SpaceX sticks the landing!

[Ruptga]

I would think length between the legs could adjust for the difference, even on the fly with variable shocks. It failed to lock, it didn't fail to land evenly.

Sure they could, but self-adjusting legs is more complexity on top of the added complexity of more legs. It's a problem that doesn't need to exist; sorting out the locking mechanism will work and is a much simpler and lighter solution. That sort of fancy solution can be put off until we're building landing legs on the moon where orbit is almost a jump away.

 

[Phoenix86]

Sure they could, but self-adjusting legs is more complexity on top of the added complexity of more legs. It's a problem that doesn't need to exist; sorting out the locking mechanism will work and is a much simpler and lighter solution. That sort of fancy solution can be put off until we're building landing legs on the moon where orbit is almost a jump away.

I'd be shocked to find out if this complexity isn't already in the design.

SHOCKED!

Get it?

Sorry, 36 hours and no sleep...

 

[CZroe]

Less atmo [on Mars] so less speed loss due to friction, also why chutes are bad to rely on. That being said I'd think a 5-6 landing leg system would be better for the very reason this failed. Redundancy.

Well when its $10,000 per kg to space, 4 legs is going to have to do .

Since the 1st stage doesn't make it to orbital velocity, adding additional mass isn't a one-one trade-off, it is for the 2nd stage.

The stated cost per kg is for the payload. They are talking about a propulsive Mars lander, which would be mass that does have to be carried into orbit... and beyond. It then becomes the first stage for an ascent vehicle, but the legs can be left behind (return vehicle will probably stay in orbit).

 

[JEDI]

oh that's way better than the nasa link.



this is awesome.

wait.. why are they landing in the ocean?
why not just send the rocket back to the launch pad like the previous one?

especially after this explanation:
http://forums.anandtech.com/showpost.php?p=37940491&postcount=83

 

[PottedMeat]

wait.. why are they landing in the ocean?
why not just send the rocket back to the launch pad like the previous one?

especially after this explanation:
http://forums.anandtech.com/showpost.php?p=37940491&postcount=83

returning to the site costs quite a bit more fuel than just releasing the 2nd stage and dropping down. most of the fuel may be needed for a particular orbit.

also you can land on a barge anywhere from any orbit requirement

a little salt spray is far different from a slam into the ocean and total immersion

 

[Phoenix86]

wait.. why are they landing in the ocean?
why not just send the rocket back to the launch pad like the previous one?

especially after this explanation:
http://forums.anandtech.com/showpost.php?p=37940491&postcount=83

First, launching over an ocean is preferred for safety for a number of reasons. A failure at any point happens over a non-populated area.

Second, the launch profile for a return is more expensive.

That boostback burn is only needed if you return to where you launched.

Without the boosback burn you end up in the ocean, following the natural trajectory of initial burn saving a lot of fuel.

With regards to salt, it's not a problem if you don't end up IN the ocean, hence the platform and ideally gentle landing. Recovery is cheaper than the fuel and easier.

 

[Phoenix86]

Like I said that time, they need a set of cables or nets, suspended above the barge, that can swing into position quickly and catch the top of the rocket.

http://gfycat.com/LiquidOrangeBoar

 

[JEDI]

http://gfycat.com/LiquidOrangeBoar

pfft.. they could at least used Optimus Prime or Voltron.
heck, even one of those NFL robots on FOX

 

[Crusty]

First, launching over an ocean is preferred for safety for a number of reasons. A failure at any point happens over a non-populated area.

Second, the launch profile for a return is more expensive.

That boostback burn is only needed if you return to where you launched.

Without the boosback burn you end up in the ocean, following the natural trajectory of initial burn saving a lot of fuel.

With regards to salt, it's not a problem if you don't end up IN the ocean, hence the platform and ideally gentle landing. Recovery is cheaper than the fuel and easier.

It's not that it is more expensive, Elon has been quoted saying it is physically impossible for some of the launches(100% payload dependent) to return to the launch site. You just can't carry enough fuel with the current rocket designs. Even with Falcon Heavy, the side boosters will RTLS and the main rocket will land on JRTI because of physical fuel constraints.

The cost of reusing a rocket vs building a new one is so drastic that they would do almost anything to ensure a 100% success rate. If that meant carrying more fuel(extremely cheap compared to a new rocket) they would, but they can't.

 

[Phoenix86]

pfft.. they could at least used Optimus Prime or Voltron.
heck, even one of those NFL robots on FOX

Ain't easy to build a robot in a rocket sim.

 

[Phoenix86]

It's not that it is more expensive, Elon has been quoted saying it is physically impossible for some of the launches(100% payload dependent) to return to the launch site. You just can't carry enough fuel with the current rocket designs. Even with Falcon Heavy, the side boosters will RTLS and the main rocket will land on JRTI because of physical fuel constraints.

Right, wasn't even thinking about 100% payload. That will -always- be a problem no matter the rocket size. Sometimes you need all you have.

 

[Brovane]

wait.. why are they landing in the ocean?
why not just send the rocket back to the launch pad like the previous one?

especially after this explanation:
http://forums.anandtech.com/showpost.php?p=37940491&postcount=83

A couple of reasons.

#1- The environmental reviews for a landing attempt at Vandenberg on land haven't been completed. Apparently some of the trajectory for a landing attempt on land at Vandenberg would pass over some environmentally sensitive areas. If a RUD would happen you could have a potential tricky clean-up. SpaceX has to explain in the environmental review how they would deal with this.

#2- Missions beyond Low Earth Orbit require a higher staging velocity for the 1st stage. This means that it the booster is going so fast away from the launch site it is possible to get back. So a down range landing on a barge needs to be a skill they develop. FYI - The barge didn't cause the failure it was the failure of landing leg to fully lock so even if this attempt had done a boost back to land you would still had a RUD.

 

[Brovane]

Right, wasn't even thinking about 100% payload. That will -always- be a problem no matter the rocket size. Sometimes you need all you have.

The original F9 could do about 10 tons to LEO, the F9v1.1 could about 13 tons to LEO and the latest version is about 30% improvement over the F9v1.1. This means the latest F9 should have enough margin now to even do commercial GTO launches and still allow a powered landing down range. Already both ULA and ESA are taking about re-usability. Just a couple of years they were both saying that re-usability for LV's was still a long ways off. Funny how quickly things change.