SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket • Hacker News Board

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#61

Post by weaksauce » Wed, Aug 31, 2016, 1:26 PM UTC

gliptic wrote: post #40

johnm1019 wrote: post #38

Hopefully someone can support/refute this: my off the cuff guess why this happened is because the discount on the launch price is about equal to the cost of building the satellite. So if it works, everyone is happy. If it explodes, they can build another one and aren't out any money (but are out time), and the launch costs for the next one are covered by SpaceX or insurance - however they have it set up.

Payloads are insured and the insurance cost in this case is reportedly more or less the same as on a new rocket. That makes it a no-brainer.

Are the opportunity costs of not having the satellite up there for the duration of however long it takes to build and launch a replacement insured as well?

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#62

Post by JshWright » Wed, Aug 31, 2016, 1:27 PM UTC

tehbeard wrote: post #33

the_duke wrote: post #27

Earlier quoted context omitted.

Don't know if this comes from SpaceX or SES. But Musk is definitely good at coming up with 'interesting' new terms. See RUD - Rapid Unscheduled Disassembly (aka Crash).

Pretty sure he nabbed that one from the KSP community. Also its not so much a crash as the rocket falling apart.

The term is _much_ older than KSP (going back to at least the 70's)

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#63

Post by JustUhThought » Wed, Aug 31, 2016, 1:55 PM UTC

kilroy123 wrote: post #2

I wonder if they'll really save money right away doing this. I imagine they'll spend a lot on inspections and getting things 100% right. Either way, it's an amazing achievement.

"Either way it's an amazing achievement."

What the what.

We've gone from "holy ish, sci-fi reusable rockets and we's living la vita future!" to qualified approval..?

No. No. This is not about satellites. This is about the primary cost component for transporting a colony to Mars. And it's already destroying the competition pricewise, and this will widen that gap enormously.

Did the Spanish Govt say, well, that's nice and all, but spices are still pretty pricey? Maybe we don't go back? No. They didn't. They said, "Awesome, lock that ish down. We want a monopoly. And bring us more funny trinkets to show off to our landlocked friends to make us giggle and feel superior."

So yes, it's a huge, amazing fucking achievement.

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#64

Post by phire » Wed, Aug 31, 2016, 2:07 PM UTC

Retric wrote: post #54

nicolapcweek94 wrote: post #48

Earlier quoted context omitted.

> You can land on a planet or moon with no atmosphere. IE: Mars, the ultimate SpaceX goal, which has just enough atmosphere to be annoying but not nearly enough to make parachutes work, so they had to find another way to land a big enough payload to transport 100 tons of stuff there

All methods of landing on Mars require an aeroshell and parachute sequence, but after that there are three choices https://en.m.wikipedia.org/wiki/Mars_landing The advantage to powered landings is they work well for delicate stuff like people. Or in space X's case they are landing a really light shell and have a really powerful engine already attached.

I feel like there is a [Citation Needed] for that Wikipedia quote.

All existing landers used an aeroshell and parachute sequence, but that doesn't mean it's impossible to land with just Rockets. The aeroshell/parachute method is used because it allows landers to come straight in from a Hoffman transfer orbit, bleed off all that extra speed and land with the least amount of fuel required. But it's way to risky for a manned lander, as the landing date (and location) are locked in months ahead of time with no option for an abort or delay.

A manned lander is likely to aerobreak into a stabke Mars parking orbit first. Allowing the crew can check the lander, check the weather at the landing site and detach from a reusable transfer module. From low Mars orbit, they are going much slower and need to disperse much less energy.

You could just throw Rockets and fuel at the problem. Or wings might be far more attractive than a parachute for slowing down in the upper atmosphere (though, any wings would have to be massive to actually glide all the way down to the lower atmosphere or land)

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#65

Post by dansze » Wed, Aug 31, 2016, 2:31 PM UTC

PDoyle wrote: post #44

glaberficken wrote: post #42

Earlier quoted context omitted.

off topic: I wonder what the "real" cost of this is across the world? You know, things like minting cent coins and transporting them around, and other things I wouldn't even imagine!

In Canada? No cost at all.

Actually, that's an interesting question: How much more efficient transportation-wise is ending prices in .95 and transporting nickels?

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#66

Post by Retric » Wed, Aug 31, 2016, 2:37 PM UTC

phire wrote: post #64

Retric wrote: post #54

Earlier quoted context omitted.

All methods of landing on Mars require an aeroshell and parachute sequence, but after that there are three choices https://en.m.wikipedia.org/wiki/Mars_landing The advantage to powered landings is they work well for delicate stuff like people. Or in space X's case they are landing a really light shell and have a really powerful engine already attached.

I feel like there is a [Citation Needed] for that Wikipedia quote. All existing landers used an aeroshell and parachute sequence, but that doesn't mean it's impossible to land with just Rockets. The aeroshell/parachute method is used because it allows landers to come straight in from a Hoffman transfer orbit, bleed off all that extra speed and land with the least amount of fuel required. But it's way to risky for a m…

In either case they use heat shields so the post heat shield second stage will be at the same velocity. Mars has ~0.6% of earths atmosphere, and ~40% the gravity so a heat shields going to hit terminal velocity at ~66 times earths terminal velocity. This only get's worse as you scale up due to mass vs surface area issues. Parachute can bleed off 80+% of that speed for little additional weight unlike wings which would need to survive supersonic retry heating making parachutes a no brainier. http://pics-about-space.com/re-entry-nasa-mars-landers?p=3#i... 1km/sec = 2,236.94 MPH.

Edit: Here, they start at well over 10,000mph heat shield drops that to ~1000mph, parashoot drops that to ~200mph. http://i.i.cbsi.com/cnwk.1d/i/tim//2010/08/12/2012MSLSkyCran...

PS: As to just burning fuel getting literally tons of wasted rocket fuel on mars is really really expensive.

PPS: At 0.6% ATM storms are only a viability problem. Only a tiny amount of ultra fine dust can get suspended.

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#67

Post by aninhumer » Wed, Aug 31, 2016, 2:42 PM UTC

timdiggerm wrote: post #56

IgorPartola wrote: post #45

So knowing nothing about this subject, why do they pursue landing rockets, or at least landing them vertically? It seems like the hardest possible way to handle this problem, as opposed to for example what the shuttles did. Can anyone explain the reasoning behind this?

The experience of the Shuttle program demonstrated that taking off like a rocket and landing like a plane has a lot of problems that make it not as great as you might think. The wings, heat shield, etc are all pretty heavy - notice that the shuttle required two whole extra rockets and a disposable fuel tank to make it to orbit - and the heat shield required for landing like a plane turned out to be a huge problem (se…

Note that the Space Shuttle only needs a heat shield because it's returning from orbital velocity. The Falcon 9 first stage is suborbital.

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#68

Post by Diederich » Wed, Aug 31, 2016, 2:50 PM UTC

JustUhThought wrote: post #63

kilroy123 wrote: post #2

I wonder if they'll really save money right away doing this. I imagine they'll spend a lot on inspections and getting things 100% right. Either way, it's an amazing achievement.

"Either way it's an amazing achievement." What the what. We've gone from "holy ish, sci-fi reusable rockets and we's living la vita future!" to qualified approval..? No. No. This is not about satellites. This is about the primary cost component for transporting a colony to Mars. And it's already destroying the competition pricewise, and this will widen that gap enormously. Did the Spanish Govt say, well, that's nice…

Well said. This is one of those things that will get a specific mention in the history books for a long, long time.

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#69

Post by aninhumer » Wed, Aug 31, 2016, 2:51 PM UTC

IgorPartola wrote: post #45

So knowing nothing about this subject, why do they pursue landing rockets, or at least landing them vertically? It seems like the hardest possible way to handle this problem, as opposed to for example what the shuttles did. Can anyone explain the reasoning behind this?

Landing vertically is very similar to taking off vertically in terms of the physical requirements of the vehicle. If you want to land like a plane, you need a much more complex design, which is almost certainly worse at taking off.

So as long as you can work out how to control it reliably, vertical landing is a lot more efficient than horizontal landing.

Re: SES-10 Launching to Orbit on SpaceX's Flight-Proven Falcon 9 Rocket

#70

Post by phkahler » Wed, Aug 31, 2016, 3:03 PM UTC

IgorPartola wrote: post #45

So knowing nothing about this subject, why do they pursue landing rockets, or at least landing them vertically? It seems like the hardest possible way to handle this problem, as opposed to for example what the shuttles did. Can anyone explain the reasoning behind this?

> So knowing nothing about this subject, why do they pursue landing rockets, or at least landing them vertically? It seems like the hardest possible way to handle this problem, as opposed to for example what the shuttles did. Can anyone explain the reasoning behind this?

It's actually the least complex way to do it. You've already got the engines to slow descent and steer the vehicle. At the highest concept level, all you need is to add more fuel and have very high-performance control system for guidance. Oh, and bolt on some landing legs, and some grid fins. That's not to say it's easy, but the added hardware is way less complex than adding wings, using a runway, etc... But if you watch their landings now they make it look easy and to suggest adding a bunch of other hardware complexity to get the rocket back seems silly in hindsight.

The challenge is to take someones simplistic idea "just have the rocket land itself" and look at it objectively even though nobody does it that way. My own preconceived ideas told me it would require way too much fuel to be practical. Turns out that's wrong. I also thought things would get too hot on re-entry. Turns out that's wrong too. But from a hardware complexity standpoint, it does seem kind of obvious doesn't it? I mean Bugs Bunny landed a rocket on mars right? Why NOT do it like that? http://www.cartoonsonnet.com/bugs-bunny-mad-as-a-mars-hare.h...