SpaceX Falcon 9 v1.1 - SES-8 - DISCUSSION THREAD

[belegor]

Though as we didn't actually see any people on screen at the third launch attempt, it's possible they were planning to go back to Molly & John initially to fill time until relight / spacecraft sep but nixed the idea for the third attempt as they didn't want to spend the time getting them both ready for screen again just in case this attempt was scrubbed too.

If I remember correctly, it was already mentioned during the first launch attempt that they would end the broadcast after SECO-1.

[Lars_J]

Their webcasts will undoubtedly get better as time goes on - the ones for the SES-8 were probably their smoothest yet, and they have started to add in graphics when the signal is out, and so on.

It's not quite to the level of realtime rendering sophistication of ULA, but they are probably getting there at some point. At least they show more rocket-cam footage than anyone else in the business. (And kudos to Orbital as well on their Antares flights)

[Wetmelon]

Their webcasts will undoubtedly get better as time goes on - the ones for the SES-8 were probably their smoothest yet, and they have started to add in graphics when the signal is out, and so on.

Evidently, the guy who does the graphics stuff for the webcasts was on reddit.  He was glad that people liked the graphic better than the "Awaiting Downlink" bit, but specifically said he wants to do as little with CGI as possible.  So I'm not sure if that means he doesn't want to do the ULA thing or if he wants to do something better.  He mentioned having cool new camera views and/or some neat stuff coming our way.

[nisse]

An interesting view of the launch. At 3:49 a clear view of the Falcon 9 staging event can be seen. After staging the first stage shoots plumes. Are these reaction control pulses?

[Lars_J]

Wow, that's a great video - and yes, that was the reaction control thrusters of the first stage firing. This is the best view of it that we have seen so far.

I'm not sure where it was filmed, but that was some pretty impressive tracking to follow the second stage until it went below the horizon. If this was truly filmed all the way from Orlando, then WOW again! More rockets should launch at this time to have the same great lighting conditions. 

[ChrisWilson68]

Yes, a very impressive video.  I just wish the camera had stayed on the first stage instead of tracking the second when they separated too far to both stay in frame -- it's possible we could have seen the first stage break up!

[bunker9603]

That was an excellent video...kudos to the person filming it. I went to the youtube site and read that he used a Nexstar 8SE telescope and a hand controller to capture this.

[neoforce]

Agree with everyone that the latest video is very impressive.  That video got me thinking...

Clearly, even without recovery plans, SpaceX used the first stage on this flight to continue testing various elements of the recovery envelope.  We all hope SpaceX tells us officially what they tested with SES.  Until they do, it is all speculation. 

I'd like to add a thought I don't think I haven't seen on these boards yet.  Maybe I'm missing the obvious, but does everyone agree that we are seeing the first stage is lit?  The fact that we see the fairing is a reflection of a perfect angle of the sun.  But for the first stage, do we all think Merlin(s) are lit and its not just a reflection?  It looks that way to my untrained eye.

If so, the most recent video seems to show the relight of the first stage within about 10-15 seconds of Second Stage Start.  During Cassiope the only timestamp reference I found is from the web cast when at around 8:00 on the mission clock there is audio about first stage relight. 

So it seems to me that instead of using the SES flight to test just the re-entry part of the flight profile (like they did on Cassiope), might they have also been testing part of the boost back phase?  (Clearly in Cassiope they did not worry about boost back at all)  I doubt they tested full boost back, due to range security concerns, but maybe they did something like cancel forward velocity to zero to get another data point?

Again, all speculation at this point.  I hope we hear details from SpaceX.


===

An interesting aside.  There are three videos on youtube of Cassiope.  People who recorded the live webcast, SpaceX edited release of that webcast, then Spacex release of mission highlights. There are problems with all three.  The spaceX ones are edited, the live webcast had audio drop out every time the downlink was lost.  As for the relight information, here is what I found in those three videos:

- 8:00 mark on mission clock shown in webcast, a voice says "first stage is burning.. uh relighting at this time"
- 8:00 mark on mission clock shown in space X release of webcast has NO audio at all.
- Mission overview video has the voice saying "first stage is relighting at this time" but doesn't show a mission clock.

These differences are probably not sinister, its just editing and audio track anomalies.  But it shows that the information I found about when the relights were for Cassiope is really not complete.  So I really can't be sure when the first relight was during Cassiope.

[bartonn]

Most importantly, Spacex's launch costs are lower than their competitors, and with a few more successful GEO missions, Spacex can show that their vehicles are a reliable alternative.  Spacex has the opportunity to take a rather large portion of the market. 

Who are the SpaceX competitors for GTO missions?  Falcon 9 v1.1 can't lift the 5-6 tonners to GTO like Proton, Ariane, or Sea Launch Zenit.  It can't even lift one half of an Ariane 5 payload to GTO.  It can't match the big range of the EELVs, which can boost 6.7 tonnes (Atlas 5) or more than 11 tonnes (Delta 4) to GTO x 1,500 m/s, far more than Falcon 9 v1.1's probably 3.7 tonnes to the same energy orbit.  The SpaceX rocket seems to sit in its own category at the moment.

The only close competition seems to be Soyuz 2.1b/Fregat from Kourou, which can haul 3 tonnes to GTO, but this launch vehicle hasn't had GTO customers if I'm remembering correctly.

 - Ed Kyle

It is true that the Falcon 9 can't carry the heavier payloads that other launchers can provide, such as the Ariane 5.  However, I think the Falcon 9 has a lower price-per-pound than the Ariane 5.  Is it possible that satellite operators would choose to launch several 4-ton class satellites rather than a smaller number of larger 6-ton class satellites?  Managing more satellites would probably add to operational costs, but it would also add redundancy, and the lower per-pound cost of the Falcon 9 might make it worthwhile. 
(sorry if this is getting OT)

[Jim]

It is true that the Falcon 9 can't carry the heavier payloads that other launchers can provide, such as the Ariane 5.  However, I think the Falcon 9 has a lower price-per-pound than the Ariane 5.  Is it possible that satellite operators would choose to launch several 4-ton class satellites rather than a smaller number of larger 6-ton class satellites?  Managing more satellites would probably add to operational costs, but it would also add redundancy, and the lower per-pound cost of the Falcon 9 might make it worthwhile. 
(sorry if this is getting OT)

The trend is in the other direction.  There are limited slots on orbit for comsats

[cambrianera]

I'd like to add a thought I don't think I haven't seen on these boards yet.  Maybe I'm missing the obvious, but does everyone agree that we are seeing the first stage is lit?  The fact that we see the fairing is a reflection of a perfect angle of the sun.  But for the first stage, do we all think Merlin(s) are lit and its not just a reflection?  It looks that way to my untrained eye.

No relight of first stage engines happened.
What you see is first stage in full sunlight against a dimming evening sky; if you have still doubts, please review the video and consider you can't see merlins' first stage plumes, while thrusters' plumes are easily visible.

[PDJennings]

The trend is in the other direction.  There are limited slots on orbit for comsats

Actually, the trend is in both directions.  The commercial satellite market has bifurcated into payloads at 3-4 tons, and payloads at 6+ tons.  Not a whole lot in between, lately.  Orbital slots is not a real limitation for the larger operators.  SES pioneered the approach of co-locating multiple active satellites in one slot.  So the satellite size trade is affected by launch options.  I would suggest the most promising commercial market for Falcon 9 is large comsats with electric-only propulsion.  These birds would be 6+ tons with chemical propulsion, but with electric only they are within the Falcon 9 capability to launch to a GTO or SSTO that shouldn't take unreasonable time to circularize.  I suspect there are other customers waiting to see how this approach turns out for the early adopters.

[edkyle99]

I'd like to add a thought I don't think I haven't seen on these boards yet.  Maybe I'm missing the obvious, but does everyone agree that we are seeing the first stage is lit?  The fact that we see the fairing is a reflection of a perfect angle of the sun.  But for the first stage, do we all think Merlin(s) are lit and its not just a reflection?  It looks that way to my untrained eye.

No relight of first stage engines happened.
What you see is first stage in full sunlight against a dimming evening sky; if you have still doubts, please review the video and consider you can't see merlins' first stage plumes, while thrusters' plumes are easily visible.

No relight of the first stage has been *announced*.  I wouldn't be surprised if SpaceX took the opportunity to at least do a very brief re-ignition during this flight, if enough residuals were present.   

If it occurred, it would probably not have happened during the time span of this video.  It would more likely have happened several minutes later, along the timeline of the first Falcon 9 v1.1 launch.  It might have been too far downrange to see clearly, even with this telescope.  In this video, we are seeing RCS pulses that are turning the stage for a relight, whether one occurred or not.

 - Ed Kyle

[kevin-rf]

It is true that the Falcon 9 can't carry the heavier payloads that other launchers can provide, such as the Ariane 5.  However, I think the Falcon 9 has a lower price-per-pound than the Ariane 5.  Is it possible that satellite operators would choose to launch several 4-ton class satellites rather than a smaller number of larger 6-ton class satellites?  Managing more satellites would probably add to operational costs, but it would also add redundancy, and the lower per-pound cost of the Falcon 9 might make it worthwhile. 
(sorry if this is getting OT)

The trend is in the other direction.  There are limited slots on orbit for comsats

Orbital will be very depressed to learn that.

[RedLineTrain]

I was under the impression that SpaceX intended to launch two 6 ton birds on a Falcon Heavy at $77 million apiece.  This seems to be a graceful pricing step up from a 4 1/2 ton at $57 million on the Falcon 9.

This would seem to put pressure on the Ariane 5, no?

[neoforce]

I'd like to add a thought I don't think I haven't seen on these boards yet.  Maybe I'm missing the obvious, but does everyone agree that we are seeing the first stage is lit?  The fact that we see the fairing is a reflection of a perfect angle of the sun.  But for the first stage, do we all think Merlin(s) are lit and its not just a reflection?  It looks that way to my untrained eye.

No relight of first stage engines happened.
What you see is first stage in full sunlight against a dimming evening sky; if you have still doubts, please review the video and consider you can't see merlins' first stage plumes, while thrusters' plumes are easily visible.

No relight of the first stage has been *announced*.  I wouldn't be surprised if SpaceX took the opportunity to at least do a very brief re-ignition during this flight, if enough residuals were present.   

If it occurred, it would probably not have happened during the time span of this video.  It would more likely have happened several minutes later, along the timeline of the first Falcon 9 v1.1 launch.  It might have been too far downrange to see clearly, even with this telescope.  In this video, we are seeing RCS pulses that are turning the stage for a relight, whether one occurred or not.

 - Ed Kyle

@edkyle99 if there is a test relight, why must it happen at the timeline of Cassiope, later in the flight?  My entire speculation is that to look at various aspects of the planned flight profile maybe they tested some part of boost back with this flight?  That would occur right after separation.

@cambrianera I have no experience at this type of video analysis, but I have indeed viewed this many times.  In addition to the first stage thruster plumes, I do see a constant "fuzzy" white off of the first stage that seems like it could be a constant thrust, that is, the Merlin's first stage plume.

Its so far away that it is impossible to know the angles we are viewing, but in my imagination is that the second stage is traveling away from the camera (the thrust is a uniform halo around the bright point light) while the first stage may be oriented with the top end more or less facing the camera.  Its not head on, so we see the Merline plume as just a smudge under the bright point source instead of a large plume.  The thrusters are very visible because if the stage is oriented that way, the exhaust shows to us at perpendicular angles.

Or it might all be light playing tricks on my eyes!!     As I said, I know this is total speculation, and I'd love SpaceX to tell us if exactly what post separation testing occurred.  Clearly they did some testing, because there is no argument that we are seeing the thrusters orienting the first stage.  I hope they give us some information on exactly what testing they did complete.

[vapour_nudge]

Forgive me if this has already been covered, but I seem to recall that the USAF required three consecutive successful GTO launches before they would consider a new rocket for any 'significant' mission. Please correct me if that is wrong. SES-8 was one, if the Thaicom launch is successful that would be 2 leaving just one more to go.
Now, for a leap, assuming all that is correct and we get 3 successful launches and no subsequent failure, how soon might an USAF significant mission feasibly launch on a F9 1.1? By significant I mean in the realms of an AEHF or GPS etc

Also, just a note that we've had 3 F9 launches this year, the same total as the Delta IV. This year - if Thaicom launches and the GPS doesn't then that will be F9 with 4 launches and Delta IV with 3 launches. (Atlas V is headed for 8 )

[cambrianera]

@neoforce,
the fuzzy around first stage is the vaning halo of the second stage contrail.
Please consider this:
when first stage engines stop, first stage contrail stops;
when second stage starts its engine, a contrail clearly starts;
when RCS thrusters pulse, the puff is clearly visible before dispersing.

No contrail is visible on first stage after first stop, neither a distinct plume different than that of thrusters.
Therefore no relight of first stage engines is visible in the video.

[Jim]

@neoforce,
the fuzzy around first stage is the vaning halo of the second stage contrail.
Please consider this:
when first stage engines stop, first stage contrail stops;
when second stage starts its engine, a contrail clearly starts;
when RCS thrusters pulse, the puff is clearly visible before dispersing.

No contrail is visible on first stage after first stop, neither a distinct plume different than that of thrusters.
Therefore no relight of first stage engines is visible in the video.

I agree.  What is seen is just a white stage reflecting sunlight and maybe some hot engine glow.  The fairings are just as bright.

[neoforce]

@neoforce,
the fuzzy around first stage is the vaning halo of the second stage contrail.
Please consider this:
when first stage engines stop, first stage contrail stops;
when second stage starts its engine, a contrail clearly starts;
when RCS thrusters pulse, the puff is clearly visible before dispersing.

No contrail is visible on first stage after first stop, neither a distinct plume different than that of thrusters.
Therefore no relight of first stage engines is visible in the video.

I agree.  What is seen is just a white stage reflecting sunlight and maybe some hot engine glow.  The fairings are just as bright.

Ok, you convinced me... you guys have so much more experience with this stuff than I do, so I guess its just my eyes playing tricks on me.