Starship Asterisk*

Here's a chart of the height of the [color=red]ISS[/color] for the last 12 months:

http://heavens-above.com/IssHeight.aspx?lat=0&lng=0&loc=Unspecified&alt=0&tz=CET

"Clearly visible are the re-boosts which suddenly increase the height, and the gradual decay in between. The ... gradual decrease is caused by atmospheric drag. As can be seen from the plot, the rate of descent is not constant and this variation is caused by changes in the density of the tenuous outer atmosphere due mainly to solar activity."

I guess big versus little re-boosts are different vehicles, perhaps with different amounts of fuel left, doing the pushing.

Left unboosted, it appears to me that the ISS falls on the order of 100 meters per day.

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And I just wanted to make sure all you [color=red]ISS[/color] fans have my favorite satellite-spotting link:

http://heavens-above.com/

Don't forget the hyphen.

[color=red]Current position of ISS[/color] is displayed on front page.

Put in your location and get times and local sky coordinates for ...

[b]Satellites[/b]

[color=red]10 day predictions for: ISS[/color] | Genesis-1 / 2 | Envisat | HST

Daily predictions for all satellites brighter than magnitude:
(brightest) 3.5 | 4.0 | 4.5 (dimmest)

Iridium Flares
next 24 hrs | next 7 days | previous 48 hrs
Daytime flares for 7 days - see satellites in broad daylight!

Spacecraft escaping the Solar System - where are they now?

Radio amateur satellites - 24 hour predictions (all passes)

Select a satellite from the database

[color=red]Height of the ISS - how does it vary with time[/color]

(Space Shuttle, too, when it's up)

[b]Astronomy[/b]

Comets currently (2008 July 21) brighter than mag. 12
C/2007 W1 Boattini | 19P Borrelly | C/2008 A1 McNaught | 6P d'Arrest
C/2006 OF2 Broughton | C/2008 J2 Beshore | C/2007 G1 LINEAR | C/2006 Q1 McNaught
C/2007 N3 Lulin

Minor planets currently (2008 July 21) brighter than mag. 10
4 Vesta | 1 Ceres | 11 Parthenope | 2 Pallas

They do frequent reboosts. The Jules Verne ATV has done at least 2 that I know of, probably more.

They will raise the orbit to a higher elevation (I think another 100 km) after the last major component is delivered in 2010. This will actually make it slightly harder to get to, but the payoff in reduced drag and therefore less frequent reboosts will make it worthwhile.

No change in the orbit needs to be made for added mass, but it does change the amount of fuel needed for a given amount of reboost. However, at the same time, it also gains more momentum to resist drag.

[url]http://apod.nasa.gov/apod/ap080623.html[/url]

Anyone know if ISS's orbit was successfully maneuvered? There was [url=http://www.physorg.com/news64676091.html]news[/url] about moving ISS higher to improve docking relations with future arrivals but I couldn't locate any further news.

I expect ISS's orbit also has to be adjusted for mass acquisition, right?

BTW - [url=http://www.spaceref.com/news/viewsr.html?pid=25421]here is a link one of my favorite ISS based pics[/url] Sorry APOD, but when I found this, it became my current desktop wallpaper.

Ahhh...I get it.

Yes, as BMAONE23 noted, one of the main solar arrays was relocated.

It was originally launched before the truss was added to provide power beyond what the small arrays on the Russian modules could generate, so the US Unity and Destiny modules would have plenty of juice. Then the truss was flown up in several segments, the P3 and S3 solar arrays were added (your September 06 picture shows the P3 array in place), and the P6 array was relocated.

I guess I can't answer for the nearly identical captions, but I was a little disappointed that they didn't choose a picture that showed Kibo clearly, since it was the main feature of this latest shuttle mission. Here's two pictures from the same angles, one taken after STS-123 and one taken after STS-124. The main differences are STS-124 added the Kibo Experimental Module to the port side of the station, and moved the Kibo Pressurized Logistics module, delivered on STS-123, from it's temporary berth on top of Harmony to its final position on top of the Kibo EM.

[url=http://spaceflight1.nasa.gov/gallery/images/shuttle/sts-123/html/s123e010043.html][img]http://spaceflight1.nasa.gov/gallery/images/shuttle/sts-123/med/s123e010043.jpg[/img][/url]

[url=http://spaceflight1.nasa.gov/gallery/images/shuttle/sts-124/html/s124e009982.html][img]http://spaceflight1.nasa.gov/gallery/images/shuttle/sts-124/med/s124e009982.jpg[/img][/url]

Also, at the bottom of the second image, the European Automated Transfer Vehicle can be recognized by it's x-shaped solar panels.

Sorry John.
The question wasn't clicking for some reason. This should explain it
STS-120 This image
[url]http://en.wikipedia.org/wiki/Image:ISS_after_STS-120_in_November_2007.jpg[/url] On Nov 5 2007 shows the relocation of the P6 truss assembly from its 2006 location to its current position
"P6 relocation-
During STS-120, the P6 solar arrays were moved from the Z1 truss on top of Unity, to their final position at the port end of the truss."

No.
Have you looked at the two pics?

The two halves of the ISS in earlier are at right angle to ecah othre and the solar panels are in different planes.
This time the halves either side of the middle section are along the saame line, and the panels are in the same plane. Can't do that by rotating them.
See pic. [url=http://img65.imageshack.us/my.php?image=isssept06june08kv7.jpg][img]http://img65.imageshack.us/img65/9541/isssept06june08kv7.th.jpg[/img][/url]

But this is not what I asked. I asked that an old caption be updated, with news, not just an old one copied.

John

Anyone got any idea what the dark area is about a quarter of the way up the right hand edge of the ISS pic might be?

John,
If you are refering to the orientation of the Solar Panels compared to the rest of the station, I believe they are rotated throughout each orbit for maximum efficiency WRT the solar position.

APOD: 2008 June 23 - The International Space Station Expands Again
http://antwrp.gsfc.nasa.gov/apod/ap080623.html

[quote="JohnD"]For instance, why has the orientation of the main limbs changed from being at right angles to being in line?

John[/quote]

I'm not sure I understand your question, but I think it's a simple matter of not understanding the orientation. Look at this rendering of the station as it will appear when finished to try to get an idea of the setup:

http://en.wikipedia.org/wiki/Image:ISSFinalConfigEnd2006.jpg

Today's APOD is a picture from what would be the upper left corner of this image, looking straight down the line formed by the pressurized modules, but with the solar arrays rotated nearly perpendicular.

Unfortunately, the APOD at that angle hides the new Kibo module behind the truss. There's a couple pictures here that show it pretty well. It sticks off perpendicular to the left of the other pressurized modules near the top the first picture.

http://spaceflight1.nasa.gov/gallery/images/shuttle/sts-124/ndxpage49.html

I believe that's the coastline of Western Sahara in the background.

Another wonderful pic of the developing ISS. And they say we are doing nothing in space!

But interesting to compare, as we are invited to do, previous pictures of the developing ISS. The legends are as identical as could be! Please may we have more contemporary explanation? For instance, why has the orientation of the main limbs changed from being at right angles to being in line?

John