 "SpaceX's Crew Dragon spacecraft which is bringing Nasa astronauts Sunita Williams and Barry Wilmore back to Earth. File image/AP")
Sunita Williams and Butch Wilmore are on the way home.
The two National Aeronautics and Space Administration ( NASA ) astronauts went to the International Space Station (ISS) in June 2024 aboard the Boeing Starliner.
The mission was initially scheduled for just eight days.
Now, a long nine months later, Williams and Wilmore are finally returning to Earth on the SpaceX’s Crew Dragon spacecraft – which arrived at the ISS on Sunday.
But what do we know about the Crew Dragon?
Let’s take a closer look:
What do we know?
As per BBC, SpaceX built the Crew Dragon mainly to ferry astronauts to the ISS.
The spacecraft has its origins in the Dragon 1 vehicle – which previously delivered cargo to the ISS nearly two dozen times.
SpaceX began developing the craft after Nasa in 2011 decided it would no longer fly astronauts to the ISS.
The concept for the craft was unveiled in May 2014 at an event in SpaceX’s California headquarters.
It is designed like a capsule – similar to the Apollo crafts that put astronauts on the Moon.
The Crew Dragon comprises a reusable space capsule as well as an expandable trunk module.
The trunk has solar panels, heat-removal radiators, cargo space and fins that provide stability during emergency situations.
The capsule and trunk are around 26.7 feet tall. The Crew Dragon has a diameter of 13 feet.
How does it work?
The Crew Dragon is carried into space the SpaceX’s Falcon 9 – a reusable two-stage rocket, as per Indian Express.
The capsule has 16 Draco thrusters that manoeuvre the vehicle in orbit.
Each Draco can create 40 kilos of force.
As Jessica Jensen, director of Starship mission hardware and operation at SpaceX, told BBC, “We have GPS sensors on Dragon, but also cameras and imaging sensors such as Lidar (laser ranging) on the nose cone as it’s approaching the space station… All these sensors are feeding data back to our flight computer to say: ‘Hey, how far away am I from the space station? What’s my relative velocity to the space station?’”
The Crew Dragon can autonomously dock with the ISS.
Its flight computer does this by using algorithms to determine the best way to fire thrusters.
However, according to the BBC, the Crew Dragon can only be used for a few months in space.
This is because the solar panels tend to degrade when exposed to space.
The Crew Dragon automatically undocks from the ISS when the astronauts begin their return journey.
The trunk then detaches from the capsule containing the astronauts.
Now, thrusters are used to bring down the capsule’s velocity and thus allows it to re-enter the atmosphere – known as a de-orbit burn.
The capsule then deploys four parachutes and splashes into the Atlantic Ocean – around 450 kilometres from Florida.
A ship then picks up the capsule – and brings the astronauts home.
With inputs from agencies