Friday, March 05, 2021

SCHADENFRUEDE
SpaceX Starship prototype sticks landing, then explodes

William Harwood 
3/4/2021

A SpaceX Starship prototype blasted off from southern Texas on Wednesday, climb
ed to an altitude of six miles, tipped over on its side as planned and plunged back to Earth in a high-altitude swan dive, flipping back vertical and then successfully landing near the launch pad. A few minutes later it exploded in a spectacular fireball.

© LabPadre 030321-launch4.jpg
SpaceX rocket successfully lands in test, then explodes





It was the company's third high-altitude Starship test flight and its first successful landing. But the rocket came to rest with a slight tilt and a fire could be seen at its base near the engine compartment. Moments later, the unpiloted prototype — SN10 — blew up, showering the pad with flaming debris.

© Provided by CBS News A few minutes after touchdown, the Starship prototype exploded, blasting the rocket's upper section away in a spectacular conflagration. / Credit: LabPadre webcast

Despite the explosion, the successful landing marked a major milestone for SpaceX founder Elon Musk in his drive to develop a fully reusable heavy lift rocket, even as it showed the risks that come with an aggressive test program.

"SpaceX team is doing great work! One day, the true measure of success will be that Starship flights are commonplace," Musk tweeted.




Speaking just before SpaceX wrapped up its launch webcast — and before the rocket exploded — company commentator John Insprucker said, "third time's the charm, as the saying goes."

"We've had a successful soft touchdown on the landing pad, capping a beautiful test flight of Starship 10," he said. "As a reminder, a key point of today's test flight was to gather the data on controlling the vehicle while reentering, and we were successful in doing so."

He closed by congratulating the Texas launch team, saying "they've steadily increased the test launch cadence over the course of the program and have delivered some of the most exciting test flights many of us have seen in a long time."

Given three dramatic launches and explosions in a row, few would argue.

© Provided by CBS News Starship prototype No. 10 blasts off from SpaceX's Boca Chica, Texas, flight facility for a short up-and-down test flight to an altitude of about six miles to test the rocket's propulsion, steering and landing systems. / Credit: SpaceX webcast

Mirroring the two earlier unsuccessful test flights, the Starship prototype, known as serial number 10 or SN10 for short, blasted off from SpaceX's Boca Chica, Texas, launch site at 6:14 p.m. ET and climbed away through a mostly clear sky using three SpaceX-designed Raptor engines.

Liftoff came about two hours after the engines ignited for an initial launch attempt, but shut down on computer command an instant later. Musk said software engine thrust limits were "slightly conservative," engineers made an adjustment and the team pressed ahead with a second launch attempt.

Burning liquified natural gas and liquid oxygen, the ascent appeared to go smoothly, and as the rocket gained altitude, one engine, then two, shut down as planned.

Reaching maximum altitude of about six miles four-and-a-half minutes after liftoff, the third engine shut down and the Starship promptly tilted over on its side and began plunging back toward Earth.

© Provided by CBS News The Starship flips horizontal after engine shutdown, relying on fins fore and aft to provide stabilization and control. / Credit: SpaceX webcast

Using computer-controlled fins at nose and tail to help maintain its orientation, the Starship carried out a horizontal dive, tracked all the way by powerful cameras operated by SpaceX and multiple independent space enthusiasts.

As it neared the ground, the Starship's engines restarted and the rocket flipped back to vertical as programmed for a tail-first touchdown using a single engine. Despite a slight tilt and the flame briefly seen at the base of the rocket, the test flight appeared to be a complete success.

"As we approached the landing pad, we successfully lit the three Raptor engines to perform that flip maneuver and then we shut down two of them and landed on the single engine as planned," Insprucker said. "A beautiful soft landing of Starship on the landing pad at Boca Chica."

He said Starship SN11 is "ready to roll out to the pad in the very near future. It's an inspiring time for the future of human space flight.
© Provided by CBS News The prototype fired up its three engines for a tail first landing. / Credit: SpaceX webcast

The rocket launched Wednesday is a prototype for the second stage of a giant rocket made up of a 230-foot-tall "Super Heavy" first stage generating 16 million pounds of thrust with 28 Raptor engines, more than twice the power of NASA's legendary Saturn 5 moon rocket. A first-stage prototype has not yet been completed.

The rocket's 160-foot second stage, also confusingly known as Starship, will use a half-dozen Raptor engines capable of boosting 100 tons of payload to low-Earth orbit. For comparison, SpaceX's Falcon Heavy rocket can put about 30 tons to orbit.

As with the two most recent test flights of Starships, SN10 was a prototype of the Starship second stage, this one using just three Raptor engines.

At least three versions of the Starship are envisioned: one for carrying heavy payloads to Earth orbit, the moon or Mars; one designed to carry propellants for orbital refueling operations; and one capable of carrying up to 100 passengers at a time.

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