SpaceX Will Launch Its First Reused Rocket Later This Month | Hacker News Reader

SpaceX Will Launch Its First Reused Rocket Later This Month

bloomberg.com

240 pointsayanai74 comments

The exciting part is if they successfully land it again.

Consider: eight first stage rockets have been landed already. One is a show piece (the first one) and at least one is too beat up to ever be reused. But that leaves a fleet of six-ish rockets. How many Falcon 9s would SpaceX need to run an active fleet that is constantly refurbished and reused, never replaced? They'd start to look less like Boeing and more like Delta.

Not exactly like Delta; Falcon 9 second stages are still one-flight throwaways, and plans for reusing them have been shelved. (That might change if they build a second stage powered by the Raptor engine currently being prototyped for their Mars project -- or a scaled-down version of it -- but that remains a poorly-sourced rumor at this point. If they're working actively on any such thing, they've kept it fairly tightly under wraps.)

See: https://en.wikipedia.org/wiki/Raptor_prototype_upper-stage_e...

While there's no money in this contract to develop the upper stage itself, only money for the engine, it's still a source.

> eight first stage rockets have been landed already.

Wow this is truly amazing! I didn't realize they've landed it 8 times already... I still remember watching the youtube live stream of the first successful landing and how exciting and moving it was to watch. We're truly entering a new phase of space exploration and I can't wait to see what comes of the next decade and beyond!

After the 4th or 5th one landed, and it suddenly became clear that this was the new normal, Musk had this wonderful tweet: https://mobile.twitter.com/elonmusk/status/72845980827000012...

My favourite part of this is how my perceptions have changed.

    - This cannot be possible
    - Awww, they got pretty close that's incredible
    - Great Scott, they've done it!
    - Heh, they're getting good at this
    - There's no way they'll fuck this up

"Any sufficiently advanced technology is indistinguishable from magic."

And then once the trick is revealed, it stops being magic and just becomes "boring" math/engineering/etc.

Then:

- Yawn, another landing. It just lands, nothing exciting to see.

luckily between here and there the'll be a lot of entertaining fireworks to be had.

the only shameful aspect of it is how the press will portray failures as terrible events for SpaceX, while they're still pushing the envelope and boundaries of what we think it's possible with failures being normal for quite some time yet.

I think SpaceX has done a good job countering this perspective so far. Their press releases and web casts consistently reinforce that the landing is merely a secondary objective and an experiment which they will learn a great deal from whether it blows up or not.

Pretty much my thinking too.

They're a ways from being Delta. One of the things that came out recently regarding crewed launches is Merlin turbines have been developing cracks under test. They're probably only good for a handful of flights.

Musk claims that's all going to be fixed in the next version. We'll see.

That didn't come out recently, that was known from the very start, as Gwynne Shotwell noted in the press conference prior to CRS-10. They have flown with cracks in the turbopumps since Falcon 9 flew for the first time and it was no big deal (customers have known and were okay with it for cargo flights). It's just that for human flights they want every most bit of safety margin they can get, so they'll fix it for Block 5.

To my knowledge there has only been one engine failure (which resulted in the secondary payload being lost), and it is not known whether that was due to the turbopump.

One other thing to consider is that most pre-Block 5 rockets won't fly that often even if/when SES-10 is successful and even lands again. Most customers get factory-new rockets and they already learned a lot on how to make the first stage easier and better to reuse. So once Block 5 comes around the older landed boosters are probably not needed much. They converted one of them into a side booster for Falcon Heavy already, as far as I know, so that may be one point for salvaging them.

What does Block 5 mean?

It's effectively a version number. SpaceX have been quite inconsistent in how they've named their rocket versions, with Falcon 9 v1.0, 1.1, 1.2, Full Thrust, another upgrade that didn't get a name (informally called Fuller Thrust), and Block 5. Perhaps Elon is just messing with us. Effectively Block 5 is supposed to be the last iteration of the Falcon 9, with a slight performance increase and a lot of improvements to reusability, mostly from what was learned from the landed cores.

I suspect at this point that Elon's entire goal in naming things these days is to troll people. The naming of his autonomous barges after sentient spacecraft from Iain Banks novels is quite clever, and his announcement of 'The Boring Company' should really put to rest any questions of whether he's messing with us with naming things. I find it quite funny, personally.

Also notice the pronunciation Space-sex, and Tesla models s,3,X (he wanted a model E, but settled for 3 after Ford complained). He is clearly trolling.

Even if a booster can only be reused 2-5 times, it's still a dramatic improvement over throwing it away after a single flight and will still have a measurable impact on launch prices. There's also savings to be had by putting all expendable flights on boosters that only have one or two launches left in them.

Seriously. Going from 1 to 2 uses is a massive improvement.

And being able to decommission, dismantle, inspect, recycle, and safely dispose, rather than throwing them in the ocean.

I think if they can only get two flights out of a launcher, it will not make economic sense to reuse them. But I think SpaceX will do much better than that.

cost = cost of single / 2 - cost of prepare the landed first stage

The "cost of prepare the landed first stage" is the big question here.

Plus the cost of the second stage.

And the additional cost of developing a rocket that can land

I agree, of course. But the comparison was to commercial air travel.

Recovering the engines allows for inspection and modifying the design to compensate for any problems.

Competitors just dump their flight-tested hardware in the ocean, when it is truly a goldmine of test data.

SpaceX is able to do all this testing with a free ride on paying launches. There's no risk to the primary mission, and they get to develop their capability.

There will be failures with reflown hardware for sure. I'm interested to know how well a failed engine can be isolated in flight so not to affect the others.

F9 has single-engine-out capability, and it's actually been used. That requires that the failure be contained.

BTW engines are often tested on the ground, so the main extra thing SpaceX learns from landing stages is data from the non-engine components.

Identifying those points of stress is the first step to building a better launch system.

Oh, I agree. I just think it's going to be awhile.

Agreed that each re-use lowers their overall operation cost for reaching orbit (and either increases profit or cuts customer cost to orbit depending on what ULA does).

I also find that it is considered 'normal' that if your developing a new orbital booster you should insure that it is re-usable if you want to be competitive. That will put an interesting pressure on Russian launch vehicles if they wish to continue to get international business.

But a critical issue which isn't resolve is 'cycle time.' For this to really be effective you can't spend as much time and money 'refurbishing' a booster as you did building it in the first place. (then re-use just saves materials and maybe time but not cost). Bezos demonstrated some pretty impressive cycle times with the New Shepard, and if they can get those type of cycle times on New Glen (a couple of weeks) they will be more competitive than Falcon 9. Fun times.

I think time matters much less than cost because you could just pipeline a bunch of boosters being refurbished. You only have to have a booster ready at the rate it takes to get one of the three pads ready.

It is nice that Blue Origin is intended to be reusable, but Long March 5/6/7 and Ariane 6 and Vulcan and Angora and GSLV mkIII are all not reusable.

Not all flight plans can lead to a recoverable rocket. GTO and polar orbits can't land back. This means there will be unrecoverable rockets from time to time.

But your question still applies to recoverable flight plans. How many do they need to cover all those?

GTO and polar orbits can still land, they just use the barge ("Autonomous Spaceport Drone Ship") instead of returning to the launch site.

There are launches which don't have enough margin to land at all. The upcoming EchoStar 23 launch is one of these. This is a GTO launch of a really heavy satellite, so getting it up there requires using the fuel the rocket would need to land.

However, this is rare, and it's likely that this will only happen a few more times at most

> However, this is rare, and it's likely that this will only happen a few more times at most

Especially once Falcon Heavy comes online.

Only six more months! As it has been for the last four years....

I think the key point there is that SpaceX can offer many new options for launch that seriously expand the kinds of contracts they can accept.

If your payload and destination allow for reuse then the cost of your launch is (cost of the whole rocket) / (number of reuses) + (landing & refurbishing costs)

If you require the full fuel of a Falcon 9 it might make sense to accept higher risk and launch on a rocket that is at it's last launch.

If you also don't want that risk, then maybe a mid-life Falcon Heavy can be cheap enough for you.

If Falcon Heavy is still too expensive even with re-use then maybe a one shot Falcon 9 is right for you.

Very few of their future flights will be expendable (in fact, the Echostar-23 launch coming up next will likely be one of the last).

The Block 5 upgrade will bring the performance of Falcon 9 (in a recoverable configuration) up to the point where flights like Echostar will be able to make downrange barge landings. Heavier payloads (which are _very_ rare nowadays) will fly on Falcon Heavy.

Polar orbits are almost always low-earth orbits, and therefore are much easier to recover. I would be very surprised if they ever flew an expendable launch out of Vandy in the future.

> Heavier payloads (which are _very_ rare nowadays)

Yes, but how much of that is because there isn't anything to launch them? When Falcon Heavy is up and running, a commercially feasible option will exist for the first time. Maybe that'll change, and we'll start seeing things in space that weren't commercially feasible before.

It's only commercially feasible if SpaceX is willing to sell that service. They are pretty firmly committed to the philosophy of reuse.

They have to fly expendable now, because customers can just fly on Ariane/Atlas/etc if SpaceX said no. Once Falcon Heavy is flying, there won't be any competitors with the same payload capacity (until New Glenn, which is also planning first stage reuse, but is still very much a paper rocket at this point).

There will always be payload that pushes the rocket to its limits, make a rocket with larger lift capacity and payloads will increase.

However, they can build that into the cost of the lift. If the rocket isn't recoverable because of what they want to put in it, just charge them for the rocket.

Either way it is better than what we have now.

Maybe... Elon is pretty firmly committed to reuse though. SpaceX is occasionally flying expendable now because they have to compete with Ariane and Atlas. Once Falcon Heavy flies, there won't be any such pressure.

yeah if computer ram size growth taught me anything is that once there's capacity, there'll be consumption.

/me looks sternly at DooM

From which flight was the one that is too beat up to be reused? What happened?

JCSAT-14. It was the first successful landing after a GTO launch and it came down quite hard. GTO launches have the first stage come back quite a bit faster and with less fuel margin than LEO launches. See for example the SES-9 launch where landing failed due to too little fuel being left.

While SpaceX opted to test this core to the breaking point, they also noted that it could have been reused despite the damage. But having a core that represents more or less the worst damage possible while still being able to refly it is valuable in itself and for comparing other landed cores against.

They have since fired the engines for numerous full-duration burns at their test site and presumably nothing exploded yet. This doesn't tell much about aerodynamic stresses imposed, but at least the engines and tanks are seemingly good to go with minimal refurbishment for a few reflights at least.

It landed too hard iirc.

Once it has been recovered, how challenging is it to recycle a the first stage? If I recall correctly, the solid state boosters on either side of the space shuttle would get reused, too, if you went out and picked them after they fell into the ocean.

EDIT:

It looks like making the shuttle boosters wasn't all that economical... https://www.quora.com/Space-Shuttle-How-much-money-was-saved...

The hope is, that long term the first stages can basically be refueled and be ready for relaunch. Of course, only experience will tell how much that is possible. One big difference though is, that unlike the space shuttle boosters, the Falcon first stages are not dumped into salt water on landing. This is one of several reasons, they chose not to go via parachutes for their first stage recovery.

Solid fuel rockets have a much simpler design, no fuel pumps or cry-cooled fuel tanks. But they are less efficient weight wise, and you cannot turn them off to abort a launch.

Unless you decide to compromise the design by manufacturing them in sections with dodgy O-ring connections.

> how challenging is it to recycle a the first stage

Depends on how well it lands. There's a 'loss-leader' booster that landed but is in bad enough condition that they're keeping it for comparison purposes as to how bad it can get (JCSAT-14, someone else posted in these comments).

In terms of time, this first refurb happened in the last year or so, because no booster had ever landed before Dec 2015.

With Echostar 23 being pushed further out I'd guess SES-10 will slip to April. It seems they're still working out the kinks of their new launch pad.

I was going to say the same thing. I've been watching the static fire for Echostar 23 get delayed twice now for undisclosed reasons. I think April is more realistic.

What a fun time to be alive, I've been hoping for this step for a long time now, reusable rockets will greatly improve our access and exploration of space and should allow some great leaps in our species progression. It makes me wonder how many years from now until rocket launches to space like this will seem like today's commercial airline travel.

The difference between a commercial airliner, and a rocket launch is four to five orders of magnitude of power.

Rockets have, and will continue to occasionally explode. (From 1% to 5% of the time.)

If airplanes would explode 1-5% of the time, there wouldn't be a commercial air travel industry.

The Martin M-130 was the main plane Pan-Am used to establish the first cross pacific passenger service. Three were built exclusively for Pan-Ams cross pacific service started in 1936, offering one flight per week.

The Hawaiian Clipper disappeared in the pacific with all hands in 1938. PanAm also used the Sikorsky S-42 on shorter legs, one exploded in mid-air in Pago Pago same year. The other two Martins crashed with heavy fatalities in 1942 & 1945, 100% loss rates. Pan-Ams ten Sikorskies had at least five fatal accidents for a 50%+ loss rate.

They were replaced by the Boeing 314, 12 were made, 3 crashed for a 25% loss rate. They were all taken out of service by Pan-Am quickly after WWII, so Pan-Ams total fatal accident rate for its seaplanes was around 45% in only about 13 total years of service for all types.

Despite this Pan-Am was hugely successful at establishing profitable ocean crossing passenger flights and changed the world doing it.

People will take a lot more risk to reach new worlds, if we only let them.

Assuming each plane flew 1-3 times a week, for 13 years... That would be 600-2000 flights. If half the planes crashed, that would give them a failure rate of 0.1-0.025%.

The Space Shuttle (Also a second generation vehicle) had a failure rate of 1.5%.

The Souyz (Widely considered to be the most reliable launch system, with a successful launch rate of 97.3%) had 2 accidents which killed everyone on board - out of 136 launches. Also a failure rate of ~1.5%.

Your estimates are a bit off. Each plane didn't fly for 13 years, on average they flew 5 or 6 years. And the pacific routes were only once a week until the first crash, and Pan Am didn't replace it, just flew the route 3 times a month.

Edit: The pacific route was nearly a week long, so obviously if you count each leg separately percentages were better, but passengers had to fly every leg to reach their destination, unless they wanted to be marooned on a remote island.

And your failure rates are backwards looking. Flying boats before 1938 certainly had even worse safety records than post 1938, so the first passengers on Pan Am flights had worse safety expectations. Counting legs separately would be like saying the Shuttle actually made 270 trips, 135 up and 135 down.

The Falcon 9 and Heavy are likely far safer than the Shuttle, which was a clearly unsafe design, from the rube goldberg melding of solid and liquid rockets to a crew cabin with no abort systems, and unproven reentry shielding on a shape that accentuated the dangers of its use.

Falcons are a refinement of proven launch technologies, combined with a much safer crew compartment with excellent abort features and using proven reentry shielding/shape. Odds are it's far safer than the shuttle.

Only 10% of Magelleons crew survived the circumnavigation of the world, yet explorers lined up to follow. If SpaceX offered rides to Mars with a 20% chance of death, there would be a waiting list of hundreds of thousands of people.

In reality it shouldn't be too hard to reduce launch safety risk by a factor of 10 from historical launches. The Dragon capsule can almost add that improvement by itself.

> Rockets have, and will continue to occasionally explode.

Will they? I don't know a tonne about rockets, but maybe as we reuse them it will make sense to make more expensive rockets that do not explode since we're going to be reusing them. At least for crewed missions.

The rocket equation is highly unforgiving. Even minor structural reinforcements, with a minor increase in vehicle mass, have disastrous consequences on the amount of payload you can carry into orbit.

At full thrust, a Boeing 747 produces ~90 MW of power. At full thrust, the Saturn V produces 166 GW of power. It's a staggering amount of energy - there is no way to make it 99.9999% safe (Which is where air travel is currently at.)

There's also payload fraction - the useful weight that your vehicle can carry. In the case of a Boeing 747, 50% of its weight is useful cargo. In the case of a Saturn V, 4% of its weight is useful cargo. [1] Rockets are incredibly wasteful.

[1] https://en.wikipedia.org/wiki/Payload_fraction

There are two changes that make the situation less dire for SpaceX.

1) It's Dragon capsule has an amazing emergency escape system that can operate safely during most (if not all) of the launch and ascent. It can escape and land with the Draco boosters on the capsule, but also has parachutes to provide safety redundancy.

2) The fuel to launch the first stage of a Falcon 9 only costs a few hundred thousand dollars. So while mass fraction is still low, the cost is potentially as low as a few million for each first stage launch/refurb cycle.

Given second stages cost a fraction of what the first stage does, it's not necessary to re-use second stages to have massive potential savings.

Having an emergency escape system is table stakes. The fact that the Shuttle didn't have one was a serious design problem.

The Souyz also had an escape system. That didn't stop one crew from decompressing, and another from pancaking into the ground (Because of a parachute failure.)

Depending on when the accident takes place, the Dragon will require both parachutes, and retro-rockets to land.

> The fuel to launch the first stage of a Falcon 9 only costs a few hundred thousand dollars. So while mass fraction is still low, the cost is potentially as low as a few million for each first stage launch/refurb cycle.

Only a few hundred thousand dollars (Discounting all labour costs... Which will not go away) to send three people to space and back.

For that much money and fuel, American Airlines can send a thousand people around the world, and throw in a soda for free.

Around the world isn't space. Space costs of anywhere near $1M a person would open a huge market.

Edit: An example is that a price of $30M per seat created a market of 1 commercial space traveler a year in the decade of the 2000s ( and with a risk of life expectation of nearly 1% ).

The Dragon 2 has 7 seats, if re-usable Falcon 9 flights drop below $30M range, you potentially have $5M a seat flights (depending on Dragon costs and number of crew members). And they likely could fill every one of those seats.

> until rocket launches to space like this will seem like today's commercial airline travel

I hope you don't mean this in a quantitative way. It would create a terrible new environmental pollution.

Is there info on how many times a Falcon 9 stage can be used before it's simply worn out?

The information on this literally doesn't exist yet. They're discovering it right now by trying to actually re-fly the first rocket. As they re-fly more of them, they will learn more about what wears out and how fast. Then they can build versions that don't wear out so fast and need less refurbishment using that knowledge.

Not really, I get a lot of my in depth SpaceX info and analysis from r/spacex (which is a pretty great little community, and one of the best places to track behind the scenes SpaceX stuff) and all I've picked up from there is "probably at least once".

It'll also depend on the difficulty of each orbit, rockets that reach higher and/or deliver payloads with more extreme orbital inclinations, experience more stress and are less likely to be reliable enough to be reused.

I think the current design can survive ~10 reuses? [1]

However, the next and last iteration of Falcon 9, Block 5, is supposed to survive much more reuses, and easier to refurbish.

[1]: https://www.reddit.com/r/spacex/comments/590wi9/i_am_elon_mu...

They've ground-tested boosters with full-flight equivalent burns hundreds of times without seeing any serious degradation. Of course that's not the same as putting them through re-entry and landings. Block 5 will include improved legs and I'm sure they will make other improvements based on lessons learned from examining the recovered boosters.

Personally I'd expect the main stresses on the system to be due to running the engines. I see no reason to suppose that the other stresses the cores experience in flight can't be engineered round to a similar degree of resiliency.

Not hundreds, but they have tested one of the boosters they recovered about 8-10 times through a full flight cycle in Texas. Doing it hundreds of times would cost a lot of money just in propellant! And the boosters (pre-Block 5) are supposed to be good for around 10 uses.

And they do test the engines a LOT. Each new engine is separately acceptance-fired (less than full mission, but not just a burp) in Texas, then integrated into a full stage and acceptance-fired again in Texas. Then, the stage is brought to the launch site and a very short static fire test is done. If there are any last-second aborts (i.e. after engine ignition but before clamp release), that puts another short cycle on the engine. So launch will be at least the 4th firing of each engine. And if it's the center engine, it'll do a boost-back burn, an entry burn, and a landing burn. So the engines get a lot of work done even on a nominal mission before we talk about reflying the stages.

And since each Falcon 9 takes 10 engines, that means they do (depending on the mission type) around 40-50 engine firings per launch, so yeah, over a half dozen or so launches, they ARE indeed doing hundreds of engine firings, just not all on the same engine and same booster.

Not yet, and as every stage requires refurbishment the question is more, what do you need to replace or inspect after how many flights. Gwynne Shotwell said that while this stage's refurbishment took 4 months it'll be less than that going forward with what they've learned. Further to that, the Falcon 9 block 5 is going to be a version that incorporates revisions to increase reusability.

A simple answer to your question. We don't know yet, and it's going to be changing for a while yet.

I don't think it's likely a system designed for say 30+ reuses and short go around time and high reliability is so close to the current system. It might look similar on the outside, but might have different propellant, different engine cycles and be made of different materials, maybe also have different staging.

'Later this month'?

Spaceflightnow.com says the next Falcon 9-SES launch is SES 10 on March 27.

That's the launch in question, and we're in the month of March...

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