Most reports of Saturday morning’s flight by SpaceX to the International Space Station note that the primary mission was successful, but that the company “failed” to stick the landing. For example, Andy Pasztor at the Wall Street Journal once again lived up to his reputation of a willing (and often unfair) basher of the company, and initially used the word “botched” to describe it in the lede graf. (“It now says “spoiled,” though the headline still says the company “stumbles,” but here is a version of the original from Marketwatch.) Though, to be fair, the rest of the piece seems well reported.
But to focus on what went wrong is to ignore the many other things that went astonishingly right, and just how close the company came this time to achieving their long-time goal of recovering the first stage of the Falcon rocket. As with the too-much-bewailed loss of its test vehicle in Texas this past summer (and the destruction of SpaceShipTwo this past Halloween), it is important to understand that this was a test flight and, as with any test flight, they were pushing the envelope to find out how the system worked in practice as opposed to theory. It was an experiment, and the only failed experiment is one in which nothing is learned.
In the ’40s, ’50s and ’60s, the NACA and, later, NASA had many flight-test programs to learn how to do new things, gradually expanding performance envelopes, often breaking airplanes (and killing pilots), but with the advent of the Shuttle and reliance (some would say over-reliance) on computer simulations, the agency has developed a tendency to instead spend months and years in analysis, without flying. The very first (delayed) flight of the Shuttle was not only all the way to orbit, but with a crew. The X-34B program in the ’90s was in fact canceled before it ever flew, even though the vehicle was complete, because NASA, in its risk aversion after the loss of a planetary probe, decided in retrospect that it shouldn’t be attempted without sufficient redundancy in key systems.
But SpaceX has picked up where the government left off, building, flying, testing and learning, then rebuilding and reflying. Its first three Falcon 1 flights all failed to deliver their payloads, but with each failure, they learned a lesson that was applied to the next flight. On the fourth flight, they succeeded, as on the fifth. The larger Falcon 9, based on the lessons learned from the Falcon 1 program, has never had a primary-mission failure. Now, they’re flight testing again, with the first stage, but only after it has completed its crucial job of getting the second stage and payload on their way to orbit.
The company understands that the key to reducing launch costs is to minimize the degree to which hardware is thrown way. The first stage, with its nine engines, is reportedly about 70% of the total vehicle cost, and the easiest part to recover, in theory. They’ve been attempting it from the beginning, but it had always broken up on entry. With the realization they’d have to sacrifice some performance in order to save enough propellant to safely enter and land, they increased the size of the vehicle to allow it to carry more. Since then, they have been slowly approaching a successful recovery, first with soft landings in the water, which still destroyed the vehicles, and then, this past weekend, with the first attempt at a precision landing on a hard surface.
What had to go right this weekend for them to land the stage intact? First, after stage separation, it would have to relight three of its nine engines to slow down from about 3000 mph to an entry speed that wouldn’t break up the vehicle. After entry, another three engine relight would have to occur to aim the vehicle toward the drone ship on which it was planned to land, and fins would be deployed to help steer it. Finally just before landing, a relight of a single engine would be required for a soft landing, with guidance continuing to be aided by the fins. It would be the most precise flight ever achieved (previous water landings hadn’t been particular about location).
With the exception of the final landing itself, almost everything went according to plan. The vehicle entered intact, flew to the ship, and (apparently literally) hit the deck, because the hydraulic fluid that controlled the fins ran short by 10% of that needed to control and softly land. But in so doing, it accomplished another major “first,” not just for a private company, but for any space ship. Previous Falcon flights had demonstrated the ability to enter the stage intact by retrothrusting (as opposed to simply braking against the atmosphere), but this was the first time such a vehicle had not only survived entry, but flown precisely to a pre-designated location, without wings.
Pictures of the drone ship being towed into port in Jacksonville, Florida, on Sunday showed some charring, and the company reported that while the ship itself was undamaged, some of the support equipment on the deck would have to be rebuilt or replaced. And as Elon Musk, the company’s CEO, tweeted Saturday morning, they would piece together what happened “from telemetry, and…actual pieces.”
Musk had previously “estimated” a “50% chance” of success (though more recently he admitted that this figure was arrived at, shall we say “ex posteriori” aka a wild-ass guess). So I expect that while he would have preferred a total success, he and the company must actually be quite elated. He later noted that they would have a 50% margin on the fin hydraulics on the next attempt,on January 29, so barring some analysis indicating why they underestimated the amount required on this flight that requires some other change, it would appear that their chances of success for that one will be much greater than 50%.
It’s interesting to note that while the company had been doing flight tests in Texas, first with its early “Grasshopper,” and more recently with the converted first stage that it lost last summer, that may be over. We’ve heard of no more flight tests, either in Texas or (as the company had long been planning) in New Mexico at Spaceport America. That is, they may now feel confident in moving forward by testing only on operational launches, with no more need for dedicated test vehicles and flight tests.
If they succeed later this month, it will be another huge first: the first time that a spaceship has landed on earth since the last Shuttle retired, and the first time any spaceship has landed on earth vertically, using only propulsion. The next step will be to determine how much it will take to reliably (and rapidly) reuse the stage. If the answer is “not much,” it will mean a revolution in reducing the cost of access to space. SpaceX’s competitors are watching carefully. CNES, the company that builds Europe’s Ariane, recently announced its own project to make its vehicles reusable, though not for many years. Tory Bruno, the new CEO of the United Launch Alliance, which operates the Atlas and Delta launch systems, will be announcing the company’s plans for its own new launch systems next month, and many (including me) will be surprised if reusability isn’t a key part of them.
@somepitch @planet4589 @SpaceX More to say about #reuse when I speak at Stanford in Feb and at the #spacesposium when I reveal our next gen
— Tory Bruno (@torybruno) January 10, 2015
SpaceX has led the way, and shown that spaceflight is not exempt from the benefits and challenges of innovation and competition, despite socialist-sounding statements from Republicans in Congress.
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