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

[old_sellsword]

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.

Clamp release and the 1.5º lean back is at T-2 minutes. The TE does throw back at T-0, but at that point it's already detached and slightly away from the rocket.

[Comga]

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?

He was gently mocking Gene Cernan and contrasting him with Neil Armstrong.  Buzz said that Neil was so conservative about not giving endorsements that he didn't wear his watch on his moonwalk, lest he be seen as giving the company a promotion. "What commander doesn't wear his watch" on a mission? he asked.  Buzz said that he wore his, and sent it to the Smithsonian, but it disappeared. 

He credited the late Dr. Chauncey Uphoff of GSFC, JPL, and later Ball Aerospace, with inventing the "backflip rendezvous" which I think may have been used in the Lunar Module rendezvous with the Command Service Module on the moon landings.  Chauncey was the author of GSFC's orbital dynamics code for interplanetary trajectories, which he took to JPL.  (Buzz is "Dr. Rendezvous" after all, so this backflip stuff was really important to him.)

He made sure I knew (which of course I did) that he invented neutral buoyancy training, and that it was some of hie "out of the box thinking".  He complained that they named the NBL after "some Navy guy" and that they only name things after people who are deceased.  A mild annoyance that he had to sort of choose between having it named after him and staying alive.  I expressed all of our preferences that  he remain ineligible for naming rights.    

The conversation was the capstone to an incredible day.

[envy887]

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.

Clamp release and the 1.5º lean back is at T-2 minutes. The TE does throw back at T-0, but at that point it's already detached and slightly away from the rocket.

I think rsdavis9 is referring to the hold-down clamps, not the TEL upper stage clamps.

[edkyle99]

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...

CRS-8:   3,136 kg cargo
CRS-9:   2,222 kg cargo
CRS-10:  2,490 kg cargo

 - Ed Kyle

[Folgers25]

I noticed in the first stage landing drone video there is a new building at LZ-1. IIRC it was not there last April during Family Day. Is it for more storage? 

[old_sellsword]

I noticed in the first stage landing drone video there is a new building at LZ-1. IIRC it was not there last April during Family Day. Is it for more storage?

It's been there since CRS-9.

[Folgers25]

I noticed in the first stage landing drone video there is a new building at LZ-1. IIRC it was not there last April during Family Day. Is it for more storage?

It's been there since CRS-9.

Guess I don't member seeing it then. Any idea what it is for?

[smh]

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.

The hosted webcast shows the time on the camera inside the solar array fairing. At it shows 14:51:11.

Assuming the clock on the camera is correct (not that I do), that would put the launch time at 14:39:11

[cwr]

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.

The hosted webcast shows the time on the camera inside the solar array fairing. At T+12:00 it shows 14:51:11.

Assuming the clock on the camera is correct (not that I do), that would put the launch time at 14:39:11

After the scrub on the 18th a half dozen reports were about evenly split on 9:38:58am EST and 9:38:59 as the targeted T=0 time for the 19th.

About 9 hours before the launch on the 19th the SpaceX home web page said that the targeted launch time was 9:38:58am EST.

Of course, the targeted launch time is determined closer to launch based on updated ISS TLEs.
About 1 hour before launch on the 19th the 45th Space Wing tweeted that launch would be 09:38:59.5 EST  and hence they would call it 09:39am EST.

I find it very difficult to believe that T=0 [and hence liftoff] did not occur between 09:38:59am EST and 09:39:00am EST on February 19th.

I usually wait for the millisecond time to be released for the definitive launch time.

Carl

[Saabstory88]

Through rolling the dice on reddit, I discovered a thread about stange "UFO" sightings over Iran from yesterday. Based on the available track in the webcast, and the fact that this was reported at about 10:15 EST, that these were videos of post SECO-1 maneuvers. I wont trouble this audience with linked directly to this strange thread, but the videos linked may be of interest. They appear to catch either dragon, or the F9 second stage performing a maneuver.

Sorry of this is the wrong thread for this, but I think additional video of post launch activities is pretty cool, especially because a thruster (or engine) impulse is visible in some of these videos.

[Flying Beaver]

Through rolling the dice on reddit, I discovered a thread about stange "UFO" sightings over Iran from yesterday. Based on the available track in the webcast, and the fact that this was reported at about 10:15 EST, that these were videos of post SECO-1 maneuvers. I wont trouble this audience with linked directly to this strange thread, but the videos linked may be of interest. They appear to catch either dragon, or the F9 second stage performing a maneuver.

Sorry of this is the wrong thread for this, but I think additional video of post launch activities is pretty cool, especially because a thruster (or engine) impulse is visible in some of these videos.

Very very cool. Must be S2 de-orbit burn.

Awesome find!

[OneSpeed]

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

Also, for both Iridium-1 and CRS-10 the first stage has not been running at full thrust. They were both at about 92% of FT for most of their burns.

[old_sellsword]

I noticed in the first stage landing drone video there is a new building at LZ-1. IIRC it was not there last April during Family Day. Is it for more storage?

It's been there since CRS-9.

Guess I don't member seeing it then. Any idea what it is for?

It's labeled as "Hangar" in the recent environmental reports on LZ-1 expansion. And with some rough Google Earth estimation, it appears to be just the right size for a first stage.

[Folgers25]

They are going to have plenty of space to store stuff. Between this LZ-1 hangar and the old Spacehab facility at the port.

[bdub217]

A quick question for the collective wisdom here.

The thick cloud layer rule for launch.  I don't remember a daytime launch going through the soupy clouds (at least from the vantage point of the camera angles) as we saw on Sunday.  How thick is too thick?  I assumed the rule was in part to allow for tracking cameras to follow the launch. 

[DaveS]

Maximum cloud thickness is 500 ft at 5000 ft.

[meberbs]

The hosted webcast shows the time on the camera inside the solar array fairing. At T+12:00 it shows 14:51:11.

Assuming the clock on the camera is correct (not that I do), that would put the launch time at 14:39:11

After the scrub on the 18th a half dozen reports were about evenly split on 9:38:58am EST and 9:38:59 as the targeted T=0 time for the 19th.

About 9 hours before the launch on the 19th the SpaceX home web page said that the targeted launch time was 9:38:58am EST.

Of course, the targeted launch time is determined closer to launch based on updated ISS TLEs.
About 1 hour before launch on the 19th the 45th Space Wing tweeted that launch would be 09:38:59.5 EST  and hence they would call it 09:39am EST.

I find it very difficult to believe that T=0 [and hence liftoff] did not occur between 09:38:59am EST and 09:39:00am EST on February 19th.

I usually wait for the millisecond time to be released for the definitive launch time.

Carl

The technical webcast showed the rocket cam and a ground camera for the landing. Using this you can estimate the lag from the rocket camera as about 10 seconds. This would roughly apply to the upper stage as well, so after accounting for lag, that clock on the camera is probably correct with the video, but the mission clock overlay does not account for video lag.

[Folgers25]

A quick question for the collective wisdom here.

The thick cloud layer rule for launch.  I don't remember a daytime launch going through the soupy clouds (at least from the vantage point of the camera angles) as we saw on Sunday.  How thick is too thick?  I assumed the rule was in part to allow for tracking cameras to follow the launch.

The cloud thickness rule is 4,500 feet extending into freezing conditions I believe. You can look at the first stage landing video and see that those clouds were not that thick. It broke out around 1,000 agl

[mme]

A quick question for the collective wisdom here.

The thick cloud layer rule for launch.  I don't remember a daytime launch going through the soupy clouds (at least from the vantage point of the camera angles) as we saw on Sunday.  How thick is too thick?  I assumed the rule was in part to allow for tracking cameras to follow the launch.

IIRC, Jessica Jensen said in the post-launch presser that the primary reason for the thick cloud rule was the risk of a lightening strike triggered by the static electricity buildup on the rocket.

As other's noted, the clouds were low but not very thick.

[mwfair]

It was so nice of SpaceX to paint the bingo squares on LZ1.  I think I won!
https://www.youtube.com/watch?v=yNmF7rhymGU?t=198