Showing posts with label ISS. Show all posts
Showing posts with label ISS. Show all posts
Wednesday, 4 January 2012
Cloud-hampered ISS pass of January 2nd, and deep twilight pass of January 3rd
The evening of January 2nd started clear, so I set up the video to film another pass (17:01 UTC) of the International Space Station (ISS) which currently has the Dutch astronaut André Kuipers on board.
Unfortunately, an episode with many clouds commenced just before the pass. I managed to film glimpses of the ISS through gaps in the cloud cover.
Very frustratingly, it was completely clear again 10 minutes after the pass.
On January 3rd, it was clear. ISS made a pass in very deep twilight (16:04 UTC), with the sun at an altitude of only -3.5 degrees! Nevertheless, the ISS was well visible by the naked eye, in a bright blue sky with no stars yet.
Friday, 30 December 2011
Footage of the ISS with Andre Kuipers on board passing over Leiden, 30 December
The footage above was shot by me this evening (30 December 2011, evening twilight, around 16:38 UTC = 17:38 local time). It shows the International Space Station (ISS) with Dutch astronaut Andre Kuipers on board, passing right over my observatory in Leiden, the Netherlands.
The movie was shot using a sensitive WATEC 902H camera and F1.4/12mm lens (this is not the best of lenses in terms of sharpness, but it has a relatively wide FOV of 30 degrees that suited this case. This lens provides a reasonably good approximation of the typical visual view as well in that the limiting magnitude of the movie is similar to that with the naked eye).
I had actually almost missed this pass, as I was busy with another task and lost track of time. So I had to set up my equipment rather in a hurry, with no time to start up and synchronize the GPS time inserter. As usual (and also because I do not yet ahve a "routine"with this new equipment) I initially had an "issue" in getting an image on the laptop monitor: when I finally had an image and could focus, the ISS was already in the sky, ascending at 45 degrees elevation in the west.The sky was still a bit bright from twilight, and some hazy clouds were in the sky.
The footage picks up the ISS in northern Cygnus, shows the ISS as it ascends and goes through the zenith, passing over Pegasus and into Andromeda and next descends through the triangle towards the east, disappearing behind the roof of the house.
I am happy to have this footage at all, as the weather is abominably bad this month.
Tuesday, 27 December 2011
Further confusion on Saturday's Soyuz r/b reentry
I earlier wrote about the confusion reigning in the press concerning the sky event over Europe of last Saturday evening. Initial confusion was over wether it was a meteor, "comet" or (and that was the correct explanation, but many Dutch and German news outlets failed to properly pick that up): the reentry of a Soyuz rocket.
Now a new confusion has arrisen: some news outlets and weblogs, e.g. that of Physorg, mistakenly link the event to last Friday's failed Russian launch of the Meridian satellite. Due to a rocket failure, this never reached earth orbit but crashed in Siberia within minutes after the launch.
As I wrote earlier, what reentered and was seen over France, Germany and the Netherlands last Saturday evening, was the 3rd stage of last Wednesday's Soyuz launch to the ISS.
The confusion probably comes from the fact that both launches used a Soyuz rocket. The failed launch that crashed in Siberia on Friday got some press attention because fragments hit a house in Russia (see a.o. here (English), with pictures of a recovered fuel tank here (Russian)).
But again: that failed launch had nothing to do with Saturdays sky event over Europe. The reentry over Europe was the 3rd stage of the earlier Wednesday launch to the ISS, that included Dutch astronaut Andre Kuipers.
Now a new confusion has arrisen: some news outlets and weblogs, e.g. that of Physorg, mistakenly link the event to last Friday's failed Russian launch of the Meridian satellite. Due to a rocket failure, this never reached earth orbit but crashed in Siberia within minutes after the launch.
As I wrote earlier, what reentered and was seen over France, Germany and the Netherlands last Saturday evening, was the 3rd stage of last Wednesday's Soyuz launch to the ISS.
The confusion probably comes from the fact that both launches used a Soyuz rocket. The failed launch that crashed in Siberia on Friday got some press attention because fragments hit a house in Russia (see a.o. here (English), with pictures of a recovered fuel tank here (Russian)).
But again: that failed launch had nothing to do with Saturdays sky event over Europe. The reentry over Europe was the 3rd stage of the earlier Wednesday launch to the ISS, that included Dutch astronaut Andre Kuipers.
Monday, 26 December 2011
11-078B Soyuz 3rd stage reentry: answers to some frequently asked questions
In the wake of the spectacular reentry over NW Europe of the Soyuz 3rd stage 2011-078B on Saturday 24 December 2011, several common questions popped up in comments, e-mails, on Twitter and in newspaper discussions. I will answer a few below.
Frequently Asked Questions:
(Q1): Are these things predictable and who makes such predictions?
(Q2) Does it really take a Soyuz rocket 3rd stage three days to fall back to earth?
(Q3) Why doesn't this happen with each Soyuz launch? Or: why not over the same location on Earth?
(Q4) has anything of the rocket stage survived to earth surface?
Answers:
(Q1): Are these things predictable and who makes such predictions?
(A): It is "sort of" predictable. Using computer models which take into account many factors of influence, one can make a prediction yielding an indication of the time a rocket stage or satellite will re-enter the atmosphere. However, even very close to that actual time of reentry, the uncertainty in these predictions is still very large. Exactly when a rocket stage will start to burn up depends on many factors, including the exact condition of the atmosphere at that moment, the shape of the rocket stage, and whether it is tumbling or not. In practise, this turns out to be very difficult to model, even with the best computer models.
Several organisations and individuals do such predictions (and you can even find software for it on the internet). However, one of the most authoritive sources of such predictions is USSTRATCOM, the American military organisation that tracks manmade objects in space (many people think NASA does that job. But that is incorrect: it is USSTRATCOM, better known as 'NORAD'). They publish these predictions as 'TIP' messages. Their first prediction is published 2 months in advance. These still have a very large uncertainty (think of: weeks). In the days close to decay, they publish new estimates as new TIP messages that gradually become more exact. But even these can have uncertainties of several hours, even for predictions made on the day of the reentry itself.
For example, the last pre-reentry TIP message issued only 2 hours before the Soyuz 3rd stage came down, still had an uncertainty window of six hours.....
Once an object has reentered, USSTRATCOM does a post-analysis of the last orbital information, and publishes a "final' TIP message mentioning when and where the object came down (so this is done "after the fact"). These can be (but are not always, as it depends on how well the object was tracked during it's last hours of existence) very accurate. Sometimes, as was the case with this reentry of the Soyuz 3rd stage, they provide a time with an uncertainty of only minutes, plus a quite accurate position. In other cases, where less recent tracking data is available, the final uncertainty is much larger.
Note that a re-entering satellite or rocket booster has a speed of 7.5 km per second (4.7 miles per second)! So even if the predicted time has an uncertainty of just 15 minutes, this amounts to an uncertainty of 13,500 km (8,400 miles) in the position of the object when it reenters! This is why it is impossible to pinpoint the expected point of re-entry beforehand, when it is not a "controlled" re-entry. (in a "controlled" re-entry, the satellite operators send a command to the satellite to make a rocket burn at a precise time, kicking it down over a designated spot, usually the Pacific ocean. This Soyuz reentry was however not such a "controlled" reentry).
Many people mistakenly think that in this day and age of supercomputers, scientists (or the military) can predict everything. In reality, satellite/rocket reentries like this are so complex that even the best computer models can only give rough indications untill just minutes before the actual re-entry.
(Q2) Does it really take a Soyuz rocket 3rd stage three days to fall back to earth?
(A) Yes, it does. That last rocket stage is jettisoned that high above earth surface, that it does not just rapidly fall back on a ballistic trajectory (such as the 1st and 2nd stages do) but actually reaches Low Earth Orbit, and stays in orbit around the earth for several days. In effect, it becomes a satellite for a while in a very low orbit around Earth. Under influence of gravity and drag from the outer atmosphere, the orbit slowly evolves and becomes smaller and smaller. On the first day only gradually, but as it slowly comes down, this gradually goes faster and faster.
The influence of our atmosphere reaches several hundreds of kilometers up: even the International Space Station experiences some atmospheric drag, and would fall down within a year if its orbit was not regurlarly raised using the rocket engines of the Progress spacecraft docked to the ISS.
It takes about 3-4 days for a Soyuz 3rd stage from a launch to the ISS to come down. The exact amount of time is variable and different in each new case, as it depends on many factors. Our atmosphere is variable in extent and density, notably under the influence of solar activity. When the sun is active and many charged particles from solar outbursts reach earth, these interact with our atmosphere and the atmosphere slightly expands as a result of this. This means that objects at the altitude of the Space Station and below that (such as the Soyuz rocket stage) will experience a "thicker atmosphere", i.e. more drag from the atmosphere's outermost layers, and as a result they will come down faster. When it reaches at altitude of only 120 km (75 miles) it goes very quick: within minutes the rocket stage has dropped tens of kilometers, slowed down considerably, and finaly plunges straight down from that moment onwards.
The exact moment this happens, is highly dependant on these variations in extend of our atmosphere due to variations in solar activity. This is another reason why a satellite or rocket re-entry is so difficult to predict: one short but intense outburst occuring on the sun will next make a rocket stage fall back much quicker than expected.
Below diagram shows the orbital evolution of the Soyuz 3rd rocket stage that decayed last Saturday. It had to make 52 full orbits (full circles) around the Earth before it burned up. It's orbit was a bit "eccentric", which means that it was not a perfect circle but an ellipse. So on each revolution around the earth, there is a point where it is a bit higher above earth (called the "apogee") and a point where it is closest to the earth (called "perigee"). In the diagram, the values for these altitudes have been plotted as a red and blue line. Note how fast these altitudes change in the final hours before re-entry.
(Q3) Why doesn't this happen with each Soyuz launch? Or: why not over the same location on Earth?
(A) It does happen with each Soyuz launch to the ISS. The Soyuz 3rd stage always comes down some 3-4 days after the launch.
That reentry however is never over the same location on earth. The reasons for this, have already been outlined as part of the answer to question (2) above. An important factor of influence on how quickly a rocket stage comes down, is the variable earth's atmosphere, under influence of variability in solar activity. These factors are different for each new case. This is why the 3rd stages of Soyuz launches to the ISS never fall down near the same spot twice.
(Q4) has anything of the rocket stage survived to earth surface?
(A) Not that we so far know of. Usually, the rocket stage almost completely burns up in the atmosphere. Sometimes, a few smaller bits survive (quite often spherical fuel tanks). For example, an object that is likely a rocket fuel tank came down in Namibia in November and might be part of a rocket stage used in a Russian November launch to the International Space Station.
Frequently Asked Questions:
(Q1): Are these things predictable and who makes such predictions?
(Q2) Does it really take a Soyuz rocket 3rd stage three days to fall back to earth?
(Q3) Why doesn't this happen with each Soyuz launch? Or: why not over the same location on Earth?
(Q4) has anything of the rocket stage survived to earth surface?
Answers:
(Q1): Are these things predictable and who makes such predictions?
(A): It is "sort of" predictable. Using computer models which take into account many factors of influence, one can make a prediction yielding an indication of the time a rocket stage or satellite will re-enter the atmosphere. However, even very close to that actual time of reentry, the uncertainty in these predictions is still very large. Exactly when a rocket stage will start to burn up depends on many factors, including the exact condition of the atmosphere at that moment, the shape of the rocket stage, and whether it is tumbling or not. In practise, this turns out to be very difficult to model, even with the best computer models.
Several organisations and individuals do such predictions (and you can even find software for it on the internet). However, one of the most authoritive sources of such predictions is USSTRATCOM, the American military organisation that tracks manmade objects in space (many people think NASA does that job. But that is incorrect: it is USSTRATCOM, better known as 'NORAD'). They publish these predictions as 'TIP' messages. Their first prediction is published 2 months in advance. These still have a very large uncertainty (think of: weeks). In the days close to decay, they publish new estimates as new TIP messages that gradually become more exact. But even these can have uncertainties of several hours, even for predictions made on the day of the reentry itself.
For example, the last pre-reentry TIP message issued only 2 hours before the Soyuz 3rd stage came down, still had an uncertainty window of six hours.....
Once an object has reentered, USSTRATCOM does a post-analysis of the last orbital information, and publishes a "final' TIP message mentioning when and where the object came down (so this is done "after the fact"). These can be (but are not always, as it depends on how well the object was tracked during it's last hours of existence) very accurate. Sometimes, as was the case with this reentry of the Soyuz 3rd stage, they provide a time with an uncertainty of only minutes, plus a quite accurate position. In other cases, where less recent tracking data is available, the final uncertainty is much larger.
Note that a re-entering satellite or rocket booster has a speed of 7.5 km per second (4.7 miles per second)! So even if the predicted time has an uncertainty of just 15 minutes, this amounts to an uncertainty of 13,500 km (8,400 miles) in the position of the object when it reenters! This is why it is impossible to pinpoint the expected point of re-entry beforehand, when it is not a "controlled" re-entry. (in a "controlled" re-entry, the satellite operators send a command to the satellite to make a rocket burn at a precise time, kicking it down over a designated spot, usually the Pacific ocean. This Soyuz reentry was however not such a "controlled" reentry).
Many people mistakenly think that in this day and age of supercomputers, scientists (or the military) can predict everything. In reality, satellite/rocket reentries like this are so complex that even the best computer models can only give rough indications untill just minutes before the actual re-entry.
(Q2) Does it really take a Soyuz rocket 3rd stage three days to fall back to earth?
(A) Yes, it does. That last rocket stage is jettisoned that high above earth surface, that it does not just rapidly fall back on a ballistic trajectory (such as the 1st and 2nd stages do) but actually reaches Low Earth Orbit, and stays in orbit around the earth for several days. In effect, it becomes a satellite for a while in a very low orbit around Earth. Under influence of gravity and drag from the outer atmosphere, the orbit slowly evolves and becomes smaller and smaller. On the first day only gradually, but as it slowly comes down, this gradually goes faster and faster.
The influence of our atmosphere reaches several hundreds of kilometers up: even the International Space Station experiences some atmospheric drag, and would fall down within a year if its orbit was not regurlarly raised using the rocket engines of the Progress spacecraft docked to the ISS.
It takes about 3-4 days for a Soyuz 3rd stage from a launch to the ISS to come down. The exact amount of time is variable and different in each new case, as it depends on many factors. Our atmosphere is variable in extent and density, notably under the influence of solar activity. When the sun is active and many charged particles from solar outbursts reach earth, these interact with our atmosphere and the atmosphere slightly expands as a result of this. This means that objects at the altitude of the Space Station and below that (such as the Soyuz rocket stage) will experience a "thicker atmosphere", i.e. more drag from the atmosphere's outermost layers, and as a result they will come down faster. When it reaches at altitude of only 120 km (75 miles) it goes very quick: within minutes the rocket stage has dropped tens of kilometers, slowed down considerably, and finaly plunges straight down from that moment onwards.
The exact moment this happens, is highly dependant on these variations in extend of our atmosphere due to variations in solar activity. This is another reason why a satellite or rocket re-entry is so difficult to predict: one short but intense outburst occuring on the sun will next make a rocket stage fall back much quicker than expected.
Below diagram shows the orbital evolution of the Soyuz 3rd rocket stage that decayed last Saturday. It had to make 52 full orbits (full circles) around the Earth before it burned up. It's orbit was a bit "eccentric", which means that it was not a perfect circle but an ellipse. So on each revolution around the earth, there is a point where it is a bit higher above earth (called the "apogee") and a point where it is closest to the earth (called "perigee"). In the diagram, the values for these altitudes have been plotted as a red and blue line. Note how fast these altitudes change in the final hours before re-entry.
(Q3) Why doesn't this happen with each Soyuz launch? Or: why not over the same location on Earth?
(A) It does happen with each Soyuz launch to the ISS. The Soyuz 3rd stage always comes down some 3-4 days after the launch.
That reentry however is never over the same location on earth. The reasons for this, have already been outlined as part of the answer to question (2) above. An important factor of influence on how quickly a rocket stage comes down, is the variable earth's atmosphere, under influence of variability in solar activity. These factors are different for each new case. This is why the 3rd stages of Soyuz launches to the ISS never fall down near the same spot twice.
(Q4) has anything of the rocket stage survived to earth surface?
(A) Not that we so far know of. Usually, the rocket stage almost completely burns up in the atmosphere. Sometimes, a few smaller bits survive (quite often spherical fuel tanks). For example, an object that is likely a rocket fuel tank came down in Namibia in November and might be part of a rocket stage used in a Russian November launch to the International Space Station.
Saturday, 24 December 2011
[Updated] Breaking News: Decay of Soyuz r/b stage from André Kuipers' launch to ISS observed from the Netherlands!
UPDATE - the final TIP for Soyuz r/b 38037 / 2011-078B has been released by USSTRATCOM near 18h GMT and it indeed shows that this was the Soyuz r/b: reentry time is quoted as 16:25 +/- 1 minute GMT at 49 deg N, 7 deg E. This fits the observations well.
In the Dutch press, there meanwhile appears to be a lot of confusion. The Dutch National Police claims that they talked to "NASA" who apparently said it was a "meteor" (or "comet"). So THAT is widely claimed in the press now, to the point of calling the identification with the Soyuz 3rd stage "speculation". Which it is not: it is based on factual data and now clearly confirmed by the USSTRATCOM JSpOC TIP message. What more do you want?!
I have no idea to whom (or even where: NASA is big...) the Police spoke, but for all things it could have been the JPL janitor....
At any rate: appart from my analysis below (which is already clear), the USSTRATCOM TIP message mentioned above makes unambiguously clear that this was the Soyuz 3rd stage.
Note that to access the USSTRATCOM TIP message via the link above you need an approved account. USSTRATCOM is the US military Command responsible for tracking manmade objects in space, and perhaps better known under their former name NORAD.
- end of update
Multiple reports are coming in, among others by experienced Dutch meteor observers Carl Johannink (Gronau) and Arnold Tukkers (Denekamp), of a bright and very slow fragmenting object seen low in the west-southwest near Venus at 16:26 UTC, 24 December.
From the descriptions it clearly was a reentry of an artificial object (space junk), as the event was too long in duration and too slow to be a meteoric fireball.
And it was not "just" a random bit of space debris, it turns out:
The observations fit with 2011-078B (#38037), the last stage of the Soyuz rocket that brought Dutch astronaut Andre Kuipers up to the ISS earlier this week. It was already predicted to decay near this moment by USSTRATCOM.
Below is the predicted trajectory of the Soyuz 3rd stage for the Gronau/Enschede area (and below that, the ground trajectory). It is based on an orbit with an epoch near noon of 24 December (epoch 11358.49032868. Source: USSTRATCOM), so a few hours old, which will introduce some minor discrepancies (a few seconds in time). But it fits the descriptions very well in terms of time and trajectory in the sky.
click images to enlarge
[UPDATE 7 October 2017]:
I recently modelled the re-entry of 2011-078B in GMAT, using the MSISE90 model atmosphere with actual Spaceweather of that time. Drag surface was set at 60% of the maximum drag surface for a Soyuz upper stage: this yields a decay position and decay time well in agreement with the JSpOC TIP position and is close to what the drag value for a tumbling, fragmenting object would be.
As seen from Gronau in Germany, it yields the following sky trajectory. Compare with Carl Johannink's description below: it matches his description well.
 |
| click map to enlarge |
- continuing original post:
Some quickly translated descriptions by two experienced Dutch meteor observers (compare to the sky trajectory map above for their area):
Arnold Tukkers, Denekamp (Netherlands):
At 17:26 CET (=16:26 UTC) I looked out of the window and saw a strange phenomena just above the rooftops behind us. It looked like a very, very slow meteor fragmented in several pieces. Like Peekskill but less bright.
Multiple fragments. Because it was so low in the sky, I walked upstairs and could still see the last part from the bedroom window. So it at least took 20 seconds. [...]
What a sight! Trajectory for me (did not see initial part) southwest-southeast. Altitude maximum 20 degrees. Colour brown-red.
Carl Johannink, Gronau (Germany):Update:
Just was looking at Venus in evening twilight.
Left of it an object appeared from behind a cloud that I first thought to be an aircraft, but next I found something was not right. The thing sometimes brightened and became fuzzy, trailing a circa 8 degree long tail. Maximum brightness about -4.
The object roughly moved from SSW to SE at an elevation of about 15 degrees. The whole phenomena took over half a minute.
To see the second part of the trajectory I had to walk to a different room. Called in Elisabeth, together we saw the object fragment into pieces (each individual piece about mag. 0 to +1) and then fade out.
The whole event looked much alike to the New Years Eve satellite decay of 1978, albeit being somewhat less bright.
A number of video's from Germany have surfaced which likely show the event. Here are a few:
video 1
video 2
Video 3 (on the Bad Astronomer's blog)
Video 4
Video 5
FAQ
Read the answers to Frequently Asked Questions for this reentry case I published later here.
Tuesday, 10 May 2011
ISS over the Sun
Late this afternoon (10 May 2011), at 17:29:25 CEST (15:29:25 UTC), the International Space Station (ISS) passed in front of the Sun disc again as seen from the SatTrackCam station, silhoueting the Space Station on the solar disc.
Like on March 24th, I used my small ETX-70 telescope equiped with a Solar Screen Filter, to photograph the event. This time I used prime focus plus a Kenko 2x converter, instead of eyepiece-projection, effectively yielding a f=700mm F/10 system.
Four images out of the series show the ISS silhouted againts the sun, along with several sunspots. Below is a composite image of the four images (showing the ISS four times), plus a detail. The ISS solar arrays are well visible.
Like on March 24th, I used my small ETX-70 telescope equiped with a Solar Screen Filter, to photograph the event. This time I used prime focus plus a Kenko 2x converter, instead of eyepiece-projection, effectively yielding a f=700mm F/10 system.
Four images out of the series show the ISS silhouted againts the sun, along with several sunspots. Below is a composite image of the four images (showing the ISS four times), plus a detail. The ISS solar arrays are well visible.
click images to enlarge
Thursday, 24 March 2011
The International Space Station (ISS) crossing the sun
The International Space Station (ISS) crossed in front of the sun disc as seen from my observatory this afternoon (24 March 2011) at 11:00:16 UTC (12:00:16 CET).
I used my modest 7-cm refractor (Meade ETX-70) to capture it: I started a series of rapid images (My EOS 450D takes 3.6 images/second) one second before the predicted pass time continuing for 5 seconds, and two out of this series show the ISS silhoueted againts the sun, with solar panels recognizable. The images also show a group of sunspots.
Below images are a single shot (with detail of the ISS at full pixel level), and an image which is a combination of the two images showing the ISS (hence the ISS silhouet shows up twice).
The telescope was equipped with a Solar Screen filter, exposure time was 1/500s at 400 ISO, eyepiece projection with a 26mm eyepiece to get a decent sized sun image (with f=350mm in the primary focus the sun disc stays a triffle too small).
Note that the telescope involved (see image below: Meade ETX-70 telescope with Canon EOS DSLR camera attached and solar filter on the lens) really is very modest: I bought it for a mere €200,- at the Lidl supermarket! The camera is 3 times as expensive as the telescope. Yet, this simple setup manages to capture it all, even though the images are perhaps not as sharp as you would like (which at least partly is due to air turbulence in the sun-heated telescope tube, by the way).
I used my modest 7-cm refractor (Meade ETX-70) to capture it: I started a series of rapid images (My EOS 450D takes 3.6 images/second) one second before the predicted pass time continuing for 5 seconds, and two out of this series show the ISS silhoueted againts the sun, with solar panels recognizable. The images also show a group of sunspots.
Below images are a single shot (with detail of the ISS at full pixel level), and an image which is a combination of the two images showing the ISS (hence the ISS silhouet shows up twice).
click images to enlarge
The telescope was equipped with a Solar Screen filter, exposure time was 1/500s at 400 ISO, eyepiece projection with a 26mm eyepiece to get a decent sized sun image (with f=350mm in the primary focus the sun disc stays a triffle too small).
Note that the telescope involved (see image below: Meade ETX-70 telescope with Canon EOS DSLR camera attached and solar filter on the lens) really is very modest: I bought it for a mere €200,- at the Lidl supermarket! The camera is 3 times as expensive as the telescope. Yet, this simple setup manages to capture it all, even though the images are perhaps not as sharp as you would like (which at least partly is due to air turbulence in the sun-heated telescope tube, by the way).
Tuesday, 8 March 2011
A farewell view of Space Shuttle Discovery
This evening in twilight (sun at -8 degrees altitude) we had a last pass of the "dynamic duo" Space Shuttle Discovery STS-133 and the International Space Station (ISS).
After it's landing tomorrow late afternoon, Discovery will be retired.
The two were well visible in a still bright blue sky, with Orion just visible. They sailed under Orion through Lepus, the Shuttle leading 37.4 seconds (about 19 degrees at culmination) in front of the ISS.
Below is one of the images I shot, using the EF 2.8/24mm lens at 4 second exposure, 200 ISO. The Shuttle is the trail on the left, ISS on the right:
Several other European observers reported a water-dump, visible as a "comet tail" behind the Shuttle. I didn't see it from Leiden though, likely because the sky was still too bright.
After it's landing tomorrow late afternoon, Discovery will be retired.
The two were well visible in a still bright blue sky, with Orion just visible. They sailed under Orion through Lepus, the Shuttle leading 37.4 seconds (about 19 degrees at culmination) in front of the ISS.
Below is one of the images I shot, using the EF 2.8/24mm lens at 4 second exposure, 200 ISO. The Shuttle is the trail on the left, ISS on the right:
click image to enlarge
Several other European observers reported a water-dump, visible as a "comet tail" behind the Shuttle. I didn't see it from Leiden though, likely because the sky was still too bright.
Monday, 7 March 2011
The ISS and Space Shuttle Discovery STS-133
Space Shuttle Discovery STS-133 undocked from the International Space Station (ISS) on Monday, and some 6 hours later made two passes visible from my locality.
The first pass was at 18:48 local time (CET) in very deep twilight, with the sun only 4 degrees under the horizon. This meant the sky was still bright blue. A crescent moon was visible (with the ISS passing only a few degrees away from it), but almost no stars.
Nevertheless both ISS and STS-133 were well visible by the naked eye around culmination: the Shuttle was about 5 to 6 degrees in front of the ISS and slightly fainter.
A second pass, this time in a dark sky, was on an extremely low elevation of 12 degrees at 19:25:30 UTC. Yet due to the very clear sky, they were well visible by the naked eye again, truely at rooftop level:
In the image, the two trails overlap at their ends, creating one long trail. A difference in brightness shows where the ISS trail ends.
The Shuttle and ISS were 7.27 seconds apart, at a distance of 2.5 degrees, with the Shuttle leading. This corresponds to 54.5 km separation in reality.
At the deep twilight passage, I used my Canon EOS 450D, laptop and "EOS Camera Movie Record" software to record a short movie (below), showing the crescent moon and the ISS passing near it, low in the west. The Shuttle was still too faint to be seen at that time, brightening to naked eye brightness only when it was closer to culmination.
The first pass was at 18:48 local time (CET) in very deep twilight, with the sun only 4 degrees under the horizon. This meant the sky was still bright blue. A crescent moon was visible (with the ISS passing only a few degrees away from it), but almost no stars.
Nevertheless both ISS and STS-133 were well visible by the naked eye around culmination: the Shuttle was about 5 to 6 degrees in front of the ISS and slightly fainter.
A second pass, this time in a dark sky, was on an extremely low elevation of 12 degrees at 19:25:30 UTC. Yet due to the very clear sky, they were well visible by the naked eye again, truely at rooftop level:
click image to enlarge
In the image, the two trails overlap at their ends, creating one long trail. A difference in brightness shows where the ISS trail ends.
The Shuttle and ISS were 7.27 seconds apart, at a distance of 2.5 degrees, with the Shuttle leading. This corresponds to 54.5 km separation in reality.
At the deep twilight passage, I used my Canon EOS 450D, laptop and "EOS Camera Movie Record" software to record a short movie (below), showing the crescent moon and the ISS passing near it, low in the west. The Shuttle was still too faint to be seen at that time, brightening to naked eye brightness only when it was closer to culmination.
Sunday, 6 March 2011
Twice the ISS
Below are two images showing the International Space Station (ISS) pass over my observatory.
The first was made on the evening of March 3 and shows it passing between the Hyades and Pleiades. It is a stack of 3 images of 10s each.
The second was taken this evening (March 6) and is a stack of 10 images of 10s each, showing it pass under Orion and Sirius.
Lens used in both cases was an EF 2.8/24mm.
The first was made on the evening of March 3 and shows it passing between the Hyades and Pleiades. It is a stack of 3 images of 10s each.
The second was taken this evening (March 6) and is a stack of 10 images of 10s each, showing it pass under Orion and Sirius.
Lens used in both cases was an EF 2.8/24mm.
click images to enlarge
Saturday, 20 February 2010
A magnificent view of the Space Shuttle Endeavour STS-130 and the ISS in tandem!
click image to enlarge
The weather predictions for this morning suggested a possibility of clear sky - and hence a possibility to see a morning twilight pass of the duo Space Shuttle Endeavour STS-130 and the International Space Station, which decoupled a few hours earlier.
I observed from the appartment of my girlfriend this time, who lives at the 2nd floor of the same building as me. This allowed a wide vista over the rooftops towards the west and southwest. The pass happened around 6:49 am local time (5:49 UTC on the 20th), the sun was at an altitude of -10 degrees, and hence twilight coloured the sky already. I could see Saturn, Spica and a couple of other stars, low in the southwest. The pass would reach a maximum altitude of 20 degrees.
The pair was easy to see as they majestically sailed over the rooftops in the twilight sky, rising over the rooftops below Saturn and then passing Spica. They were very close, 1.7 degrees apart around 5:49:30 UTC (measured from the photograph above), passing the same point about 3.7 seconds apart. The Shuttle, at around magnitude 0 to +1 the fainter of the two, was slightly ahead of, and a tiny bit lower in declination than, the ISS, which attained about magnitude -1 to -2. A magnificent view!
Above is one of three pictures I took. They suffered a bit from vibrations, as I had only limited space to put up the tripod in the window-sill of my GF's bedroom, and the window-sill apparently did transfer some vibrations to the tripod & camera. The picture shown above shows the duo close to Spica (alpha Virgo) and is the image with the least "wobbly" trails. Movement of both objects is from right to left in the picture.
Friday, 11 September 2009
Space Shuttle Discovery STS-128
Yesterday it was a close call whether I would see the Space Shuttle Discovery STS-128 or not. A large field of clouds passed in late twilight, and only moved away some 10 minutes before the Shuttle pass. The clouds made me miss the newly launched Japanese HTV cargo ship to the ISS.
But the clouds moved away in time, and there it was: about mag. +2 to +2.5 and fast, and...39 seconds early on predictions based on orbital elements of earlier that day.
Three minutes later, the ISS sailed by in its majestic fashion.
The image below shows the shuttle passing through Ophiuchus.
But the clouds moved away in time, and there it was: about mag. +2 to +2.5 and fast, and...39 seconds early on predictions based on orbital elements of earlier that day.
Three minutes later, the ISS sailed by in its majestic fashion.
The image below shows the shuttle passing through Ophiuchus.
click image to enlarge
Saturday, 18 July 2009
ISS yesterday
Yesterday in twilight, I shot this image of a fine pass of the International Space Station:
(click image to enlarge)
Monday, 13 July 2009
ISS and Progress chasing each other
This evening I finally was able to see the ISS and the recently decoupled Progress M-02 M (09-024A) cargoship chasing each other over the sky. The couple was some 20 degrees apart, with the Progress leading. A very neat sight.
The Progress was around +2.5 to +3, ISS attained about -3.5 and was distinctly orange. The photo below shows the couple while still low in the sky, ascending in the west.
I also observed USA 161 (01-044A) passing east some 10 minutes later.
The Progress was around +2.5 to +3, ISS attained about -3.5 and was distinctly orange. The photo below shows the couple while still low in the sky, ascending in the west.
I also observed USA 161 (01-044A) passing east some 10 minutes later.
(click image to enlarge)
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:
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!
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!
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.
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.
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)
Saturday, 21 March 2009
Very bright International Space Station (Updated)
This evening I observed a magnificent pass of the International Space Station (ISS), with the Shuttle docked to it.
At about 40 degrees altitude in the west, during its approach, it shortly became very bright. A conservative estimate by me placed it at at least magnitude -5; Leo Barhorst observing the same pass from Almere, some 30 km North of me, estimated magnitude -6. After that, it slightly fainted, remaining bright but not as bright as it had been in the west.
Update: telescopic images by Quintus Oostendorp on SpaceWeather.com show that the brightening was due to the solar panels reflecting sunlight.
This brief brightening was captured by my camera. The Hyades are visible to the left, the Pleiades to the right.
At about 40 degrees altitude in the west, during its approach, it shortly became very bright. A conservative estimate by me placed it at at least magnitude -5; Leo Barhorst observing the same pass from Almere, some 30 km North of me, estimated magnitude -6. After that, it slightly fainted, remaining bright but not as bright as it had been in the west.
Update: telescopic images by Quintus Oostendorp on SpaceWeather.com show that the brightening was due to the solar panels reflecting sunlight.
This brief brightening was captured by my camera. The Hyades are visible to the left, the Pleiades to the right.
(click image to enlarge)
More flashing Iridium 33 wreckage, ISS, USA 200 and other high objects
As I wrote in my previous post with the image of USA 129 flaring, yesterday evening I hauled a rich batch of objects.
It started in twilight with a nice pass of the International Space Station (ISS). The image below shows it rising through Orion:
Next I photographed passes of Lacrosse 3 (97-064A) and the NOSS 3-4 rocket (07-027B).
The wreckage of Iridium 33 (97-051C) was observed flashing again. Two photographs yielded five flashes, and like 3 days ago they fit a flash periodicity of 4.6 to 4.7 seconds. The timings were derived by measuring the flash positions astrometrically, and fitting the obtained positions to the most recent Iridium 33 tle. Here are the two images, with the flashes indicated:
I also targeted some HEO (High Earth Orbit) objects again, this time experimenting with different camera settings. USA 200 (08-010A) was captured again, this time somewhat better than 3 days ago:
I combined 4 of the images into an animated GIF, showing the movement of the sky and the satellite over a 1 minute period:
On the same image series I captured a piece of debris, USA 144 debris (99-028C), as a stray. In addition, I imaged another object in a Molniya orbit, USA 179 (04-034A) and the USA 198 rocket (07-060B) this evening.
It started in twilight with a nice pass of the International Space Station (ISS). The image below shows it rising through Orion:
(click image to enlarge)
Next I photographed passes of Lacrosse 3 (97-064A) and the NOSS 3-4 rocket (07-027B).
The wreckage of Iridium 33 (97-051C) was observed flashing again. Two photographs yielded five flashes, and like 3 days ago they fit a flash periodicity of 4.6 to 4.7 seconds. The timings were derived by measuring the flash positions astrometrically, and fitting the obtained positions to the most recent Iridium 33 tle. Here are the two images, with the flashes indicated:
(click images to enlarge)
I also targeted some HEO (High Earth Orbit) objects again, this time experimenting with different camera settings. USA 200 (08-010A) was captured again, this time somewhat better than 3 days ago:
(click image to enlarge)
I combined 4 of the images into an animated GIF, showing the movement of the sky and the satellite over a 1 minute period:
On the same image series I captured a piece of debris, USA 144 debris (99-028C), as a stray. In addition, I imaged another object in a Molniya orbit, USA 179 (04-034A) and the USA 198 rocket (07-060B) this evening.
Tuesday, 17 March 2009
Magnificent view of Shuttle and ISS just before docking!
I had a pass of the Space Shuttle Discovery STS-119 and the ISS this evening about one hour before they docked. This meant they were moving as a very close pair. The pass was around 19:10 UTC at 25 degrees altitude.
It was a beautiful sight, as the pair rose in the southwest and then majestically sailed past Sirius. Here's a picture:
The Shuttle is the object slightly fainter and lower in the sky. Movement is from right to left. Here's a second picture:
It was a beautiful sight, as the pair rose in the southwest and then majestically sailed past Sirius. Here's a picture:
(click image to enlarge)
The Shuttle is the object slightly fainter and lower in the sky. Movement is from right to left. Here's a second picture:
(click image to enlarge)
Friday, 13 March 2009
A close call for the ISS
Shortly after the collision of Iridium 33 and Kosmos 2251, the news agencies are buzzing with a close call of the International Space Station and a piece of space debris. Astro/Kosmonauts in the station shortly evacuated to their Soyuz re-entry capsule for safety reasons.
The piece of space debris in question was 93-032D (25090), a piece of a PAM-D rocket engine, part of the launch of the Navstar 32 GPS satellite on 13 May 1993. It is small, but even small can be lethal to the ISS. The nominal orbits for the ISS and the space debris piece have it pass as close as within 2.4 km of each other at 12 March, 16:39:41 UTC. The close encounter occurred over the southern Atlantic, near the southernwest coast of Africa.
The piece of space debris in question was 93-032D (25090), a piece of a PAM-D rocket engine, part of the launch of the Navstar 32 GPS satellite on 13 May 1993. It is small, but even small can be lethal to the ISS. The nominal orbits for the ISS and the space debris piece have it pass as close as within 2.4 km of each other at 12 March, 16:39:41 UTC. The close encounter occurred over the southern Atlantic, near the southernwest coast of Africa.
(click images to enlarge)
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