SpaceX Picks Rocket for First Relaunch
fortune.com
fortune.com
You can watch it live on spacex.com or their YouTube or or ustream channel.
https://www.reddit.com/r/spacex/comments/4t2umd/rspacex_spac...
https://www.youtube.com/watch?v=FCCyVCvN2bo (Technical webcast; less talk)
https://www.youtube.com/watch?v=ThIdCuSsJh8 (Hosted webcast; lots of explaining)
The top comment is, however, about today's launch which was a new rocket as you have commented. Your comment was positioned as a reply to a different top-level comment which was on the thread's topic and it doesn't make sense in that context.
It'll be examining the rocket engines for faults, replacement of degraded parts, examining the whole structure for defects, and replacement of any other parts if required - however, that will still be cheaper than completely building a 1st stage from scratch.
Here's hoping the re-use will be a successful one!
Eventually, I think they're aiming for airliner-style reuse. Engineer any frequently-breaking parts to be better, then check every X flights once they've got the kinks worked out.
Not that it has brought launch costs down much, considering how the ULA loves their juicy government contracts for billion dollar NSA/NRO satellite launches.
IIRC the Falcon 9 engine design is the opposite of an RS-68, which is the "one huge fucking engine" design philosophy, which is why a falcon9 has a cluster of many smaller engines and is tolerant of an individual engine failure during launch.
Indeed! A Falcon 9 mission has lost an engine mid-flight, and the flight system adjusted the burn duration on the fly to compensate:
After all, you never put passengers on the very first flight of a new airliner. You test it out first, and then once it's demonstrated you start using it for real. We'll know that reusable rockets have really made it when the first flight of a new one is done as a test flight without risking any lives, and only afterwards is it put into normal use.
SpaceX deliberately engineered lower performance, higher reliability engines. Think minivan instead of Ferrari. The SSMEs were genuine marvels of engineering, but that came at significant cost to reusability.
But I'm pretty convinced they're trying to avoid this. The engines have been test-fired many, many, times (30 starts is a figure that has been mentioned a few times. Remember that the first recovered stage (Orbcom) was returned to the launch pad and went through a static fire just a few weeks after landing. It seems clear to me that they've got their eye on reasonably-quick-turnaround reuse.
If there's a major problem, they already know about it.
Well, the Shuttle engines were, on the order of $50M or something like that. But the Merlin-1D, according to a former SpaceX employee on Reddit, is in the ballpark of $1M per unit. They've really streamlined the design for mass production, so even if thrown away after a single use, the Merlins are actually much cheaper than the Shuttle engines even if you take RS-25 reuse into consideration (9 launches per one RS-25 unit in average - so about $5-6M per engine-launch in just amortized manufacturing costs?). They're also much simpler and sturdier, much like the F-1 engines - despite not being designed for it, it turned out that those could have been used for about twenty-thirty times without major problems and without major component replacements. The RS-25s pretty much required general overhaul after every flight.
On the other hand, that SSME cost figure is probably in 1970s-era dollars....
Anyway, my point is, even if all that SpaceX had to work with for reuse was the main rocket body and a pile of the majority of the engines in working order, that would easily add up to tens of millions of dollars worth of equipment, and thus tens of millions of dollars of cost savings on reflight. There's practically no way that reflight could be more expensive than a new rocket, there's just not enough complexity in the vehicle for that to realistically be possible.
I;m reminded of the story of Shuttle's tires. They were designed to last four or five flights, but famously were replaced every time. SpaceX wants to end such things. Parts are to do what they are designed to do. A part designed to last multiple flights without the need to be x-rayed every time, isn't going to be x-rayed every time.
No, it's real world engineering. You can't simulate everything when you're doing something totally new. You need to make tests on real hardware to confirm that your model is good.
Not doing any x-ray testing would be completely negligent.
Look at the aviation industry for a good example. A pilot might check certain parts of the aircraft before starting it up each time. They'll likely check more things more closely for their first flight of the day. Then it'll get ever closer inspections every X days by maintenance personnel. These checks catch faults.
For a lot of companies this sort of thing is not at all cheaper. They're set up for production, not for disassembly, inspection and refurbishment. It'll be interesting to see how SpaceX tackles this as their launch service solidifies.
As an engineer you get a lot of know how just doing something. The first time I used a CAD program professionally it took me like 10 times more effort and time than what it takes me now. Now is second nature.
Nobody knows what it takes to relaunch a rocket. The exciting news is that they will discover it. In the end it will be way cheaper.
Well, apart from Blue Origin, I guess. They've done four sub-orbital missions now, with their production hardware. I know there are differences, but it's a similar problem-space, so they are an existence proof that it's possible.
A kilogram of water on Earth is worth a few pennies. In space, it's worth $5,000 - $10,000. The value-add difference is the launch cost.
Take a bunch of cheap stuff you'd like to have (but don't need essentially, and can readily replace), and pack it on a refurbed booster. If successful, you've gained a few thousand dollars per kg mass. If failed, you're only out the source materials (and the booster, though since this is a test, it's the outcome that's most significant).
The truly hard part for SpaceX has been getting tthe insurance providers onbaord.
But even if that was not the case and it could throttle down enough, suicide burn is the most efficient way of landing a rocket (the least amount of fuel required) as it has very small gravity losses - the faster you slow down, the less you have to fight against gravity, so they would use it in most cases.
The amount of fuel left when going anywhere besides low earth orbit (or the international space station) is so big that they hardly have any to spare - the tyrany of the rocket equation and all that... You can test it all out yourself in Kerbal space program :-)
Adding another (different) engine also complicates things. Currently they only have a single engine type for the whole rocket (plus thrusters), the one on the second stage having a different nozzle. This greatly reduces complexity and thus cost and risk.
Mass on the second stage is on the rocket during both 1st and 2nd stage burns, while you get to leave 1st stage mass behind for the 2nd stage burn.
When they land the first stage, it has already burned >90% of the fuel. Plus it doesn't have the second stage / payload obviously. :)
There is a VERY low risk factor that companies which launch these will accept. These satellites drive business for companies for years their life cycle is 20 years or so. They are a massive investment, and any risk on getting the satellite to space is seen as something to avoid at all costs. Different rocket companies are considered to be the gold standard because they introduce VERY low risk to your payload. Even though these payloads are insured it's still not worth loosing one because you loose out on a ton of revenue.
I'm speaking strictly of GEO satellites right now, but the whole economy around satellites will have to be rethought if we can cheaply get devices out there. I suspect that using "tried and true" hardware would become much less important and the cost of the massive satellites would go down because we can launch 5 a year every year instead of 1 or 2 a year. If one of them fails that's fine, we can replace it with something new and margins of safety that are applied in the industry can be reduced.
Fortunately, there seems to be no shortage of ways out of this - new large markets like massive LEO constellations and fuel depots for more capable exploration missions immediately come to one's mind.
[1] https://mobile.twitter.com/elonmusk/status/75219082879835340...
> Misunderstanding of what "beta" means to Tesla for Autopilot: any system w less than 1B miles of real world driving
Since Pokémon GO's client requires functional GPS and locks out when it cannot use one (to prevent cheating around turning off one's GPS when one is at a location of interest to pretend you haven't left it), it will fail to operate at ISS orbital altitude, even if it has reliable network link to the Pokémon GO servers.
So the answer to your question is "Only if one of the crew packed a Game Boy and a copy of one of the previous games." ;)
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