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Elon Musk's SpaceX to build 'Grasshopper' hover-rocket



 
 
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  #11  
Old September 29th 11, 10:09 PM posted to sci.space.policy
[email protected]
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Posts: 687
Default 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?
  #14  
Old September 30th 11, 03:00 PM posted to sci.space.policy
Jeff Findley[_2_]
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Posts: 1,388
Default Elon Musk's SpaceX to build 'Grasshopper' hover-rocket

In article , says...

(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


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
  #15  
Old October 1st 11, 02:08 AM posted to sci.space.policy
Matt Wiser
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Posts: 575
Default 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)
  #17  
Old October 2nd 11, 09:15 AM posted to sci.space.policy
Mike DiCenso
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Posts: 150
Default 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
  #18  
Old October 2nd 11, 09:18 AM posted to sci.space.policy
Mike DiCenso
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Posts: 150
Default 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  
Old October 2nd 11, 09:26 AM posted to sci.space.policy
Mike DiCenso
external usenet poster
 
Posts: 150
Default 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
  #20  
Old October 2nd 11, 09:29 AM posted to sci.space.policy
Mike DiCenso
external usenet poster
 
Posts: 150
Default 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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