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Have they announced a timeline for actually implementing the grasshopper tech for real launch purposes?! When that happens, spacex will have won the race to spa

by ricw 14y ago

Have they announced a timeline for actually implementing the grasshopper tech for real launch purposes?! When that happens, spacex will have won the race to space. No other company would be able to match their launch price, given how high the cost of "disposable" rockets these days..

adastra 14y ago
You won't find a bigger supporter of SpaceX, and no one wants Grasshopper to be doing operational flights tomorrow more than I do. But it will take 10 years, minimum. Keep in mind no one has successfully done powered vertical landing from orbit. It's never been done. (Well, not from Earth orbit anyway. The LEM landed vertically from lunar orbit.) SpaceX is getting a taste of how hard this is by trying to recover their first stages using parachutes - their every attempt to do so has failed. If they could focus the bulk of their engineering workforce on this problem they might be able to do it faster. But they have to massively scale up production to meet the orders they've taken, they have to keep their reliability up, they are constantly working on performance upgrades for Falcon 9's engines, and they have to get Falcon Heavy going to crack the DoD market. Oh, and there's this little thing called Dragon and NASA's Commercial Crew program. Something about launching those living sacks of meat and bones we call people tends to hold your focus pretty intensely.
- simonh 14y ago
  They don't have to do powered descent from orbit for this to be worthwhile. Just doing powered descent for the recovery of the first stage would be a huge win.
  - adastra 14y ago
    The first stage isn't going at orbital velocity of course, but the second stage is. The SpaceX announcement for Grasshopper refers to both: http://www.space.com/13140-spacex-private-reusable-rocket-elon-musk.html http://www.space.com/13140-spacex-private-reusable-rocket-el... I'm sure they'll start with just the first stage, but you can't just do a powered descent - that would leave it in the middle of the Atlantic ocean. It has to be a return-to-launch-site maneuver and landing, which is what you see in the video linked to above. At the point where the vehicle does a 180-degree turn (referred to as a "death swoop" by rlv enthusiasts), it's going Mach 6 and is 1000 miles downrange. That's hard.
    - jlgreco 14y ago
      With their planned "helicopter like inaccuracy", could they just land it on a barge out in the middle of the Atlantic instead?
      - Gravityloss 14y ago
        Jeff Bezos has actually tried to patent the barge landing. Go figure. http://ipinspace.com/2012/02/13/repeat-after-me-patent-applications-are-not-patents/ http://ipinspace.com/2012/02/13/repeat-after-me-patent-appli...
        adastra 14y ago
        Bezos, or his handlers anyway, can be pretty outrageous with this kind of stuff. Water landings of VTVL's have been talked about since the 1960's by various people. It would be pretty ridiculous if he was granted the patent for it.
arrrg 14y ago
Not really. There are some savings, but they are not super-great. Plus, we do not yet know whether this works and if what the timeline is. This is hard! What SpaceX is doing is totally awesome but – for the foreseeable future – a risky business.
dasmoth 14y ago
Not a timeline. However, there have been some reports recently that the first Falcon 9 v1.1 flight (currently scheduled for this June) will attempt to flip the first stage around after separation, relight one of its engines, and use it to slow down before landing on the ocean. IF this can be demonstrated successfully, it links up with the Grasshopper work very nicely. So, a more aggressive schedule than I would have expected just a few days ago. Source: http://forum.nasaspaceflight.com/index.php?topic=30385.msg1023706#msg1023706 http://forum.nasaspaceflight.com/index.php?topic=30385.msg10... (and generally a good place to look for SpaceX updates...)
- JulianMorrison 14y ago
  Given that they already have thrust vectoring, isn't "grasshopper" basically just the software? IOW, this is a full "grasshopper" attempt for the first stage, and the only difference from ideal is that it will land on water.
  - dasmoth 14y ago
    Legs (strong enough to land on, light enough not to zero out your payload) are a non-trivial issue. There's a Grasshopper 2 plan in the works (using a v1.1 tank) which will supposedly have rather more flight-like legs than the current one. But I'm sure that a lot of what they've learned from Grasshopper will be going into the June test.
    - Gravityloss 14y ago
      Relighting / staging while the first stage motor is running at "idle" or something like that will be interesting. For a relight, you need some propellant at the feed pipes to restart, though if you have small enough aero forces, you could just vent some stuff to accelerate the rocket forward slightly so you can start ingesting liquid again, instead of the pressurant gas and can then proceed with relight. Then again, since the empty rocket's bottom end is heavy, it could orient itself the right way aerodynamically anyway (acceleration vector pointing the way of the nose) so the liquids go towards the engine end. If it comes like a dart and not tumbling (which presents its own problems), such a big stage has lots of mass per frontal area and it will come in quite fast. Interesting aerodynamic problems. I wonder if we might see some maneuverable mini fins or wings at some point.

by ricw 14y ago

adastra 14y ago

You won't find a bigger supporter of SpaceX, and no one wants Grasshopper to be doing operational flights tomorrow more than I do. But it will take 10 years, minimum. Keep in mind no one has successfully done powered vertical landing from orbit. It's never been done. (Well, not from Earth orbit anyway. The LEM landed vertically from lunar orbit.) SpaceX is getting a taste of how hard this is by trying to recover their first stages using parachutes - their every attempt to do so has failed. If they could focus the bulk of their engineering workforce on this problem they might be able to do it faster. But they have to massively scale up production to meet the orders they've taken, they have to keep their reliability up, they are constantly working on performance upgrades for Falcon 9's engines, and they have to get Falcon Heavy going to crack the DoD market. Oh, and there's this little thing called Dragon and NASA's Commercial Crew program. Something about launching those living sacks of meat and bones we call people tends to hold your focus pretty intensely.

simonh 14y ago
They don't have to do powered descent from orbit for this to be worthwhile. Just doing powered descent for the recovery of the first stage would be a huge win.
- adastra 14y ago
  The first stage isn't going at orbital velocity of course, but the second stage is. The SpaceX announcement for Grasshopper refers to both: http://www.space.com/13140-spacex-private-reusable-rocket-elon-musk.html http://www.space.com/13140-spacex-private-reusable-rocket-el... I'm sure they'll start with just the first stage, but you can't just do a powered descent - that would leave it in the middle of the Atlantic ocean. It has to be a return-to-launch-site maneuver and landing, which is what you see in the video linked to above. At the point where the vehicle does a 180-degree turn (referred to as a "death swoop" by rlv enthusiasts), it's going Mach 6 and is 1000 miles downrange. That's hard.
  - jlgreco 14y ago
    With their planned "helicopter like inaccuracy", could they just land it on a barge out in the middle of the Atlantic instead?
    - Gravityloss 14y ago
      Jeff Bezos has actually tried to patent the barge landing. Go figure. http://ipinspace.com/2012/02/13/repeat-after-me-patent-applications-are-not-patents/ http://ipinspace.com/2012/02/13/repeat-after-me-patent-appli...
      - adastra 14y ago
        Bezos, or his handlers anyway, can be pretty outrageous with this kind of stuff. Water landings of VTVL's have been talked about since the 1960's by various people. It would be pretty ridiculous if he was granted the patent for it.

arrrg 14y ago

Not really. There are some savings, but they are not super-great. Plus, we do not yet know whether this works and if what the timeline is. This is hard! What SpaceX is doing is totally awesome but – for the foreseeable future – a risky business.

dasmoth 14y ago

Not a timeline. However, there have been some reports recently that the first Falcon 9 v1.1 flight (currently scheduled for this June) will attempt to flip the first stage around after separation, relight one of its engines, and use it to slow down before landing on the ocean. IF this can be demonstrated successfully, it links up with the Grasshopper work very nicely. So, a more aggressive schedule than I would have expected just a few days ago. Source: http://forum.nasaspaceflight.com/index.php?topic=30385.msg1023706#msg1023706 http://forum.nasaspaceflight.com/index.php?topic=30385.msg10... (and generally a good place to look for SpaceX updates...)

JulianMorrison 14y ago
Given that they already have thrust vectoring, isn't "grasshopper" basically just the software? IOW, this is a full "grasshopper" attempt for the first stage, and the only difference from ideal is that it will land on water.
- dasmoth 14y ago
  Legs (strong enough to land on, light enough not to zero out your payload) are a non-trivial issue. There's a Grasshopper 2 plan in the works (using a v1.1 tank) which will supposedly have rather more flight-like legs than the current one. But I'm sure that a lot of what they've learned from Grasshopper will be going into the June test.
  - Gravityloss 14y ago
    Relighting / staging while the first stage motor is running at "idle" or something like that will be interesting. For a relight, you need some propellant at the feed pipes to restart, though if you have small enough aero forces, you could just vent some stuff to accelerate the rocket forward slightly so you can start ingesting liquid again, instead of the pressurant gas and can then proceed with relight. Then again, since the empty rocket's bottom end is heavy, it could orient itself the right way aerodynamically anyway (acceleration vector pointing the way of the nose) so the liquids go towards the engine end. If it comes like a dart and not tumbling (which presents its own problems), such a big stage has lots of mass per frontal area and it will come in quite fast. Interesting aerodynamic problems. I wonder if we might see some maneuverable mini fins or wings at some point.