Many things went right with Spacex landing attempt and gamechanging reusability seems likely in months

Rand Simberg describes the many things that went right with the Spacex attempted first stage landing.

Spacex 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.

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.

Spaceflightnow had a picture of the damaged landing barge as it returned to port

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.

The Marmac 300 is 300 feet long and 100 feet wide — the size of a football field. Musk tweeted in November the Falcon 9 landing barge has extendable wings to expand the width to 170 feet.

“It’s very difficult to hit a platform of that size,” Koenigsmann said before Saturday’s launch. “When you look at it on the ground, I think it’s probably a very big platform, but if you look at (from space), then it looks like a very, very small place to land on.”

SOURCE – Pjmedia, Spaceflightnow

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