Skip to comments.Atlas 5 Live Launch Thread 11:46 a.m. PDT/2:46 p.m. EDT
Posted on 05/03/2012 8:57:10 AM PDT by Jack Hydrazine
Rocket: Atlas 5 Payload: AEHF 2 Date: May 3, 2012 Window: 2:46 to 4:46 p.m. EDT Site: SLC-41, Cape Canaveral, Florida Feed: SES 2, Transp. 21, C-band, 87° West
Watch live coverage here: http://www.spaceflightnow.com/atlas/av031/status.html
or here: http://www.ulalaunch.com/site/pages/Webcast.shtml
Welcome to liftoff day for the United Launch Alliance Atlas 5 rocket carrying the Air Force's next durable and secure communications satellite in the Advanced Extremely High Frequency series.
The countdown clocks are starting to tick right now, beginning a seven-hour sequence of work that will prepare the rocket, payload and ground systems for today's blastoff at 2:46 p.m. EDT (1846 GMT).
Soon the launch team will begin powering up the rocket to commence standard pre-flight tests. Over the subsequent few hours, final preps for the Centaur's liquid oxygen and liquid hydrogen systems will be performed, along with a test of the rocket's guidance system and the first stage propulsion and hydraulic preps, internal battery checks and testing of the C-band system used to track the rocket as it flies downrange, plus a test of the S-band telemetry relay system. The Complex 41 site will be cleared of all personnel at 11:51 a.m.
A planned half-hour hold begins at 12:06 p.m. when the count reaches T-minus 120 minutes. Near the end of the hold, the team will be polled at 12:33 p.m. to verify all is in readiness to start fueling the rocket for launch.
Supercold liquid oxygen begins flowing into the Centaur upper stage around 12:53 p.m., followed by the first stage filling around 1:06 p.m. 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 starting at 2:32 p.m. That 10-minute pause will give everyone 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.
Today's launch window extends from 2:46 to 4:46 p.m. EDT (1846-2046 GMT).
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Why they couldn’t just put it in orbit with a Gou’auld cargo ship is beyond me...
(Un-ashamed Stargate SG-1 reference there.)
Mmmmmm... Goa’uld TV.
I was reading the timeline for the launch and saw something that surprised me. The RL-150 engine that powers the Atlas V first stage...is of Russian design.
Whoa. Who knew?
And to think...the Atlas 1 design was an ICBM....to be used AGAINST Russia (or, more pecisely, the Soviet Union). Now we know one of the construction materials used on the Atlas V: irony.
The rocket engines used in the SeaLaunch rockets are Russian, too!
Pretty soon they’ll be making our fighter jets for us.
HOLD EXTENDED purge line issue
First...the launch is on hold while they look at an overheating issue with the Centaur interstage motors. Launch is likely not going to be on-time, but they have a 2-hour launch window, so it still may happen of they get the issue taken care of in time.
Secondly, a correction. The engine on the Atlas V 1st stage is the RD-180, NOT RL-150. Dunno where I got that one.
looking at sending a team out to the pad, will that fit in the window?
They are possibly discussing going out to the pad to see if a manual valve is in the proper configuration.
How’d you like to go up next to a fully-fueled rocket to open her up and see what’s wrong? I assume they pay good money for that.
Yes, they seem to think that may fit into the window...provided the launch team makes a fairly quick decision.
From the Twitter feed....
Dispatching the crew to the launch pad, however, would present a lengthy hold here at T-minus 4 minutes, but the potential to still launch today. The Atlas team has until 4:46 p.m. EDT to get the rocket airborne this afternoon.
The weather is fine and no other technical issues have been noted throughout the countdown.
The anomaly team is putting together a plan to send a special team into the pad to check the configuration of a manual valve within the mobile launch platform upon which the Atlas rocket sits. That valve could be mis-configured, and resetting it would allow the rocket to launch today.
now a range interference issue crops up.
Maybe you were thinking of the RL-10 engine.
LD calls for scrub!!!
24-hour scrub. Nothing today.
“Today’s planned liftoff of the United Launch Alliance Atlas 5 rocket carrying the Air Force’s next durable and secure communications satellite in the Advanced Extremely High Frequency series was postponed by a purge problem feeding to the Centaur interstage adapter. Launch from Cape Canaveral has been rescheduled for Friday at 2:42 p.m. EDT (1842 GMT).”
I’ll post the live thread tomorrow morning.