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Another successful SpaceX launch and landing
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#22
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Another successful SpaceX launch and landing
bob haller wrote:
i wonder if stages could be put in orbit, strapped together somehow, and used to boost very large cargo runs to mars? the boosters would need refueled. but their cost would be very low There are those who disagree with me, but I've never seen the point of refueling until we have a LOT more going on. Since you've got to boost the fuel up anyway, why not just boost fully fueled stages? -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
#23
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Another successful SpaceX launch and landing
You can go to hell McCall.
On Thursday, July 21, 2016 at 6:02:43 AM UTC+12, Fred J. McCall wrote: William Mook wrote: It is something I promoted at NASA's Huntsville office back in the 1990s ... Oh, lord. More self-aggrandizing Mookery... -- "Ordinarily he is insane. But he has lucid moments when he is only stupid." -- Heinrich Heine |
#24
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Another successful SpaceX launch and landing
"Fred J. McCall" wrote in message
... bob haller wrote: i wonder if stages could be put in orbit, strapped together somehow, and used to boost very large cargo runs to mars? the boosters would need refueled. but their cost would be very low There are those who disagree with me, but I've never seen the point of refueling until we have a LOT more going on. Since you've got to boost the fuel up anyway, why not just boost fully fueled stages? Yeah... that's the part I can't figure out... what you really save here. I'll admit I think it's an interesting idea, but not sure how it works (besides the obvious logistical issues already mentioned.) -- Greg D. Moore http://greenmountainsoftware.wordpress.com/ CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net |
#25
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Another successful SpaceX launch and landing
On Tuesday, July 19, 2016 at 9:08:56 AM UTC+12, William Mook wrote:
On Monday, July 18, 2016 at 10:58:52 PM UTC+12, Jeff Findley wrote: In the very early hours today (EDT), SpaceX successfully launched the cargo Dragon transporting the IDA-2 to ISS. Also, the Falcon 9 first stage successfully landed on LZ-1 at Cape Canaveral Air Force Station. This bodes well for the first planned reuse of a Falcon 9 first stage later this year. At the SpaceX/NASA press conference, representatives from both SpaceX and NASA said that they will reuse a Dragon capsule for the first time on SpX-11 or SpX-12 (future ISS resupply missions). This is big. It means that conventional thinking at NASA is starting to change, for the better, towards accepting reuse of hardware. I don't know about everyone else, but this is an order of magnitude more exciting than talking about the architecture of a 50 year old computer used on a flags and footprints mission to the moon. Throwing away many millions (or in NASA's case a few billions) of dollars of hardware on each and every flight is insanity. Yet, that is exactly what NASA plans to do with SLS/Orion. SpaceX is shifting the manned space hardware paradigm, and it's happening right before our very eyes. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. It is something I promoted at NASA's Huntsville office back in the 1990s when I sought to build a TSTO-RLV "Greenspace" for my company Orbatek back at that time. The first stage was to use a de-rated SSME and four RL-10 engines and the orbiter stage four RL-10 engines - that carried 10 tons to LEO. There were people at NASA who were very excited, even though the fellow at TRW Aerospace, which is what I was organising to buy, started his career at Convair with the Atlas, and thought a soda can approach was the way to go given the low mass fractions. So, its not the management at NASA so much as the engineering managers in the companies. To their minds they're giving up a steady stream of revenue by building one steady rocket instead of throwaways. Also, with a high chance of failure say one launch in 25 blowing up, the thought was eventually every single reusable will crash and that is politically untenable. Airliners that crashed after 25 flights on average, would be seen as an unworkable technology. These were the thoughts back in the day. I fought all these. I told everyone that we have to get our reliability far higher. That the rocket companies like the trains back in the Old West, would have to share in the revenue they generate, and sell transport services that grow demand for those services, rather than sell hardware. SpaceX bought TRW's pintle fed engines, and did all these things and more.. So, it was a lot more than building a reusable. Credit goes to them. While the USA has let its capacities in the construction of engines erode and never really mature, Russia has hung on to its engine technology and is now a source of engines, for the world, including the USA. https://www.youtube.com/watch?v=0h2HbczuBbw Date.............. 2001 Designer NPO Energomash Manufacturer. NPO Energomash / Proton-PM (in transition) Application.... Main engine Predecessor.. RD-170 Status............ In use Liquid-fuel engine Propellant...... LOX / RP-1 Mixture ratio.. 2.6 Cycle............. Oxidizer-rich Staged combustion Configuration Nozzle ratio 37 Performance Thrust (vac.) 2.090 MN (470,000 lbf) at 100% throttle Thrust (SL) 1.920 MN (432,000 lbf) at 100% throttle Throttle range 27–105% Thrust-to-weight ratio 89 Chamber pressure 25,800 kPa (3,740 psi) Isp (vac.)...... 337 s (3.30 km/s) Isp (SL)........ 310.7 s (3.047 km/s) Burn time..... 325 s (Angara A5 core stage) Gimbal range 8° Dimensions Length.......... 4,000 mm (160 in) Diameter....... 1,450 mm (57 in) Dry weight.... 2,200 kg (4,900 lb) Three engines operate within three parallel stages each 881,402 lbs. Each 15.3 ft in diameter and 76.6 ft long. The central stage capped by a propellant section 21.9 ft long and 15.3 ft in diameter. 244,734 RP-1 636,308 LOX 26,431 Structure Three engines propel each of the stages at lift off and the two outboard tanks drain. The outboard tanks are jettisoned when emptied, and fall away. The central stage carries on until it is emptied. It too is then jettisoned and drops away, leaving the third stage. That stage delivers 143,103 pounds into Low Earth Orbit by burning 176,730 pounds of LOX and 67,973 pounds of Fuel. * * * HEAVY LIFTER A seven element version has 21 engines and four of the tanks operate as the first stage, two as the second stage, and the central tank, as the third stage. This puts 333,850 pounds into Low Earth Orbit. * * * COST ESTIMATES At $18 million each 10 engines are $180 million and 21 engines are $378 million. The airfames are $158.6 million each. Three elements $475.8 million. Seven elements $1,110.2 million. $3,325 per pound for a three element throw-away system. $3,277 per pound for a seven element throw-away system. * * * A kerosene version has been tested as well as a LNG version. Discussions with the manufacturer indicates that a LH2 version is also possible with some development lead time. An aerospike nozzle that has three sections, each fed by a separate RD-191 pump set is also interesting. This increases specific impulse and thrust at take off. A reusable version is of interest as well! Uses $/pound 1 $3,325 - single use 10 $350 - limited reuse 100 $ 35 - full reuse 1000 $ 4 - highly reusable At 10,000 Watts/pound for sun pumped laser beaming system, 3.3 billion watt solar power satellite may be launched with this system. At $0.11 per kWh this satellite generates $3.1 billion per year! A tremendous rate of return for less than $2 billion including development of the launcher in the first place. A 6 ton payload for a very capable direct beaming power satellite, with open optical laser communications between similar satellites on orbit, mean that 27 satellites may be placed per launch, a sufficient number to capture the bulk of the communications throughout the world, by beaming virtual cells across the face of the Earth. At $15 million per satellite, This generates $1.8 trillion per year with an investment of less than $2 billion including development of the launcher in the first place. A fleet of three vehicles, with launch center, in combination with an integrated supply chain for communications and power satellites, is developed for $6 billion. A global communications network is deployed along with half a dozen power satellites, to generate $3.6 trillion in annual sales. Once in place, other aerospace and robotics companies are acquired to expand on the basic infrastructure. |
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Another successful SpaceX launch and landing
William Mook wrote:
You can go to hell McCall. You can kiss my ass, you top posting ****. On Thursday, July 21, 2016 at 6:02:43 AM UTC+12, Fred J. McCall wrote: William Mook wrote: It is something I promoted at NASA's Huntsville office back in the 1990s ... Oh, lord. More self-aggrandizing Mookery... -- "Ordinarily he is insane. But he has lucid moments when he is only stupid." -- Heinrich Heine |
#27
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Another successful SpaceX launch and landing
On Thursday, July 21, 2016 at 2:16:01 PM UTC+12, Greg (Strider) Moore wrote:
"Fred J. McCall" wrote in message ... bob haller wrote: i wonder if stages could be put in orbit, strapped together somehow, and used to boost very large cargo runs to mars? the boosters would need refueled. but their cost would be very low There are those who disagree with me, but I've never seen the point of refueling until we have a LOT more going on. Since you've got to boost the fuel up anyway, why not just boost fully fueled stages? Yeah... that's the part I can't figure out... what you really save here. I'll admit I think it's an interesting idea, but not sure how it works (besides the obvious logistical issues already mentioned.) -- Greg D. Moore http://greenmountainsoftware.wordpress.com/ CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net http://www.spacefuture.com/archive/t..._company.shtml If Diemos has as much water as its low density suggests, the best place to set up a base for Mars exploration and development will likely be Diemos. One way to get there is using a low thrust ion engine using a nuclear or solar energy source https://www.youtube.com/watch?v=iEg7dF5rg8Y&t=40m8s Status: Study 1954. Date: 1954. Payload: 136,000 kg (299,000 lb). Thrust: 490 N (110 lbf). Gross mass: 660,000 kg (1,450,000 lb). Unfuelled mass: 328,000 kg (723,000 lb). Specific impulse: 8,200 s. Height: 46.00 m (150.00 ft).. It would take 2.5 Falcon Heavy launches to put one of Stuhlinger ships on orbit. This has a jet energy of 19.7 megawatts and a 25 MW power plant. It is interesting to notice that a 500 ft diameter (153 meter diameter) solar collector intercepts 23 MW of solar energy at 1 AU and 10 MW at 1.5273 AU. A 707 ft diameter (216 meter diameter) intercepts 46 MW of solar energy as 1 AU and 20 MW of solar energy at 1.5273 AU. http://web.mit.edu/aeroastro/labs/spl/research_ieps.htm http://energy.gov/sites/prod/files/2..._ganapathi.pdf http://theconversation.com/living-in...habitats-57570 A ring type inflatable habitate that spins to produce gravity https://www.youtube.com/watch?v=1wJQ5UrAsIY Basically, the capsule that carries the crew to orbit, is docked with the solar powered ion rocket array and is used to support a crew of 7 during transit. Two Falcon Heavy launches, one with power, fuel manufacturing, and drive section, the other with the habitat, capsule, and crew. These dock, and we're good to go. The entire system uses the solar powered ion engine to transfer to Mars and lands a water extractor on Diemos. This is powered by a solar pumped laser system to produce LOX and LH2 along with purified water. These are transferred periodically by drone to the spinning spacecraft loitering above. The capsule doubles as a landing vehicle and is fuelled from propellants made on Diemos. Hydrogen and oxygen that is used to land a vehicle on the Martian surface and return to Diemos. If water is not found on Diemos, no landing is attempted, and Phobos is next explored. If no water is found on Phobos, the crew returns, leaving the ion powered vehicle in Earth orbit, ready for reuse, and the capsule is used to land the crew on Earth. Next synodic period, 57 metric tons of propellant is carried along and used to execute two landings and returns on the Martian surface from Mars orbit. If water is found, on either Diemos or Phobos, surplus energy available after ion engine shut down, is used to break that water down into hydrogen and oxygen, and that is used to create breathable oxygen along with propellant, and fuel for fuel cells, which also produce potable water. Now, Diemos' semimajor axis is 23,463.2 km. That's 6.92 Mars radii. It takes 30.312 hours to complete one orbit of Mars and it moves at an average 1..3513 km/sec. A rocket that slows its speed at Diemos from its orbital velocity to 0.6794 km/sec - that is a change of 0.6719 km/sec - drops from 6.92 Mars radii to 1.00 mars radii in 6.56 hours. At that distance, the ship is moving at 4.7018 km/sec. It uses aerobraking to slow to zero velocity and land at the desired point on Mars. Returning to Diemos, the ship blasts back to this speed, and cruises for 6.56 hours arriving back at Diemos, and using rockets to add another 0.6719 m/sec to its speed. Total delta vee from Diemos to Mars and back to Diemos: 6.0456 km/sec. With a hydrogen oxygen rocket that has a 4.54 km/sec exhaust speed, we require 0.7360 propellant fraction, for a single stage rocket. Another 0.0240 for tank structure fraction - we have 0.7600 for propellant and rocket and 0.2400 for payload. A Dragon has a dry mass of 4,200 kg (9,300 lb). The Dragon trunk, is modified to ride forward of the main capsule, and LOX/LH2 rocket engines replace the NTO/MMH propellants (though NTO/MMH igniter is used similar to the RD-191 engine). This allows the 'trunk' to be used during and after landing to provide power whilst on Mars. With 3,310 kg (7,300 lb) of payload we have 7,510 kg (16,600 lb) total payload, so this implies a 31,292 kg (68,842 lbs) stage weight at departure with 23,782 kg (52,322 lbs) propellant. Using 20 MW of power it takes 7.2 days to create the propellant required for this mission at Diemos. https://goo.gl/6KFrii Stay times range from 90 days to 450 days depending on mission. This permits 12 landings and take offs to 62 landings and take offs - per ship. A dozen ships each carrying 7 astronauts (84 crew members) permit between 144 and 744 landings on Mars to take place - substantially exploring many areas of interest on the planet. * * * Suspended animation is a solved problem according to Mark Roth. Adapting today's techniques for interplanetary spaceflight, means that people going to Mars to stay, can be sent in suspended animation, re-animated at Diemos, checked out medically, and then dispatched to any one of the hundreds of landing points on the planet. * * * Self replicating machinery is a solved problem according to Vik Oliver. Adapting today's techniques for survival on Mars, means that people going to Mars to stay, will have sufficient infrastructure, made from material found on Mars itself, to make a desirable life for themselves. |
#28
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Another successful SpaceX launch and landing
I top post, bottom post, or interleave post, as is appropriate to the situation.
On Thursday, July 21, 2016 at 3:15:21 PM UTC+12, Fred J. McCall wrote: William Mook wrote: You can go to hell McCall. You can kiss my ass, you top posting ****. On Thursday, July 21, 2016 at 6:02:43 AM UTC+12, Fred J. McCall wrote: William Mook wrote: It is something I promoted at NASA's Huntsville office back in the 1990s ... Oh, lord. More self-aggrandizing Mookery... -- "Ordinarily he is insane. But he has lucid moments when he is only stupid." -- Heinrich Heine |
#29
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Another successful SpaceX launch and landing
on 7/20/2016, Rick Jones supposed :
Jeff Findley wrote: In article , ess says... I watched part of a video of the event. The constant premature cheering annoyed me, so I switched off. Then watch the SpaceX technical stream. It's "old school" and only has the audio feed with phrases like "main engine cutoff". I'll second the suggestion to go with the "technical webcast." In previous flights, with the general feed and the non-PAO commentators, there has been several good explanations of a) what the purpose of the flight is a.1) information about the payloads b) what events are supposed to happen during the launch c) what technical issues might be involved in the flight These are, of course, done as cuts ... either to a pre-recorded descriptive B-roll, to a live update from another team member, or from one of the commentators having moved to a position where they can point things out on a model or a sample. The a) and c) parts are mostly done before ignition; the b) parts are done before ignition and again before major events (such as staging). For most of the flight, the technical audio is easily heard, and the commentators make short interruptions, even if all of Hawthorne seems to be at a party. The commentators have changed from flight-to-flight, though some may have had the job more than once ... I haven't kept careful track. I haven't listened to this last flight yet, so there may be excursions from the prior style of coverage and I don't know it yet. I don't usually listen real-time, and I haven't found a technical-feed-only video offered for later playback, but one can skip ahead with the later playback. /dps -- The presence of this syntax results from the fact that SQLite is really a Tcl extension that has escaped into the wild. http://www.sqlite.org/lang_expr.html |
#30
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Another successful SpaceX launch and landing
After serious thinking Snidely wrote :
on 7/20/2016, Rick Jones supposed : Jeff Findley wrote: In article , ess says... I watched part of a video of the event. The constant premature cheering annoyed me, so I switched off. Then watch the SpaceX technical stream. It's "old school" and only has the audio feed with phrases like "main engine cutoff". I'll second the suggestion to go with the "technical webcast." In previous flights, with the general feed and the non-PAO commentators, there has been several good explanations of a) what the purpose of the flight is a.1) information about the payloads b) what events are supposed to happen during the launch c) what technical issues might be involved in the flight These are, of course, done as cuts ... either to a pre-recorded descriptive B-roll, to a live update from another team member, or from one of the commentators having moved to a position where they can point things out on a model or a sample. The a) and c) parts are mostly done before ignition; the b) parts are done before ignition and again before major events (such as staging). For most of the flight, the technical audio is easily heard, and the commentators make short interruptions, even if all of Hawthorne seems to be at a party. The commentators have changed from flight-to-flight, though some may have had the job more than once ... I haven't kept careful track. I haven't listened to this last flight yet, so there may be excursions from the prior style of coverage and I don't know it yet. Making my first pass through it now. The landing legs stand out pre-launch at 15:43 and again in early flight (after turning towards the horizon) at 17:20. That's a trivia note, of course. At about 19:38, in 2nd stage startup, is there a band or something around the bell that flips away as the bell heats up? I don't usually listen real-time, and I haven't found a technical-feed-only video offered for later playback, but one can skip ahead with the later playback. Or turn the sound off. /dps -- The presence of this syntax results from the fact that SQLite is really a Tcl extension that has escaped into the wild. http://www.sqlite.org/lang_expr.html |
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