Apparently they test fired the recovered stage last night, as they prepare for tomorrow’s Vandenberg launch:
Elon Musk, the chief executive of SpaceX, confirmed in tweets that the company had just conducted a static test firing of the Falcon 9 first stage. “Data looks good overall, but engine 9 showed thrust fluctuations,” he wrote.
The engine in question, he said, is an “outer engine” on a ring of eight that surround a center engine. Musk suggested “debris ingestion” might be the cause of the thrust fluctuations, with more study of the engine planned.
It will be interesting to see if they have a similar problem on tomorrow’s recovered stage (assuming they succeed, of course), or if it was an anomaly. But they’ll know more after they borescope it.
Also, this is the first I’d heard that they can’t do a land landing tomorrow due to paperwork issues. I think people had been saying it was performance. And it’s pretty silly to worry about the environment, considering all the other activity going on there.
[Update a while later]
SpaceX’s success launches space start ups to new heights.
It’s hard to overestimate the psychological impact of this sort of thing. Ultimately, it will be the death knell for pork projects like SLS.
[Update a few minutes later]
OK, I don’t understand this piece:
Landing on ship at sea offers a greater safety margin, especially as SpaceX ventures farther into space, said Scott Pace, director of the Space Policy Institute at George Washington University. “If you are coming back at higher speed, a small error can mean a large miss distance,” he said. “For safety purposes, you have a wider area to work with with a drone ship.”
A drone ship also offers SpaceX greater flexibility for landings, given the potential for land-based space ports to become crowded, he said. For Sunday’s launch, there’s another, even more practical consideration: SpaceX does not have a landing pad at Vandenberg. In the successful Dec. 21 rocket landing, SpaceX’s Falcon 9 booster came to rest less than 10 minutes after launch at a location about six miles south of the Cape Canaveral launch pad.
Does that make sense to anyone else? As far as I know, the only reason to land on a ship is because you don’t have the performance to come back to the launch site. And Koenigsmann himself said they weren’t coming to Vandenberg because they hadn’t completed environmental paperwork, not because they didn’t have a place to land.
They may also want to do a barge landing just to get experience with barge landings, as those will be necessary for recovery in some launches.
How much “experience” do they need? It’s all done by computer, as far as I know. What are they going to learn, if they succeed?
They’ll learn if they missed any unknown unknowns. There’s no substitute for actually doing one of these things.
Maybe, but they came so close the last two times, and landed so almost on the dime in Florida, it seems likely to succeed, absent a rogue wave.
The barge landing may be difficult in the way that a carrier landing is a serious test skill.
The barge (or the carrier) does not stay put — it bobs and heaves with the waves. I don’ think it follows a predictable sine wave motion either but rather traces a low-pass filtered random walk.
There are random disturbances for the control system to counteract landing on dry land — mainly wind effects. But the ocean-platform landing problem seems more difficult.
I agree it’s more difficult, but it’s not clear that it becomes less so with experience.
Even as a private pilot, I found that every landing is a little bit different. Experience always helps. The launch appeared perfect but apparently the landing failed. The waves were around 12-15 feet and before the barge video stopped, you could see the deck pitching several degrees. With stiff landing legs, that might have been all that was needed to cause a failed landing.
I don’t know what the sea state for the drone ship was, but the surf at Surf Beach at Vandenberg, on the Central Coast, was impressive. We were looking at waves of at least twenty feet.
My guess is they both could not get environmental impact hassles out of the way, plus they’d like to use this low-value core for ASDS landing practice. The core is low value because it’s the last F9 1.1, it’s not the full thrust version they performed the RTLS with.
And, I have to say, the idea that we’ve got a in-this-case frivolous environmental impact report standing in the way of something, again, is outrageous.
So they may deliberately crash the expended stage in the ocean, but may not attempt to recover it intact with less environmental impact?
I know, how dare I use logic in such matters.
This looks like a job for Executive Order Man!
Some late reflections after several views of the failed landing video…
I think the jury is still out on the practicality of at sea landings. Deck roll and pitch I think are giving SpaceX fits. Either a more robust landing leg solution is needed, (read active hydraulics) or go with those Navy islands west of LA. Perhaps the semi-submersible approach would also be viable but that would be a redesign of the ASDS, in both platform and support fleet. That this might be necessary anyways to support reuse at Boca Chica is possible, but if a Floridian flyover were to get FAA approval not truly necessary. How much a redesign of the landing system to better accommodate sea conditions is a bit of a gamble in these early days of F9 flight. It’s a decision I would assume Elon would prefer to defer. At least until the “rocket fleet” itself is in a more operational mode. The good news here is that as long as orbital objectives are met, customers will likely little care if Elon continues to tinker with the first stage recovery. Still, tho, a bit of a tight-rope walk that is at least right now, in the early days. It a question of perception & marketing, not engineering.