LIVE: Atlas V AV-011/WGS

[Jim]

Payload goes to the pad on Sept 27

[PDJennings]

I thought the Atlas didn't roll out to the pad until the day before launch.

[Antares]

OK, payload goes to the VIF and is erected on September 27.

[eeergo]

Some background about this satellite:

http://www.globalsecurity.org/space/systems/wgs.htm
http://www.defenseindustrydaily.com/americas-wideband-gapfiller-satellite-program-02733/

Basically a military communications satellite, in the middle point between old MILSTARs and the new generation AEHF, to increase bandwidth for US troops as a temporary solution until AEHF comes online (as its own old name suggests, Wideband Gapfiller Satellite, because it's been changed since its conception to Wideband Global SATCOM (rolls eyes) )

Apparently, it's coming 3 years late, as this first satellite should have been launched way earlier. It's also, according to the DID link, 33% over budget.

Boeing photo (http://www.boeing.com/news/releases/2002/photorelease/q1/01546_450.jpg) depicting the satellite.

[Jim]

It is a DSCS replacement vs MILSTAR

[Skyrocket]

The comparison to Milstar and AEHF is not so fitting, as WGS offers wideband communications that are "unprotected" against jamming and nuclear effects.

On the other hand, each WGS will have ten times the communications capacity of a DSCS-III satellite

WGS will replace the DSCS-III and the GBS-payload on the UFO satellites.

[Skyrocket]

On the launch vehicle side, i guess, the WGS requires the stretched 4m fairing of the Atlas-V-421 (although some sources are giving the launch vehicle as a Atlas-V-521).

Does anyone have info on the shroud?

[Rocket Guy]

It is a 421. I do not believe it is a stretched fairing.

[GW_Simulations]

Jim - 2/10/2007  5:15 PM

It is a DSCS replacement vs MILSTAR

Milstar will be replaced by AEHF, I think.

The first AEHF launch is scheduled for April next year at the earliest.

[tnphysics]

On what rocket?

[Skyrocket]

On an Atlas-5(531)

[GW_Simulations]

Launch is scheduled for 10 October, the window runs from 00:22 - 01:33 GMT.

Webcast will start at 23:58 GMT on the 9th.
http://www.ulalaunch.com/index_webcast.html

[eeergo]

Skyrocket - 2/10/2007 6:29 PM On the launch vehicle side, i guess, the WGS requires the stretched 4m fairing of the Atlas-V-421 (although some sources are giving the launch vehicle as a Atlas-V-521). Does anyone have info on the shroud?

http://www.spaceflightnow.com/atlas/av011/071007preview.html

In this article, there's a photo of WGS' Atlas. I think that's a 421, isn't it?

Also, I found this strange: This will be flight No. 11 for the Atlas 5 rocket fleet, and everyone involved hopes and expects to see a successful outcome when the massive satellite is deployed into a supersynchronous orbit a half-hour after liftoff...

I suppose they are trying to say supersyncronous transfer orbit, but why supersyncronous anyway? Isn't SSO considered a 'graveyard' orbit?

[Skyrocket]

Certainly it is a supersyncronous transfer orbit. This kind of transfer orbit saves satellite fuel, as it costs less Delta-v to raise the perigee from a higher apogee and then lower the apogee to GSO. It is often used when a launch vehicle has a higher performance than needed for GTO.

COncerning the image, yes it is a 421 and it uses a long 4m fairing.

[Rocket Guy]

No, the photo in the article is of Inmarsat 4F1's 431 in early 2005. That had an extended fairing.

The rocket does not roll to the pad until this morning.