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SpaceX Plans to Land Next Falcon 9 on Solid Ground

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Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#81

Post by daeken »

grecy wrote: post #78
daeken wrote: post #38

Earlier quoted context omitted.

> They need to be able to stabilize the rocket's landing in all sorts of conditions if they want to have any hope of landing it on another planet. Well, not really. Dragons (and Red Dragons, for interplanetary travel) are way, way less sensitive to the whims of weather. The issue with the first stage is that you have a very large, very fragile, very bottom-heavy tin can that you're trying to balance on a moving platf…

If Dragon lands on some other planet, how does it get back without a stage 1 also landing on said planet?

It's refueled in-situ and launched back up with a minimal payload weight. Getting off the surface of Mars back into an orbit with a low weight (basically crew + life support + minimal payload) is pretty straightforward, considering the low gravity and thin atmosphere. From there, you can dock to a much larger tug ship and go back to Earth orbit, refueling on orbit and landing propulsively again.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#82

Post by lotsofmangos »

daeken wrote: post #52
[deleted] wrote: post #41

Earlier quoted context omitted.

[deleted]

As far as I'm aware, there's no plan for rocket refueling on Mars. That makes sense, considering that the stages we normally think of as the 'rocket' will be gone long before our pods get to Mars. We will refuel the pod, which has its own rocket engines on it, and use that to get back up (with a tiny fraction of the original payload) from the surface. Mars' gravity well and atmosphere are a fraction of Earth's, so th…

You could probably put a rocket stage capable of a Mars landing and then takeoff after refueling on top of a stage capable of an Earth landing.

I think this is being looked at, as though the gravity well is smaller than Earth's, it is not small enough for a crewed pod ascent like the moon landing.

From my understanding this is one of the reasons other than looking for life to want easy to access water, as then you can make rocket fuel with solar panels.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#83

Post by Already__Taken »

jccooper wrote: post #73
kllrnohj wrote: post #20

Earlier quoted context omitted.

https://www.youtube.com/watch?v=4Ca6x4QbpoM http://www.space.com/13140-spacex-private-reusable-rocket-el... "After separating in orbit, the two stages of the rocket would come back to Earth and land at the launch pad." They've always intended both the boosters and the second stage to return to the launch site.

Recent statements indicate that they've given up on second stage recovery for the F9. Just too hard given current margins. That'll be in some future architecture.

It's just the least valuable thing to try to recover. Pick your battles and all that. While a recoverable payload yes its much harder but bringing something back which is valable on top of the spacecraft.

Getting S2 backs seems like 90% of the problems plus some others and not much of a payoff.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#84

Post by themgt »

ridgeguy wrote: post #19
sergiosgc wrote: post #13

Does this mean they'll be launching from another facility? Right now, the trajectory goes over to the sea, and bringing the first stage back to dry land is expensive. They'd have to launch far away from the east coast.

There's a Falcon 9 launch from Vandenberg scheduled for July 22. VAFB is a large coastal installation with lots of room for a return to land. schedule: http://spaceflightnow.com/launch-schedule/ read near the end of this story for a statement that booster return to land is planned for the July 22 launch: http://www.nasaspaceflight.com/2015/03/spaceport-america-spa...

Sounds like a July 22nd party in Cape Canaveral is in order?

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#85

Post by Crito »

travelton wrote: post #39
chinathrow wrote: post #14

I just love the term "flight termination system". It sounds so much better than "self destruction system" :)

Anyone know how this flight termination system works? Obviously it self-destructs. But, under what parameters? Does Mission Control send the signal, or does the rocket determine this on its own?

The range safety officer has a button that they can press. I'm not sure if the rocket can do it on its own as well.

Somewhat amusingly, the Russians do not use these systems. They launch from the desert in Kazakhstan, so they just let their rockets crash and burn.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#86

Post by david-given »

travelton wrote: post #39
chinathrow wrote: post #14

I just love the term "flight termination system". It sounds so much better than "self destruction system" :)

Anyone know how this flight termination system works? Obviously it self-destructs. But, under what parameters? Does Mission Control send the signal, or does the rocket determine this on its own?

My understanding is that there's a bunch of automated triggers --- e.g. if the vehicle leaves its flight corridor, it's supposed to get terminated. That doesn't necessarily mean that it goes bang; for a vehicle like the F9, shutting down all the engines is fine in most circumstances.

However, there is also a Range Safety Officer with a hand on a big red switch (or at least, a metaphorical hand on a metaphorical switch). They're the final authority on whether the vehicle lives or dies.

The shuttle may or may not have had a self-destruct system in the orbiter itself; I'm finding conflicting references. The SRBs and tank certainly did; the RSO pushed the button after Challenger disintegrated on launch to stop the SRBs flying away.

Yes, pushing the button while the SRBs and tank were attached to the orbiter would have killed the crew. Being the RSO is a job for very sober, very thoughtful people.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#88

Post by timfrietas »

themgt wrote: post #84
ridgeguy wrote: post #19

Earlier quoted context omitted.

There's a Falcon 9 launch from Vandenberg scheduled for July 22. VAFB is a large coastal installation with lots of room for a return to land. schedule: http://spaceflightnow.com/launch-schedule/ read near the end of this story for a statement that booster return to land is planned for the July 22 launch: http://www.nasaspaceflight.com/2015/03/spaceport-america-spa...

Sounds like a July 22nd party in Cape Canaveral is in order?

Vandenberg is actually in California :)

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#89

Post by sparkzilla »

flountown wrote: post #49

Are there any articles or press out there that describe the stabilization tech used on the barge? A lot of the things when looking through Google seem to focus on the challenges of guiding the rocket but not stabilizing the platform. I guess it tends to be a non-issue since it seems their plan all along was landing it on land, but I'd be really interested to see the design story that went into the barge.

There are two kinds of stabilization required: Side-to-side, which would use azimuth thrusters, and up-down which can be implemented with SWATH: http://en.wikipedia.org/wiki/Small-waterplane-area_twin_hull

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#90

Post by mikeash »

jccooper wrote: post #80
netcan wrote: post #58

Earlier quoted context omitted.

wow. I guess I overstepped a line. *I don't really have an ex from Miami. Never been there. No ill wishes for the city. ..just to be clear.

HN does not take well to joke comments. It's not specifically mentioned in the guidelines, but falls generally under "off-topic". Feeling is "this isn't Reddit."

Especially un-funny joke comments. Of course that line is vague and hard to spot, but I'm comfortable in saying that this particular attempt was way on the wrong side of it. I think it could have been rather amusing if it had stopped about a third of the way in.
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