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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
Whatever happened to the "Glide Back" booster proposals that
would allow the booster to fly downrange, as well as vertically, and still be able to return to the launch site? |
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
(Niels Jørgen Kruse) writes:
Jochem Huhmann wrote: It's still curious. Landing a first stage or a booster would mean having some ground to land it on, which would mean having to launch over land. Which SpaceX doesn't. Or they mean to land the thing on a ship or barge out there.... Go straight up until first stage separation? You would have to transport the stage back otherwise. SpaceX just has published a video and some photos how this is meant to work. They're somewhat skipping over how the stage gets back to the launch site though... http://www.spacex.com/npc-luncheon-elon-musk.php Jochem -- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery |
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
On Sep 30, 7:00*am, Jeff Findley wrote:
In article , says... (Niels J rgen Kruse) writes: Jochem Huhmann wrote: It's still curious. Landing a first stage or a booster would mean having some ground to land it on, which would mean having to launch over land. Which SpaceX doesn't. Or they mean to land the thing on a ship or barge out there.... Go straight up until first stage separation? You would have to transport the stage back otherwise. SpaceX just has published a video and some photos how this is meant to work. They're somewhat skipping over how the stage gets back to the launch site though... http://www.spacex.com/npc-luncheon-elon-musk.php From the video, it looks like the sequence is this: 1. *First stage shuts down 2. *First stage separates (and second stage starts) 3. *First stage rotates 180 degrees 4. *First stage ignites three of the nine engines and does a burn to put it on a trajectory back to KSC 5. *First lands at KSC on one engine (ala DC-X) I don't see any big "gotcha" here. *Restarting liquid fueled rocket engines has been done since the 60's. *DC-X proved step 5 two decades ago, and its results have been recently replicated by other start-ups. * The only thing which has not been done is actually building and flying a reusable TSTO VTVL launch vehicle. *I'm sure SpaceX will start with the first stage, since it will be far easier than the upper stage. *If successful, they can implement a reusable first stage on both Falcon 9 and Falcon Heavy. Falcon Heavy's LEO payload capacity is 117,000 lb (53 metric tons). * Even if making a Falcon Heavy reusable ate up 1/2 of the payload, it would still be capable of putting more payload into orbit than the space shuttle. * Jeff -- " Ares 1 is a prime example of the fact that NASA just can't get it * up anymore... and when they can, it doesn't stay up long. " * *- tinker- Hide quoted text - - Show quoted text - Assuming they can get this to work, of course. It's an interesting concept, to be sure. Good luck to Lord Musk-he's gonna need it. (and no, he's not the Messiah when it comes to HSF-which a lot of folks, especially those on spacepolitics.com, seem to think) |
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
On Sep 30, 7:00*am, Jeff Findley wrote:
Falcon Heavy's LEO payload capacity is 117,000 lb (53 metric tons). * Even if making a Falcon Heavy reusable ate up 1/2 of the payload, it would still be capable of putting more payload into orbit than the space shuttle. * Actually that would only be 26.5 tons, and the Shuttle's maximum LEO payload was 28.8 tons. -Mike |
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
On Oct 1, 10:16*pm, Alan Erskine wrote:
On 30/09/2011 7:09 AM, wrote: However, if they had, it might have saved Columbia and its crew. How could that have mattered since the foam fell off the ET bipod ramp, not the SRBs? -Mike |
#19
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
On Sep 30, 6:08*pm, Matt Wiser wrote:
On Sep 30, 7:00*am, Jeff Findley wrote: In article , says... (Niels J rgen Kruse) writes: Jochem Huhmann wrote: It's still curious. Landing a first stage or a booster would mean having some ground to land it on, which would mean having to launch over land. Which SpaceX doesn't. Or they mean to land the thing on a ship or barge out there.... Go straight up until first stage separation? You would have to transport the stage back otherwise. SpaceX just has published a video and some photos how this is meant to work. They're somewhat skipping over how the stage gets back to the launch site though... http://www.spacex.com/npc-luncheon-elon-musk.php From the video, it looks like the sequence is this: 1. *First stage shuts down 2. *First stage separates (and second stage starts) 3. *First stage rotates 180 degrees 4. *First stage ignites three of the nine engines and does a burn to put it on a trajectory back to KSC 5. *First lands at KSC on one engine (ala DC-X) I don't see any big "gotcha" here. *Restarting liquid fueled rocket engines has been done since the 60's. *DC-X proved step 5 two decades ago, and its results have been recently replicated by other start-ups. * The only thing which has not been done is actually building and flying a reusable TSTO VTVL launch vehicle. *I'm sure SpaceX will start with the first stage, since it will be far easier than the upper stage. *If successful, they can implement a reusable first stage on both Falcon 9 and Falcon Heavy. Falcon Heavy's LEO payload capacity is 117,000 lb (53 metric tons). * Even if making a Falcon Heavy reusable ate up 1/2 of the payload, it would still be capable of putting more payload into orbit than the space shuttle. * Jeff -- " Ares 1 is a prime example of the fact that NASA just can't get it * up anymore... and when they can, it doesn't stay up long. " * *- tinker- Hide quoted text - - Show quoted text - Assuming they can get this to work, of course. It's an interesting concept, to be sure. Good luck to Lord Musk-he's gonna need it. (and no, he's not the Messiah when it comes to HSF-which a lot of folks, especially those on spacepolitics.com, seem to think)- Hide quoted text - What this reminds me of, ironically enough, is the recovery system for the now defunct Kistler K-1 reusable rocket, minus the three parachutes and landing airbags. -Mike |
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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket
On Oct 1, 10:16*pm, Alan Erskine wrote:
On 30/09/2011 7:09 AM, wrote: You mean the Boeing idea for the shuttle (if I remember correctly, it involved four boosters, two on each side of the ET)? * Actually, that system was two big LOX/Kerosene boosters that were supposed to be powered by surplus F-1As that had been intended for use on the Saturn V, but were never used despite being built and certified. -Mike |
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