SpaceX Falcon 9 v1.1 - Jason 3 - SLC-4E Vandenberg - Jan 17, 2016 - DISCUSSION

[cscott]

What time is this launch? Would a nighttime landing be visible from LA?

[Bubbinski]

10:42 am Pacific time, 30 second window

[Lars-J]

What time is this launch? Would a nighttime landing be visible from LA?

This is a daytime launch. (see post above)

And, no, a landing would not be visible from LA (day or night). The barge will be below the horizon. But you should be able to observe the boost-back and reentry burns, if weather permits.

[Prober]

What time is this launch? Would a nighttime landing be visible from LA?

This is a daytime launch. (see post above)

And, no, a landing would not be visible from LA (day or night). The barge will be below the horizon. But you should be able to observe the boost-back and reentry burns, if weather permits.

maybe not viewed from LA but other ships, other locations.  Lot's of moving parts on this.  If anyone has the time.

http://www.marinetraffic.com/

The last Sea Launch was monitored in real time.....very enlightening 

[Prober]

Any long range weather?  This article just popped up.

http://www.usatoday.com/story/weather/2016/01/04/california-storms-el-nino-snow-rain-drought/78256992/

[Bubbinski]

I saw on weather.com a forecast that had rain showers predicted for the 17th, but that was the very end of its forecast.  Edit to add: 40% chance of precipitation, winds SSW 12 mph

What is the launch weather criteria for the Falcon 9?

[hartspace]

I may have missed it, but I'm curious as to why the ASDS will be due south of VAFB.  The Jason launch inclination is 66 degrees, which would place the flight path well east of the ASDS location.

[CameronD]

FWIW, I notice the USCG have now classed the "Marmac 303" as an "Industrial Vessel" (no 'research' any more?) so I guess that means the modifications required for her transformation into a fully-fledged ASDS have been approved and she's good to go.

[Lars-J]

I may have missed it, but I'm curious as to why the ASDS will be due south of VAFB.  The Jason launch inclination is 66 degrees, which would place the flight path well east of the ASDS location.

They have enough performance to do it, so perhaps this is just a demonstration of side-boost capability.

[macpacheco]

I may have missed it, but I'm curious as to why the ASDS will be due south of VAFB.  The Jason launch inclination is 66 degrees, which would place the flight path well east of the ASDS location.

The orbit is 66 degrees prograde (I think). A launch directly onto that orbit isn't allowed (over land and populated areas). So the first stage flies a southerly direction and the 2nd stage makes the plane change
Not a rocket engineer. Doing some guessing here... Please correct me.

[Steven Pietrobon]

You want to do plane changes when your inertial velocity is low, as that has the lowest delta-V penalty. When going into a low Earth orbit, that occurs during the first stage burn.

[sdsds]

I think with this kind of steering the instantaneous impact point trace and the vehicle trajectory do not follow the same path. It doesn't matter much what the vehicle overflies; it matters a lot where the IIP trace goes!

[Coastal Ron]

Though this isn't explicitly stated, presumably they would not launch with rain, due to the buildup of ice that would occur on the skin of the rocket, particularly on the very cold LOX tanks.

Not sure if you were implying sub-cooled LOX, but Jason 3 is using the last of the non-sub-cooled stages (i.e. not Full Thrust).  As to ice due to rain, would that be a problem normally?  I would think once the engines started up that the vibration would shake off any ice build up.

Anyone with any direct knowledge about ice issues on Falcon 9?

[Kabloona]

I may have missed it, but I'm curious as to why the ASDS will be due south of VAFB.  The Jason launch inclination is 66 degrees, which would place the flight path well east of the ASDS location.

The orbit is 66 degrees prograde (I think). A launch directly onto that orbit isn't allowed (over land and populated areas). So the first stage flies a southerly direction and the 2nd stage makes the plane change
Not a rocket engineer. Doing some guessing here... Please correct me.

Not exactly. Launch azimuth is probably around 155 degrees in order to avoid Channel Islands, then first stage is expected to dogleg east to an azimuth of about 143 degrees. (Remember that azimuth and inclination are two different things.)

Sources:

Before 2006, some further easterly flight was allowed, but since then, flight azimuths are generally limited to a ~155 deg direction.

http://forum.nasaspaceflight.com/index.php?topic=29457.msg1393254#msg1393254

Launch azimuth is said to be 142.8 (once clear of land and over the Pacific).

http://forum.nasaspaceflight.com/index.php?topic=29457.msg1465556#msg1465556

[andrewsdanj]

Though this isn't explicitly stated, presumably they would not launch with rain, due to the buildup of ice that would occur on the skin of the rocket, particularly on the very cold LOX tanks.

Not sure if you were implying sub-cooled LOX, but Jason 3 is using the last of the non-sub-cooled stages (i.e. not Full Thrust).  As to ice due to rain, would that be a problem normally?  I would think once the engines started up that the vibration would shake off any ice build up.

Anyone with any direct knowledge about ice issues on Falcon 9?

I think non sub-cooled LOX is still a bit chilly. The soot 'protection' on the 1.1 FT launch shows that (at least that) ice/frost can stay attached for a good deal of the first stage flight. No direct knowledge, just my 2 cents.

[abaddon]

From the Update thread:

Expecting rollout and static fire this week, per L2 (subject to all staying within the timeline). Will be writing an article for it, so when confirmation of events (next being rollout), I'll get an article on ahead of the firing....then update when the firing is confirmed.

Isn't it a little early for a static fire, for a Jan 17th launch?  I guess there isn't really a reason to get it out of the way a little early, and maybe I've become used to SpaceX pushing the tempo and having little margin between static fire and launch.

[psloss]

Isn't it a little early for a static fire, for a Jan 17th launch?  I guess there isn't really a reason to get it out of the way a little early, and maybe I've become used to SpaceX pushing the tempo and having little margin between static fire and launch.

AnalogMan posted an earlier version of the pre-launch schedule up-thread:
https://forum.nasaspaceflight.com/index.php?topic=29457.msg1380593#msg1380593

That showed that spacecraft mate is planned for after the static fire.  That may be customer and/or launch provider preference for this spacecraft.  The timings appear to have changed a little bit -- NASA's last blog post had S/C mate a week from today, 12 January -- but mating after WDR/static fire still looks to be the case.

[QuantumG]

What else will be on this launch? Seems kinda strange that they'd stand up an F9 for just 510 kg of payload, but CASSIOPE was about the same mass. There's secondary payloads on this flight too, right?

[Dante80]

What else will be on this launch? Seems kinda strange that they'd stand up an F9 for just 510 kg of payload, but CASSIOPE was about the same mass. There's secondary payloads on this flight too, right?

I don't know. What I do know is that the guys in the Jason committee are probably ρissed, and wanted this in orbit asap for quite some time now...

No distractions.

[Star One]

Seems an over empathises on launcher rather than payload.