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The crowds assembled near Boca Chica Beach on Saturday evening.Trevor Mahlmann for Ars
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Elon Musk took the stage at about 8:30pm CT.Trevor Mahlmann for Ars
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He was ready to show off his Starship Mk 1 prototype.Trevor Mahlmann for Ars
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Musk spoke about the company's past, including the Falcon 1 rocket, at right.Trevor Mahlmann for Ars
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This rocket first reached orbit 11 years ago, on Saturday.Trevor Mahlmann for Ars
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Perspective on Starship at night.Trevor Mahlmann for Ars
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The founder of SpaceX, in profile.Trevor Mahlmann for Ars
BOCA CHICA BEACH, Texas—Elon Musk spoke about his vision of a brighter future for humanity on Saturday evening, in South Texas.
Musk acknowledged that there are a lot of problems here on Earth, and it is important for those to get fixed. But it also is important to give people hope for the future, and sense of optimism. He believes the exploration of space, and human expansion into the Solar System, provides this kind of a hopeful vision.
And so, beneath a big Texas sky full of stars, he offered hope in the form of a large spaceship. Mere hours after a team of SpaceX engineers, technicians, and contractors completed assembly of a prototype of the Starship vehicle, Musk revealed it to the world. He did so in an open-air shipyard, hard by the Rio Grande River, where he intends to build dozens if not hundreds of Starship spacecraft.
The prototype loomed behind Musk as he addressed a crowd of a few hundred people, including employees, local residents from Brownsville and surrounding towns, as well as members of the media. Earlier, as the Sun dipped below the horizon, reddish hues glinted off the Starship's surface. As night fell and Musk climbed onto a small dais, it rose tall, dark and imposing.
"This is the most inspiring thing that I have ever seen," said Musk, dressed in a black blazer, t-shirt, and jeans, of the towering spaceship. The crowd cheered. In the moment, Mars seemed a little closer than it had before.
Progress
Three years ago, Elon Musk took the stage in Guadalajara, Mexico, to share the full scope of his Mars ambitions for the first time. He spoke of building a large, interplanetary spaceship—it was not yet named Starship— and a large rocket booster with dozens of engines that would carry 100 people to Mars at a time.
At the time, it seemed audacious, mad, and brilliant at the same time. But mostly the vision seemed like science fiction. Standing in a field in South Texas on Saturday night, it felt a little more like science, and a little less like fiction.
Three years ago, the idea of flying 37 engines on a single rocket seemed fanciful. And then, in early 2018, the company launched with Falcon Heavy with 27 engines. Three years ago, the notion of landing and re-flying a large rocket multiple times seemed distant. But now SpaceX has done this dozens of times.
But most futuristic of all seemed the notion of a 50-meter tall spaceship that could launch into space, fly on to the Moon or Mars, and return to Earth. And yet this was what Musk put on display with the Starship Mk 1 vehicle. Soon, perhaps within one or two months, it will launch to an altitude of 20km. Simultaneously, the company is building a second prototype, Mk 2, in Cocoa, Florida. It will start work on a third version in Texas later this fall, and so on.
Each design will iterate on the last. Engineers will look for ways to shave mass—the Mk 1 prototype weighs 200 tons, and SpaceX would like to eventually cut the overall mass to 110 tons to maximize Starship's lift capacity. Ultimately, a slimmed-down Starship should be able to lift 150 tons of payload into low-Earth orbit, Musk said. Its first orbital flight, launched by a big booster named Super Heavy, could come next year.
This payload capacity is more than any other launch system built before, and would be especially remarkable given that SpaceX has designed both the booster and Starship to be fully reusable. "A rapidly reusable orbital rocket is only barely possible given the physics of Earth," Musk said.
Man of steel
During the presentation, Musk offered several updates on changes to Starship's design. However he spent the most time discussing the use of stainless steel as the skin of the vehicle. "Stainless steel is by far the best design decision we have made," he said.
Yes, Musk said, steel is heavier than carbon composite or aluminum-based materials used in most spacecraft, but it has exceptional thermal properties. At extremely cold temperatures, stainless steel 301 does not turn brittle; and at the very high temperatures of atmospheric reentry, it does not melt until reaching 1500 degrees Centigrade. Starship therefore requires only a modest heat shield of glass-like thermal tiles.
Another benefit is cost, which matters to a company building Starships on its own dime, with the intent to build many of them. Carbon fiber material costs about $130,000 a ton, he said. Stainless steel sells for $2,500 a ton.
"Steel is easy to weld, and weather resistant," Musk added. "The evidence being that we welded this outdoors, without a factory. Honestly, I'm in love with steel."
Listing image by Trevor Mahlmann for Ars
NASA watches
NASA has followed the progress of Starship from afar, investing almost nothing in a vehicle that has the potential to revolutionize human spaceflight—as well as to dramatically bring down the costs of launch.
On Friday, the eve of Musk's Starship presentation in Texas, NASA administrator Jim Bridenstine even splashed some cold water on the proceedings. Bridenstine noted that SpaceX was one of NASA's partners in the commercial crew program, intended to launch astronauts to the International Space Station.
"NASA expects to see the same level of enthusiasm focused on the investments of the American taxpayer," Bridenstine said of SpaceX's apparent zeal for Starship. "It's time to deliver."
Asked about this, Musk replied that the company is only investing about 5 percent of its human resources into developing Starship. The bulk of the company's 6,000 employees are working on the Falcon 9 rocket and Crew Dragon spacecraft to be used for the commercial crew program, he said.
A timeline
After the event, as the hour approached 11pm local time, Musk offered some additional insight during an interview with Ars. Seated alongside the company's principal Mars development engineer, Paul Wooster, Musk expounded upon his timeline for going to the Moon and Mars.
"It depends on whether development remains exponential. If it remains exponential, it could be like two years," Musk said of landing on the Moon. A cargo trip to Mars could happen by 2022, due to the availability of launch windows, he added. "I mean these are just total guesses, as opposed to checking a train schedule."
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This gallery comprises a number of high resolution images of Starship Mk 1 taken earlier on Saturday.Trevor Mahlmann for Ars
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The ship was built outdoors, in South Texas.Trevor Mahlmann for Ars
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No really, outdoors. Not in a factory.Trevor Mahlmann for Ars
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SpaceX's Boca Chica site is at the southern tip of Texas.Trevor Mahlmann for Ars
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Wing flaps!Trevor Mahlmann for Ars
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Some nose cone action.Trevor Mahlmann for Ars
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Close-up, full-length view.Trevor Mahlmann for Ars
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The site is really remote. About a 30 minute drive from any vestige of a town.Trevor Mahlmann for Ars
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Lower-flap details.Trevor Mahlmann for Ars
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Close up detail shot.Trevor Mahlmann for Ars
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Is it Batman, or a Starship?Trevor Mahlmann for Ars
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Starship, with the Falcon 1 rocket first stage for scale.Trevor Mahlmann for Ars
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Setting up the Falcon 1 on Saturday.Trevor Mahlmann for Ars
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More nature.Trevor Mahlmann for Ars
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Starship is 50 meters tall.Trevor Mahlmann for Ars
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It's pretty, you know?Trevor Mahlmann for Ars
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Final shot of the Starship base.Trevor Mahlmann for Ars
SpaceX is funding the Starship project with its own money. Some of that comes from positive cash flow from satellite launches. The company has also raised nearly $1 billion from private investors in recent months, and it has also received an undisclosed payment from Japanese Billionaire Yusaku Maezawa as the first customer for a mission to lunar orbit and back.
"I think we're able to see a path to getting the ship to orbit, and maybe even doing a loop around the Moon," Musk said. "Maybe we need to raise some more money to go to the Moon or landing on Mars. But at least getting the Starship to an operational level in low Earth orbit, or around the Moon, I feel like we're in good shape for that."
Life support
A common question about Starship is how the company plans to keep people alive on board the vehicle when it is flying crew instead of cargo missions. SpaceX has some experience with life support after developing the Crew Dragon spacecraft for NASA.
"We definitely have learnt a lot, and we would do it differently," Musk said. "The Dragon life support system is not really all that renewable. It's basically mostly expendable."
For example, Dragon uses lithium hydroxide as a "scrubber" to remove carbon dioxide exhaled by humans, producing lithium carbonate and water as byproducts. This is perfectly adequate for four people for four days, and perhaps could even be used for short missions around, and to the surface of the Moon.
But using Starship to go to Mars would require six months for a journey there, and up to 2.5 years for a roundtrip mission. With as many as 100 people on board the vehicle, that would require a regenerative life support system that will, Musk acknowledged, "take a bit of work."
Urgency
Earlier this month, the senior Senator from Alabama, Richard Shelby, offered a congratulatory tweet to NASA. "Good news," Shelby wrote, noting agency technicians had joined five structures together that make up the core stage of the Space Launch System. "This is the first time since the Apollo program that a rocket of this size has been joined together—a milestone accomplishment," Shelby added.
Four rocket engines must still be attached to the core stage before it is complete. But then, finally, the key component of NASA's mammoth rocket should be ready to undergo ground-based testing. To be sure, NASA and the core stage contractor, Boeing, are to be commended for a technical achievement. However, one might reasonably ask what took so long to get to this point.
In the spring of 2014, I visited the Michoud Assembly Facility, based in southern Louisiana. Already, technicians were building barrels for the Space Launch System rocket's core stage. And NASA was investing tens of millions of dollars to modernize Michoud to produce the rocket. At the time, an aerospace analyst for the Rand Corporation, Peter Wilson, explained that, "They’re throwing the money into this program, into places like Michoud, to make it very expensive to change course."
NASA has not changed course. And after at least 5.5 years, during which time NASA has spent more than $10 billion on the SLS rocket, they are finally almost done assembling that first core stage, consisting of two large fuel tanks, four main engines, and all of a rocket's associated plumbing.
One answer to the question of why this has taken so long, and required so much money, is that there has been a lack of urgency. Large complex development programs—like, say, super heavy lift rockets—work best with low levels of funding during the design phase, a spike during development, and then diminished funding during flight production. Instead, after Congress created the SLS rocket program with a baseline of about $2 billion a year, it kept funding at more or less flat levels plus inflation. This is great strategy for creating and sustaining jobs, but a poor way to go about rocket development.
SpaceX's Starship prototype, fabricated in a field in South Texas in five months, offers a counter example to what a sense of urgency can accomplish.
The SLS rocket core stage, consisting of four space shuttle main engines, measures 64.6 meters tall, with a diameter of 8.4 meters. The Starship Mk1 vehicle is 50.0 meters tall, with a diameter of 9.1 meters. So they are roughly the same size. Neither is the complete rocket. On the launch pad, the SLS will have two very large side-mounted solid-rocket boosters, derived from the space shuttle. And Starship is actually the upper stage of SpaceX's next-generation rocket, Super Heavy.
By itself, the SLS core stage cannot get to orbit. In fact, according to physicist Scott Manley, without its side-mounted boosters a fully-fueled SLS core stage cannot even lift off the launch pad. The SpaceX Starship prototype, with three Raptor engines instead of a full complement of six, also cannot get to orbit. But it should be able to reach at least 25 to 30km, said Manley, who has a popular rocket science YouTube channel.
The SLS rocket remains a couple of years from its maiden flight. Starship, however, will likely make a 20km flight in November, Musk said.
Perhaps the biggest difference between the two new rockets is the velocity of their development. The SLS core stage, which uses heritage technology from the space shuttle, including its main engines, has taken at least 5.5 years to build, and billions of dollars.
Starship Mk 1 didn't even exist until this spring, and it may leap off the pad before year's end. The appears to underscore the value of urgency and clarity of purpose. At SpaceX the urging comes from the top. As Musk said of schedules on Saturday night, "tight is right, long is wrong." And Starship has a clear exploration purpose as well, allowing humans to settle other worlds, and fuel optimism in humanity's future.
https://arstechnica.com/features/2019/09/after-starship-unveiling-mars-seems-a-little-closer/
2019-09-29 08:30:00Z
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