SpaceX F9 : CRS SpX-17 : May 4, 2019 - DISCUSSION

[intelati]

He’s more knowledgable than many though.

That's quite the quote tree...

How about we just wait for the updates as they come in? I find the ASDS landing permit encouraging though (for the CRS program at least).

[jcm]

The Space Test Program-Houston 6 (STP-H6) payload is inside the Space Station Processing Facility high bay at NASA’s Kennedy Space Center in Florida on March 19, 2019. It is being prepared for its move to the SpaceX facility where it will be will be stowed in the trunk of the Dragon spacecraft for delivery to the International Space Station on SpaceX’s 17th Commercial Resupply Services mission (CRS-17) for NASA.

STP-H6 is an x-ray communication investigation that will be used to perform a space-based demonstration of a new technology for generating beams of modulated x-rays. This technology may be useful for providing efficient communication to deep space probes, or communicating with hypersonic vehicles where plasma sheaths prevent traditional radio communications.
 
Photo credit: NASA/Ben Smegelsky

https://www.flickr.com/photos/nasakennedy/albums/72157690594188053

This doesn't seem to be quite correct re STP-H6 (replace "is an.." with "includes among other experiments...")

 The STP-H6-XCOM x-ray communications experiment is definitely the most interesting one on STP-H6, but there are reportedly 5 others, including possibly:
  iMESA electrostatic analyser for ionospheric studies, USAF Academy
  SSIVP supercomputing for image and video processing, with dual Earth imaging cameras, from U Pittsburgh
  Plasma impedance probe, NRL
  ACES-RED-1 US Army SMDC package with student-built experiments for future Army cubesat technology
   including a GoPro and a Raspberry Pi
  and one other unknown to me.

[zubenelgenubi]

That's quite the quote tree...

I think 7 nested quotes is the upper limit allowed in this version of SMF?

I think I've tried and failed 8 and 9 nested quotes.

[intelati]

That's quite the quote tree...

I think 7 nested quotes is the upper limit allowed in this version of SMF?

I think I've tried and failed 8 and 9 nested quotes.

Interesting.

I was just commenting on the horrid visuals to see that big block of blue, old text.

And yeah. Just tried that comment and "Error: The message body was left empty"

[Comga]

https://twitter.com/ken_kremer/status/1122909070275555329

#SpaceX #Falcon9 has been lowered, rolled back away from #pad40 to hangar where techs now attaching the #CargoDragon for @NASA #CRS17 resupply launch to #ISS May 1, 358 AM ET & #OCISLY droneship landing 8 min later just offshore of @jettypark

Is that one minute earlier (3:58) than previously posted (3:59)?

T-36 hours!

[ZachS09]

Well, it's disappointing to hear about the SpX-17 mission being delayed by two more days.

The reason why is because I was planning on filming this launch from Embry-Riddle in Daytona Beach, hoping to see the light show created by the boostback burn.

And I fly back to my home in South Carolina on the morning of the 2nd.

[Thorny]

Do we know how much more time SpaceX needs to finish debris recovery/cleanup from LZ-1? Would another day or two delay bring CRS-17 back to being an LZ-1 instead of ASDS landing?

[ChrisGebhardt]

It would have to be a lengthy delay at this point since the FCC permit was amended. A couple of days delay this close to launch won't change the ASDS landing plan for this mission.

[Comga]

So far so good. Thursday is key of course.

Updated the article:
https://www.nasaspaceflight.com/2019/04/electrical-issue-station-dragon-crs-17/

A Friday launch would occur around 3:12 AM EDT.
Will NASA wait for the ISS report before doing the late load?
How late on Thursday can they make the decision and still make the launch?
Didn't Musk say SpaceX wanted to be able to roll out and launch in a few hours?
This could be a test if they're at that point.

[ChrisGebhardt]

So far so good. Thursday is key of course.

Updated the article:
https://www.nasaspaceflight.com/2019/04/electrical-issue-station-dragon-crs-17/

A Friday launch would occur around 3:12 AM EDT.
Will NASA wait for the ISS report before doing the late load?
How late on Thursday can they make the decision and still make the launch?
Didn't Musk say SpaceX wanted to be able to roll out and launch in a few hours?
This could be a test if they're at that point.

Late load will occur Thursday morning.

They will progress through all steps toward a launch on Friday, 3 May until told otherwise by NASA.

Yes, he did.  But that's not possible for Dragon cargo flights that have to late load cargo roughly 24hrs ahead of launch for ISS missions.

[Joffan]

Late load will occur Thursday morning.

I'm not sure if you're speaking from definite knowledge of CRS-17 schedule or if that's an estimated convenient point for "less than 24 hours before launch", but CRS-15 for example had late load about 12 hours before launch https://forum.nasaspaceflight.com/index.php?topic=45853.msg1834008#msg1834008 so it's possible to load later if the ISS status is likely to get clearer through the course of Thursday.

[Bananas_on_Mars]

Direct quote from the NET:

This is the Launch Director on the countdown NET. Called a hold for an issue with our droneship. Unable to maintain power to allow us to proceed with launch on time, and we simply ran out of time. At this point we're proceeding with propellant offload. Once we complete that and TEA/TEB sweeps, we'll prepare to lower the vehicle. And we'll address a helium leak on the second stage QD interface. And we'll set up for a 24 hour recycle.

I think that‘s the long awaited scrub due to recovery related systems.
No more expending boosters if the droneship isn‘t ready.

[meekGee]

Direct quote from the NET:

This is the Launch Director on the countdown NET. Called a hold for an issue with our droneship. Unable to maintain power to allow us to proceed with launch on time, and we simply ran out of time. At this point we're proceeding with propellant offload. Once we complete that and TEA/TEB sweeps, we'll prepare to lower the vehicle. And we'll address a helium leak on the second stage QD interface. And we'll set up for a 24 hour recycle.

I think that‘s the long awaited scrub due to recovery related systems.
No more expending boosters if the droneship isn‘t ready.

On a NASA ISS mission

[meekGee]

Direct quote from the NET:

This is the Launch Director on the countdown NET. Called a hold for an issue with our droneship. Unable to maintain power to allow us to proceed with launch on time, and we simply ran out of time. At this point we're proceeding with propellant offload. Once we complete that and TEA/TEB sweeps, we'll prepare to lower the vehicle. And we'll address a helium leak on the second stage QD interface. And we'll set up for a 24 hour recycle.

I think that‘s the long awaited scrub due to recovery related systems.
No more expending boosters if the droneship isn‘t ready.

On a NASA ISS mission no less

What's the world coming to?

[codav]

I think that‘s the long awaited scrub due to recovery related systems.
No more expending boosters if the droneship isn‘t ready.

On a NASA ISS mission no less

What's the world coming to?

I see one problem here that they probably can't easily reconfigure the booster's flight plan that late in the countdown to an expendable trajectory, so the booster might crash into the droneship (into the equipment on board, or the railings) if the position is a bit off or some communication equipment required to lead the booster to the ASDS doesn't work.

[fraser]

I see one problem here that they probably can't easily reconfigure the booster's flight plan that late in the countdown to an expendable trajectory, so the booster might crash into the droneship (into the equipment on board, or the railings) if the position is a bit off or some communication equipment required to lead the booster to the ASDS doesn't work.

Is there any communication to lead the booster to the ASDS?  I thought they just both aimed for the same GPS coordinates?

[TrevorMonty]

Launch on Saturday, 4 May, will be at 02:48:58 EDT (0648:58 UTC). 

Checking on when berthing will be with new launch date.

Proceeded by Electron at 6:00 UTC. Two launches only a few minutes apart. High probability at least one will launch so worth getting up for if on EDT.

[crandles57]

I see one problem here that they probably can't easily reconfigure the booster's flight plan that late in the countdown to an expendable trajectory, so the booster might crash into the droneship (into the equipment on board, or the railings) if the position is a bit off or some communication equipment required to lead the booster to the ASDS doesn't work.

Even if they could change booster flight plan, wouldn't they have a problem with hazard notifications?

[Herb Schaltegger]

I see one problem here that they probably can't easily reconfigure the booster's flight plan that late in the countdown to an expendable trajectory, so the booster might crash into the droneship (into the equipment on board, or the railings) if the position is a bit off or some communication equipment required to lead the booster to the ASDS doesn't work.

Is there any communication to lead the booster to the ASDS?  I thought they just both aimed for the same GPS coordinates?

There is no equipment, capability or requirement to “lead the booster to the ASDS.” The booster aims for a defined point in 3D space, supplemented in the last kilometer or so by radar altimeter data (IIRC). Other than that, there is no external data required or used for landing.

[cscott]

It's been hinted at above, but I think the "near to shore" position of the ASDS had a role here: even if they'd be okay with the risk of hitting the drone ship and crashing into the sea at the normal recovery location, there could be complicating factors doing so close to land. Much greater risk of debris washing up on beaches, for one. Also bureaucratic issues such as being bound by the preexisting hazard notices, etc.