SpaceX Falcon 9 / Dragon 2 : SpX-DM2 : May 27, 2020 : DISCUSSION

[FutureSpaceTourist]

https://twitter.com/dutchspace/status/1264808558438342657

Out of curiosity (ok I was bored before work...) comparing DM1 vs DM2 timeline it is interesting to see that S/C SEP is a full minute later on the DM2 timeline #DM2

Also SECO is 12s earlier on DM-2

[FutureSpaceTourist]

twitter.com/therealbuzz/status/1264645237760237575

This brings back great memories! Keep it up @SpaceX and @NASA

https://twitter.com/elonmusk/status/1264757137839845376

Thanks Buzz!

[sferrin]

Just what we'd want in the early part of the 21st century.

Well, no.

I'm not knocking the Dragon, but sci-fi from the 80s is laughing at us for only being able to achieve a 7-person capsule in 2020.

I was hoping for something more like this by now:

[rdale]

So I know the official forecast is pretty much a lock on no launch, and maybe I'm just an optimist, but I have to think it's not as bad as some are saying.

Now that we're in the range of the US short-term modeling, it really doesn't look that bad. Especially compared to today [First image]

The NAM doesn't do anything with developing a tropical wave into something, and while models don't always do well in doing so to begin with, the lack of any hint of it developing is a promising sign.

And again we don't take the model forecast of thundershower development 57 hours away to be anywhere near realistic, but it does help us in patterns. And this pattern doesn't appear to be one with completely cloudy and wet weather.

Second snap is the rainfall totals from 4pm - 5pm on Wednesday, and the next is cloud cover at 5pm (white = cloudy.)

Finally ocean waves don't appear to be a big issue in the last pic.

[joek]

I have to wonder about the long view if it's a choice between losing the booster or disappointing the president.

I hope and expect that the professionals at NASA and SpaceX will adhere to all appropriate protocols and make the right decisions--regardless of what amateurs might be present in the peanut gallery and disappointed by the outcome of those decisions.

[dsmillman]

I have to wonder about the long view if it's a choice between losing the booster or disappointing the president.

I hope and expect that the professionals at NASA and SpaceX will adhere to all appropriate protocols and make the right decisions--regardless of what amateurs might be present in the peanut gallery and disappointed by the outcome of those decisions.

Given what happened at the CDC and FDA dealing with the virus in January and February I don't expect much from NASA.
I think SpaceX will do better since SpaceX has a lot at stake.

[kevinof]

I'm assuming it's upper level winds or something because the only other thing for the next week is 24-27 knots a little north east of the cape.

So agreed the professionals will make a decision and us amateurs can only speculate.

I have to wonder about the long view if it's a choice between losing the booster or disappointing the president.

I hope and expect that the professionals at NASA and SpaceX will adhere to all appropriate protocols and make the right decisions--regardless of what amateurs might be present in the peanut gallery and disappointed by the outcome of those decisions.

[lonestriker]

woods170 mentioned this a few pages ago.  If all else is "go" other than booster recovery, the booster is toast and DM-2 flies.  No "disappointments" enter into the equation.

Booster recovery is a secondary objective. If the ascent route weather is good, including the abort zones, and only the booster recovery area is a no-go, than SpaceX will ditch the booster.

[Vettedrmr]

I have to wonder about the long view if it's a choice between losing the booster or disappointing the president.

I doubt it.  If the conditions are good for launch and in the abort recovery zones, they'll launch, regardless of the chance of recovering the booster.  And nothing disappoints people more than losing crews.

Have a good one,
Mike

[CorvusCorax]

I still think Falcon9 landing constraints are more forgiving than Dragons emergency watering constraints, both in regard to wind, waves, and thunderstorms.

If the area where the F9 comes down has weather so bad that they can't even try a landing (aka too harsh for the recovery fleet) then this would almost certainly create at issue for Dragon's emergency landing for aborts during late S1 flight.

At that point the vehicle is not fast enough yet for Dragons abort systems +- 300-ish m/s deltaV  to translate into hundreds of miles of cross range for the landing spot. The chances of a weather system to be so severe that F9 cannot land - yet so localized that Dragon is guaranteed to be able to aboid it -- I think those are pretty slim.

My guess, if there's any severe weather in the flight path, Dragons constraints would be violated much before the F9 recovery fleet would have issues. And that means scrub.

[MediumFidelity]

Now that we're in the range of the US short-term modeling, it really doesn't look that bad. Especially compared to today [First image]

My search-fu was weak, and didn't turn anything up, so I'll ask.  Why is the 45th not issuing a forecast for a 24hr delay (assuming poor weather on the first attempt)?  If there is a delay, do we know if NASA/SpaceX will wait more than 24 hours?

Thanks!
-MF

[Cmdr.Eayrn]

Now that we're in the range of the US short-term modeling, it really doesn't look that bad. Especially compared to today [First image]

My search-fu was weak, and didn't turn anything up, so I'll ask.  Why is the 45th not issuing a forecast for a 24hr delay (assuming poor weather on the first attempt)?  If there is a delay, do we know if NASA/SpaceX will wait more than 24 hours?

Thanks!
-MF

If there is a scrub on the 27th, the next launch opportunity is not until the 30th of May, so I suspect that is outside of their typical forecast window.

[Joffan]

Now that we're in the range of the US short-term modeling, it really doesn't look that bad. Especially compared to today [First image]

My search-fu was weak, and didn't turn anything up, so I'll ask.  Why is the 45th not issuing a forecast for a 24hr delay (assuming poor weather on the first attempt)?  If there is a delay, do we know if NASA/SpaceX will wait more than 24 hours?

Thanks!
-MF

My expectation is that launch opportunities - at least for this test mission - are more restricted to ensure a low enough phasing to ISS that rendezvous will take less than (say) a day. So you may well not have a launch opportunity every day, despite rotating into the plane of ISS orbit every day.

[cebri]

If the weather conditions doesn't improve. What's the chance of this getting scrubbed 12-24h before the launch?

[padrat]

And so, the anxiety begins.

It's been WAYYYY too long....

[rdale]

If the weather conditions doesn't improve. What's the chance of this getting scrubbed 12-24h before the launch?

It would be silly to cancel 24 hours out for a 40% chance unless there are extenuating circumstances (I.e. they are behind in preps, they’ve tried 3 times in a row and people are exhausted, etc.)

[kdhilliard]

If the weather conditions doesn't improve. What's the chance of this getting scrubbed 12-24h before the launch?

That is a very good question.  I do not share dsmillman's concern about NASA pushing for a launch when they shouldn't, simply to humor a VIP attendee.  But we all know that NASA is well aware of the PR value of this launch, and that repeated last minute scrubs reduce that value among many audiences.  So I could imagine the Administrator suggesting that this launch be postponed early under conditions where a less visible launch might push on hoping for the weather to break in their favor (such as with last Saturday-week's Atlas launch attempt, which came closer to a GO than many people realized).  Whether 40% is below that threshold, I don't know.

[cebri]

If the weather conditions doesn't improve. What's the chance of this getting scrubbed 12-24h before the launch?

It would be silly to cancel 24 hours out for a 40% chance unless there are extenuating circumstances (I.e. they are behind in preps, they’ve tried 3 times in a row and people are exhausted, etc.)

While I'd agree with your statement 99% of the time and I'm probably wrong, I think we need to take into account some considerations:
- This event is going to grab a lot of attention from the non-space community.
- It will possibly be broadcasted by all major networks.
- The president is planning on attending.
- We are in the mid of the worst crisis in recent history.

This could be a major PR event for NASA (& SpaceX) and I feel a last minute scrub may take some of the excitement out of it. NASA is going to need as much public support as possible for the Artemis program and this could be a moment to advertise Bridestine's plans about the future and get people excited about it. That's why I'd prefer more favorable moment to make the first try.

Edit:

If the weather conditions doesn't improve. What's the chance of this getting scrubbed 12-24h before the launch?

That is a very good question.  I do not share dsmillman's concern about NASA pushing for a launch when they shouldn't, simply to humor a VIP attendee.  But we all know that NASA is well aware of the PR value of this launch, and that repeated last minute scrubs reduce that value among many audiences.  So I could imagine the Administrator suggesting that this launch be postponed early under conditions where a less visible launch might push on hoping for the weather to break in their favor (such as with last Saturday-week's Atlas launch attempt, which came closer to a GO than many people realized).  Whether 40% is below that threshold, I don't know.

Yes, those are exactly my thoughts.

[rdale]

I understand they don’t want a last minute scrub - but right now it’s just about 50/50. Florida - in the summer - WELCOMES odds that good

If it was today then sure - scrub yesterday.

[leetdan]

It would be silly to cancel 24 hours out for a 40% chance unless there are extenuating circumstances (I.e. they are behind in preps, they’ve tried 3 times in a row and people are exhausted, etc.)

Bingo.  I clearly remember STS-135, where I could've taken off work to drive out to the last shuttle launch.  "Nah, 70% chance of violation, I'll save my vacation days for the next attempt."  Oops.