The odd bit

Once is an accident, twice is a coincidence, three times is an enemy action.

The odd bit - Once is an accident, twice is a coincidence, three times is an enemy action.

STS-121: Launch Time – Take 3

Yesterday’s crack in the external tank’s foam and the subsequent foam loss has been cleared by the Mission Management Team and Discovery has been given the green light for today’s launch countdown.

The weather is looking good with only a 20% chance of weather prohibiting a launch. If everything is “go” this will be the first shuttle launch on Independence Day. The launch should happen around 20:38 CET.

Update: Things continue to go well for the shuttle, but there’s one thing to watch. The sea breeze causes cross winds at the runway. The runway is used in case a return-to-launch-site abort is issued. Speed limits for crosswinds to guarantee a safe landing are set at 15 knots and the wind keeps flirting with the limit. An average speed will be calculated later on.

There was also an issue with a back-up circuit breaker. It controls the primary heaters on the segment joints of both SRBs. The “Red Team” was going to head down to the mobile launcher platform to replace the failed circuit breaker, but the launch team decided to fly in the current condition. There is no problem flying with just the main circuit breaker functioning.

We’re now at T-9 minutes and holding for another 31 minutes.

Update 2: The wind issues are gone according to Mission Control in Houston. All team members have been polled and we are counting again!

There may be an unscheduled hold at T-31 seconds to allow the LOX (liquid oxygen) inlet temperatures to drop to normal levels. The temperatures are slightly higher than the past few days and they need to be right in order to start the engines.

We’re now at T-5 minutes and counting.

Update 3: And what a smooth ride it was! Not a single problem during liftoff and ascent. It has completed main engine cut-off (MECO) and external tank separation is complete. Two astronauts will now take footage of the external tank and downlink it later in the flight for analysis.

I did not notice the T-31 seconds hold so I assume it did not happen. Discovery is in space!

Category: Space
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