Featured Image Source: Elon Musk
SpaceX ultimate mission is to make life multiplanetary by colonizing Mars. The rocket company is developing Starship to complete the mission. Starship will consist of a spacecraft and a massive ‘Super Heavy’ rocket booster, which will only be required to take the craft out of Earth's atmosphere. According to Starship’s ‘User Guide’ it will have the “capability to transport satellites, payloads, crew, and cargo to a variety of orbits and Earth, Lunar, or Martian landing sites." The prototypes of the spacecraft are under construction at the company’s South Texas facility located in Brownsville, Boca Chica Beach, TX. SpaceX engineers are manufacturing a production line of many stainless-steel Starships, to test out different features. The founder and chief engineer at SpaceX, Elon Musk, aims to scale up production to build at least one Starship prototype per week. He says, “A high production rate solves many ills. If you have a high production rate, you have a high iteration rate.” A high production rate will enable them to test fast and innovate faster. Since February, Musk has spent most of the time working alongside his employees in South Texas, he shared on Tuesday:
“Am in Boca working on the rocket with an awesome team.”
Currently, SpaceX is working on the fourth Starship prototype, referred to as Starship SN4. Engineers aim to develop a craft that can withstand highly pressurized propellant and stresses of flight. Previous prototypes, SN1 and SN3 collapsed during cryogenic pressurization tests this year, in January and early April. Regarding the test failures Musk previously said, “Production is by *far* the hard part. That’s why I’m not super worried about early Starship failures. Initial serial numbers are suboptimal, so would be lawn ornaments if they survived. That said, as lawn ornaments go, they’re pretty sweet…” Teams rapidly assembled Starship SN4 in about 2 weeks, and are actively building the next Starship –SN5.
Starship SN4 tank on test stand pic.twitter.com/zN2OmMp1OS— Elon Musk (@elonmusk) April 23, 2020
Today, April 23, SpaceX transported the SN4 test vehicle to the launch pad, which is approximately 3 miles away from the assembly site at Boca Chica Beach. “Starship SN4 tank on test stand,” Musk shared a drone photograph of the vehicle via Twitter this afternoon. Boca Chica residents have documented the construction progress and shared footage of the massive stainless-steel structure transported down the road to the launch pad [video below].
Starship SN4 will undergo a series of pressurization tests. One of the tests will involve cryogenic pressurization, in which the craft is filled up with sub-cooled liquid nitrogen, to determine if the stainless-steel structure can withstand high pressure. The test also serves to determine the weld quality strength ahead of flight. Starship needs to withstand a pressure in between ~6 and ~8.5 bar strength; a ~6 bar is needed for orbital flight and ~8.5 bar is needed for crewed flights. If the tests go well and it meets the pressure strength standards, the craft is expected to conduct a debut test flight of 150 meters with one to three sea level-optimized Raptor engines. The company then will be poised to conduct a 20-kilometer flight with up to three Raptor engines. An orbital flight would require testing out 6 Raptor engines, three of those are vacuum-optimized nozzles for space travel.
Boca Chica’s Cameron County website announced beach road closures, which typically indicate SpaceX is preparing to conduct some vital Starship tests. The primary road closure is scheduled for April 26 from 9:00 a.m. to 11:59 p.m. Central Daylight Time (CDT). And back up testing dates are April 27 and 28 from 9:00 a.m. to 11:59 p.m. CDT. Additionally, SpaceX filed a NOTAM with the Federal Aviation Administration, which is a notice for pilots to fly cautiously above the area.