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

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

#51

Post by Symmetry »

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.

My sense is that satellites range in price from $100 million or so for the sort of standard commsat that it's going to be launching this time to $10 billion for custom government spysats or top tier research satellites. But the really expensive ones usually go up on something like the Atlas V which is now at ~100 launches without a failure.

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

#52

Post by andars »

nicolapcweek94 wrote: post #48
DanielStraight wrote: post #46

Earlier quoted context omitted.

Why land? Fuel makes up a very small percent of the launch cost of a rocket. Landing also allows a much better experience for cargo and crew return, and it makes it possible to bring equipment to other planets or moons. Why vertical? Vertical landing is much more flexible. You can land on a barge at sea. You can land on the launchpad itself. You can land on a planet or moon with no atmosphere.

> 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

The first stage will not land on Mars.

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

#53

Post by JoachimS »

Patrick_Devine wrote: post #11
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.

There is a bigger question which was asked in the Economist this week ( http://www.economist.com/technology-quarterly/2016-25-08/spa... ), which is can SpaceX create a big enough market where they can realize the savings of reusability? Right now satellites cost more than the price of the rocket, so if you shave off $10 million on a launch that's pretty much a drop in the bucket compared to the overall price. This is…

If you can lower the cost for launching, you should also open up the market for cheaper satellites. Possibly not built the same rigorous way that a 100M satellite goes through.

This should also put pressure on the satellite manufacturers to lower costs.

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

#54

Post by Retric »

nicolapcweek94 wrote: post #48
DanielStraight wrote: post #46

Earlier quoted context omitted.

Why land? Fuel makes up a very small percent of the launch cost of a rocket. Landing also allows a much better experience for cargo and crew return, and it makes it possible to bring equipment to other planets or moons. Why vertical? Vertical landing is much more flexible. You can land on a barge at sea. You can land on the launchpad itself. You can land on a planet or moon with no atmosphere.

> 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.

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

#55

Post by the_duke »

marvin wrote: post #32
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).

RUD has been a rocket engineering term for decades, same as e.g. lithobraking (slowing your spacecraft down by smashing it into the ground)

You can always learn something new on HN. ^^

I only ever read in articles about SpaceX.

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

#56

Post by timdiggerm »

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 (see: The Columbia Disaster).

Plus, it turns out that landing a rocket vertically is now possible. I'm not clear on if it's now possible thanks to advances in technology (particularly in automation) or if it's just that no one had tried it until now.

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

#57

Post by mattferderer »

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?

I recommend checking out episode 1313 of the podcast .Net Rocks. They do an awesome job explaining this subject even if you have no background knowledge on it.

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

#58

Post by nicolapcweek94 »

andars wrote: post #52
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

The first stage will not land on Mars.

No it won't, but they're definitely gonna reuse the tech they're developing to land the S1 on Earth to land the MCT on Mars

And to land the BFR S1 on Earth, which I'd guess would be a bit too much for parachutes even with Earth's relatively thick atmosphere, if what people have been saying on Reddit is right

September 21st can't come soon enough!

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

#59

Post by nicolapcweek94 »

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.

Well, they're landing a really light shell with a really powerful engine for now, on Earth.

Mars is gonna be a different story, considering the Red Dragon mission in 2018 (with already existing infrastructure, since the Red Dragon will basically be a Dragon 2 capsule and the S1 for the mission will be a Falcon Heavy) is gonna have the heaviest payload ever landed on mars with a semi-empty Dragon 2, and all the missions after that will probably try to land at least one MCT, which would be heavier of a Dragon 2 by itself, with some cargo...

Luckily the MCT will have an even more powerful engine, and Mars's lighter gravity will probably help!

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

#60

Post by JshWright »

andars wrote: post #52
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

The first stage will not land on Mars.

No, but the cool thing is, SpaceX is using their first stage landings to do research that will advance their goals on Mars.

In order to land large payloads on Mars, SpaceX is going to have to do something that, up until recently, has never been done before. They're going to have to fire a rocket engine 'backwards' in an atmosphere (albeit a thin one) while travelling at supersonic speeds. This will be necessary in order to slow down enough to actually land (parachutes don't buy you much on Mars).

This 'supersonic retropropulsion' is something that has been modeled a lot, but is really hard to actually test. You would need to get a rocket up to supersonic speeds, in the thin upper stages of Earth's atmosphere (where the conditions are close to that of Mars) and have it fire its engines backwards. As luck would have it, that's exactly what the Falcon 9 first stage does during its reentry burn. The data they are collecting now will be invaluable in designing their Mars bound spacecraft.

NASA is also very interested in this data: https://www.nasa.gov/press/2014/october/new-commercial-rocke...

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