SpaceX F9 : RCM (RADARSAT) : Vandenberg : June 12, 2019 - DISCUSSION

[EspenU]

I'm surprised that the Falcon 9 model they were using in the webcast was so inaccurate. The SpaceX logo is not placed/sized correctly, there is no Falcon 9 logo, the interstage is not the correct size, and the grid fins are placed below the interstage.
You would expect them to have better models on their own webcast than I have on my desk (Oli model).

[Johnnyhinbos]

I'm surprised that the Falcon 9 model they were using in the webcast was so inaccurate. The SpaceX logo is not placed/sized correctly, there is no Falcon 9 logo, the interstage is not the correct size, and the grid fins are placed below the interstage.
You would expect them to have better models on their own webcast than I have on my desk (Oli model).

They need too get in touch with Oli Braun...

https://twitter.com/oli_braun/status/1103003366785994752

[hootowls]

It's the second mission of its type and, same as the first, the boostback and reentry occur over land.  Any description of it being over the water is only true of a different profile at another range.    The other thing to keep in mind is the altitude involved; if you were a passenger on stage 1, you'd receive astronaut wings from any country in the world that has such an award.  This is about failure at high altitudes not about landing area goofs.

I'm sorry but this has just gotten out-of-hand. No, no way a sun synchronous launch from Vandenberg has a boost back phase over land.  Just stop. Its not even a close call

Those decades of learning the business, the hundreds of times of counting down to the uncertainty of T-0 and flight, all just a dream.  Even this morning, thinking that I was at my own console workstation watching telemetered data and making flight calls, seeing the payoff of all the collaborative efforts of the many people involved in such an enterprise, including my own, turns out to be just an overactive imagination, according to the internet.  I should really see someone about this delusion - my working life has been a sham.  But then who's been paying me?  Man, now I'm really confused.  I tell you though, if I were to dream it all over again there'd be less meetings.

[stcks]

14 CFR 417 has requirements that can only be met with a risk-based approach to public safety for such missions.  The updated CFR is in its NPRM period - the new Part 450 has some interesting tidbits that will come into play if they survive as written.

Wow thanks for this. Now I have a lot of reading to do.....

[Mandella]

I'm surprised that the Falcon 9 model they were using in the webcast was so inaccurate. The SpaceX logo is not placed/sized correctly, there is no Falcon 9 logo, the interstage is not the correct size, and the grid fins are placed below the interstage.
You would expect them to have better models on their own webcast than I have on my desk (Oli model).

I'm pretty sure that was a very last minute addition upon realizing just how bad the pea soup was out there. They very likely snatched it off somebody's desk -- or ran down to the gift shop.

[mme]

I'm thinking of trying Providence Landing Park. It won't be as sonically awesome given the distance, but you can almost see the pad from there.

699 Mercury Ave, Lompoc, CA 93436

Curious if you or anyone else gave this a whirl and what the experience was like?

Thanks!

My buddy wanted to be close for the sonic goodness which is my normal preference so we ended up at the corner of Ocean and Floradale. The launch was much quieter than from Ocean and Union Sugar which is my favorite spot but was unaccessible today. The fog was so dense, we could not see anything. Not even a hint of glow (which is why I wanted to go to Providence Park in hopes of being out of the marine layer and seeing the rocket punch through the clouds.) The sonic boom was still glorious.

Next foggy day I'll try Providence ...

[Tommyboy]

Those decades of learning the business, the hundreds of times of counting down to the uncertainty of T-0 and flight, all just a dream.

It appears so. Landing burn over land? Agreed. Boostback and re-entry burn over land? No way. There is no land for thousands of miles in the direction the F9 took off today. Check the images attached to the following post, and tell us where the land downrange from the launch site is. Or stop trolling.

Launch Hazard Areas for M1349 RADARSAT Constellation Mission based on issued NOTAMs.
Stage2 Reentry Debris Area east of Hawaii after the first orbit in window between 15:54 and 16:30 UTC.

[hootowls]

Those decades of learning the business, the hundreds of times of counting down to the uncertainty of T-0 and flight, all just a dream.

It appears so. Landing burn over land? Agreed. Boostback and re-entry burn over land? No way. There is no land for thousands of miles in the direction the F9 took off today. Check the images attached to the following post, and tell us where the land downrange from the launch site is. Or stop trolling.

Launch Hazard Areas for M1349 RADARSAT Constellation Mission based on issued NOTAMs.
Stage2 Reentry Debris Area east of Hawaii after the first orbit in window between 15:54 and 16:30 UTC.

The original conversation is getting lost as we were talking about the risk to public in the landing area.  The risk comes not from where the booster's nominal position is in flight but where it's impact point will be at the end of its thrust.  The physical boostback and cutoff are indeed over water but the impact point of the booster finishes over land at MECO-2.  I guess that's the part that's not intuitively obvious.  Any failure of stage 1 just prior to MECO-2 and all times after puts debris on land, the extent of which depends on such factors to include the method of failure, its altitude, and winds.  I was pointing folks to 14 CFR for more info but this discussion seems to have gone in different direction.

[mn]

Those decades of learning the business, the hundreds of times of counting down to the uncertainty of T-0 and flight, all just a dream.

It appears so. Landing burn over land? Agreed. Boostback and re-entry burn over land? No way. There is no land for thousands of miles in the direction the F9 took off today. Check the images attached to the following post, and tell us where the land downrange from the launch site is. Or stop trolling.

Launch Hazard Areas for M1349 RADARSAT Constellation Mission based on issued NOTAMs.
Stage2 Reentry Debris Area east of Hawaii after the first orbit in window between 15:54 and 16:30 UTC.

The original conversation is getting lost as we were talking about the risk to public in the landing area.  The risk comes not from where the booster's nominal position is in flight but where it's impact point will be at the end of its thrust.  The physical boostback and cutoff are indeed over water but the impact point of the booster finishes over land at MECO-2.  I guess that's the part that's not intuitively obvious.  Any failure of stage 1 just prior to MECO-2 and all times after puts debris on land, the extent of which depends on such factors to include the method of failure, its altitude, and winds.  I was pointing folks to 14 CFR for more info but this discussion seems to have gone in different direction.

There was alot of discussion (aka shouting match) about the impact point before the landing burn here:

I guess this footage should end the debate of whether or not a stage will overshoot or undershoot it’s landing spot if the engines fail to light for the landing burn. (But who am I kidding, of course it won’t)

Yes, the video clearly shows the stage coming in at an angle and overshooting the ASDS. For those who missed it, the great "overshoot vs. undershoot" debate started here:

https://forum.nasaspaceflight.com/index.php?topic=44778.msg1788585#msg1788585

...and lasted several pages, so is worth revisiting in light of the new video. Hopefully all debaters will view the video and some will see the error of their ways.  Meanwhile, you may bask in the knowledge that you were indeed correct. 

[CorvusCorax]

It would be more "fun" to discuss why the F9 did a 180 degree roll during ascent

My favorite explanation would be something like  "they routinely adjust the flight parameters during routine launches to acquire data from different subsets within the vehicles design flight-envelope to refine models and continuously improve our understanding of the vehicle and how it behaves..."

but Elon probably had the better answer on Twitter

[JonathanD]

It would be more "fun" to discuss why the F9 did a 180 degree roll during ascent

I was wondering about that too!  Seemed to roll more for the gravity turn than usual.  Maybe an optimal orientation for the payload during ascent?  Or maybe just for the cameras?

[Vettedrmr]

More boring, but maybe I'll learn something:

I thought the roll programs that most (if not all) launches do is to align their gyro packages with the inclination of the desired orbit.  The packages launch at a fixed alignment which (I think) is predicated by the TEL alignment.

Have a good one,
Mike

[Tommyboy]

The 180 degree roll seems to be standard practice at Vandenberg, check the Iridium-5 mission at for example, around 22:00-23:00. You can clearly see the booster rolling if you focus on the decals on the faring.

[JonathanD]

More boring, but maybe I'll learn something:

I thought the roll programs that most (if not all) launches do is to align their gyro packages with the inclination of the desired orbit.  The packages launch at a fixed alignment which (I think) is predicated by the TEL alignment.

Have a good one,
Mike

That would make much more sense.  Now I feel dumb :p

[DaveJes1979]

Falcon 9 has a modern guidance system, it doesn't need to do the old-school roll program before pitching.  If it needs to roll, it is because of the payload.  The payload may not be able to take certain orientations, structurally.

And when F9 flies with a crew Dragon, I assume it will roll so as to orient the astronauts into a certain angle, either for reasons of comfort or reasons of field-of-view (so they can see the horizon out the window).

[sewebster]

Is there a source that tells what the mass of the dispenser is? I know the total payload mass is more than 4,290 kilograms.

Don't think that has been published. Ruag said it was their heaviest product developed at their Linkoping facility...

[Comga]

Falcon 9 has a modern guidance system, it doesn't need to do the old-school roll program before pitching.  If it needs to roll, it is because of the payload.  The payload may not be able to take certain orientations, structurally.

And when F9 flies with a crew Dragon, I assume it will roll so as to orient the astronauts into a certain angle, either for reasons of comfort or reasons of field-of-view (so they can see the horizon out the window).

The payload has no idea where "down" is, the line to the center of the Earth.  It only feels the acceleration vector.
But the Falcon is pushed from behind, as are all rockets.
In inertial space, that puts the thrust vector down the axis.
The exception is when there are aerodynamic loads from the sides
(Or during strong rotational motions which they don't do before stage separation.)
It's hard to see where and when significant lateral forces are induced.

[DaveJes1979]

In inertial space, that puts the thrust vector down the axis.
The exception is when there are aerodynamic loads from the sides
(Or during strong rotational motions which they don't do before stage separation.)
It's hard to see where and when significant lateral forces are induced.

For F9 the payload is required to take +/- 2 g's lateral, I don't know if in reality that applies 360 degrees around.

In any case that is just one possibility relating to the payload.  The point is that whatever it is, it is probably stemming from the payload.  Another possibility is that they wanted the payload to be oriented a certain way at fairing separation.

[ZachS09]

Is there a source that tells what the mass of the dispenser is? I know the total payload mass is more than 4,290 kilograms.

Don't think that has been published. Ruag said it was their heaviest product developed at their Linkoping facility...

Could a reason for it not being published involve the Canadian government keeping it classified? After all, the government owns the RCM sats instead of MDA being the owner.

[gongora]

https://twitter.com/PeterGuggenbach/status/1139185911147704321

https://twitter.com/RuagSpace/status/1139502322374062080