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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
In article , nospam@
127.0.0.1 says... On 9/26/2012 10:00 AM, Jeff Findley wrote: This makes no sense. Launches from KSC are to the east and those don't happen until downrange is clear (i.e. no aircraft, boats, and etc in the area). Landing a first stage means it will come back to KSC from the east. That approach is still going to be clear, since it was cleared for launch. Jeff, remember the term downrange. Implies your V is west to east. Now I've read that SpaceX plans to make the trajectory for the F9 1st stage nearly vertical in order to enable a RTLS. Otherwise flying out over the ocean is going to require some interesting flight maneuvers to reverse course, esp. with that long lever arm of empty tankage waiting to be blown around by cross-winds. I'd say a return that doesn't require V reversal makes more sense than a complete RTLS in this case. It's not that costly to barge tankage around... OR flying a nearly vertical trajectory, but even so the east coast of Fla is heavily populated, its not like you're bringing this back over the Everglades. As an aside; has the FAA granted waivers to the AF for drone training in US Airspace? What are the restrictions there? Nearly vertical may be the case, but any horizontal component will most certainly downrange. That and I would not rule out the stage performing a portion of the flight gliding. Yes the L/D won't be spectacular, but there will be some ability to glide back towards the launch/landing site. I don't believe the FAA has much say over what the military does. It's not like the FAA certifies military aircraft, so I wouldn't expect them to have any control over unmanned military aircraft either. Landing the second stage is a bit more tricky. In that case, you might want to land it on an uninhabited island in the Pacific, that way the stage does not overfly the continental US. Landing on an island off the east coast of Florida would still mean the second stage would overfly at least Florida. Actually if that could be done it would be a cool way to save expense, one site to retrieve both 1st and 2nd stages. Maybe an abandoned drilling rig? I don't see an "abandoned" drilling rig being inexpensive. It would have to be maintained at some minimal level to make it useful, and safe, and salt water is not nice to metal. I can't imagine that being cheaper than maintaining a concrete landing pad or (ex-shuttle) runway. Besides, SpaceX isn't the only company who has gotten approvals to fly, and have actually flown, a VTVL rocket powered vehicle. Sure theirs will be bigger, but it will also be mostly empty of fuel and oxidizer when attempting to land. Um, you know as well as I do dry mass counts; aka mv**2. If those rocket motors were to fail on return, it really won't matter that much to whomever is in the way. I witnessed first hand the aftermath of a B58H crash from altitude. Very impressive. Thank God it was an empty field.... True, which is why you'd aim for a landing that's clear of people. KSC isn't a terribly small landing area and it has acceptable security. If it was "good enough" for the space shuttle, I don't see why a vertical lander would be much different. The nice thing about a VTVL is that it can be incrementally tested under its own power. You can expand the flight envelope incrementally so that the first orbital flight isn't much different than the last flown test flight. That could not be done with the shuttle, which is one reason why landing at Edwards (even for the Enterprise drop tests) was a good idea. Jeff -- "the perennial claim that hypersonic airbreathing propulsion would magically make space launch cheaper is nonsense -- LOX is much cheaper than advanced airbreathing engines, and so are the tanks to put it in and the extra thrust to carry it." - Henry Spencer |
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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
If this VTVL Falcon is going to have a first stage that does almost
all vertical and no horizontal, just how much horizontal delta-v is being lost to this, to be made-up for by the second stage (presumably)? Compared to Falcon9 as it stands today. rick jones -- It is not a question of half full or empty - the glass has a leak. The real question is "Can it be patched?" these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
In sci.space.policy message
om, Tue, 25 Sep 2012 13:29:43, David Spain posted: It's going to be interesting to see how SpaceX approaches FAA certification for this. I'm going to bet that it would be easiest for SpaceX to appropriate an otherwise uninhabited island off the East Coast of Florida for a landing pad and barge it back to the Cape, rather than try to fly this thing back over populated territory. Either that or a sea barge landing platform. The United States of America does not seem to have any such islands, on a reasonable interpretation of "off" and "East". It might be possible to rent space on a minor Bahama - appropriation could lead to war with HM QEII et al. -- (c) John Stockton, nr London, UK. Mail via homepage. Turnpike v6.05 MIME. Web http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms and links; Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc. No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News. |
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Elon Musk's new re-usable, hovering rocket ship in first testliftoff
On 9/26/2012 5:31 PM, Dr J R Stockton wrote:
In sci.space.policy message om, Tue, 25 Sep 2012 13:29:43, David Spain posted: It's going to be interesting to see how SpaceX approaches FAA certification for this. I'm going to bet that it would be easiest for SpaceX to appropriate an otherwise uninhabited island off the East Coast of Florida for a landing pad and barge it back to the Cape, rather than try to fly this thing back over populated territory. Either that or a sea barge landing platform. The United States of America does not seem to have any such islands, on a reasonable interpretation of "off" and "East". It might be possible to rent space on a minor Bahama - appropriation could lead to war with HM QEII et al. Bad choice of words, rent would be better or buy outright. When I wrote that I was thinking of a US territory, but you may be right that the US doesn't have any that are convenient, I haven't checked. I don't think SpaceX plans to go to war with anyone... :-) Dave |
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Elon Musk's new re-usable, hovering rocket ship in first testliftoff
On 9/26/2012 2:30 PM, Jeff Findley wrote:
In article , nospam@ 127.0.0.1 says... Actually if that could be done it would be a cool way to save expense, one site to retrieve both 1st and 2nd stages. Maybe an abandoned drilling rig? I don't see an "abandoned" drilling rig being inexpensive. It would have to be maintained at some minimal level to make it useful, and safe, and salt water is not nice to metal. I can't imagine that being cheaper than maintaining a concrete landing pad or (ex-shuttle) runway. True. Or a towable sea barge landing platform, but any land-based option at KSC would be the cheapest. Besides, SpaceX isn't the only company who has gotten approvals to fly, and have actually flown, a VTVL rocket powered vehicle. Sure theirs will be bigger, but it will also be mostly empty of fuel and oxidizer when attempting to land. Um, you know as well as I do dry mass counts; aka mv**2. If those rocket motors were to fail on return, it really won't matter that much to whomever is in the way. I witnessed first hand the aftermath of a B58H crash from altitude. Very impressive. Thank God it was an empty field.... True, which is why you'd aim for a landing that's clear of people. KSC isn't a terribly small landing area and it has acceptable security. If it was "good enough" for the space shuttle, I don't see why a vertical lander would be much different. Well there are several distinct differences; probably from the FAA's perspective the biggest issue is that fact that this would be a "remotely piloted vehicle". Not sure how much existing regulation there is to deal with this. Now if the KSC is all considered to be military reservation as far as air space is concerned, maybe you can avoid that problem, or if you locate your landing pad at the Canaveral AF Station (Patrick AFB). But the FAA is likely to treat SpaceX somewhat differently than it would NASA I would think. The nice thing about a VTVL is that it can be incrementally tested under its own power. You can expand the flight envelope incrementally so that the first orbital flight isn't much different than the last flown test flight. That could not be done with the shuttle, which is one reason why landing at Edwards (even for the Enterprise drop tests) was a good idea. Yes, I'm sure we'll be reading about more "hops" out in MacGregor (sp?) TX as this progresses. Dave |
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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
how about using a retired aircraft carrier as a landing pad? the
military has lots of ships in storage |
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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
David Spain wrote:
Now if the KSC is all considered to be military reservation as far as air space is concerned, maybe you can avoid that problem, or if you locate your landing pad at the Canaveral AF Station (Patrick AFB). But the FAA is likely to treat SpaceX somewhat differently than it would NASA I would think. Presently SpaceX launches Falcon 9 from Canaveral AFS rather than KSC right? (Not that I know where one ends and the other begins...) rick jones -- It is not a question of half full or empty - the glass has a leak. The real question is "Can it be patched?" these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
In sci.space.policy message -
september.org, Wed, 26 Sep 2012 10:05:28, Jeff Findley posted: In article , says... Does Falcon 9 launch over populated territory when it launches from Canaveral? If not, unless the route back is somewhat circuitous wouldn't the return to the launch site also avoid population centers? No, it launches to the east, just like every other launch vehicle that launches from there. If the Shuttle launched to the East, how come I've seen it, and its tank, passing slightly to the North of here? -- (c) John Stockton, nr London, UK. Mail via homepage. Turnpike v6.05 MIME. Web http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms and links; Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc. |
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Elon Musk's new re-usable, hovering rocket ship in first test liftoff
"Dr J R Stockton" wrote in message . invalid... In sci.space.policy message - september.org, Wed, 26 Sep 2012 10:05:28, Jeff Findley posted: In article , says... Does Falcon 9 launch over populated territory when it launches from Canaveral? If not, unless the route back is somewhat circuitous wouldn't the return to the launch site also avoid population centers? No, it launches to the east, just like every other launch vehicle that launches from there. If the Shuttle launched to the East, how come I've seen it, and its tank, passing slightly to the North of here? Because last I checked London was east of KSC. It also happens to be north. No one claimed it launched "due" east. -- Greg D. Moore http://greenmountainsoftware.wordpress.com/ CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net |
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