SpaceX's Big Falcon Topic 2

[Erik of Hazelfield]

Needing 5-10 flights before reusable rockets become profitable sounds like a high figure to me. I mean, if the first stage is 60% of the launch cost like Elon says, then you make quite the cost save with as little as two flights per rocket.

I’d love to see the calculations and most importantly the assumptions that lie behind that figure. For one thing, I’m not convinced that the reusability requirement add all that much to the design budget of SpaceX. Or it probably does, but I think it’s not that bad. After all they are much cheaper than the competition even for the expendable rockets. And as for the reduced payload, that’s only a problem if the payload mass is so large that you can’t spare the extra fuel to recover the first stage. But even then it’s not a real problem - I can’t see why the cost penalty for having a reusable rocket wouldn’t be minimal even if you do expend it. 

Lastly, the cost of refurbishment between flights is known to be ridiculous for the space shuttle but it’s probably much cheaper for Falcon 9 and I believe Elon’s stated goal is that it should be negligible in the future. 

[Free Northman Reborn]

On 5/13/2018 at 2:34 PM, Fall Bass said:

I found this rather interesting bit about reusable rockets and SpaceX:

IIRC None of the Falcon 9's have been flown more than twice at this point. But it still could be worth it if it ultimately allows for a much higher schedule of launches.

That is a nonsense article.

[Spring Bass]

On 5/13/2018 at 2:01 AM, Erik of Hazelfield said:

Lastly, the cost of refurbishment between flights is known to be ridiculous for the space shuttle but it’s probably much cheaper for Falcon 9 and I believe Elon’s stated goal is that it should be negligible in the future. 

I'll believe it when we see it. One of the downsides of SpaceX being a private company is that we have no idea of how much it's actually costing them to recover and refurbish the rocket engines between flights. I'm skeptical that it's cheap, otherwise they would have reflown them more than twice by now. 

 

 

[Free Northman Reborn]

3 hours ago, Fall Bass said:

I'll believe it when we see it. One of the downsides of SpaceX being a private company is that we have no idea of how much it's actually costing them to recover and refurbish the rocket engines between flights. I'm skeptical that it's cheap, otherwise they would have reflown them more than twice by now. 

 

 

The Block 3 and 4 was not designed for multiple reuses. The Block 5 has incorporated the technology for 10 or more uses.

With Block 5’s imminent arrival they actually started throwing returning Block 4 cores into the ocean after their 2nd use because they had too many to use up.

 

 

 

[SpaceChampion]

52 minutes ago, Free Northman Reborn said:

With Block 5’s imminent arrival they actually started throwing returning Block 4 cores into the ocean after their 2nd use because they had too many to use up.

Already arrived.    Most recent flight was the debut.  They're burning off the remainder Block 4s and 3s this year -- probably including a Falcon Heavy with block 3s -- and given that there should >20 launches this year I could see next year being nothing but Block 5.

[Free Northman Reborn]

1 hour ago, SpaceChampion said:

Already arrived.    Most recent flight was the debut.  They're burning off the remainder Block 4s and 3s this year -- probably including a Falcon Heavy with block 3s -- and given that there should >20 launches this year I could see next year being nothing but Block 5.

I meant that they started disposing of Block 3 and 4 cores in the ocean at a time that Block 5’s arrival was imminent. Not that Block 5’s arrival is STILL imminent. Sorry for the unclear wording.

I was watching its maiden launch with bated breath like all the other hardcore fans.

 

[Erik of Hazelfield]

The refurbishment cost is an interesting and highly relevant figure. I’m not sure what it is for the Falcon 9 boosters but the refurbishment time should be an indication. Does anyone know what the shortest time has been between two flights of the same stage?

[Altherion]

1 hour ago, Erik of Hazelfield said:

Does anyone know what the shortest time has been between two flights of the same stage?

There's a wiki page listing all of the boosters. The shortest so far has been 5 months and 9 days, but barring unforeseen problems, this should change shortly. The one launching this Tuesday will only have spent 4 months and 13 days on the ground and the one on June 18th will nearly halve that at 2 months and 10 days. Hopefully will see times less than a month with Block 5.

[Free Northman Reborn]

2 hours ago, Erik of Hazelfield said:

The refurbishment cost is an interesting and highly relevant figure. I’m not sure what it is for the Falcon 9 boosters but the refurbishment time should be an indication. Does anyone know what the shortest time has been between two flights of the same stage?

Musk has stated that in 2019 they will refly a Block 5 in 24 hours, just to demonstrate that capability. I suspect it will be on one of their own Starlink missions.

[SpaceChampion]

There appears to be only four Block 4s left (and no Block 3s), so should be used up fairly quickly.  We'll start to get a good idea of Block 5 reflight frequency by the fall, I imagine.

[SpaceChampion]

Launch today from Vandenburg, of the next half-batch of Iridium satellites and a pair of science sats to do gravity experiments for NASA and the Germans.

A Block 4 first stage will be expended on this one, so no attempted landing.  Attempted fairing recovery though.  Previously this block 4 Falcon 9 first stage flew on the Zuma mission earlier this year.

Lift-off expected in two hours from now 12:47pm PT (19:47 UTC).

 

[SpaceChampion]

Fairing from Tuesday's launch was not successfully caught, but it did hit the water fairly close to the ship, and survived intact with little damage.  Getting closer!

Regarding the situation a few months ago where SpaceX was barred by the some government agency from showing video of the second stage in space, seems like today's actions by the White House to establish a new streamlined regulatory framework should clear that from being a problem in the future.  Formalizing recommendations from the National Space Council, it looks like a single license in the future will be required for commercial launches, including those going to and doing work on the Moon.  It'll cover launch, satellites and remote sensing.

Next SpaceX launch is for the SES-12 mission of commercial sats on the 31st.

[DireWolfSpirit]

Did anyone else catch that story regarding the asteroid from outside our galaxy that is now orbitting in our system but traveling in the opposite direction of almost every asteroid in our galaxy? 

I'm sure the link wouldnt be to difficult to find with a google search if anyone wanted to read about this rare space development/discovery.

[Ser Scot A Ellison]

12 hours ago, DireWolfSpirit said:

Did anyone else catch that story regarding the asteroid from outside our galaxy that is now orbitting in our system but traveling in the opposite direction of almost every asteroid in our galaxy? 

I'm sure the link wouldnt be to difficult to find with a google search if anyone wanted to read about this rare space development/discovery.

I did see that.  It seems much more likely to be a weird rock than the large cigar shapes asteroid that came through the system a couple of months ago.

[Which Tyler]

4 hours ago, DireWolfSpirit said:

Did anyone else catch that story regarding the asteroid from outside our galaxy that is now orbitting in our system but traveling in the opposite direction of almost every asteroid in our galaxy? 

I'm sure the link wouldnt be to difficult to find with a google search if anyone wanted to read about this rare space development/discovery.

By "Galaxy" do you mean "Solar System" - because otherwise... I'm calling bull

[DireWolfSpirit]

7 hours ago, Which Tyler said:

By "Galaxy" do you mean "Solar System" - because otherwise... I'm calling bull

Maybe Scott has the link if your interested in the specifics, I am only working off recollection from reading it recently though.

[Erik of Hazelfield]

Yeah, we saw it.

It’s pretty cool because almost everything that is in the solar system is made from the same accretion disc that made the sun, the planets, the asteroid belt and pretty much everything. If this thing is retrograde it’s got to be from outside the solar system. 

That’s what’s cool about it. I don’t know more, I’m drunk. But I think it’s cool that we got something extrasolar in our solar system. Cheers!

[maarsen]

16 minutes ago, Erik of Hazelfield said:

Yeah, we saw it.

It’s pretty cool because almost everything that is in the solar system is made from the same accretion disc that made the sun, the planets, the asteroid belt and pretty much everything. If this thing is retrograde it’s got to be from outside the solar system. 

That’s what’s cool about it. I don’t know more, I’m drunk. But I think it’s cool that we got something extrasolar in our solar system. Cheers!

Venus and Uranus both rotate in a direction opposite to all the other planets. A hyperbolic orbit is a sure sign of coming from interstellar space. Any elliptical orbit, not so much. 

[Erik of Hazelfield]

Wait, what? I thought they were rotating retrograde around themselves, but their orbits are the same as everything else in the solar system? And the new thing with this asteroid is that it circles the sun in the opposite direction of everything else in the solar system?

Please correct me if I’m wrong.

[maarsen]

3 minutes ago, Erik of Hazelfield said:

Wait, what? I thought they were rotating retrograde around themselves, but their orbits are the same as everything else in the solar system? And the new thing with this asteroid is that it circles the sun in the opposite direction of everything else in the solar system?

Please correct me if I’m wrong.

You are right. The assumption is that conserving angular momentum requires all bodies in our solar system to have the same angular momentum as the original cloud from whence all came. Having a few large bodies not following the rules  means smaller bodies not following the rules are not a sign of much. Consider also that the axial tilt of Uranus is 90 degrees, and as such is also at odds with the other planets in terms of angular momentum.