Launch News NROL-41 on Atlas V from Vandenberg AFB

[Star Voyager]

The first Atlas V rocket flying in the 501 configuration will launch from Vandenberg AFB, California on September 7 from SLC-3E. A launch time has not been given and will most likely not be until 24 hours before launch due to security reasons. More information is expected soon:

[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]Sept. 7[/SIZE][/FONT][FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1] Atlas 5 • NROL-41[/SIZE][/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-2]Launch window:[/SIZE][/FONT][FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-2] TBD[/SIZE][/FONT]
[SIZE=-2][FONT=Verdana, Arial, Helvetica, sans-serif]Launch site: SLC-3E, Vandenberg Air Force Base, Calif.[/FONT][/SIZE]
[SIZE=-2][FONT=Verdana, Arial, Helvetica, sans-serif]

[/FONT][/SIZE]
[SIZE=-2][FONT=Verdana, Arial, Helvetica, sans-serif]The United Launch Alliance Atlas 5 (AV-025) rocket will launch a classified spacecraft payload for the U.S. National Reconnaissance Office. The rocket will fly in the 501 vehicle configuration with a five-meter fairing, no solid rocket boosters and a single-engine Centaur upper stage. [/FONT][/SIZE]

http://ulalaunch.com/site/pages/Launch.shtml#/10/

 

[Star Voyager]

Launch will be on September 20:

Sept. 20 Atlas 5 • NROL-41
Launch window: TBD
Launch site: SLC-3E, Vandenberg Air Force Base, Calif.

The United Launch Alliance Atlas 5 (AV-025) rocket will launch a classified spacecraft payload for the U.S. National Reconnaissance Office. The rocket will fly in the 501 vehicle configuration with a five-meter fairing, no solid rocket boosters and a single-engine Centaur upper stage. Delayed from Sept. 7.

The ULA link above has also been updated.

 

[orb]

According to www.zarya.info's calendar page, launch window spans from 03:29 to 04:29 UTC on 21st Sept. / 11:29 p.m. on 20th - 12:29 a.m. on 21st EDT.

2010 Sep 21|03:29|NROL-41 Launch

{colsp=2} |Atlas V, VAFB LC-3E

{colsp=3}Opening of 60 minute launch window for a government or military reconnaissance satellite.

I couldn't find it confirmed though neither by ULA, nor by other space flight related sites on Internet.

Here's calendar event that will be eventually updated if launch window is different. You can request a reminder for this event just now, to not forget about it later.

 

[Star Voyager]

Everything is looking good for Monday's launch, which will occur at 8:29 p.m. PDT:

http://ulalaunch.com/site/pages/Launch.shtml#/10/

 

[orb]

Spaceflight Now:

• Atlas 5 rocket assembled for launch (PHOTO GALLERY)
• Mission Status Center

An Atlas 5 rocket carrying a classified cargo for the nation's spy satellite agency plans a primetime blastoff Monday evening from California's Vandenberg Air Force Base.

Liftoff is targeted for 8:29 p.m. local (11:29 p.m. EDT; 0329 GMT) from Space Launch Complex 3-East. The 19-story rocket should be visible across the region as a flame in the night sky, streaking southward to orbit.

...

The Launch Readiness Review was held Friday morning and gave approval to proceed with the mission, known as NROL-41, for the National Reconnaissance Office.

Weather forecasters are predicting a 70 percent chance of acceptable conditions for the evening launch opportunity. Gusty winds are the only concern.

The outlook includes some scattered low- and high-level clouds, clear visibility of 7 miles, north-northwesterly winds of 20-25 knots with gusts to 30 knots and a temperature of 52 to 55 degrees F.

 

[orb]

Launch of Atlas V 501 carrying NROL-41 is scheduled in 13 hours now.

You can watch the launch live via webcast. The live stream will be available 20 minutes prior to launch via this media player stream link.
The webcast for first launch attempt [eventtimer]2010-9-21 3:9?will start in|started;%c% %h% hours, %m% minutes[/eventtimer][eventtimer]2010-9-21 3:9?.| ago.;%c%[/eventtimer]

Here are instructions how you can watch it, in a case the above link doesn't open the player's window or embedded player on browser's page.

Updates of the launch can be also followed on twitter.

---------- Post added at 19:28 ---------- Previous post was at 16:28 ----------

There are 10 hours until the planed time of launch yet.

Spaceflight Now published a few photos of the rocket from yesterday:

• Atlas 5 rocket awaits countdown (A QUIET SUNDAY ON THE PAD - PHOTO GALLERY).

A quote from Mission Status Center:

Rollback of the mobile service tower from around the rocket is scheduled to start about five hours before launch.

Crews at the pad will make preparations to systems and equipment before the site is cleared of all personnel before fueling can start.

A planned hold begins when the count reaches T-minus 120 minutes. With five minutes remaining in the hold, the team will be polled to verify all is in readiness to start loading propellant into the rocket for launch.

Supercold liquid oxygen begins flowing into the Centaur upper stage, followed by the Atlas first stage. Liquid hydrogen fuel loading for Centaur will be completed a short time later.

A final hold is scheduled at the T-minus 4 minute mark. That will give the team a chance to finish any late work and assess the status of the rocket, payload, Range and weather before proceeding into the last moments of the countdown.

---------- Post added at 22:28 ---------- Previous post was at 19:28 ----------

Weather forecast for the launch (source):

In their latest forecast, meteorologists are predicting a 60 percent chance of favorable conditions for tonight's launch of the Atlas 5 rocket from Vandenberg Air Force Base, California.

Those odds have decreased slightly because of strong winds expected at the launch base behind the passage of a cold front.

The launch time outlook includes scattered-to-broken low clouds and a few high clouds, no widespread fog and 7 miles of visibility, sustained northwesterly winds between 22 and 28 knots and a temperature around 53 degrees F.

 

[Orbinaut Pete]

Florida Today's "The Flame Trench" Blog: "ULA set to launch Atlas V from West Coast".

 

[Star Voyager]

Weather forecast for the launch (source):

...22 and 28 knots...

That's pushing it. I think I read somewhere that the limit is 25 kts. (or somewhere in that region, but please correct me if I'm wrong). I'll be up to watch and provide commentary here. But here's a general countdown info page by NASA (although it's not a NASA launch):

http://www.nasa.gov/mission_pages/launch/atlas_V_count_101.html

 

[orb]

That's pushing it. I think I read somewhere that the limit is 25 kts. (or somewhere in that region, but please correct me if I'm wrong).

Yes, the upper limit for flight of Atlas V is 25 knots. That's why the weather is only 60% now. If I remember correctly some launch of Atlas V from CCAFS this year was scrubbed because of too strong wind.

 

[Star Voyager]

I think it was SDO (first launch attempt, Feb. 9 at 11:23 a.m.):

http://www.spaceflightnow.com/atlas/av021/status.html

 

[orb]

Atlas V has been launched at 9:03:30 p.m. PDT / 12:03:30 a.m. EDT / 04:03:30 UTC, after T-4 minutes hold was extended 4 times.

NASASpaceFlight: ULA Atlas V launches with classified NROL-41.

Spaceflight Now: Tower rolled back for Atlas 5 launch (MOBILE SERVICE GANTRY ROLLED BACK - PHOTO GALLERY).

---------- Post added at 10:29 ---------- Previous post was at 10:19 ----------

Video replay of the launch

 

[Star Voyager]

Sorry I wasn't able to provide commentary guys. But the holding 4 times because some idiot was at SLC-8 sounds riduculous :facepalm:! Anyway, my thanks to orb who kept us up to date and my congrats to the NRO team on a successful launch :tiphat:!

 

[Orbinaut Pete]

Spaceflight Now: "Images: Liftoff of the Atlas 5 rocket".