~OBSERVING ~
the International Space Station
With particular emphasis on The Atlantic Canada Sky
NOTE: When is ISS visible in Atlantic Canada?
Dec 4 to 7 visible in morning sky;
Dec 8 to 15 no visible passes,
Dec 16 visible passes begin in the evening sky.
Click here for next current ISS Visible Pass Schedule
Neat photo of ISS making a transit of the Moon (via spaceweather's Nov 8-9/03 eclipse gallery p.4)
Links (NASA sites)
International Space Station Current Onboard Status 
 
Return To Flight (Discovery Landed safely Aug 9th, 2005)
 
Current NASA Missions-Status Reports
 
International Space Station Photos (index to NASA photo history of ISS construction; click the photo for a 77K version from the NASA site)
 
STS-107 Memorial Page
 
Future Missions to the Space Station
 
General Satellite Observing
Links (this site)
Observing Guidelines (observing pointers from my own experiences)  
Current ISS Visible Pass Schedule (Atlantic Canada)
How to get a pass schedule specific to your location
 
Mir Space Station Deorbited (an old friend laid to rest)
Shuttle Launch Observations (It is not necessary to go all the way to Florida to view a shuttle launch. Observations of shuttle launches from Horton Bluff have been possible for both night and day launchings)
 
 
 

NASA photo
SOME OBSERVING CONSIDERATIONS
The International Space Station (ISS), travelling at about 7 km/s, makes a complete orbit of the Earth about every 1.53 hours, making a fraction more than 15 orbits per day. Its orbit path is inclined about 51 degrees to Earth's equator which brings it well above the horizon of mid latitude ground locations. Each orbital track of ISS shifts westward as Earth rotates eastward. Of the 5 or 6 passes per day that ISS will make through the sky of a particular ground location, a number of variations in conditions determine whether or not someone at that ground location will see a the pass of the spacecraft.
WHAT ARE THE OBSERVING CONDITIONS?
Most important: 
1) clear sky! To help check on expectations for sky weather conditions, the following websites provide a current satellite photo showing cloud cover: General selections http://weather.ec.gc.ca/satellite/index_e.html ; I suggest the Visible scaled 1:2 for daytime and 10:70 scaled 1:2 for after dark.
 
or http://wwwghcc.msfc.nasa.gov/GOES/goes8conus.html offers a good grey scale satellite photo, by clicking a location on the master GOES 8 satellite photo.
or observe the satellite graphics shown by local TV stations such as ATV.
 
2) observer on the ground must be in Earth shadow while ISS, at its 365+ km altitude, is in sunlight. When the sky is reasonably clear, the visible passes are narrowed to two possible viewing windows:
* the hour or two after sunset
* the hour or two before sunrise.
To be visible, the space station must pass through the observer's sky during one of these two periods
The duration of the window is longer in summer and shorter in winter. In the long twilight of summer, near the summer solstice, I have seen 3 passes in one night; the sun lingers for a much longer period just below the northern horizon for the observer, while the space station at its higher altitude remains in continuous sunlight

3) the ISS orbital track must reach 10 to15 degrees or more above the observer's horizon. Atmospheric dust and haze usually extinguishes any light being reflected from the craft when it is lower. Each visible pass takes a different track and time because Earth is continually rotating beneath the orbiting spacecraft. When one observes a number of passes, predictable patterns become apparent, for example, during a cycle of passes one notices that visible passes, two days apart, have a track and time that are similar. Some passes clear the horizon just enough to be seen for a few seconds, others will pass near overhead and be in view for 5 or more minutes. Click here or on the small orbit diagram for an enlargment with comments.

Visible passes go in cycles that alternate from a period of two or three weeks when visible in the evening, eventually followed by two or three weeks of visibility in the morning sky. Usually there is a period of a week or two between the evening and morning cycles when it is not visible during any time. The rotation of Earth with respect to the orbiting spacecraft brings the visible windows in and out of sync with the observer.
WHAT A VISIBLE PASS OF THE SPACE STATION LOOKS LIKE
The space station looks like a bright star moving across the sky. Its light does not blink on and off like a passing aircraft.
 
Its visible pass may last up to 5 minutes or more ( between 2 and 3 minutes is more typical), this all depends upon the maximum altitude of its track and where, at the time of the pass, the edge of Earth's shadow is at the altitude of the space station.
 
The brightness of ISS varies as it passes but it is generally as bright or brighter than the brightest stars. It can rival the brightness of Jupiter (magnitude -2 or brighter). If it is an evening pass, it generally gets brightest shortly after it begins to move away from the observer to the east; a morning pass is the reverse, it tends to be brightest in the west as it comes toward the observer, shortly after coming into view. Once it goes east of the observer it is between observer and Sun, thus ISS has more of its shadowed side toward the observer.
 
For most passes, the bright, reflected light of the space station can be seen and followed easily with the unaided eye. Once it enters Earth's shadow, the spacecraft no longer reflects sunlight, therefore, it abruptly disappears from view.

Because of its altitude being nearly 400 km above Earth, the Space Station can be seen at approximately the same time and in the same part of sky, over a large area on the ground. For example, within approximately the same minute of time, observers all across Nova Scotia will observe the ISS pass.

Except for the weather component, conditions governing the visible passes of ISS are quite predictable using mathematics and a set of orbital elements (numbers describing the orbit with time). Fortunately, in this computer age, one can quite easily get around the mathematics by using a satellite tracking program which can be found at a few websites online. One of the most useful website which generates a schedule of visible passes is given in the next section.
Click here for current ISS Visible Pass Schedule
HOW TO GET A SPACE STATION (ISS) SCHEDULE for YOUR LOCATION
There are various websites on the internet where one can obtain predictions for when the International Space Station (ISS) is visible. My pick <Heavens Above > provides a schedule of visible passes calculated specifically for one's own location on Earth (the schedule I post at the end of this page is for my location. I have also placed links for a few other selected places which may be near you). Diagrams and explanations can be obtained for several other satellites. The main home page of the site also provides access to other predictions of astronomical interest.
 
If a person has access to the internet, the only requirement upon first reaching the website is that one must select a location so that calculations can be made based on the given location. That is conveniently handled by clicking on linked text.

So, if you want to know when the space station will be visible for you, and you know where you live or can provide the name of a larger community near where you live (in case your specific location is not in the database), then go to this website: http://www.heavens-above.com/main.asp and establish your location, then get a predicted ISS visible pass schedule. Once your location is established, bookmarking will retain the location for future returns to the site. Now click on the linked text for ISS and up will come a schedule covering up to 10 days, all worked out for your location. Graphics at the site show the current location of the Space Station.

At the end of this page, I post an updated, prediction for ISS passes from Avonport, a reasonable guide for other Maritime locations.

* * If your web browser is a reasonably recent edition, this site [http://liftoff.msfc.nasa.gov/realtime/JTrack/Spacecraft.html] gives an excellent view of the track and location of major satellites, especially ISS and the shuttle when it is in orbit. The information it gives out can be made relative to your location. Be patient when you first access the tracker as it loads in satellite information and sets up the tracker. It will continue to track the satellite even after you go off line.

International Space Station Status links
1) http://spaceflight.nasa.gov/station/index.html
2)http://spaceflight.nasa.gov/station/assembly/elements/uslab/
3) Staying Cool on the ISS 
4) This link is an excellent graphic (J-Track) showing, on a world map, the location of the space station and other satellites. It updates at 1 minute intervals.

 
INTERPRETING THE SCHEDULE
As an example, I've included the current schedule below. This one is worked out specifically for Avonport, however, the schedule will be an approximate guide for many places in the Maritimes.
 
The most important part in this mess of numbers is the maximum altitude, time and direction (Az).
 
As you begin to observe, stand facing the maximum altitude direction (Az), then glance toward the Start direction (generally westward) where ISS will first come into view. It will reach its highest and generally brightest, in the maximum altitude direction, then move away to the End direction (generally eastward). Begin watching 3 or more minutes before the maximum altitude time. Find these references in the headings of the chart.
 
45 degrees is half way up between the horizon, 0 degrees, and overhead, 90 degrees. A quick handy reference is the closed fist, extended vertically at arm's length; it cuts an arc of about 10 degrees against the sky. Mag is about brightness; as the number becomes negatively larger, the brighter it appears, the larger the posotive number, the dimmer it will appear. Mag 0 is the approximate brightness of the brightest stars. Big Dipper stars are approximately Mag 2, Jupiter is Mag -2. Remember that ISS brightness varies as it crosses the sky, as more or less of its lighted parts are exposed to the observer.

Note: occasionally in evening pass schedules, when end time is the same or nearly the same as maximum altitude time, then the maximum visible altitude was reached as the craft was entering Earth's shadow. Person's on board the spacecraft will be experiencing sunset at that time. On the other hand, for morning passes, if the maximum altitude time is the same or close to the start time, this is the moment the craft, at its altitude, is leaving Earth's shadow and becomes visible to ground observers. Person's on board the spacecraft would be experiencing sunrise.
Click here for current ISS Visible Pass Schedule
( Home )
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TRAGIC Re-entry as STS-107 was in the last 16 minutes of its 16 day mission,
Space Shuttle Columbia, for reasons unknown at this time, broke up on re-entry
from Earth orbit early morning, February 1. Its crew of 7 did not survive.
SPACE SHUTTLE Columbia, mission STS-107  Visible Passes 
Search Period Start: 12:00 Wednesday, 29 January, 2003
 Search Period End:    09:53 Saturday, 01 February, 2003 (planned re-entry)
 Observer's Location:  Avonport ( 45.1000¡N, 64.2500¡W)
 Local Time:           Atlantic Standard Time (GMT - 4:00)
 Orbit:                265 x 277 km, 39.0¡ (Epoch 29 Jan)

                   Starts           Max. Altitude              Ends
   Date  Mag   Time    Alt.  Az.    Time    Alt.  Az.    Time    Alt.  Az.

   This pass of Columbia was observed in a clear morning sky at Horton Bluff.
 30 Jan  0.5  06:59:27  10    SW   07:01:14  19    S    07:03:01  10    SE


 Two orbits after this pass was the re-entry orbit that went tragically wrong.
 Because of overcast, this pass was not observed from Horton Bluff.
                Starts           Max. Altitude              Ends
   Date  Mag   Time    Alt.  Az.    Time    Alt.  Az.    Time    Alt.  Az.
 01 Feb 0.7  06:55:26  10    SW   06:56:54  15    SSW  06:58:22  10    SSE
Quoted from the website developed and maintained by Chris Peat, Heavens-Above, http://129.247.177.10/main.asp