SpaceX’s Starship Rocket Represents The Future Of Spaceflight
Credit to Author: Guest Contributor| Date: Mon, 30 Sep 2019 04:55:19 +0000
Published on September 30th, 2019 | by Guest Contributor
September 30th, 2019 by Guest Contributor
By Harry Stoltz
SpaceX’s presentation on Saturday night in Boca Chica was an exciting and uplifting event that focused mainly on development changes since last year’s “Dear Moon” event for their rocket, Starship. I was at the Boca Chica event to report back on the updates for CleanTechnica.
SpaceX CEO Elon Musk kicked off the presentation by talking about the company’s Starship MK-1 rocket, which dazzled in the moonlight behind the stage at the event. Musk detailed that the main purpose of the event was to “inspire the public, and to excite people about our future in space.” Musk stressed the importance of becoming a spacefaring civilization that makes people “excited to be alive.” In order to achieve multi-planetary status, rockets will need to reach rapid reusability of all components.
Among the critical components, SpaceX focused on the raptor engines that will fly Starship. Musk drew a comparison to engines on an airliner, which need to be rapidly refueled and flown consistently. Additionally, SpaceX designed the raptor engines to be “incredibly mass efficient,” which will reduce the dead weight on Starship.
Image courtesy SpaceX.
Another result of reducing unnecessary mass, the new design of Starship no longer has three “fins” on the bottom of the craft. Previous designs featured three fixed fins, which all doubled as landing legs. The current design ditched the third fixed fin and added six retractible single-purpose legs, and the two remaining fins are only for aerodynamic and steering purposes. Starship also has two moveable canards near the tip of the vehicle. These four aerodynamic surfaces can steer the ship in all 3 axes of control by increasing and reducing drag. Starship steers through descent in a “controlled fall,” as demonstrated in this video from SpaceX:
As yet another reduction of total mass, SpaceX has switched to stainless steel for the body of Starship. The use of SpaceX’s 301 stainless steel is much cheaper than other materials like carbon fiber. Additionally, the 301 stainless steel actually makes the rocket lighter, because of its ability to withstand high and low temperatures without becoming brittle. This results in less material needed for the heat shield, which lowers the overall weight of the vehicle. It seems that SpaceX has settled on hexagonal tiles made of ceramic to serve this purpose. The reasoning for the change is that these ceramic tiles are light and crack resistant.
Image by Harry Stoltz, CleanTechnica
Starship will be 55 meters tall (165 meters once fully assembled with its booster “super heavy”). The dry mass (the mass of the ship without fuel or payload) is 120 tons, and can launch 150 tons into orbit, to the moon, or to Mars, with full reusability. Starship will have 3 fixed vacuum optimized raptor engines and 3 gimbaling sea-level engines.
Image courtesy SpaceX.
Starship’s booster, “Super heavy,” features 37 raptor engines and 6 landing legs, and steers using grid fins, not unlike Falcon 9. Super Heavy boasts over twice the thrust as a Saturn V, at a 1.5 thrust-to-weight ratio.
Image courtesy SpaceX.
Another interesting part of the presentation was the discussion about Starship’s fuel efficiency. “The cost of a reusable system is basically the cost of propellant, which its mostly oxygen,” Musk stated. Starship’s raptor engines require 3.5 tons of oxygen for every 1 ton of fuel. In contrast, SpaceX’s falcon 9 rocket uses 2.5 tons oxygen for each 1 ton of fuel. This system is of note, because it will help to keep Starship’s launch costs low.
Eventually, for missions to Mars, SpaceX plans to create propellant on the planet. The company strategy is to pull carbon dioxide out of the atmosphere using energy from solar arrays on the surface, and melt the ice on the plant’s poles. Combining water and carbon dioxide through a reaction with a ruthenium catalyst produces methane and oxygen, which are the two things needed to launch Starship. Musk also mentioned that this Martian process will ultimately be the long-term plan for Earth-based production as well.
Musk also stressed the importance of orbital refilling during the presentation. This maneuver is achieved by two Starship rockets matching each other’s orbit and transferring fuel, so one of them can reach the moon or Mars, and the other lands back on Earth.
Image courtesy SpaceX.
Musk ended his presentation with a passionate argument for establishing humanity on other worlds. “As far as we know, we’re the only life that’s out there,” Musk stated. Musk cited that if it would have taken life to evolve just 10% longer, consciousness would not have developed here on Earth. The Earth formed over 4.5 billion years ago, and only in the last couple million has life existed on Earth. In a few more million years, the sun will expand to a point that will make Earth uninhabitable. Musk emphasized that consciousness in the universe might be a fleeting moment and that we should maximize our interplanetary existence while we have the chance.
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