Less than a month after SpaceX’s first successful rocket landing, billionaire Elon Musk’s company tried to do it again today – but this time, one of the rocket’s landing legs failed, resulting in a tumble onto its oceangoing landing platform.
Oh, and the Falcon 9 rocket launched a satellite, too.
The primary objective of today’s launch was to put the Jason 3 ocean-mapping satellite into orbit for NASA, the National Oceanic and Atmospheric Administration, Eumetsat and the French space agency CNES. Jason 3 is designed to monitor changes in sea level from orbit, continuing a decades-long campaign of measurements.
The rocket rose into the fog from its launch pad at Vandenberg Air Force Base in California, right on time at 10:42 a.m. PT.
#Jason3 has successfully separated from the 2nd stage and is on its own. Go #Jason3! Watch: https://t.co/L5Lav544li pic.twitter.com/0zI2bL4osE
— NOAA Satellites (@NOAASatellites) January 17, 2016
The launch was judged as a success, but SpaceX had been hoping for a successful landing, too. After the Falcon 9’s second stage separated, sending Jason 3 into orbit, the first stage relit its engines and went through a set of autonomous maneuvers.
The rocket firings decelerated the booster from supersonic speeds and sent it toward an autonomous drone ship sitting out in the Pacific Ocean. The ship was christened “Just Read the Instructions.” That’s a tribute to the late science fiction writer Iain M. Banks, who used that name for a sentient starship in one of his novels.
A half-hour after launch, SpaceX reported that the rocket booster descended to the ship on target, but that one of its four landing legs failed to lock into place as it touched down amid choppy seas.
As a result, the booster tipped over onto the deck and blew up, as shown in a dramatic Instagram video posted by Musk. He said the root cause of the failure might have been “ice buildup due to condensation from heavy fog at liftoff.” Here’s how the tweets came in:
First stage on target at droneship but looks like hard landing; broke landing leg. Primary mission remains nominal → https://t.co/tdni53IviI
— SpaceX (@SpaceX) January 17, 2016
Definitely harder to land on a ship. Similar to an aircraft carrier vs land: much smaller target area, that's also translating & rotating.
— Elon Musk (@elonmusk) January 17, 2016
However, that was not what prevented it being good. Touchdown speed was ok, but a leg lockout didn't latch, so it tipped over after landing.
— Elon Musk (@elonmusk) January 17, 2016
After further data review, stage landed softly but leg 3 didn't lockout. Was within 1.3 meters of droneship center
— SpaceX (@SpaceX) January 17, 2016
Well, at least the pieces were bigger this time! Won't be last RUD, but am optimistic about upcoming ship landing. pic.twitter.com/w007TccANJ
— Elon Musk (@elonmusk) January 17, 2016
It was SpaceX’s third not-completely-successful attempt to land a rocket on a platform at sea.
Twice before, SpaceX came close to landing boosters on a drone ship in the Atlantic, after launches from Cape Canaveral. Each time, the rocket crashed on deck and exploded. (That’s what’s known jokingly as a “rapid unscheduled disassembly,” or RUD in Musk’s tweet.)
Last month, SpaceX finally scored with a rocket touchdown on land. And last week, that rocket’s engines were tested in a hold-down firing. Musk reported in a tweet that the test results were “good overall,” although one of the nine engines had a problem.
Maybe some debris ingestion. Engine data looks ok. Will borescope tonight. This is one of the outer engines.
— Elon Musk (@elonmusk) January 16, 2016
The booster from last month’s landing could be used for further ground testing, but when SpaceX is done with it, it’s due to go on display rather than flying again.
Even though landing a rocket at sea is harder than an on-land touchdown, SpaceX still wants to perfect the procedure for times when bringing the booster back to land isn’t an option.
As mentioned before, ship landings are needed for high velocity missions. Altitude & distance don't mean much for orbit. All about speed.
— Elon Musk (@elonmusk) January 17, 2016
If speed at stage separation > ~6000 km/hr. With a ship, no need to zero out lateral velocity, so can stage at up to ~9000 km/h.
— Elon Musk (@elonmusk) January 17, 2016
There was another reason behind today’s at-sea attempt: SpaceX wasn’t able to obtain regulatory approval for an on-land touchdown in California. However, the company eventually hopes to get clearance to use what it calls “Landing Zone 2” on the West Coast.
After Musk’s updates, a fellow Twitter user asked whether today’s Falcon 9 booster would have taken a similar tumble if it had tried to set down on land. Musk answered: “Probably.”
@Uncle_Gus probably
— Elon Musk (@elonmusk) January 17, 2016
Being able to land rocket boosters intact once they’ve done their job is a key part of SpaceX’s strategy for affordable rocket reusability. Such reusability could lead to a drastic reduction in the cost of putting payloads (and people) into space. If SpaceX pulls that off, that would be a giant leap toward Musk’s goal of sending tens of thousands of colonists to Mars and making humanity a multiplanet species.