SCRUB: SpaceX - Falcon I (Mk.II) NET March 19

[BarryKirk]

Ignition occurs at T-03 seconds.  It take about 3 seconds for the engine to build up to full thrust.

[meiza]

Ah, now I sound so stupid..

[Comga]

"Ignition occurs at T-03 seconds. It take about 3 seconds for the engine to build up to full thrust."

Its not just the thrust building up.  Musk has said that there are a lot of automated tests being conducted and checked in that interval.

[jabe]

Anyone know the static fire test time?  iWeb site just says 19th california time... last time i believe it was about 4:00 pm est

[braddock]

Kimbal Musk is back online blogging at: http://kwajrockets.blogspot.com/

Kwaj is UTC + 12H; the static fire is actually scheduled for Saturday Kwajalein time.  They usually try to start operations first thing in the morning. Sunrise is 7:09am Kwaj time.  That would be around 7pm UTC, 11am US Pacific time, or 2pm Eastern.  If I got all my math right.

Don't know when we might hear the results of the test though.  SpaceX still does not have a replacement public relations executive.  If I recall, we didn't always get to hear the results of a static fire the same day in the past.

[jabe]

braddock - 19/1/2007  6:49 AM

Kimbal Musk is back online blogging at: http://kwajrockets.blogspot.com/

I forgot about that Blog site..may not be 100% accurate or on time for updates but it is better than nothing

[HIP2BSQRE]

Falcon 1 DemoFlight 2 Launch Update: January 19, 2007

During our final check-outs prior to static fire, we uncovered an anomaly with the thrust vector control (TVC) pitch actuator on the second stage that will result in launch being pushed to February.  Since this is not used during the static fire, we have decided to push forward with that test in order to acquire valuable data on engine ignition, pad acoustics, and the overall system response.  The static fire is now planned to occur between Saturday and Tuesday (California time).  This test will proceed very slowly and then only burns for about four seconds, so will not be webcast to avoid boring people silly.  We will post a video afterwards.

Upon completion of the static fire, we will take the rocket back into the hangar to thoroughly investigate the TVC issue.  With the range available to us only until January 23 (Kwaj needs to reconfigure for an incoming Minuteman mission), this means launch is now planned for mid-February.  As I’ve mentioned previously, don’t hold your breath for this launch.  Given the large number of robustness improvements and the fact that our vehicle/pad health verification system has increased from about 30 checks to almost 1000, shifts in the launch date are to be expected.  Overall, the SpaceX team is quite happy with the smooth progress so far.

That's interesting - the preflight checklist has exploded from 30 to 1000 checks.  I guess launching a rocket isn't all that easy after all.

[William Graham]

bhankiii - 19/1/2007  8:17 PM

That's interesting - the preflight checklist has exploded from 30 to 1000 checks.

Oh, well, at least the rocket itself hasn't exploded.

[BarryKirk]

Yes, but most of those checklist items are automated.

Every time I hear a post from Elon it builds confidance.  They are again checking out an anomly.  This sounds like an issue that may and probably is harmless, but it needs to be understood before they launch.

The fact that they are finding this stuff out is a good sign.

[BarryKirk]

I know it is impossible to static test an upper stage when the vehicle is stacked up.

We've seen test fires of the Merlin engine.

Has anyone heard or seen of a test fire of a Kestrel engine?

Can a Kestrel engine operate at sea level?

[hyper_snyper]

http://en.wikipedia.org/wiki/SpaceX_Kestrel

There's a picture of a Kestrel test on that web page.  The same picture is on SpaceX's website but without any indication if it's a Merlin or Kestrel.

[meiza]

They test upper stage engines with truncated nozzles on sea level afaik.

[aero313]

There are actually two ways to test altitude engines on the ground.  The first is a truncated nozzle as noted previously.  This is a common test method but does not provide a full, flight-like test.  TVC inertias and response are different, thermal conditions are different, etc, etc.  The better (and infinitely more expensive) way to do it is in an altitude test chamber such as the Air Force has at AEDC.   I don't think even Elon has enough money.

The problem is that long-time propulsion vendors have exerience with both testing at AEDC and with actual flights that allow them to run truncated nozzle tests and extrapolate the data to flight conditions.  This is usually coupled with a rigorous component qual test program, and the two together provide confidence that the engine will work at altitude.  As an example, based on experience gathered from years of ICBM development tests at AEDC (and later in flight testing), the Pegasus motors were only fired at sea level with truncated nozzles.  Despite this, there were still issues found in flight.

[BarryKirk]

Thanks for the info.

So that leaves the question about what the anomoly is.  Of course, Elon himself may not understand the cause of the anomoy himself.  That is probably an object of intense research right now at Space X.

[edkyle99]

BarryKirk - 20/1/2007  9:44 AM

Thanks for the info.

So that leaves the question about what the anomoly is.  Of course, Elon himself may not understand the cause of the anomoy himself.  That is probably an object of intense research right now at Space X.

The SpaceX update made the problem fairly clear - "an anomaly with the thrust vector control (TVC) pitch actuator on the second stage".   There would have been a point in the countdown when the engine would have been swiveled briefly to test it.  It must not have passed the test.  The problem is said to be associated with one of the two TVC actuators that move the engine.  According to the SpaceX web page:  "thrust vector control is provided by electro-mechanical actuators on the engine dome for pitch and yaw."  

 - Ed Kyle

[bbliss]

edkyle99 - 20/1/2007  7:42 PM

The SpaceX update made the problem fairly clear - "an anomaly with the thrust vector control (TVC) pitch actuator on the second stage".   There would have been a point in the countdown when the engine would have been swiveled briefly to test it.  It must not have passed the test.  The problem is said to be associated with one of the two TVC actuators that move the engine.  According to the SpaceX web page:  "thrust vector control is provided by electro-mechanical actuators on the engine dome for pitch and yaw."  

Fortunately, like many (most, virtually all?) parts of the Falcon I, the TVC actuator is built in-house according to SpaceX's PR.  This means, of course, that they can troubleshoot the issue, make repairs or adjustments, and get back on their way fairly rapidly.  This is, of course, as opposed to a vendor-supplied component, which would have to be flown back to the states for analysis, months of re-work, etc.  The vertically integrated manufacturing concept sure has its beauty at times.

I really hope they get good second stage separation and ignition data from the February launch attempt.

[Comga]

Space.com is listing the flight as NET February 18  (27 days 8 hours 10 minutes 36 seconds according to their countdown clock!)

http://www.space.com/missionlaunches/launches/next_launch.html

Perhaps they know something about the availability of the range.  There have been no new postings on the SpaceX website since last week.

[meiza]

I wonder if it's corrosion related

[BarryKirk]

Are we past the time of the last day in the window for a static test to occur?

Has anybody heard anything about the results yet?