Aethon

Blue Origin Thread (merged)

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1 hour ago, monophonic said:

Rules can be changed. After all, airliners are allowed to overfly cities and they come down wrong occasionally too. But those particular rules won't change easily, or soon. I'll guess we have to be into daily launches with perfect record before any overflight permits will start to get issued. And those will be special cases for single launches at first too.

Airline flight safety reliability is at least a million times better than rocket booster flight safety reliability. Six orders of magnitude is a conservative estimate.

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21 hours ago, Veeltch said:

How much a fully reusable F9 (first and second stage) could put into LEO? About 20 metric tonnes?

 

20 hours ago, IncongruousGoat said:

In all seriousness, though, it depends on how SpaceX goes about reusing the second stage, and what kind of mass penalty that incurs. Although I suspect it would probably be closer to 15 tons.

That's much too optimistic, I'm afraid... for multiple reasons.

First, SpaceX has stated that first stage recovery inflicts a roughly 30% performance penalty on the Falcon 9. Currently, SpaceX advertises a theoretical 22.8 metric tons to LEO (where "LEO" is defined as a useless 200x200km short term parking orbit at the inclination of Kennedy Space Center). So it follows that first stage reuse drops the maximum payload to ~16 tons already.

Next, you need to make assumptions about second stage recovery. The Falcon 9 as a whole is weighted more towards the second stage than other rockets would be in terms of dV budget, so that the first stage doesn't go too fast and has an easier time recovering. With stage 2 fielding the lion's share of dV to orbit, asking it to reserve fuel or carry additional dry mass for recovery hurts it more than the first stage. Unfortunately, we don't know the method of return that stage 2 will be using, which has a massive influence on how much investment will be required for recovery. But, let's guess at two cases. The optimistic guess says that it takes another 30% hit to payload capacity to return stage 2; the pessimistic guess says that it takes a 50% hit to payload capacity.

Optimistic: 11.2 tons
Pessimistic: 8 tons

However, there's another factor in play here, namely the fact that there's a hard limit on how much actual mass you can bolt onto the beefiest available payload adapter for the F9. And that is 10.8 metric tons. This doesn't affect the pessimistic guess, but it does affect the optimistic guess. So, as a result:

Optimistic: 10.8 tons
Pessimistic: 8 tons

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4 minutes ago, Streetwind said:

the fact that there's a hard limit on how much actual mass you can bolt onto the beefiest available payload adapter for the F9. And that is 10.8 metric tons.

And is the same payload adapter going to be used for the FH? Because that seems silly, considering that an expendable FH can theoretically carry 63.8 tons (!)(according to spacex.com). :/ 

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29 minutes ago, TheEpicSquared said:

And is the same payload adapter going to be used for the FH? Because that seems silly, considering that an expendable FH can theoretically carry 63.8 tons (!)(according to spacex.com). :/ 

Almost certainly, yes. There's no such thing currently as a commercial 10 ton payload, a 60 ton payload is total fantasy.

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37 minutes ago, TheEpicSquared said:

And is the same payload adapter going to be used for the FH? Because that seems silly, considering that an expendable FH can theoretically carry 63.8 tons (!)(according to spacex.com). :/ 

 

6 minutes ago, Kryten said:

Almost certainly, yes. There's no such thing currently as a commercial 10 ton payload, a 60 ton payload is total fantasy.

Mister Everyday Astronaut himself reported on Reddit that it is getting a much more physically impressive payload adapter. No hard performance numbers, but well, we can assume those to be under NDA until the Falcon Heavy User's Guide is made public.

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4 hours ago, Streetwind said:

 

Mister Everyday Astronaut himself reported on Reddit that it is getting a much more physically impressive payload adapter. No hard performance numbers, but well, we can assume those to be under NDA until the Falcon Heavy User's Guide is made public.

I think it's safe to assume that the S2 for F9H has also been beefed up?

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Gonna cross-post from my usual haunt over at Orbiter Forum...

 

Got another walk through the plant today. Guess what was available for photo ops?

o8CyTi2.jpg

That, folks, is the crew capsule mockup for New Shepard. It's very nicely fitted out. Window frames are handholds, there's a ring of handholds in the ceiling and around the abort motor housing, and the seats are, well...

j4vliSG.jpg

(of course I'm grinning like an idiot. Can you honestly claim you'd do differently?)
As advertised, the view from the windows will be utterly amazing. GREAT view upwards while in the seat, so you can watch the sky go black as you climb, and the view down is pretty good if you turn your head a little in the headrest. And the view outwards will be incredible.

Headspace for 6'3"/190cm tall me was somewhat limited in the capsule while standing... I could stand up straight and put my head into the cushioned ceiling with a moderate amount of force, which could be useful for freefall... should I ever get the opportunity to ride for real.

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11 minutes ago, MaverickSawyer said:

Got another walk through the plant today. Guess what was available for photo ops?

o8CyTi2.jpg

 

What's  that thing in the background that looks like they Flying Bedstead? 

Is this place in Texas or Kent?

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Kent, WA plant. Texas is just a facility for more... energetic... operations.

And the thing in the background is a banner with an image of Blue Origin's first flying vehicle. Don't remember the name of it, but it's powered by a quartet of Viper turbojets and was used to validate several flight control algorithms that were used on later vehicles. Not sure how many times it flew.

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@MaverickSawyer, nice!

I read a post on NSF that someone looking for a Kent tour was told that after some point in May the tour would be less interesting...

The take away is that the NS boosters and BE-4s will be either in TX, or OTW for testing. I'm hoping they try some flights, I might well drive down to TX to try and see one (the facility is right over the State line with NM where I am). I haven't seen a launch since I got passes to see one of Deke Slayton's launches at White Sands years ago.

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Yeah, stuff is always shifting in the shop, and that's pretty normal for these kinds of operations. But, there's always something cool to see, whether it be a few prototype/test version BE-4s in various stages of assembly, or a NS booster being built.

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28 minutes ago, MaverickSawyer said:

Yeah, stuff is always shifting in the shop, and that's pretty normal for these kinds of operations. But, there's always something cool to see, whether it be a few prototype/test version BE-4s in various stages of assembly, or a NS booster being built.

Can just anyone get a tour, or do you have to be Jeff Bezos's uncle's father’s brother’s nephew’s cousin’s former roommate?

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Typically need to have insider connections from an employee. There's more than a thousand people working at Blue now, from what I've heard.

 

Oh, and you have to be an American citizen. No way around that, because ITAR.

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Can anyone think of a good way to get a flat-earther on the first flight?

 

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13 minutes ago, Skylon said:

Can anyone think of a good way to get a flat-earther on the first flight?

 

Sure, buy one a ticket.

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Just now, tater said:

Sure, buy one a ticket.

How much will they be? 

Maybe we could start a crowdfunding campaign aimed at the science community. The question is, who would we choose to go? The leader/founder (of the modern society)?

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14 minutes ago, Skylon said:

How much will they be? 

Maybe we could start a crowdfunding campaign aimed at the science community. The question is, who would we choose to go? The leader/founder (of the modern society)?

We can crowdfund a ticket for Elon Musk!

.

.

.

Oh... right.

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Stage 2 is weird. It provides most of the DV for falcon 9 in order to keep the first stage slow for recovery. But the Space x website advertises the same burn time for F9 and FH second stages, implying no more propellant for S2 on FH. Combined with doubling the payload, that has got to do awful things to S2's DV.

Either I'm missing something or the core stage 1 is going to have to separate crazy-fast compared to falcon 9. How then do they plan to do core recovery?

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Either by reserving plenty of fuel to slow down, or by hoping it can survive a faster re-entry, which would at least allow more data collection.

 

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27 minutes ago, RCgothic said:

Stage 2 is weird. It provides most of the DV for falcon 9 in order to keep the first stage slow for recovery. But the Space x website advertises the same burn time for F9 and FH second stages, implying no more propellant for S2 on FH. Combined with doubling the payload, that has got to do awful things to S2's DV.

Either I'm missing something or the core stage 1 is going to have to separate crazy-fast compared to falcon 9. How then do they plan to do core recovery?

As far as I know, they will use the same S2 with Falcon Heavy. I think that FH are mainly going to be fully reusable rocket for current sized commercial payloads. In such situation they have good margins for all stages. If higher mass is needed, they can launch it partly of fully expendable.

 

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2 hours ago, RCgothic said:

Stage 2 is weird. It provides most of the DV for falcon 9 in order to keep the first stage slow for recovery. But the Space x website advertises the same burn time for F9 and FH second stages, implying no more propellant for S2 on FH. Combined with doubling the payload, that has got to do awful things to S2's DV.

Either I'm missing something or the core stage 1 is going to have to separate crazy-fast compared to falcon 9. How then do they plan to do core recovery?

Even before first stage reuse second stage had most Dv, simply as it don't have to haul the second stage to the edge of space and 2 Km/s help. 
More optimized LH2 upper stages like centaur is even more extreme, have to be inside fairing and have balloon tanks. 

In KSP we get a bit biased because the low orbital speed combined with bad TWR and high dry mass we also need an higher TWR on second stage to reach orbit.

 

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5 minutes ago, magnemoe said:

Even before first stage reuse second stage had most Dv, simply as it don't have to haul the second stage to the edge of space and 2 Km/s help. 
More optimized LH2 upper stages like centaur is even more extreme, have to be inside fairing and have balloon tanks.

Yes, this is the key. The payload of stage 2 is the satellite. The payload of stage 1 is (stage 2 + satellite). This is why first stages have so much less delta-v.

I would guess that a weight-optimized FH would have a bigger stage 2 than a F9 has, but that a cost-optimized FH might well have the same stage 2 just because of the commonality benefits.

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3 hours ago, mikegarrison said:

Yes, this is the key. The payload of stage 2 is the satellite. The payload of stage 1 is (stage 2 + satellite). This is why first stages have so much less delta-v.

I would guess that a weight-optimized FH would have a bigger stage 2 than a F9 has, but that a cost-optimized FH might well have the same stage 2 just because of the commonality benefits.

The booster does not provide much of the dV to orbit, but it provides a great deal of the energy to orbit, because it accelerates the fuel of the second stage.

5 hours ago, RCgothic said:

Stage 2 is weird. It provides most of the DV for falcon 9 in order to keep the first stage slow for recovery. But the Space x website advertises the same burn time for F9 and FH second stages, implying no more propellant for S2 on FH. Combined with doubling the payload, that has got to do awful things to S2's DV.

Either I'm missing something or the core stage 1 is going to have to separate crazy-fast compared to falcon 9. How then do they plan to do core recovery?

According to the pricing page on the SpaceX website, where standard prices are quoted assuming reuse, FH can put 8.0 tonnes into GTO with full recovery. I'll use that as a starting point for everything else.

According to the SpaceX website, F9 can put 22.8 tonnes of payload into LEO expendable, while FH can put an ungodly 63.8 tonnes into LEO expendable. S2 dry mass is 4 tonnes and fuel load is 107.5 tonnes. Thus, for expendable launches, the F9 second stage provides 5.5 km/s while the FH second stage provides just 3.2 km/s. FH staging velocity is 2.3 km/s higher than F9. For GTO, F9 can put 8.3 tonnes into GTO while FH can put 26.7 tonnes into GTO, both expendable. So the second stage provides 7.8 km/s for F9 GTO and 5.1 km/s for FH GTO. FH staging velocity is 2.7 km/s higher than F9.

But that's all expendable. What about recoverable launches? Well, we know that the F9FT managed to put the 5.5-tonne SES-10 into GTO with (yay reused!!) core recovery at a staging velocity of 2.28 km/s; this was likely the upper limit of F9 FT's performance (in fact, SES-10 was originally planned to go up on FH). The F9 S2 delivered a whopping 8.6 km/s of dV to the satellite. In contrast, Echostar XXIII's staging velocity was 2.7 km/s. In order to reach the same (approximate) orbit as SES-10, the second stage needed to give it 8.2 km/s. By my numbers, this puts Echostar's mass at 6.8 tonnes.

This information allows us to estimate how much dV the first stage for the SES-10 launch reserved. Using vacuum isp and treating SL isp losses as an additional source of dV drag, the dV delivered by the first stage in the Echostar 23 launch was 4.17 km/s, meaning total drag losses (gravity, air, and isp) were 1.47 km/s. This means the SES-10 first-stage booster delivered approximately 3.75 km/s in dV including losses; it would have had 21.6 tonnes of propellant remaining, representing about 2.1 km/s of dV for the empty first stage.

So what does it look like when Falcon Heavy puts 8 tonnes into GTO with full core recovery? Well, that's 7.8 km/s of dV for S2, meaning that it needs to be staged at 3.1 km/s. In order to survive the same re-entry profile as the SES-10 booster, the core will need to burn off 0.82 km/s of dV more than SES-10 did, so it needs to reserve about 35.7 tonnes of propellant.

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6 hours ago, RCgothic said:

Stage 2 is weird. It provides most of the DV for falcon 9 in order to keep the first stage slow for recovery. But the Space x website advertises the same burn time for F9 and FH second stages, implying no more propellant for S2 on FH. Combined with doubling the payload, that has got to do awful things to S2's DV.

Either I'm missing something or the core stage 1 is going to have to separate crazy-fast compared to falcon 9. How then do they plan to do core recovery?

I think that SpaceX just wants for the time being save money on the development of a specialised 2nd stage for Falcon Heavy. The Falcon 9 2nd stage is good enough for the first flights of Falcon Heavy and provides it with a meaningful payload capacity, even if it means that recovering the core stage will cost a lot more fuel and thereby cost a lot in terms of payload fraction.

And lets not forget that SpaceX wants to recover 2nd stages, so they are planning for quite some development in terms of Falcon 2nd stages, unlike the first stages, where most of the development already seems to have happened.

After all, Falcon wouldn't be the first rocket that got a new second stage at some stage in its life cycle.

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