Thursday 4 June 2020

From Trampoline to ISS

Since COVID-19 has hit the planet, there’s only been some news that made us happy. Marking the Silver Jubilee edition of IEEE Student Branch NITPs’ “Tech- Thursdays”, we present you the insights to an attempt to transform all your sci-fi fantasies to reality as Elon Musk has given us another reason to cheer about.

Dragon 2 is a class of reusable spacecraft developed and manufactured by American aerospace manufacturer SpaceX as the successor to the Dragon 1 cargo spacecraft. It has two variants; Crew Dragon, a human-rated capsule capable of ferrying up to seven astronauts, and Cargo Dragon, an updated replacement for the original Dragon spacecraft. Let's begin our voyage into the Crew Dragon in this blog!

On the 30th of May, 2020, SpaceX became the first private company to successfully launch humans into orbit through their Demo-2 mission. The mission was to fly two veteran NASA astronauts Bob Behnken and Doug Hurley to the ISS. Though this mission is considered a test, it still carried enormous weight for the United States. The last time people launched to orbit from the US was during the final flight of NASA’s Space Shuttle on July 8th, 2011. Since then, Russia’s Soyuz rocket has been the only vehicle available to do crewed flights to the ISS, and just one seat on the Soyuz runs NASA about $80 million.

At the heart of the mission was Crew Dragon, a state of the art, completely autonomous vehicle that launched on one of the reusable Falcon 9 rockets. 

Falcon 9 is a two stage rocket designed and manufactured by SpaceX for reliable and safe transportation of people and payloads into Earth orbit and beyond. It’s the world’s first orbital class reusable rocket driving down the cost of space access, as reusability allows SpaceX to refly the most expensive parts of the rocket. 

Powered by Merlin Engines, Falcon 9 represents the greatest technological development in rocket engineering. Its ability to precisely land on an autonomous floating drone ship makes it a true engineering marvel.

When SpaceX performs a rocket launch with the Falcon 9, the rocket separates into two stages in the earth's atmosphere. The second stage of the rocket carries the payload into space while the first stage booster returns to earth and lands at a landing site for re-use. The booster is programmed to follow a precise flight path back to earth, and it must autonomously perform a series of controlled maneuvers in order to maintain that path and land vertically on the landing pad.

On the exterior, Crew Dragon is broken into two segments: The capsule which is designed to carry critical pressurised cargo and people and the trunk which is an unpressurized service module. Outside the module you will find the Draco thrusters that help propel the vehicle and around the truck you can find solar arrays that power the spacecraft.


Now stepping inside Crew Dragon, you definitely start to get Space Odyssey vibes. Contrary to the Soyuz capsule or the Space Shuttle which had buttons lining the walls, Crew Dragon is a minimalist design outfitted with seats for the passengers who face touch screen displays. Plus, the craft has an environmental control and Life Support System that helps in keeping a stabilized pressure for humans and other life on board and also controlling temperatures between 18 to 27 degree Celsius.




Before the Launch, SpaceX conducted a series of tests to showcase the functionality of the spacecraft, to ensure that the parachutes, back-up engines and detachment controls are all in working order.

In 2019, NASA expressed their concerns over the parachute systems based on previous tests where the spacecraft hit the ground harder than it should have and sustained damage. To resolve the issue, they integrated Zylon, a high performance polymer material that's lightweight and known for its strength, with the parachutes. After this Musk suggested that the parachutes are 10 times safer than the previous versions.

Leading up to the mission SpaceX and NASA blew up a Falcon 9 on January 19, 2020 to assess the Crew Dragon's Escape System in case of a rapid unscheduled disassembly, the technical term for an unplanned explosion. Whenever this happens Crew Dragon will detach from the Falcon 9 and propel itself and humans inside away from the rocket. Then the capsule will let loose a parachute and drift safely down to earth.

In steps we can understand the mission as:

1. Astronauts board via Crew Access Arm


The walkway connects the Fixed Service Structure (FSS) of Pad 39A to the tip of the Falcon 9 rocket, where the astronauts will board the Crew Dragon. 

2. Lit Off


The Falcon 9 rocket lift off from Launch Complex 39A at NASA's Kennedy Space Center in Cape Canaveral, Florida on Saturday (May 30) at 3:22 p.m. EDT (1922 GMT). 


3. Return of the Falcon 9 booster


About 2.5 minutes after lift-off, the Falcon 9's first stage booster separated from the upper stage and begun preparations for a landing back on Earth. SpaceX plans to land the rocket on a drone ship called "Of Course I Still Love You," which will be stationed in the Atlantic Ocean off the coast of Florida. 

4. Dragon separation


Just a few seconds after the first stage separation, the rocket's second stage fired its engines for about six minutes. The Crew Dragon spacecraft separated from the rocket's second stage. At that point, Crew Dragon was on its own in space for the first time. For the cargo version of SpaceX's Dragon spacecraft, this was when the solar arrays would deploy to begin powering the spacecraft. However, the Crew Dragon has its solar panels built into the body of the spacecraft, so no big, shiny solar panels unfolded.

5. Approaching the ISS


Once Crew Dragon separated from the rocket's upper stage, the spacecraft performed a series of phasing maneuvers to gradually approach and autonomously dock with the International Space Station (ISS).  The phasing burns will raise Crew Dragon's altitude to the altitude of the ISS, which orbits Earth at an average altitude of about 250 miles (400 km). The first phase burn is scheduled to begin 47 minutes after lift-off.

6. Docking the ISS


When Crew Dragon gets close to the ISS, entering an imaginary 650-foot (200 meters) bubble around it known as the "keep-out sphere," it will align with its docking port at the Pressurized Mating Adapter PMA-2 on the Harmony module of the ISS. The spacecraft will then inch very slowly toward the station and dock with a fully autonomous docking system. If needed, the astronauts on board can also take over manual control of the spacecraft.

7. Stay at Space, ISS


The Demo-2 astronauts will spend anywhere from 30 to 119 days at the International Space Station — NASA and SpaceX have not yet decided exactly how long the mission will last. The duration of the Demo-2 mission will depend on the state of the Crew Dragon capsule in orbit as well as the progress on the next Crew Dragon vehicle, which is slated to launch the first operational mission, called Crew-1, as early as Aug. 30.

8. Demo 2 crew heads home


Whenever the Demo-2 mission departs the ISS, the procedure for its departure will be much like the arrival, only backwards. The spacecraft must first slowly exit the "keep-out sphere" before conducting more phasing burns to lower its orbit. The entire descent will be about a two-day flight sequence. 

9. Trunk separation of Crew Dragon


As it gets closer to Earth, the Crew Dragon spacecraft will jettison its service module, known as its "trunk," before conducting a deorbit burn that will send it plummeting into Earth's atmosphere. The trunk is a cylindrical, finned module that contains the spacecraft's built-in solar arrays and other equipment required for its flights to and from the space station. Crew Dragon jettisons its trunk during re-entry to clear the spacecraft's heat shield and prepare the spacecraft for splashdown.

10. Re-entry into Earth


The Crew Dragon spacecraft will enter Earth's atmosphere traveling at a speed of about 17,000 mph (27,000 km/h). The friction of particles in the atmosphere will create a drag force, slowing it down drastically while heating the outside of the capsule to temperatures nearly as hot as the sun. 

11. Deploying parachutes


Once Crew Dragon has completed the fiery re-entry phase of its return flight, the spacecraft will deploy its four Mark 3 parachutes, which will slow down the vehicle as it descends for a gentle splashdown in the Atlantic Ocean off the coast of Florida. 

12. Splash search


A search and recovery crew will be waiting nearby on SpaceX's GO Navigator ship to help the Demo-2 crew out of the Crew Dragon and hoist the spacecraft out of the water so it can return to Cape Canaveral, where SpaceX and NASA crews will inspect it. 

We hope you all loved reading the twenty-fifth edition of our Thursday effort and would keep on supporting the days ahead!

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