SpaceX vertical landing attempt on the 16th

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Jim Logajan

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Weather and technicalities permitting, SpaceX's Falcon 9 rocket will be attempting a rocket powered soft landing of the first stage (on water, since it is still being tested) on Sunday. They added legs to the first stage to replicate the configuration that would be needed for a solid ground landing. Article:
http://www.space.com/25019-spacex-rocket-engine-test-success.html

A stabilization system that can guide a rocket on ascent should (in theory) have no problem guiding it on descent.
 
Jim Logajan said:
A stabilization system that can guide a rocket on ascent should (in theory) have no problem guiding it on descent.
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Yes, but rocket science is ALL about the details.

A fuel control system for an Arianne 4 should work on an Arianne 5, right?
 
Riddle me this: if the next flight innaugurates a test campaign for F9R, why do they need Grasshopper II at all? The water quasi-landigns are going to test everything the real stage experiences in flight, because they are performed by the real stage. So, what's left?
 
Sunday launch is off.

Subject: SpX press release

To ensure the highest possible level of mission assurance and allow additional time to resolve remaining open items, SpaceX is now targeting March 30th for the CRS-3 launch, with April 2nd as a back-up. These represent the earliest available launch opportunities given existing schedules, and are currently pending approval with the Range.
Both Falcon 9 and Dragon are in good health; given the critical payloads on board and significant upgrades to Dragon, the additional time will ensure SpaceX does everything possible on the ground to prepare for a successful launch.
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Last January I flew near the SpaceX McGregor test facility and noticed there was a new rocket out there, the next to the big crane:

Ax8Y1fdl.jpg


The smaller one is the 'Grasshopper'. I posted this image on a couple of places where we SpaceX fanbois hang out. It caused quite a sensation, since SpaceX had not announced this mystery ship yet.

It turns out that this is 'Falcon 9r-dev1', the full sized hovering rocket.

It's a nice motorcycle ride out there from my house, so I've gone back a couple of times since then. Last weekend it looked like this:

cZ0Lf4cl.jpg


SpaceX has said that after testing in McGregor this vehicle will be sent to Spaceport New Mexico where it can fly higher than 2,500 feet.
 
Yeah, it used to be known as Grasshopper 2. The question is what is it for if normal launches are going to provide the same information for free?
 
zaitcev said:
Yeah, it used to be known as Grasshopper 2. The question is what is it for if normal launches are going to provide the same information for free?
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I'm just guessing, but I suspect they've flown this already. I know it's been fired, because two weeks before this image the bottom of the rocket was covered with black stuff.

In any case, I'm sure they want to do as much testing in private and away from their customers as they can.
 
zaitcev said:
Yeah, it used to be known as Grasshopper 2. The question is what is it for if normal launches are going to provide the same information for free?
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SpX uses the Grasshopper tests to prove and improve the control systems for the real rockets.

The real vehicles only launch for paid missions, and they come back to the surface way out to sea when launched from Florida. That's a lousy way to collect test data.

Having a controlled environment like the one in Macgregor gives SpX better opportunities to test/learn/refine before doing it with the "real" rocket. They can turn the testbed around quickly and fly many times in-between F9 launches from Florida. They can even "control" the flight environment by choosing calm-wind days, windy days, etc.

So the point is not that the real launches are generating new data. The point is that they've already collected the data via Grasshopper, so that hopefully there are no surprises with the real vehicle.
 
What they are trying to do is best shown in the following video between the 0:40 and 1:09 marks in this video:

http://www.youtube.com/watch?v=5_1WJ7UUm8I

They've already flipped the rocket around and ignited the first stage a second time on earlier flights. :yes:
 
I still don't understand how the legs are supposed to prevent the axial spin, which as I understand it was Elon's claim regarding the premature shutdown. They are symmetrical against the main axis. If anything, any minute imperfection in their shape due to aerodynamic deflection would create a larger spin moment due to the large arm. If the corking of Merlin's plume can spin the stage, legs should be able to spin it harder with ease. Maybe they should think about landing on 2 Merlins.
 
zaitcev said:
I still don't understand how the legs are supposed to prevent the axial spin, which as I understand it was Elon's claim regarding the premature shutdown.
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The booster has thrusters to control the spin, SpaceX says it understands what happened with the spin incident and have fixed the problem.

I suspect the legs extend only moments before touchdown in any case.
 
Jim Logajan said:
Weather and technicalities permitting, SpaceX's Falcon 9 rocket will be attempting a rocket powered soft landing of the first stage (on water, since it is still being tested) on Sunday. They added legs to the first stage to replicate the configuration that would be needed for a solid ground landing. Article:
http://www.space.com/25019-spacex-rocket-engine-test-success.html

A stabilization system that can guide a rocket on ascent should (in theory) have no problem guiding it on descent.
Click to expand...

I don't believe that's really true. During ascent you start from a relatively stable vertically balanced attitude and stability increases as you gain speed. On a descent you start with something that's not balanced or all that stable and have to tighten things up into the landing. Very similar to the difference between the difficulties encountered with a normal takeoff vs a normal landing in an airplane.
 
I also don't understand the reasoning behind using thrust to land. IIRC every extra pound lifted into orbit requires something like 10-20 more pounds of fuel and structure so the cost of lifting the fuel used to land ought to be prohibitive.
 
gismo said:
I also don't understand the reasoning behind using thrust to land. ...
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The booster doesn't go in to orbit.

Musk says landing the booster reduces costs by more than 50%. Their motors have enough thrust to lift customer payloads and still do a full stop landing on the ground.
 
It wasn't due to weather. There were other reasons they weren't ready. Weather would be a day-of-launch scrub call.
 
The rumor is that they found 'contamination' in the trunk of the Dragon as they were about to install it on the Falcon booster.

SpaceX only has a one second launch window. If they miss the window then they have to coordinate with the Air Force range controllers, the ISS management, the Russians, and Isaac Newton to determine the next launch opportunity.
 
I see that although they missed the March 16th date, they finally managed to launch on the 18th ... of April.

http://www.nbcnews.com/science/space/spacex-launches-cargo-tries-rocket-recovery-n84266

Too early yet for data from the SpaceX tracking plane, so no word on how the first stage fared on its landing attempt. NASA had also planned to have a P-3 flying so it could monitor the supersonic thruster firings on the booster's descent (presumably the data would be for use in planning a Mars mission) but icing prevented their flight (https://twitter.com/NASAWatch).
 
Yesterday SpaceX released a flight test video of the Falcon9r at McGregor doing a vertical takeoff and landing:

http://youtu.be/0UjWqQPWmsY

Today's launch seemed to have gone perfectly, and early tweets from SpaceX indicate the vertical water landing went as planned.
 
After some flakey comm issues, ISS captured the Dragon right on time.
 
Let me opine a few opine's.
In no particular order
Landing the tall booster on those narrow legs with that high of a CoG in good weather and in bad will in the end be found impractical - the hard way
Hurtling tons of reentry vehicle back at the populated land will generate some spectacular headlines in the not distant future when the magic smoke leaks out of some electronic bit
Can you imagine what all this would have cost had we sent NASA to do it with tax dollars
ya, ya, ya I know there are now tax dollar contracts made to Space X, but they are spending them magnitudes more efficiently
I'm thinking in the end capturing the booster will go to a controlled/soft water landing and tow it to the harbor - some things are the way they are just because they work
I'm thinking that the days of NASA deciding who does what in space are numbered - and short
 
Dr. O said:
I'm thinking in the end capturing the booster will go to a controlled/soft water landing and tow it to the harbor - some things are the way they are just because they work
I'm thinking that the days of NASA deciding who does what in space are numbered - and short
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SpaceX has repeated tried to recover their boosters from water landings. Based on their experiences with those attempts, they've decided to pursue this "fly back to land" approach. Note that while they currently recover their orbital Dragon craft via water landing, they would also like to transition that to a land-based recovery as well, for similar reasons.

Re: NASA, that may be true. But regardless of what you think about NASA, they're the only reason SpaceX exists right now. SpaceX could not have gotten the investors or commercial customers needed to "get off the ground" without first the seed money and then the contracts that NASA awarded them--that gave them the legitimacy to draw in the rest. Plus the $1.6B from their contracts to deliver cargo to ISS currently dwarfs all their other launch contracts combined.

They also used numerous bits of the body of research that NASA has compiled over the decades in their booster and orbital vehicle development. They didn't start with a blank sheet of paper and do all their development in a vacuum. In short, they would not be who they are without NASA.

As for the future...

Today, "civil commercial space" = "launching communications and earth-observation satellites", plus the new and tiny role of SpaceX and Orbital in launching cargo to ISS.

Tomorrow and for the foreseeable future, "civil commercial space" = "launching communications and earth observation satellites", plus the new and tiny role of SpaceX and Orbital in launching cargo to ISS, plus possibly resuming the launch of US astronauts to the ISS in a few more years.

Beyond that, there ain't nuthin' new happening "soon", and nuthin' new's gonna happen until someone...maybe SpaceX, maybe someone else...figures out how to make a buck out of it.

Virgin Galactic's trying to create a business around selling rides into space on their SpaceShipTwo, but they've been working on that for over 15 years now, so I guess it depends on what you mean by "soon" and how game-changing you believe that commercial venture to be re: NASA's future.
 
How come when an all metal airplane is ditched in the ocean and recovered, it is considered scrap due to corrosion issues, but these rocket boosters splash down in the sea and they're good to go again? :confused:
 
Lots of issue with salt water, Dave. That is why Elon is trying hard to avoid it.
I could get all nerdy and do a back of the paper napkin estimate of the actual CG of that soft landing booster and opine a rough idea of how much side vector drift it will tolerate when landing during a dark and stormy night - but I won't. I am sure ELon has that white paper in his Ipad.

Space X may go on to greatness, or may not. We shall see.
And, I am well aware that Space-X is an industrial-military consortium of the kind that Eisenhower warned darkly - just not one of the good-old-boys favored by rocket people with a military background.

But given a total of 8 years of 'dismantle that nasty military so we can buy votes with that money', which we will have by the end of the current administration - and given the conservatives have not shown any ability to out maneuver the liberal dems for the popular vote, and given there might be another 4 years of liberal control (and possibly 8) I do not foresee a budget increase for NASA nor a likelihood that they will be back in the heavy launch business in my lifetime.

Could be wrong. Been told I was lots of times over a very long life.
 
Dr. O said:
Lots of issue with salt water, Dave. That is why Elon is trying hard to avoid it.
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Perhaps they should consider "landing" in Lake Huron?
I could get all nerdy and do a back of the paper napkin estimate of the actual CG of that soft landing booster and opine a rough idea of how much side vector drift it will tolerate when landing during a dark and stormy night - but I won't. I am sure ELon has that white paper in his Ipad.
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Go ahead, I love it when you get nerdy. :D:D
 
Dr. O said:
But given a total of 8 years of 'dismantle that nasty military so we can buy votes with that money', which we will have by the end of the current administration - and given the conservatives have not shown any ability to out maneuver the liberal dems for the popular vote, and given there might be another 4 years of liberal control (and possibly 8) I do not foresee a budget increase for NASA nor a likelihood that they will be back in the heavy launch business in my lifetime.

Could be wrong. Been told I was lots of times over a very long life.
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Neither Republicans or Democrats particularly like NASA. Neither wants to fund them. Only when there is a possible defense tie in do they get the money.
 
gismo said:
Perhaps they should consider "landing" in Lake Huron?
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The great lakes are great idea, but I think they are too far north. Need something closer to the equator. Still, if they think they have the precision control to set one of these things down on a launch pad, why not put it down in fresh water lake that is in the south?
 
Dr. O said:
Space X may go on to greatness, or may not. We shall see.
And, I am well aware that Space-X is an industrial-military consortium of the kind that Eisenhower warned darkly - just not one of the good-old-boys favored by rocket people with a military background.
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Well, SpaceX would like to get into the military launch game, but they don't have the track record yet that will allow them to compete for those contracts, so today they're purely civil. A little premature to lump them into military-industrial complex.

Re: culture, SpaceX certainly benefits greatly from its youth and energy. They have accomplished fantastic things with a very small workforce. (Though still modest in size, they're a huge company now compared to what they were when they had their first successful Falcon 1 launch.)

Elon Musk was able to build a company of very bright, highly-motivated people to accomplish things no one else had done, and in a surprisingly short time.

NASA was like that once. So were a lot of successful companies.

SpaceX has also benefitted from the entrepreneurial "everything is new and challenging" environment of their development phase. While they are still working on innovative projects, there is also now a significant sustaining component. I.e., it was huge to fly the first Falcon 9 and the first Dragon mission to space. Now, the're in the process of doing that 11 more times.

Lots of people want to climb Mt. Everest...once. Not everyone wants to be a Sherpa.

Some key members of the "first generation" of SpaceX employees are no longer with the company. Many of their employees work long hours and take little vacation, and most individuals cannot (or will not) sustain that pace for too long, especially if the challenges/rewards aren't as good as they were "in the good ol' days". So far, they've been pretty good at maintaining their pace of success as people leave and are replaced.

I wonder if they will continue to do so indefinitely. It will be very interesting to see how the culture of the company evolves, and whether it can remain "young and nimble", or whether it will end up looking more like Boeing or Lockheed...or NASA.
 
Space-X is an industrial-military consortium
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Actually, SpaceX is an 'anti-consortium'. Musk brings every single thing that he can into his Hawthorne factory. SpaceX has genetic programming against 'consorting' with anybody if they can possibly avoid it.

SpaceX designed its own in flight cameras, they designed their own gesture based 3D CAD/CAM software.

Everybody else bought cheap motors from Russia or used 60s era legacy motors. SpaceX motors are all designed, built, tested an flown by SpaceX.

United Launch Alliance is a typical consortium. It outsources as much as it can, preferably to all fifty states to buy votes.

SpaceX is a private sector company that makes rockets for customers who need objects launched into orbit at half the price of the ULAs of the world.

Well, SpaceX would like to get into the military launch game, but they don't have the track record yet that will allow them to compete for those contracts
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SpaceX has been qualified to bid on NRO payloads.
 
Dav8or said:
The great lakes are great idea, but I think they are too far north. Need something closer to the equator.
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Actually, they need something closer to wherever they're launching from (to-date, Cape Canaveral, but Vandenberg launches are expected too). We're talking about recovering their 1st stage booster, which drops off pretty early in the launch phase. It only burns for 3 minutes.
 
Dav8or said:
How come when an all metal airplane is ditched in the ocean and recovered, it is considered scrap due to corrosion issues, but these rocket boosters splash down in the sea and they're good to go again? :confused:
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As SpaceX has demonstrated multiple times with Grasshopper, Falcon and F9rDev1, they have the technology to land their boosters vertically on legs on land.

They are currently installing F9rDev2 in New Mexico, where they can fly it to high altitudes, in Texas they can only climb to 2500 feet.

As far as weather goes, these recoverable boosters are VMC vehicles. They land only a few minutes after the launch, so there is no requirement to land in IMC or high winds

In the future expect to see both the Falcon second stage boosters and the Dragon capsule perform vertical landings with legs on land.

In the post launch news conference of this week's launch Musk said that the roll rate problem was solved, they tweaked the thrusters on the booster to null out roll for landing.
 
Dr. O said:
Landing the tall booster on those narrow legs with that high of a CoG in good weather and in bad will in the end be found impractical - the hard way
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They currently only plan to take off in good weather - so why would they end up taking off in good weather and land in bad weather? I know Florida weather can change fast, but boy....

Also - what makes you think the CoG is all that high? All the heavy bits are near the base and the tank is empty or nearly so on landing.

Hurtling tons of reentry vehicle back at the populated land will generate some spectacular headlines in the not distant future when the magic smoke leaks out of some electronic bit
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Why would landing be any different than a takeoff where an aberrant rocket could fly an arc into anything within hundreds of miles? At least on return the amount of flammables on board is near a minimum.

I guess I don't see how the landing could be considered any more difficult or hazardous than the takeoff. By my own reckoning it should be safer. I believe you are engaging in special pleading to make a case for hazards and difficulties where a like-for-like comparison would show your concerns are not objective.
 
SpaceX is well along with buying enough land for a private launch site in Brownsville, Texas.

And they have leased the old Apollo/Space Shuttle launch pad to launch their gigantic 'Falcon Heavy', possibly sometime next year.
 
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Jim_R said:
Actually, they need something closer to wherever they're launching from (to-date, Cape Canaveral, but Vandenberg launches are expected too). We're talking about recovering their 1st stage booster, which drops off pretty early in the launch phase. It only burns for 3 minutes.
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Doesn't Florida have some sizable fresh water lakes? California is much tougher. Closest is Lake Cachuma, but it's a drinking water supply, so I doubt that will be approved. Same for Lake Casitas. Closest agricultural reservoir I can think of off the top of my head is Lake Lopez, but it's pretty small.
 
Jim Logajan said:
I see that although they missed the March 16th date, they finally managed to launch on the 18th ... of April.
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The delay wasn't completely SpaceX's fault. The Cape Canaveral AFB range radar had a fire and the range wasn't going to issue waivers to launch without it. Their backup radar was in mothballs and it took a while for it to get restarted and recertified.

--Carlos V.
 
Unbeliever said:
The delay wasn't completely SpaceX's fault. The Cape Canaveral AFB range radar had a fire and the range wasn't going to issue waivers to launch without it. Their backup radar was in mothballs and it took a while for it to get restarted and recertified.

--Carlos V.
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True. But this mission was originally scheduled for launch in Feb, and all the other slips were for SpaceX issues.
 
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