sojourner
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Posts posted by sojourner
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A station at eml2 as a gateway to the moon and the rest of the solar system for manned missions.
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The fairings are aluminum and carbon fiber. They cost an estimated 2 to 6 million each (for the whole fairing, not just per half). definitely worth looking into reuse and shouldn't be too difficult. After all they reach terminal velocity pretty quick due to their large surface area to mass ratio. Most of the damage is from hitting the water.
Also, from what I've read the fairings are also a bottleneck in production. They're so large that they only have limited equipment to produce them, so reuse would speed things along.
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6 hours ago, sevenperforce said:
Re-entry heat. If you watch the landing videos it is already scorched black from re-entry before it nears the ASDS.
Most of it is soot from the engine burns, not re-entry heat. Remember, it does a boost back burn as well as a re-entry burn to slow the stage and prevent it from re-entering too fast. The landing burn is the last of (a possible) 4 times the engines are fired during a mission.
The stage never attains enough speed on the way down for re-entry heating to char it.
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56 minutes ago, Wingman703 said:
Elon stated that this stage would not return directly to the cape, but would go to some undisclosed harbor in the Gulf(Elon said he "forgot" or "didn't know", I guess that was just an attempt to keep some secrecy? Not many places you can unload a rocket and ship it back to the Cape I would think, Alabama seems the most likely...)
I think the normal distance for the barge during an ISS mission is 200-300 miles off the coast? Probably wrong but that's what I'm remembering.
Not sure where you guys are getting this from. The barge is in the Atlantic and will be in Port Canaveral late today/early tomorrow.
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unhosted.
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At this stage (no pun intended) I believe the main goal in SpaceX's landing attempts is to retrieve intact first stages. Based on that I am guessing that they will still try to get approval for another RTLS. Remember that the last RTLS only got approved about 2 days before launch.
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I don't think NASA has totally ruled out RTLS landings though. I believe they left some room in the contract to eventually allow it. If they approve.
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Some of you guys are talking about the Dragon V2 and some of you are talking about Falcon 9 first stage. You really should clarify for the OP.
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It's the great weakness of the entire space industry - schedule slip.
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7 hours ago, fredinno said:
https://en.wikipedia.org/wiki/Raptor_(rocket_engine) The raptor was also small enough for F9 1st stage, even before then. There's no way the engine will be tested first on a MCT, since it's going to require so much more new tooling not already in place.
And? Nothing there indicates that SpaceX is actually working on making F9 first stage methane based. You're making suppositions. Second stage may get methane but that remains to be seen.
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1 hour ago, Rakaydos said:
Where is this supposed methane falcon mentioned?
In fredinno's fertile imagination. SpaceX has only hinted at a possible new methane second stage for F9. There's been no indication that they will build a methane F9 first stage.
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1 hour ago, KerbonautInTraining said:
SES-9 is in exactly 5 days.
The first launch I watched after getting into spaceflight was CRS-7. I got used to the massive gap between launches that launching once a month is totally new to me and I love it.
Don't hold your breathe on that. Most indications are that it has been delayed until at least late Feb.
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I don't think there is another backup set of chutes. 4 is it.
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There arer no 1.1's left to retrofit. All existing Falcon 9's are 1.2's.
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Early February. SES-9.
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1 hour ago, Motokid600 said:
Atleast his post involved ice. Theres no correlation. Challenger failed due to cold temperature comprising an o-ring. Physical ice had nothing to do with it. Even if it did... c'mon.
Oh, right. to be precise, they were both caused by cold temperatures, but hey, pretty sure you got the gist of it the first time around.
And how is it "picking on Challenger" to note that there were some small similarities in the situations? Heck, I think it actually presses home the tragedy of it. Here we are 30 years later still able to make mistakes that highlight the difficulty of what is being attempted. It reminds us that people can lose their lives if we let our attentions slip or come to think of these things as "routine". Better to be reminded of that than some clever line from a movie.
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Not anymore off topic than the post that preceded it.
But hey, if you can't see the correlation to an earlier reusable rocket that was destroyed due to an unforeseen icing complication, I'm not sure what to tell you.
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I can't help but think of another rocket that had icing problems during a January launch, about 30 years ago.
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SES-9 is next with CRS-8 to follow.
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2 hours ago, tater said:
It's not beyond the scope at all. OP even goes to some length to show that there is little or no economic motive early on. Positing a mature colony without a rationale seems absurd to me---literally in Mars One territory of irrationality.
Maybe the mature colony grew out of the strong market for the space unicorns they start raising just after the phenomenal success of Mars One.
Well, we all await something constructive from you regarding the topic other than "there's no reason to go to mars".
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3 hours ago, tater said:
Positing a mature Mars colony is already making assumptions, frankly. If there is no early economic motive, there is no early Mars colony to become mature, IMO. It's like talking about California wines---they'd not be a thing if there was no reason to come to North America in the first place---how many Antarctic wines are there? Why is there no mature colony there? Because it's not worth it to bother. I'd hazard that more people live on oceanic oil rigs than live on the entire Antarctic continent. This is a good analogy to asteroids vs Mars, frankly.
Yes, this is all very true, but beyond the scope of the question in the OP. There are other threads asking the question of where it makes more sense to build a colony.
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1 hour ago, tater said:
Martian wine would end up being valuable simply because it was from Mars, frankly. Studies have shown that even wine experts cannot actually tell expensive wines from cheap wines, and if you tell people a wine is really expensive, they will like it better than the same wine given a lower price.
None the less, transportation costs are vastly too high to make those goods cost-effective as products. It's a novelty for the super rich, I don't see it being the major economic driver. Expensive wine on earth has exactly the same fixed costs as cheap wine, really. You could just as well send some barrels around the moon and back and sell "space wine."
Sadly I don't think there are any sound economic reasons for Mars.
All of the reasons you give are why it's not feasible now or anytime soon. Which pretty much everyone in the thread has already acknowledged. I'm talking about in the long run. Eventually, if a Mars colony reaches a mature stage, the shipping infrastructure will reduce cost somewhat. Cheaper than shipping from Florida to California? No. But some goods will find a market even at high incurred shipping costs if the desire is there.
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1 hour ago, tater said:
If you think there is something special about the chemical balance of Martian soil for wine, add that to the soil in your O'Neil colony.
If this is so easy, why do people praise one wine over another on earth? Some things cannot be reproduced. Having said all that. You would need a very mature Mars colony to begin with before local luxury goods would start to see any demand back on earth. Look how long it took for similar things to develop in the Americas. Do you think there was any demand in europe for Kentucky Bourbon ten years after Columbus? 100 years? No, it took a good half a century.
Mars has nothing to offer in return in the near future beyond being a life boat for humanity. It will take hundreds of years for it to develop into anything resembling even a small earth bound nation in terms of economy.
Realistic Space War
in Science & Spaceflight
Posted
A "realistic space war" would look different based on the technology levels involved. So the question cannot be answered until you decide on what technologies are available.