Author Topic: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion  (Read 85898 times)

Offline LouScheffer

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #140 on: 04/03/2018 02:56 pm »
I have not heard any calls about the re-entry burn start/complete in the webcast. Has there been re-entry burn?

I’m not sure. Maybe this new landing profile involved reentering the atmosphere WITHOUT conducting an entry burn, and using a 3-engine landing burn at the last second.
As far as I can recall, there has never been a case where the stage was destroyed during entry, or survived but was damaged enough it could not restart/land.  So SpaceX has not yet found the shortest entry burn that could be used.  This would have been (and maybe still is) a great set of experiments for the old block 3/4 boosters they are not trying to re-use.  Try shorter and shorter entry burns, and for each one make sure the landing burn still works, the grid fins were not destroyed, and so on.  They would not want to try this with a block 5, since finding the edge of the envelope means losing a booster.

Offline stcks

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #141 on: 04/03/2018 02:58 pm »
I seem to recall hearing on the webcast in the flight audio loop a call out saying that Stage 1 AFTS had been safed. That was considerably after the time frame where the first stage would have "landed". Could this be some proof that Stage 1 survived its landing regime and splashdown and SpaceX has to deal with another floater? ::)

Yes the callout was at T+7:44, over a minute later than a typical GTO mission. Does it prove anything? Nope. What it suggests is that the first stage flew to a higher apogee (and in fact, this is confirmed if you compare the telemetry) and thus the stage spent more time falling back.

Online gongora

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #142 on: 04/03/2018 03:20 pm »
Could this be some proof that Stage 1 survived its landing regime

In the post launch press conference Jessica Jensen said they didn't do a landing test, there was no soft landing in the ocean.

Offline whitelancer64

Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #143 on: 04/03/2018 03:23 pm »
I'm surprised that nobody has mentioned the apparent debris that was visible on the video after solar array deploy.


The first object flew past quickly from left to right at T+15:03 to 15:05.

The second one moved much more slowly and tumbled.  It was visible from T+15:10 to 15:24 when it disappeared in front of the solar panel.  It seemed to me to have lodged in the wiring harness.

It was most likely just flecks of ice. The thrusters are doing small firings at this point, and the primary byproduct of hydrazine combustion is water. Some small bits of ice build up on the thrusters and occasionally come loose.
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Offline Demidrol

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #144 on: 04/03/2018 03:51 pm »
That was considerably after the time frame where the first stage would have "landed".
Presumably this is due to more late MECO.

Offline deruch

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #145 on: 04/03/2018 05:17 pm »
Did you watch the CRS-14 Pre-launch Press Conference?  NASA had 3 people there.  The Air Force had one person there. And SpaceX had one person.  Almost all of the questions from the press and social media sites were for SpaceX.  So, no it's not boring.  SpaceX is where the action is.
According to Chris G, there were only 10 members of the press at the prelaunch conference. I am not saying your claim isn't valid, but the evidence supporting it is not the greatest.

Easter weekend (it's a 3-day, right?) launch with the prelaunch conference on Easter Sunday itself.  Not sure one should take too much from the attendance at this one.
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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #146 on: 04/03/2018 05:29 pm »
In the post launch press conference Jessica Jensen said they didn't do a landing test, there was no soft landing in the ocean.

I missed the post news conference. Thanks for this info I didn't have!

Offline sewebster

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #147 on: 04/04/2018 01:57 am »
I have not heard any calls about the re-entry burn start/complete in the webcast. Has there been re-entry burn?

I’m not sure. Maybe this new landing profile involved reentering the atmosphere WITHOUT conducting an entry burn, and using a 3-engine landing burn at the last second.
As far as I can recall, there has never been a case where the stage was destroyed during entry, or survived but was damaged enough it could not restart/land.  So SpaceX has not yet found the shortest entry burn that could be used.  This would have been (and maybe still is) a great set of experiments for the old block 3/4 boosters they are not trying to re-use.  Try shorter and shorter entry burns, and for each one make sure the landing burn still works, the grid fins were not destroyed, and so on.  They would not want to try this with a block 5, since finding the edge of the envelope means losing a booster.

Maybe, but they might have already landed something that was more damaged by entry than they liked... e.g. for re-use, or even reliable landing.

Offline Olaf

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #148 on: 04/04/2018 07:26 am »
The 5 additional sample carriers mentioned in that NASA explanation are being transported in the pressurized section of the Dragon, in CTBs.  They will be transferred out through the JEM A/L and robotically installed on the Flight Facility after that is on the ELC.
This JAXA schedule http://iss.jaxa.jp/kiboexp/plan/status/images/schedule_180404.pdf suggest, that on April,13 will be "Prepare for outside boarding" (google translation) of the MISSE Transfer Tray, so we can expect the installation of the five MISSE Sample Carriers in the week starting with April, 16.

Offline sanman

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #149 on: 04/04/2018 10:20 am »
They would not want to try this with a block 5, since finding the edge of the envelope means losing a booster.

Also, even the shortest "successful" landing could incur thermal and mechanical loads that significantly shorten the life of the booster. An optimal landing is also one that preserves the longevity of the vehicle.

Offline LouScheffer

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #150 on: 04/04/2018 01:45 pm »
They would not want to try this with a block 5, since finding the edge of the envelope means losing a booster.

Also, even the shortest "successful" landing could incur thermal and mechanical loads that significantly shorten the life of the booster. An optimal landing is also one that preserves the longevity of the vehicle.
However you define "successful", they do not want to get too close to this boundary with a Block 5, either to see it fail or reduce its life.  Hence these experiments are best done with boosters that they do not intend to re-use.  That's why now is an excellent time to try this, since they do not intend to keep or reuse the older block 3/4 boosters anyway.

Offline su27k

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #151 on: 04/05/2018 12:50 pm »
More photos from Artemyev

Why do I always end up feeling like the Russians have better photographers?  Or maybe they just have cleaner windows, IDK?

I wonder if there're agreements between NASA and SpaceX to limit the resolution of the photos taken, because SpaceX doesn't want to show too much details of the Dragon hardware?

Offline OnWithTheShow

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #152 on: 04/05/2018 01:59 pm »
They would not want to try this with a block 5, since finding the edge of the envelope means losing a booster.

Also, even the shortest "successful" landing could incur thermal and mechanical loads that significantly shorten the life of the booster. An optimal landing is also one that preserves the longevity of the vehicle.

You also wont know about the damage unless you recover the booster to inspect it.

Online zubenelgenubi

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #153 on: 04/05/2018 06:31 pm »
More photos from Artemyev

Why do I always end up feeling like the Russians have better photographers?  Or maybe they just have cleaner windows, IDK?

While we learn by taking selfies they're learning the rule of thirds & composition.

I do wonder, if Roskosmos partnered with an IMAX documentary/"mission" production company, what kind of companion large-format feature that the cosmonauts could shoot, perhaps as a companion work to A Beautiful Planet 3D.

A thought.

(Not knocking the photographic/cinematographic abilities of the NASA/ESA/JAXA/CSA astronaut corps--they've done a great job over the decades--the popular Shuttle/Station/Hubble IMAX titles of past and present are a testament of their skills and dedication.)
« Last Edit: 04/05/2018 06:36 pm by zubenelgenubi »
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Offline jeng_eo

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #154 on: 04/06/2018 08:50 am »
I noticed in the ISS Daily Summary Report that they used "Forced Based Capture, a software enhancement to the Latching End Effector (LEE)" to catch the dragon but I could not find further information about this. Does anyone know more about this new procedure?

Offline eeergo

Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #155 on: 04/06/2018 09:06 am »
I noticed in the ISS Daily Summary Report that they used "Forced Based Capture, a software enhancement to the Latching End Effector (LEE)" to catch the dragon but I could not find further information about this. Does anyone know more about this new procedure?

The snare cable on the new LEE-A (the old POA-LEE) was found to be damaged during a few trial runs shortly after swapping it during the latest US EVAs. From 03/21'2 ISS Status Report:

Quote
During a survey of LEE A on February 28th, one of the snare cables was found to be damaged. CSA analysis predicts load limit exceedances for certain SpaceX-14 capture scenarios. Ground teams are coordinating to determine the forward path for SpacX-14 capture operations.

They performed some tests in the last few days before SpX-14's arrival, grappling the SPDM and other PDGFs on Station to assess loads, and apparently they developed a new procedure to make loads acceptable. A new LEE is coming up on SpX-15, it remains to be seen whether they accept the current LEE-A as-is or prefer to swap it out directly with the new unit.

Offline BradyKenniston

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #156 on: 04/07/2018 04:45 pm »
Here is a link to a 245 megapixel stitched photo of B1039.2 I shot on the morning before launch. Scroll in to see all the little details!

https://easyzoom.com/imageaccess/807980b0ca5f40b7b38281628e74f4fc
« Last Edit: 04/07/2018 05:03 pm by BradyKenniston »

Offline Olaf

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Re: SpaceX Falcon 9 : CRS-14 : April 2, 2018 - Discussion
« Reply #157 on: 04/16/2018 03:32 pm »
The 5 additional sample carriers mentioned in that NASA explanation are being transported in the pressurized section of the Dragon, in CTBs.  They will be transferred out through the JEM A/L and robotically installed on the Flight Facility after that is on the ELC.
As we have learned today, there are only four additional sample carriers. The fifth must be the one, which was already on earth installed on MISSE-FF.
https://blogs.nasa.gov/stationreport/2018/04/
Quote
The crew then reconfigured the JEM ORU Transfer Interface (JOTI) and installed the MISSE-FF Transfer Tray (MTT) on the slide table and loaded it with 4 MISSE Sample Carriers.

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