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

[sublimemarsupial]

No conspiracy required. The Range only wanted accuracy but SpaceX wanted their booster back, so they used a barge.

Accuracy is necessary but not sufficient.  The Range wants more than just accuracy.

What? The Range just demonstrated that accuracy alone was sufficient to allow a RTLS for them. It literally just happened three weeks ago.

[HIP2BSQRE]

No conspiracy required. The Range only wanted accuracy but SpaceX wanted their booster back, so they used a barge.

Accuracy is necessary but not sufficient.  The Range wants more than just accuracy.

What? The Range just demonstrated that accuracy alone was sufficient to allow a RTLS for them. It literally just happened three weeks ago.

Where is the paperwork that the range wanted accuracy and a successful landing?

[cscott]

This discussion is perilously unmoored.  Hearsay about the range combined with overly close reading of a SpaceX statement about what the range "wants"... There are not enough verifiable facts here.  We're just going to be talking past each other based on flimsy evidence.

I recommend we let the subject drop.

[macpacheco]

No conspiracy required. The Range only wanted accuracy but SpaceX wanted their booster back, so they used a barge.

Accuracy is necessary but not sufficient.  The Range wants more than just accuracy.

Yes, accuracy and a good likelyhood the rocket wont blow into bits upon impact. It is a preservation area around after all.

[Robotbeat]

No conspiracy required. The Range only wanted accuracy but SpaceX wanted their booster back, so they used a barge.

Accuracy is necessary but not sufficient.  The Range wants more than just accuracy.

Yes, accuracy and a good likelyhood the rocket wont blow into bits upon impact. It is a preservation area around after all.

Obviously you're wrong because SpaceX/Elon publicly estimated just like 60-70% or so probability of success this time. SpaceX built a large pad and buffer around the pad big enough that simply achieving the accuracy of their previous attempts would be sufficient to contain the vast majority of the debris in case it failed.

[wannamoonbase]

Delivery of payload to the proper orbit is always top priority.  But I do love the 'extras' that SpaceX puts in.

I think they are going to stick the barge landing this time, seas permitting.

[Herb Schaltegger]

So back to discussing this actual mission  .... (please!) ....

How's the weather looking for SoCal today and the rest of the week? I'm curious if the static fire will slip further.

[Johnnyhinbos]

Here's tomorrow's forecast for VAFB, per weather.com. The 17th shaping up ok for the launch, and actually the sea state looks to be calming too...

[Dante80]

And...they are rolling out.

My guess is that they need a good shakedown of the pad and the ground systems, its been a long time since the CASSIOPE mission.

They wont have to deal with propellant densification this time though, that's a relief of shorts.

Fingers crossed for a smooth procedure, I would expect delays though.

[Lars-J]

And...they are rolling out.

My guess is that they need a good shakedown of the pad and the ground systems, its been a long time since the CASSIOPE mission.

They wont have to deal with propellant densification this time though, that's a relief of shorts.

Fingers crossed for a smooth procedure, I would expect delays though.

Keep in mind that they already did tanking tests with a first stage a few months ago, so the pad has not been completely dormant for the last 2.5 years.

[Jcc]

No conspiracy required. The Range only wanted accuracy but SpaceX wanted their booster back, so they used a barge.

Accuracy is necessary but not sufficient.  The Range wants more than just accuracy.

Yes, accuracy and a good likelyhood the rocket wont blow into bits upon impact. It is a preservation area around after all.

Spacex proved that out, twice, by hitting the target within 50 m AND exploding. The explosion was not enough to significantly damage the ASDS, and would not harm anything beyond a few hundred meters of the impact point in any case. The second landing was within 10 m apparently. The DSCOVR water landing was apparently a bull's eye  also, and the record of each water landing attempt showed better end better accuracy every time. That is evidence enough to show that the risk of harming anything outside of LZ-1 is minimal, even if it exploded.

[Bubbinski]

Question: are there any webcams on the VAFB premises that might have a view of the Falcon 9 doing its test firing?

Edit: I've drawn a big zero on a web search.

[Flying Beaver]

So SpaceX is now targeting a barge landing, but the first stage has the fuel required to RTLS. A barge landing only requires a partial boostback (or no boostback at all), instead of a full reversal of horizontal V need for RTLS.

So I assume that the stage will be more fuel-heavy on landing? Or could this extra fuel been expended in a extended reentry and/or landing burn.

[pericynthion]

So SpaceX is now targeting a barge landing, but the first stage has the fuel required to RTLS. A barge landing only requires a partial boostback (or no boostback at all), instead of a full reversal of horizontal V need for RTLS.

So I assume that the stage will be more fuel-heavy on landing? Or could this extra fuel been expended in a extended reentry and/or landing burn.

I would expect them to land with the same (minimal) amount of residual propellant.  The rocket would still be launched fully fueled, but would stage later than it would with a heavier payload, leaving more margin for the second stage.

[Craftyatom]

So SpaceX is now targeting a barge landing, but the first stage has the fuel required to RTLS. A barge landing only requires a partial boostback (or no boostback at all), instead of a full reversal of horizontal V need for RTLS.

So I assume that the stage will be more fuel-heavy on landing? Or could this extra fuel been expended in a extended reentry and/or landing burn.

I would expect them to land with the same (minimal) amount of residual propellant.  The rocket would still be launched fully fueled, but would stage later than it would with a heavier payload, leaving more margin for the second stage.

I'd think so too, but a good way to test would be going through the launch video frame-by-frame and comparing it to OG2 - from there, one can figure out the TWR on each of the flights.  The payload doesn't make too much difference itself, but the fuel would.  Just a thought, something I'd do myself if I had a decent video editor and more time.

[Jim]

I'd think so too, but a good way to test would be going through the launch video frame-by-frame and comparing it to OG2 - from there, one can figure out the TWR on each of the flights.  The payload doesn't make too much difference itself, but the fuel would.  Just a thought, something I'd do myself if I had a decent video editor and more time.

don't need to.  Cryogenic launch vehicles aren't launched with partial propellant loads.

[kdhilliard]

Cryogenic launch vehicles aren't launched with partial propellant loads.

Interesting.  Why not?

~Kirk

[Jim]

Cryogenic launch vehicles aren't launched with partial propellant loads.

Interesting.  Why not?

a.  it limits the amount of analysis that has to be done
b.  There are only empty and full sensors on the tanks
c.  hard to determine load by head pressure accurately due to prop boil off.

Just easier to launch full and deal the excess on orbit

[Avron]

So SpaceX is now targeting a barge landing, but the first stage has the fuel required to RTLS. A barge landing only requires a partial boostback (or no boostback at all), instead of a full reversal of horizontal V need for RTLS.

So I assume that the stage will be more fuel-heavy on landing? Or could this extra fuel been expended in a extended reentry and/or landing burn.

this vehicle is the old F9 version, will do no boost-back, just entry and landing, will have some fuel on landing, it must or that engine is not going  be happy running out of fuel

[Johnnyhinbos]

From the horse's mouth... (Note the use of "full duration")