Meta & Fysikken: Afsnit 73: Diverse rum-opdateringer
I dette afsnit taler vi naturligvis om Artemis 1, der er sikkert nede på jorden igen. Japanerne rører også på sig, og der er masser af spændende måne-projekter igang, der skal give os ny og vigtig viden i de kommende år. Og hvordan beskytter man besætningen på lange rum-missioner? Plus alt det løse…
Her er spiseseddelen til i dag:
1: Opfølgning på Artemis I missionen:
2: Mere måne: Privat måne sonde
3: Spin launch nu med kamera
4: Mini hul i Soyuz: nok en mikro meteorit
5: Cold Welding: Kold svejsning
1: Opfølgning på Artemis I missionen:
25 dages mission Orion kom tilbage til Jorden og kom ind i atmosfæren med 40,000 km/t
As it re-entered the Earth's atmosphere, the gumdrop-shaped capsule had to withstand a temperature of 2,800 degrees Celsius.
The main goal of this mission was to test Orion's heat shield – for the day when it is humans and not test mannequins riding inside.
Sådan et fedt billede.
2: Mere måne: Privat måne sonde
Firmaet ispace:
ispace, a global lunar resource development company with the vision, “Expand our Planet. Expand our Future.”, specializes in designing and building lunar landers and rovers. ispace aims to extend the sphere of human life into space and create a sustainable world by providing high-frequency, low-cost transportation services to the Moon.
The Series 1 Lander used for “HAKUTO-R” Mission 1 was successfully launched by a SpaceX Falcon 9 rocket at 2:38 a.m., Saturday, December 11, 2022 (U.S. Eastern Time) and inserted into its scheduled orbit.
Planen er at den lander på månen om 4.5 måneder.
Mission 2 and Mission 3, which also will contribute to NASA’s Artemis Program, will further improve the maturity of ispace’s technology and business model. Future announcements on progress of milestone achievement are expected to be released once attained.
https://ispace-inc.com/news-en/?p=4139
The US space agency wants to develop the lunar economy in the coming years by building a space station in orbit around the Moon and a base on the surface.
It has awarded contracts to several companies to develop landers to transport scientific experiments to the surface.
Among them, the American companies Astrobotic and Intuitive Machines should take off in 2023, and could arrive at their destination before ispace by taking a more direct route, according to reports.
3: Spin launch nu med kamera
https://www.freethink.com/space/spinlaunch-video?
Det er en super cool video. 1min lang
4: Mini hul i Soyuz: nok en mikro meteorit
https://www.sciencealert.com/a-tiny-meteorite-could-be-behind-an-uncontrolled-leak-on-soyuz-capsule
5: Cold Welding: Kold svejsning
At rejse i rummet er svært!
Video:
https://www.homemadetools.net/forum/cold-welding-gif-56268
https://nerdfighteria.info/v/Cm2CciHTRd8/
https://en.wikipedia.org/wiki/Cold_welding
If you touch two CLEAN blocks of the same metal together in space, they weld!
Atoms in solid metals move a bit. Touch two clean surfaces together, and the atoms can't tell they're in different blocks so they become one group of atoms, ie ONE SOLID.
During cold welding, metals can join without heat, by mechanical contact alone. It can happen with clean, flat surfaces of similar (but not necessarily identical) metals, under vacuum. We first discovered cold welding in the 1940s.
Interestingly, cold welding is problematic in space travel. Cold welding is usually prevented by the various contaminants and oxides present on metal surfaces. However, the absolute vacuum of space eliminates these, leaving two perfectly clean metal surfaces. This was notably brought to attention after studying an incident in 1991, during which an antenna attached to the Galileo spacecraft failed to open.
The reason it doesn't happen on Earth when you put two of the same metals together is because of oxygen, which causes metal to rust. That oxide layer sits the two metal surfaces, so atoms in each block see a layer of different atoms, and know that's their "limit" for movement.
If you're wondering if this has affected space missions, it has! The Galileo space probe sent to Jupiter couldn't deploy its high gain antenna on the way to Jupiter because the metal rods that were to open up the "umbrella" got cold welded together!
It's not normally a problem because spacecraft parts are well lubricated and oiled, so there's always a layer between two metals of the same type. But Galileo waited in storage for nearly 5 years before being launched, so the lubrication probably wore off.
Another thing that prevents cold welding in space is using two different metals (then atoms can distinguish themselves from their neighbors because they're different!), plastic, or some other material, if it's to touch metal. This bypasses the need for a layer between two parts.
But HOW COOL IS IT that touching two surfaces of the same metal together in space can cause them to weld BECAUSE THE ATOMS CAN'T TELL THEY'RE PART OF A SEPARATE DISTINCT GROUP OF SOLID BLOCKS?! This is literally visible evidence of how the VERY SMALL works. PHYSICS IS PHENOMENAL
More in depth - if you want to:
Metal atoms have a crystalline arrangement of face-centered-cubic, body-centered-cubic, or hexagonal-close-packed. If you're sliding two surfaces of the same metal past one another, it's a good bet the atoms are going to lock in at some point without any obstacles like oxygen.
It's most likely because of the Sea of Electrons, moving the metal causes some electrons to migrate to the other side, causing more to cascade across, & lock into place according to the valence orbitals. If we were to look at the energy bands, you'd see a low eV potential for it.
On Earth, atmosphere prevents this phenomenon because of interference of the infinitesimal amounts of Nitrogen, Oxygen, & other gases which exist between the metal layers. The gases have much smaller cores with more tightly bound valence electrons because of electronegativity.
In space, with no interfering layer of gaseous atoms present, the probability of an electron jumping the macroscopic gap between the block metal crystalline lattices becomes much more likely, especially if the surfaces move across one another, exposing many sites for these jumps.