Slashdot Mirror
SpaceX Sends Dragon To ISS But Falcon 9 Rocket Misses Landing Pad (cnet.com)
On Wednesday, SpaceX successfully sent a Dragon spacecraft to the International Space Station to deliver supplies, but unfortunately it wasn't able to recover the Falcon 9 rocket that launched with it. "The first stage of the Falcon 9 launch vehicle appeared to lose control as it approached Landing Zone 1 at Cape Canaveral," reports CNET. "The live feed from the rocket cut away on the SpaceX webcast, but video from people in the media area at the cape showed the Falcon 9 appearing to regain control before making an unplanned landing in the water rather than ashore at the landing area." From the report: Musk tweeted shortly afterward that cutting the live feed "was a mistake" and shared the full clip of the water landing from the rocket's perspective. The rocket took off from Kennedy Space Center in Florida at 1:16 p.m. local time, a little more than 48 hours after SpaceX sent another Falcon 9 to space from the West Coast on Monday. Dragon's flight to low-Earth orbit was supposed to happen Tuesday, but the mission was pushed back a day to replace some food being sent to the space station for experimental mice living there.
SpaceX had planned to land the first stage of the brand-new Block 5 Falcon 9 rocket at a landing zone ashore at Cape Canaveral, but as the rocket descended toward the cape, the live feed from the booster's onboard cameras appeared to show the craft going into some sort of uncontrolled spin. Musk tweeted that the problem was that a "grid fin hydraulic pump stalled, so Falcon landed just out to sea." Musk also tweeted that the pump that failed didn't have a backup because "landing is considered ground safety critical, but not mission critical. Given this event, we will likely add a backup pump & lines."
SpaceX had planned to land the first stage of the brand-new Block 5 Falcon 9 rocket at a landing zone ashore at Cape Canaveral, but as the rocket descended toward the cape, the live feed from the booster's onboard cameras appeared to show the craft going into some sort of uncontrolled spin. Musk tweeted that the problem was that a "grid fin hydraulic pump stalled, so Falcon landed just out to sea." Musk also tweeted that the pump that failed didn't have a backup because "landing is considered ground safety critical, but not mission critical. Given this event, we will likely add a backup pump & lines."
The more impressive thing is that it managed to splash down intact, under full control. Due to the stuck hydraulics for the grid fins, it was rolling at a fairly extreme rate. The rocket had already aimed at this spot in the water (it's designed this way) and was actually able to arrest the roll just prior to splash down. After splash down, it remained operational, despite falling onto its side, and successfully safe itself. Apparently it was still in communications and operational while bobbing away in the ocean.
For the uninitiated, the landing profile has the initial trajectory set with the booster aimed for a region away from the landing pad, be it the one on the ground, or the barge. This is in case of exactly a situation such as this, if something goes wrong during the landing process and the booster loses control authority, it will impact somewhere safe. It's only during the final landing burn (aka the hoverslam) that the booster side slips and changes its trajectory to land in the landing zone.
So yeah, the system worked exactly as designed, and is fail safe. All in all a successful failure.
...si hoc legere nimium eruditionis habes...
Except that's 100% wrong. This is an unmanned spent rocket husk, and if it's got any malfunctions the idea is to keep it away from the population as much as possible. The ocean is pretty unpopulated with people. Try again.
As far as I understand once they land in saltwater, they are no longer usable. Electronics don't hold up well once exposed to saltwater
There are quite a lot of non-electronics though that can still be reused.
From this link: A Falcon 9 first stage is too fragile to just let fall into the water.
That would be a crash but it not what it did in this case, it still did a burn kind of like it was intending to land., touched down lightly and was fetched fairly quickly.
From the ACTUAL ARTICLE linked to in the summary, which you probably should have read before you scoured the internet for other random Falcon9 links:
"Appears to be undamaged & is transmitting data. Recovery ship dispatched," Musk wrote, latter adding: "We may use it for an internal SpaceX mission."
"There is more worth loving than we have strength to love." - Brian Jay Stanley
From the article: "Remarkably, it seems SpaceX may still be able to recover the rocket."
What this means is that it was like a plane landing on water so gently that it could be removed and reflown. What is amazing here is that a major system failure didn't result in a terminal velocity crash into the ocean with the total loss of the vehicle. If this had been a crewed mission:
a) The crew would have been safe in orbit.
b) Even if a human were onboard the landing was survivable/soft.
I say well done SpaceX - even when something goes wrong it goes right.
This really is a case where a picture is worth a thousand words.
Bruce Perens.