SpaceX Falcon 9 CRS/SpX-10 Dragon - Feb. 19, 2017 - Discussion

[Steven Pietrobon]

Watching the hosted webcast, they gave some more details about the TVC issue. The primary TVC was working fine, but the backup secondary TVC was not working properly. A similar thing happened with the Apollo 16 CSM while orbiting the Moon. With Apollo 16, they decided to continue since the secondary system could still be used. As we all know now, SpaceX decided to scrub the launch at T-13 seconds and perform some replacements of the TVC system. That was the right call in my opinion since if the primary system failed during flight, the secondary system could probably not be relied upon to do its job.

[Bob Shaw]

Looks like there *was* a camera on the LUT - still, but the brief video shot during the countdown suggests there may be video to come as well.

[ugordan]

Looks like there *was* a camera on the LUT - still, but the brief video shot during the countdown suggests there may be video to come as well.

There is a video camera on the tower, it was shown on the hosted webcast at T-57sec and at T+5sec, but it's located at a lower level than the photo above. I'm guessing the latter is one of Ben Cooper's remote cameras.

[old_sellsword]

Do we have an exact launch time ?
Ed Kyle :14:38
http://www.spacelaunchreport.com/

14:38:59
http://www.orbita.zenite.nu/

14:39:00
http://forum.nasaspaceflight.com/index.php?topic=8184.1240

16:38
http://prehled-druzic.blogspot.de/2017/02/2017-009.html#yA

It was originally 14:38:59 going into Sunday, but they updated it to exactly 14:39:00 a few hours before launch.

[Jim]

Is it just me or did the rainbirds activate awfully late?
Visible on this clip: https://streamable.com/v9zjg

Here's a Youtube link to the same moment; you can slow it down to 1/4-time to get a better look at the water plume.

It looks to me like they never quite reached the platform, rather were missing it.  But that is based on this one camera angle and zero experience.

The rainbirds are for sound suppression.   The peak sound is usually occurs after the vehicle is few hundred above the pad.  And it is the sound reflected of the pad structure that is the issue.  This when the rainbirds need to be at their full volume and not at T-0.  That how it was with the shuttle.

[DanseMacabre]

Is it just me or did the rainbirds activate awfully late?
Visible on this clip: https://streamable.com/v9zjg

Here's a Youtube link to the same moment; you can slow it down to 1/4-time to get a better look at the water plume.

It looks to me like they never quite reached the platform, rather were missing it.  But that is based on this one camera angle and zero experience.

The rainbirds are for sound suppression.   The peak sound is usually occurs after the vehicle is few hundred above the pad.  And it is the sound reflected of the pad structure that is the issue.  This when the rainbirds need to be at their full volume and not at T-0.  That how it was with the shuttle.

You can see the rainbirds at full throttle at this point of the webcast:

When the shot goes a bit wider, you can see the rainbirds really ramp up after the rocket clears them.

[Alter Sachse]

Do we have an exact launch time ?
Ed Kyle :14:38
http://www.spacelaunchreport.com/

14:38:59
http://www.orbita.zenite.nu/

14:39:00
http://forum.nasaspaceflight.com/index.php?topic=8184.1240

16:38
http://prehled-druzic.blogspot.de/2017/02/2017-009.html#yA

It was originally 14:38:59 going into Sunday, but they updated it to exactly 14:39:00 a few hours before launch.

Thank you !
*some are now corrected

[edkyle99]

SECO seemed to happen about 20 seconds late, any explanation?

Some, if not all of that, is webcast latency.  There was, for example, a 10 second delay between ground and on-board views of the first stage landing on the SpaceX split-screen.  I would guess that the second stage view has 10 seconds or more of delay.  The on-screen mission elapsed time clock does not have the same delay.

 - Ed Kyle

[Johnnyhinbos]

This debris really looks like birds as they "flap" past the camera... Of course, its much too high up in the atmosphere to be actual birds flying there, but could it be that there were birds (or bats?) which somehow hiked a ride on the first stage (weren't there stories about bats and birds clinging to the main tank of several space shuttle flights?), died outside the atmosphere and were only shaken loose once the first stage started to re-enter the denser parts of the atmosphere?

Cork

[rsdavis9]

This debris really looks like birds as they "flap" past the camera... Of course, its much too high up in the atmosphere to be actual birds flying there, but could it be that there were birds (or bats?) which somehow hiked a ride on the first stage (weren't there stories about bats and birds clinging to the main tank of several space shuttle flights?), died outside the atmosphere and were only shaken loose once the first stage started to re-enter the denser parts of the atmosphere?

Cork

I should know this... What sections of the exterior is the cork exactly?

[envy887]

This debris really looks like birds as they "flap" past the camera... Of course, its much too high up in the atmosphere to be actual birds flying there, but could it be that there were birds (or bats?) which somehow hiked a ride on the first stage (weren't there stories about bats and birds clinging to the main tank of several space shuttle flights?), died outside the atmosphere and were only shaken loose once the first stage started to re-enter the denser parts of the atmosphere?

Cork

I should know this... What sections of the exterior is the cork exactly?

Most of the interstage and part of the octaweb are insulated with cork.

[toruonu]

Congrats to Buzz Aldrin, who made it to another launch. (Had a conversation with him!  He praised a mutual colleague, touted some of his own inventions, and told a chiding and affectionate story about Neil Armstrong.  It was another amazing few minutes.)

Can we please have those stories retold here?

[Jarnis]

There was a delay on the onboard views for sure, but it doesn't fully explain the difference vs. press kit times. I assume the press kit was wrong, unless some other information comes up.

[ugordan]

Going back to CRS-8 and CRS-9 webcasts to compare, curiously, SECO was significantly *later* on CRS-8 with the ASDS landing than on CRS-9, a RTLS flight. One might have expected the opposite to be the case, given lower delta V requirements for ASDS, even despite CRS-8 apparently carrying 900 kg more cargo.

CRS-10 falls in the middle in terms of SECO timing.

[clegg78]

Could there be a weight difference in the loading of Dragon on the different flights.  From what I understand even small changes in weight up there have pretty noticeable changes in burn times, etc...

[mvpel]

I wonder what caused the plume that appeared at the upper stage umbilical area on the TEL as it was leaning back? Seems like those propellant lines should be purged by that point. Maybe exhaust glare reflecting from a LOX cloud?

[russianhalo117]

I wonder what caused the plume that appeared at the upper stage umbilical area on the TEL as it was leaning back? Seems like those propellant lines should be purged by that point. Maybe exhaust glare reflecting from a LOX cloud?

residual prop igniting or TEL LOX are the usual culprits

[Thorny]

I wonder what caused the plume that appeared at the upper stage umbilical area on the TEL as it was leaning back? Seems like those propellant lines should be purged by that point. Maybe exhaust glare reflecting from a LOX cloud?

I think that's just a reflection of the engine plume off vented LOX.

[jcm]

Space-Track has cataloged the ejected solar panel covers as objects B and C, named "DRAGON CRS-10 DEB" but
object A (42053) is still named  "OBJECT A" by them instead of "DRAGON CRS-10". Possibly they are not sure yet  if they are tracking CRS-10 or the second stage  (which shouldn't be in orbit any more)?

In related news, no orbit maneuvers by object A yet. I don't know the rendezvous schedule for CRS-10, some
CRS missions raised orbit in a few hours, others took over a day.

[rsdavis9]

I watched the launch videos and I cant see any difference in time between clamp release and tel throwback. ( at least as far as youtube single step). So I would say the tel is NOT released even 10ms before the falcon is released.