SpaceX Dragon CRS-3 (ISS mission thread)


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SCRUBBED!!

From SpaceX:

CRS-3 Update

Today?s launch has been scrubbed due to a Helium leak on Falcon 9?s first stage. A fix will be implemented by the next launch opportunity on Friday April 18, though weather on that date isn?t ideal. Check back here for updates.

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Next launch window: April 18 at 15:25 Local (EDT)

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Beittil

Aw shite, i cant watch this friday :(

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IsItPluggedIn

How many of the Falcon 9 first launch attempts have been scrubbed because of issues with the rockets?

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A few, but scrubs are a fact of life in the launch business. Everyone has them.

Shuttles fuel level sensors became known to ground crews as "Launch Preventers." Another much delayed NASA launch went 10 years before all its bugs were squashed.

SpaceX's problems tend to be marginal outsourced small valves, which are easy to replace and for the vehicle health system to pick up.

Previously the cause has been the manufacturer changing the part with insufficient notification of the changes, which is why Dragon's thrusters got twitchy during an early ISS flight.

They've been bringing a lot of the valves back in-house because of this.

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Addendum:

This was a Helium (He) gas leak, and He poses a problem.

An atom of He is extremely tiny, even smaller than molecular Hydrogen, so it's going to work its way out through even the tiniest gaps in a seal. This was one of those times.

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Beittil

Don't they use the helium on those legs?

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FloatingFatMan

Addendum:

This was a Helium (He) gas leak, and He poses a problem.

An atom of He is extremely tiny, even smaller than molecular Hydrogen, so it's going to work its way out through even the tiniest gaps in a seal. This was one of those times.

 

Better to err on the side of caution IMO.  The last time a leaky seal was ignored during a launch (by NASA), it cost the lives of 7 astronauts.

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If not the 18th, the next ISS launch window is the 22nd.

April 15, 2014 - 9:20 AM EDT

If NASA and SpaceX officials decide to attempt to launch SpaceX-3 to the International Space Station on Friday, April 18, there is a 40 percent chance of favorable weather. The U.S. Air Force 45th Weather Squadron issued its L-3 forecast, which predicts a chance of showers and thunderstorms that could result in violating the Thick Cloud, Lightning and Flight Through Precipitation rules.

Monday's launch attempt was scrubbed because of a helium leak in the first stage of the Falcon 9 rocket. The next possible launch opportunity would be April 18 at 3:25 p.m. EDT, pending resolution of the issue and a decision by NASA space station and SpaceX managers.

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SpaceX:

NASA and SpaceX have confirmed Friday, April 18 for the next launch attempt for the Falcon 9 rocket to send the Dragon spacecraft on the company's third commercial resupply mission and fourth visit to the space station. Launch is targeted for 3:25 p.m. ET. The launch will be webcast live at www.spacex.com/webcast beginning at 2:45 p.m. ET.

A launch on Friday results in a rendezvous with the space station on Sunday, April 20 and a grapple at 7:14 a.m ET.

During Monday?s launch attempt, preflight checks detected that a helium valve in the stage separation pneumatic system was not holding the right pressure. This meant that the stage separation pistons would be reliant on a backup check valve.

No issue was detected with the backup valve and a flight would likely have been successful, but SpaceX policy is not to launch with any known anomalies. We have brought the vehicle back to horizontal and are replacing the faulty valve, as well as inspecting the whole system for anything that may have contributed to the valve not working as designed.

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The weather may not cooperate for the 18th (Friday) due to high level winds being out of the safety range. A front stalled, causing the probability of good weather to be only 30-40%.

Normally another scrub would result in a 4 day reset to the 22nd (Tuesday) due to orbital phasing, but at the prelaunch conference SpaceX and NASA came up with an alternative plan;

IF they change from a 2nd day of flight rendezvous with ISS to a 3rd day arrival they could launch on the 19th (Saturday). This way they can get that urgent late-loaded part for the MDM repair on station ASAP.

Result: if they can't fly Friday the plan is to fly Saturday. That instant window would be 15:02 Local DST.

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Rollout, vertical and power on. Propellant loading is next up.

USAF 45th Space Wing Meteorology is reporting a 60% chance of weather violation. Concerns are,

Range criteria

Surface electrical field rule

Lightning rule

Cumulative cloud rule

Attached anvil cloud rule

Distributed weather rule

SpaceX criteria

First stage landing <6 foot waves

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NASA ISS Program Manager Mike Suffredini said in this mornings meeting about the MDM repair spacewalk that the F9 launch options are now April 18, 19, 22, and possibly the 25th.

The really need to get this bird up there.

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Propellant load started at 1147 Local EDT (1547 GMT)

Musk noted that because of the triple-redundant avionics, you could put a bullet into one of the avionics boxes and keep flying.

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Props are loaded and LOX is in topping off mode. A squall line moved through and now only the cumulus cloud rule is currently being violated.

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SALSN

Where do you guys stream from?

When I stream from spacex.com or directly from livestream.com directly, then I get 5 seconds of stream, and then it's just buffing.

A link to a stable restream would be greatly appreciated :-)

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SALSN

If anyone has similar problems, nasa has their own stream, but then you don't get the SpaceX speakers.

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xendrome

I stream from my eyes, as I can walk outside and see it launch.

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ImUtrecht

I had similar problems, i watched the nasa stream but it had a delay of around 30 seconds.

Any news on the recovery of the first stage ?

Hope it was a succes

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@b0yle 25s

.l@SpaceflightNow quotes @SpaceX team member as saying #Falcon first-stage reignited during descent and video was being sent back.

And there was a sequence on Livestream showing the retro-fire from the 1st stage cam.

Dragon separated, opened her solar panels and appears to be on the way.

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DocM

Catalog #39680. Space-Track data shows a 313x332km x 51.6? orbit

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