrong button on the stopwatch by mistake. When I had pointed the telescope to the point near where NOSS 3-4 A & C should pass and took up the stopwatch, I discovered to my horror that it was no longer running and had no lap times in it's memory! I lost all gathered points so far.

Next, in the confusion of having to start up the stopwatch anew just before the NOSS 3-4 duo pass, I lost that pass.

Now, I can't quite stand such things happening, it makes me very irritated for a while. Luckily my neighbours have double-pane glass, so probably they did not hear my swearing...

What saved the night was that before turning to the telescope, I had triggered the Ixus camera in addition during the Lacrosse 2 (91-017A) pass. The trail showed up faint but well enough defined to measure against the late twilight sky, which meant I had an image providing two positions.

After data reduction, it turned out that the satellite was 17.3 seconds early relative to Mike's 07357.17849791 TLE. On the 6th of January, the difference to this TLE was 1 second. So I reckoned 91-017A must have made a manoeuvre recently. Which, it turns out, it indeed did, a small manoeuvre changing the mean-motion slightly on or near the 6th. What I had missed was that Mike had just issued and update of the 91-017A orbit incorporating the manoeuvre yesterday morning.
That 91-017A still does manoeuvre, points out it is still alive and probably still being used for reconnaisance almost 17 years after it was launched.

(click image to enlarge)

Lacrosse 2 (91-017A) crossing through Cygnus 17.3 seconds early

I set my alarm-clock to see if it would still be clear in the morning (allowing me in that event to catch amongst others Progress M-61). But alas, it had become overcast.

NOSS-es, Lacrosses and ISS

Yesterday evening the 9th it was clear in twilight, but clouds came in a while later. Nevetheless there was time enough to get out the ETX-70 again and bag the NOSS 3-4 duo (07-027A and 07-027C), the NOSS 3-3 duo (05-004A and 05-004C) and Lacrosse 3 (97-064A). In total, 7 points were obtained. In the morning of the 10th, I observed the International Space Station just before clouds again interfered.

About 3 minutes before the NOSS 3-4 duo pass, another faint sat crossed the telescope field in a similar trajectory. I was just making a last check of the star field in view against a plotted map to ensure I had the correct location in view, so hadn't the stopwatch in my hands. At first I was a bit worried it was one of the 07-027 objects but very early, so I was relieved when 3 minutes later the real 07-027A sailed into the FOV.

Later that night it cleared again. Below is the image of the ISS I shot a few hours later, during the morning hours. It can be seen passing from Corona borealis into Hercules. It was bright, around mag. -4. My main intended target for that early morning was Progress M-61, but clouds (already visible in the ISS image) intervened.

(click image to enlarge)

More NOSS 3-4

It shortly cleared around twilight this evening. There were flying clouds and some thin high altitude streaks in the sky, but I managed to get a pass of the NOSS 3-4 A and C pair (07-027A, 07-027C) and get two points on each as they passed close to mu Andromeda. Like during my observ ations on the 6th, the sats had a clear yellow colour.

This time I had no trouble with handling the stopwatch to retrieve the logged timings any more. Also, comparing with other observer's results, my timings seem good, but I might need to work a bit on the cross-track error.

Shortly after the observation cloud cover returned.

USA 193, first ETX observations of NOSS 3-4, and comet 17P/Holmes

Last two nights (the evenings of 2008 Jan 5 and 6) were the first nights I tried to do visual position determinations on fainter satellites. Targets were the NOSS 3-4 A & C pair (07-027A & 07-027C).

The Meade ETX-70 (see picture below), a small and compact 7 cm/f 350 mm (F5) rich-field refractor, turns out to be a very nice instrument for satellite observing. It was cool to see 07-027A sail majestically in and out of the FOV, half a minute later followed by 07-027C. At 14x magnification with the 25 mm eyepiece, the FOV is over 3 degrees with (from the light-polluted mid-town location Cospar 4353 in Leiden center) a limiting magnitude at mag. +9.5.

(click image to enlarge)

The Meade ETX-70. Attached is a home-made piggyback mount for my camera

I had some problems operating my (new too) stopwatch though. During the Jan 5 attempt, I pushed a wrong button when I wanted to read out the memory, resulting in the loss of all 4 points. During the Jan 6 attempt, I did the same with 2 points on 07-027A after I had succesfully retrieved 2 points on 07-027C (plus another point on the same object taken during an earlier pass). Evidently, I still need some practise. Logging with the stopwatch, estimating the fraction between two stars crossed, and operating Ted's Obsreduce software all went surprisingly well though.

On Jan 5th in deep twilight I observed USA 193 (06-057A) zipping by. I got two camera points on it but apparently the times are off. This failed (?) reco sat keeps being a fine object to view as it is bright and very fast. If it's orbit continues to decay as it does now, the object will end its life around the first week of April.

On Jan 6th I observed, apart from the NOSS 3-4 pair, also Lacrosse 2 & 3.

The evening of January 6th was very clear, and I used the ETX-70 to function as guiding mount for the Canon Ixus camera. Target: comet 17P/Holmes.

The comet has grown very large (about 1.12 degree currently) and vey diffuse. Below is a photograph showing the comet which is a stack of 39 images of 15 second exposure each. The open cluster in top of the image is M34, the bright star below the comet is Algol. Because the ETX-70 is on an alt-azimuth mount and the comet was near the zenith, where the effect is largest, some field rotation is visible in the stars near the image edges.

(click image to enlarge)

Comet 17P/Holmes coma now over 5.5 million km wide: 4 times size of the sun!

Using my photograph of the 29th, astrometrically measured with Astrorecord, I updated my diagram of the growing size of comet 17P/Holmes' coma.

The coma is now over 5.5 million km wide. That is 4 times the size of the sun!