SpaceX set to re-fly a Block 5 rocket for the first time tonight

https://arstechnica.com/science/2018/08/tonight-spacex-to-reuse-its-first-block-5-variant-of-the-falcon-9/

by Tomte • 8 years ago

178 73 8 years ago

vertline2• 8 years ago

This blows my mind and I have naive questions. How can the materials withstand such forces? Is a piece inside replaced (he said without taking it apart)? Is ablation a factor at all?

InTheArena4• 8 years ago

They've worked hard to get rid of pieces that have significant re-engineering. A good example is the grid-fins which have been moved to titanium, because they old ones were being worn away.

nickik4• 8 years ago

There is a heat-shield in the button of the rocket. PICA-X is a technology that SpaceX is working on and have been for a long time.

There is heat coating on the new rest of the rocket.

bluGill• 8 years ago

presumably a combination. Most parts on the rocket don't actually see that much stress. Find the parts that take the most stress. Then either make them stronger; or make them quick/easy to replace quickly and cheap to manufacture.

thebluehawk• 8 years ago

It's important to note that the first stage (which is about 70% of the rocket) is the part that is being reused. The top of the rocket (the second stage, the fairings, and the payload) are not reused (At least not yet. They are working on recovering fairings and there are rumors of second stage reuse).

When the stages separate, the first stage is going about 1.5 - 2.5 km/s. Then the second stage takes the payload the rest of the way to orbital speeds of 7+ km/s, and the first stage returns to earth.

So the first stage is going fast (several thousand miles per hour) but not as fast as things that re-enter from orbit. It still does need heat shielding, but not as much as the space shuttle or a capsule.

mr_toad• 8 years ago

The retropropulsion actually helps shield the rocket from heat.

https://space.stackexchange.com/questions/13935/how-does-the...

mozumder• 8 years ago

OK I get that booster reuse cuts down costs, but the fact is the 2nd stage is still not reused, which limits the economic benefits needed to open new markets. We get a 50% reduction in costs, instead of the 95% reduction in costs.

You can get a 50% reduction in costs just by going to India for launch..

Is SpaceX going for 2nd stage reuse at all? That's going to be a lot harder than booster stage reuse, since you're returning to land at orbital velocity.

And then there's the whole issue of increasing reliability of the 1st stage for reuse hundreds (or thousands) of times needed for new business models...

bosdev• 8 years ago

The first stage is significantly larger and therefore more expensive than the second.

My guess is the first full-reuse rocket you'll see will be the SSTO BFR.

lorenzhs2• 8 years ago

SSTO BFR

[citation needed] - I don't think BFR is intended to be single-stage to orbit?

martythemaniak• 8 years ago

The answer is, this is Falcon 9's final form. You can get it in single or triple core variants.

All new work is now on BFR, which will have 2nd stage reusability, orbital refueling, better economics etc. I think you're also underestimating how far this Falcon will get them - their timelines suggest that this is what they'll use to launch their global internet satellite network, not BFR.

fooker6• 8 years ago

India can not launch payloads in the same weight class as Falcon 9.

bjnord• 8 years ago

"Is SpaceX going for 2nd stage reuse at all? That's going to be a lot harder"

Yes, they are (and yes, it will be): "SpaceX also continues to study the feasibility of returning and reusing the second stage of the Falcon 9, and Musk said he’s confident it can be done. The question is what “mass penalty” will have to be paid, primarily in terms of the fuel needed to slow the second stage down so that it can make a controlled descent back through Earth's atmosphere.

"Still, Musk believes the Falcon 9 will get to full reusability. In terms of the rocket’s overall cost, the first stage accounts for 60 percent, the upper stage 20 percent, the fairing 10 percent, and the remainder are costs associated with the launch itself (fuel costs are between $300,000 and $500,000), Musk said."

https://arstechnica.com/science/2018/05/spacexs-block-5-rock...

InTheArena4• 8 years ago

The first stage represents about 75% of the cost of the vehicle, not 50%. This represents the actual cost of the metal on the launchpad, but not the services around the rocket, including launch control costs, etc.

You can't take a rocket to India and you can't manufacturer that rocket in India (Skilset, US based corporation, ITAR) so you can't achieve your savings that way.

Even Russia - which is using a very old tried and true rocket design - can't match prices at this point. In addition, the budget cuts in Russia have resulted in a massive reduction in reliability, which has blown up their insurance cost recently.

In terms of second stage re-usability, they are looking at that for FalconX, and it's designed in at the start for BFR. Landing something from a second stage is as difficult comparatively vis-a-vis landing the first stage, as landing the first stage was compared to the suborbital hops that Blue Origin is doing.

The latest SpaceX idea (judging by Elon's tweets) appear to be some sort of Ballute based approach.

The first stage re-use should be good for 10 flights without a overhaul, with a complete tear-down on flight 10.

golem14• 8 years ago

"You can't take a rocket to India and you can't manufacturer that rocket in India (Skilset, US based corporation, ITAR) so you can't achieve your savings that way."

Out of curiosity -- can they _fly_ a rocket to India (maybe have a booster return to India instead of a drone ship ? Too far/out of the way ?

That may not help much since stage 2 would still have to be shipped around, which is probably not cost effective, and there might be other regulations that make it infeasible to launch anywhere but in the USA.

the8472• 8 years ago

they are looking at that for FalconX

I have not heard of that one and neither has google.

kerbalspacepro• 8 years ago

If you can get a 50% reduction in costs by going to India, people would be doing it.

stetrain3• 8 years ago

Basically the answer to all of those is SpaceX's next gen BFR rocket. It is scaled up significantly which makes second stage reuse practical. The challenge with a rocket the size of the Falcon 9 is that added significant fixed mass to the second stage (heat shielding, parachutes, etc.) will significantly Affect payload mass / performance.

By going to a much larger class of rocket, those concessions for re-use become a smaller fraction of the total stage 2 mass.

ashraymalhotra• 8 years ago

It is worth recalling that SpaceX only flew a "used" booster for the first time in March 2017.

It's amazing this happened just a little over a year ago.

InTheArena4• 8 years ago

It was a epoch defining change. It does feel like a ton of time ago, and everyone in the industry (most notably ULA, Arianespace and the Chinese) are trying to figure out what they do now that the SpaceX steamroller is in full force.

growlist3• 8 years ago

Indeed. Could be that having a legacy rocket programme is if anything a hindrance in this new world of reusability - Ariane in particular seems to be in danger of becoming mainly an employment scheme that builds rockets on the side. For fairness I guess I should say SLS isn't looking too clever at this point either.

JumpCrisscross2• 8 years ago

It was a epoch defining change

Not yet. Costs haven't fallen. The epoch-defining change would be back-to-back commercial launches with the same booster in a short period of time with zero or little retrofitting.

romwell2• 8 years ago

It was a epoch defining change. It does feel like a ton of time ago, and everyone in the industry (most notably ULA, Arianespace and the Chinese) are trying to figure out what they do now that the SpaceX steamroller is in full force.

Nitpicking on the language: why would SpaceX be a steamroller? Steamrollers are slow. Also, what does it mean for a steamroller to be in full force? Steamrollers push downward at a constant force, don't they?

I understand that SpaceX is crushing its competition, so you want to bring the steamroller metaphor, but perhaps for what you are saying other metaphors would be a better fit.

Further reading: Orwell, Politics and the English language[1]

[1]https://ebooks.adelaide.edu.au/o/orwell/george/o79p/

SEJeff• 8 years ago

Don't forget Roscosmos, who is going to be in a world of hurt when NASA and other customers stop using their services and instead use SpaceX.

https://arstechnica.com/science/2018/06/russia-may-lack-the-... sums it up nicely.

oh_sigh2• 8 years ago

Have actual cost saving numbers been published? I remember reading estimates back in 2016 or so of ~60% but I'd be interested in what the real numbers were

ygra• 8 years ago

Gwynne Shotwell once noted that even the very first refurbished booster cost less than 50 % of a new one to refurbish. They've learned a lot since then and Block V is designed to do at least 10 launches I think without refurbishment (this one has been taken apart, though, since it's the very first one that launched).

thekingofh3• 8 years ago

Have they realized their cost savings yet? Or are the teardowns and smaller redesigns still keeping the launch price up? Basically, are we in the future yet?

gliptic• 8 years ago

The refurbishing costs of even their first reused booster was less than half the price of a new booster [1], so something above 50%*70% = 35% saving assuming that the booster is 70% of the cost of the launch. The new block 5 version rocket is supposed to reduce that refurbishing cost by a lot.

However, they have development costs of something like a billion dollars to pay back, and no reason to lower the price drastically at this point, so new launches on reused rockets are going for ~50 million instead of 62 million.

[1] https://spacenews.com/spacex-gaining-substantial-cost-saving...

thekingofh3• 8 years ago

From that link. Holy cow: "“Looking forward for reusability, we don’t believe it really, really counts unless you can turn it around rapidly, or almost as rapidly, as you turn around an aircraft,”.

I had no idea they were aiming for this level. That is just mind boggling how drastic a change it's going to be.

SpaceX set to re-fly a Block 5 rocket for the first time tonight

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