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Source: (consider it)
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Thread: It ain't the kind of place to raise your kids?
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Martin60
Shipmate
# 368
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Posted
The answer to Fermi is of course that they're everywhere, at least every 10K LY, every half a billion worlds, but all experience the same socio-economic constraints.
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Love wins
Posts: 17586 | From: Never Dobunni after all. Corieltauvi after all. Just moved to the capital. | Registered: Jun 2001
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
A rocket is a complex piece of machinery. As you say, lots of little interconnecting bits and pieces. And, when they have ignition everything has to work properly (unless you build in multiple levels of redundancy - and that increases cost). If an engine misfires it can send the rocket wildly off-course, or result in the destruction of the whole thing. If the guidance and control systems fail to work then the rocket doesn't put the payload into the correct orbit, or maybe doesn't reach orbit at all. Leaks in fuel lines, thousands of circuits that can fail ... it's a substantial list. A rocket is a bomb that explodes in a controlled manner - too much control and the rocket doesn't lift off, too little and it reverts to it's natural state.
No one has denied that preparing and testing an as-yet unflown rocket for a launch in less than 24 months isn't a challenge. Nor is preparing and testing the Dragon V2 payload. It's a massive challenge, and a very tight deadline. Deadlines have the habit of focussing minds and making the impossible an astounding achievement. They can also result in corners getting cut, details missed, mistakes made. And, with the margin for error practically zero that can very easily end up in a rocket spread all over the place.
Do you honestly think that SpaceX can get every single part of the heavy lift Falcon, and it's payload, right first time? That you don't think there will be dozens of components that take a month or two longer to get right that than the ambitious timetable allows for? Do you expect the first test launch to take place November this year? And, for it to happen without identifying any issues that will take some time to remedy? Do you expect that a second launch a mere four months later can be prepared on that timescale, implementing whatever adjustments the first launch show are necessary? How many months of delay are allowed in that schedule for a May 2018 launch?
Musk wants two firsts - the first private mission to Mars, and the first major engineering project completed on schedule. I think he's probably ahead of the field to achieve the first, it wouldn't surprise me if he launched in the 2020 window. But, on the second Murphy still rules.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Baptist Trainfan
Shipmate
# 15128
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Posted
I read somewhere that the Saturn V rocket had 6 million individual parts. Just a 0.1% failure rate meant the failure of 6000 pieces. So it had to be much, much lower.
Conversely, the Black Knight rocket which put the Prospero satellite into orbit had a lot of the redundancy taken out as it was believed that simplicity aided reliability as well as saving weight. It's still the only all-British satellite launch.
[ 09. May 2016, 14:47: Message edited by: Baptist Trainfan ]
Posts: 9750 | From: The other side of the Severn | Registered: Sep 2009
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Martin60
Shipmate
# 368
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Posted
Aye, 6 million of which 2 million were moving. So the failure of only 3 missions out of 16 is pretty impressive.
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Love wins
Posts: 17586 | From: Never Dobunni after all. Corieltauvi after all. Just moved to the capital. | Registered: Jun 2001
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mark_in_manchester
not waving, but...
# 15978
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Posted
quote:
Conversely, the Black Knight rocket...
There's a good chapter on this in Francis Spufford (of 'Unapologetic' fame)'s 'Backroom Boys'.
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"We are punished by our sins, not for them" - Elbert Hubbard
(so good, I wanted to see it after my posts and not only after those of shipmate JBohn from whom I stole it)
Posts: 1596 | Registered: Oct 2010
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Graven Image
Shipmate
# 8755
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Posted
As we are messing up the planet we are living on with wars, trash, warming, destroying the land with strip mining, and fracking, chemicals and more we should not be allowed to leave here and go any other place until we can prove to have wised up.
Posts: 2641 | From: Third planet from the sun. USA | Registered: Nov 2004
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by Alan Cresswell:
[more emphatic statements about how space flight is hard]
Yes, thank you, I get the picture. So far you haven't said anything to convince me that you know more about this than I do. quote:
Do you honestly think that SpaceX can get every single part of the heavy lift Falcon, and it's payload, right first time? That you don't think there will be dozens of components that take a month or two longer to get right that than the ambitious timetable allows for? Do you expect the first test launch to take place November this year? And, for it to happen without identifying any issues that will take some time to remedy? Do you expect that a second launch a mere four months later can be prepared on that timescale, implementing whatever adjustments the first launch show are necessary? How many months of delay are allowed in that schedule for a May 2018 launch?
As I noted before, the very first launch of the Falcon 9 was a success, and that was arguably riskier than the Falcon Heavy, which is mostly more of the same.
I don't know whether they'll be able to do it or not, but you haven't provided any particular grounds for skepticism besides your personal incredulity, which as far as I can tell is not especially informed by familiarity with this program in particular or launch vehicle development in general.
My skepticism of your skepticism isn't invulnerable - maybe there were massive delays in the Falcon 9 development schedule, now forgotten in the haze of celebration, or maybe SpaceX is hopelessly behind in the manufacture of critical self-sealing stem bolts. I don't know - but then, neither do you (apparently.)
(You needn't feel obliged to continue this tangent - I won't think less of you for stopping.)
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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LeRoc
Famous Dutch pirate
# 3216
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Posted
[QUOTEGraven Image: As we are messing up the planet we are living on with wars, trash, warming, destroying the land with strip mining, and fracking, chemicals and more we should not be allowed to leave here and go any other place until we can prove to have wised up.[/QUOTE]You're about the fourth saying this on this thread, and none of you have reacted to the answers that were given to this. Could one of you please tell me why it matters if we mess up a lifeless planet?
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
Posts: 9474 | From: Brazil / Africa | Registered: Aug 2002
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
quote:
Originally posted by Dave W.:
My skepticism of your skepticism isn't invulnerable - maybe there were massive delays in the Falcon 9 development schedule, now forgotten in the haze of celebration
You're right I'm not an expert on the details - nuclear physics not rocket science is my area of expertise. But, I can read Wikipedia the same as anyone
quote:
The original NASA COTS contract called for the first demonstration flight of Falcon in September 2008, and completion of all three demonstration missions by September 2009 ...
The first launch attempt occurred at 1:30 pm EDT on Friday, June 4, 2010 (1730 UTC). The launch was aborted shortly after ignition, and the rocket successfully went through a failsafe abort. Ground crews were able to recycle the rocket, and successfully launched it at 2:45 pm EDT (1845 UTC) the same day.
The second Falcon 9 launch, and first COTS demo flight, lifted off on December 8, 2010.
Original schedule: first flight in September 2008 with three more by September 2009.
Actual performance: first flight June 2010 (21 months behind schedule, 9 months after the three demo missions were supposed to have flown), and that was not without a hitch.
And, it took 6 months to get the second launch off the ground, which is significantly slower than the original 3 in a year schedule.
If SpaceX does by some miracle actually pull a 2018 launch off then I'll be among those toasting a remarkable achievement. Even more so if they then succeed in getting Red Dragon onto the surface of Mars. I'm not going to bet on it though. I could probably get very good odds form a bookie for a 2018 Mars launch, but I would only be giving the bookie some of my money. I'd do better on the Lottery, and that's a mugs game as well.
I believe that we will get people onto the surface of Mars, I may even live to see it happen. But, I don't think it will happen by a SpaceX or Mars Direct rush job. It will happen through careful development of technology, by small intermediate steps (back to the Moon being among them) and probably development of a more efficient transit method than simply strapping the biggest rocket we can manage under the capsule.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by Alan Cresswell:
quote:
The original NASA COTS contract called for the first demonstration flight of Falcon in September 2008, and completion of all three demonstration missions by September 2009 ...
The first launch attempt occurred at 1:30 pm EDT on Friday, June 4, 2010 (1730 UTC). The launch was aborted shortly after ignition, and the rocket successfully went through a failsafe abort. Ground crews were able to recycle the rocket, and successfully launched it at 2:45 pm EDT (1845 UTC) the same day.
The second Falcon 9 launch, and first COTS demo flight, lifted off on December 8, 2010.
Original schedule: first flight in September 2008 with three more by September 2009.
Actual performance: first flight June 2010 (21 months behind schedule, 9 months after the three demo missions were supposed to have flown), and that was not without a hitch.
And, it took 6 months to get the second launch off the ground, which is significantly slower than the original 3 in a year schedule.
Thanks, Alan - that seems a more convincing argument. (And since I suggested early customers amounted to a vote of confidence, I should probably note this article as evidence against optimism.) quote:
I believe that we will get people onto the surface of Mars, I may even live to see it happen. But, I don't think it will happen by a SpaceX or Mars Direct rush job. It will happen through careful development of technology, by small intermediate steps (back to the Moon being among them) and probably development of a more efficient transit method than simply strapping the biggest rocket we can manage under the capsule.
What do you mean by a more efficient transit method? Big rockets have the distinct virtue of having delivered payloads to Mars before; they seem the most likely choice for the first mission with people.
And if Mars is the eventual goal, going back to the moon seems like a pointless detour, your previous post on the topic notwithstanding. I don't know of any reason to think that low-G effects aren't bounded by those of 1-G and 0-G, we hardly need to go there to study the effects of isolation, and predicating a Mars mission on the development of a lunar mining industry seems like an elaborate way of saying we're really not interested in going to Mars.
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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LeRoc
Famous Dutch pirate
# 3216
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Posted
When it comes to colonisation, I do see the merits of going back to the Moon first.
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
Posts: 9474 | From: Brazil / Africa | Registered: Aug 2002
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
quote:
Originally posted by Dave W.:
What do you mean by a more efficient transit method?
An example might be an Aldrin Cycler. You need a big rocket to get the cycler running, but once it's up and running you have a single big ship running non-stop on a long orbit carrying the reactor, life support, shielding etc needed for the transits between Earth and Mars then all you need are smaller transfer ships to get from Earth orbit to intercept the cycler, and from the cycler to Mars orbit (vice versa for the return trip). Small ships mean a lot less propellant to get them up to speed.
The first few Mars trips will probably mean launching a section of the cycler along with the Mars lander, so the savings for those will be minimal but in the longer term the savings can be substantial.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
and, re: the Moon. One of the biggest challenges to efficient interplanetary travel is getting fuel into space for the trip. If it's possible to extract fuel from the Moon, then a base there will make fuelling Mars bound ships much cheaper.
The other viable technology for getting fuel (and other non-fragile equipment and supplies) into LEO suffers from political bad press after Gerald Bull decided to get help from a pro-western government in the Middle East. And, then found that pro-Western is not the same as nice and got himself assassinated shortly before the Wests best friend in the region turned in to public enemy number 1.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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LeRoc
Famous Dutch pirate
# 3216
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Posted
I like this cycler. I hadn't heard about it before.
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
Posts: 9474 | From: Brazil / Africa | Registered: Aug 2002
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Martin60
Shipmate
# 368
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Posted
Why bother with Lunar fuel when you can kick them up the arse with this. 1st link
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Love wins
Posts: 17586 | From: Never Dobunni after all. Corieltauvi after all. Just moved to the capital. | Registered: Jun 2001
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Because you still need to get the fuel into orbit - whether that's chemical or nuclear.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Martin60
Shipmate
# 368
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Posted
Twenty million times less for nuclear fission, no? One hundred and forty million times less for fusion? Kick 'em up the arse.
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Love wins
Posts: 17586 | From: Never Dobunni after all. Corieltauvi after all. Just moved to the capital. | Registered: Jun 2001
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Dave W.
Shipmate
# 8765
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Posted
What will be the reason behind all these trips to Mars, do you imagine? I can see the motivation behind an exploratory mission, or two or three, but that hardly seems enough to justify contemplating setting up an entire lunar mining industry. As for the cycler - I suppose building a 750 mile bridge from Tierra del Fuego to Trinity Peninsula might make getting to Antarctica more efficient, but I really don't think the demand would justify it.
And I doubt Gerald Bull's questionable associations would matter in the slightest as far as the acceptability of his proposed technology is concerned - just ask SS-Sturmbahnfuehrer von Braun.
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
quote:
Originally posted by Dave W.:
What will be the reason behind all these trips to Mars, do you imagine?
As you note, exploration doesn't require many human expeditions - robotic missions are cheaper, safer, provide similar scientific value. But, are less "sexy" than human boots on Martian soil. The scientific value of repeated human visits to extra-terrestrial locations is clearly demonstrated by the lack of visits to the Moon after the Apollo missions.
The only real reason for lots of missions to Mars, where a cycler becomes incredibly beneficial, is to establish a permanent human presence there. I suppose the fundamental question is there a reason for a permanent human presence on Mars? If there is then that justifies the lunar fuel production, the cycler and so on.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Martin60
Shipmate
# 368
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Posted
Which it never will. Ever. Naming your boats after Ian M. Banks' won't help.
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Love wins
Posts: 17586 | From: Never Dobunni after all. Corieltauvi after all. Just moved to the capital. | Registered: Jun 2001
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LeRoc
Famous Dutch pirate
# 3216
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Posted
quote:
Martin60: Naming your boats after Ian M. Banks' won't help.
I know a better way to find a name for a boat.
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
Posts: 9474 | From: Brazil / Africa | Registered: Aug 2002
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