Importantly, the missions primary purpose is to test and demonstrate the vehicles capability to safely carry crew to and from Earth orbit, as the first step in the plan of commencing regular ISS missions and commercial space flights.
The extreme velocities and temperatures the vehicle must endure present a major challenge to engineers and makes reentry the most perilous part of a mission.
The danger starts with finding the right angle of the trajectory as the spacecraft enters the upper atmosphere. If it is too steep, the astronauts will experience potentially fatal g-forces, and the friction of the air drag could cause the spacecraft to explode. If it is too shallow, the capsule will instead catastrophically skip off the atmosphere and back into Earth orbit.
The spacecraft will enter the upper atmosphere at 27,000km/hour. That is 7.5km/second, or more than 20 times the speed of sound. In whichever units you prefer this is fast. At these velocities, a very strong shock wave forms around the front of the vehicle, compressing and superheating the air. Managing the immense thermal load is a huge reentry engineering challenge.
At the most extreme stage, the temperature of the air in the shock layer exceeds 7,000C. By comparison, the temperature at the surface of the Sun is around 5,500C. This makes the vehicles heat shield so hot that it starts to glow a process called incandescence. SpaceXs new and advanced PICA-X material heat shield has managed to protect the capsule in test flights, later being recovered in a very charred state.
The air molecules around the vehicle also break down into positively charged atoms and free electrons a so-called plasma. When some of the molecules recombine, excess energy is released as photons (light particles) giving the air around the vehicle an amber glow.
This plasma layer may be beautiful, but it can cause radio blackouts. When an electron travels along a conductive wire, we have electricity. Similarly, when free electrons move through the plasma around the vehicle, we have an electric field. If the electric field becomes too strong, it can reflect and attenuate the radiowaves trying to reach the spacecraft.
Blackout not only leads to a loss of connection to on-board crew and flight data, it can also make remote control and guidance impossible. The Apollo missions, the Mars Pathfinder and the recent, failed 2018 Soyuz rocket launch all incurred communications blackout on the order of minutes. NASA mission control are anticipating a nervous six minutes of blackout during the peak heating phase of Crew Dragons return if anything goes wrong during this time, its in the hands of the astronauts.
Another risky stage is the parachute-assisted landing. The Crew Dragon will deploy four parachutes upon the final stage of reentry, as the vehicle descends toward a gentle splashdown in the Atlantic Ocean off the coast of Florida. This manoeuvre has been tested by SpaceX 27 times prior to next weeks crewed landing, so it should work.
A successful landing will have huge implications lowering the cost of space exploration through the use of reusable rockets and enabling private space exploration. While SpaceX engineered the Crew Dragon vehicle under contract to NASA, the company is free to use the spacecraft for commercial flights without NASA involvement after operational certification.
SpaceX has a partnership with commercial aerospace company Axiom Space, which has the ultimate goal of building the worlds first commercial space station. The proposed commercial activities for the station are broad: from in-space research and manufacturing to space exploration support.
Then there is space tourism. Private citizens are already queuing for their ticket to space, and with a successful Crew Dragon splashdown, they wont be waiting long. American space tourism company, Space Adventures (partnered with SpaceX), are planning to offer zero-gravity atmospheric flights, orbital flights with a spacewalk option and laps of the Moon by late 2021.
Whether the costs, environmental impact and dangers of spaceflight is justified for space tourism is debatable. As this articles shows, the required safety briefing for Space Adventure ticket holders will be much more comprehensive than your regular please take a moment to read the safety card in the seat pocket in front of you.
Heather Muir, PhD in Computational Physics, University of Cambridge
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Read this article:
- View On Astronomy: April means it's time to say farewell to winter constellations - The Independent - April 5th, 2021
- Astronomers find the 'safest place' to live in the Milky Way - Space.com - April 5th, 2021
- Light pollution from satellites 'poses threat' to astronomy - The Guardian - April 5th, 2021
- The Vera C. Rubin Observatory and Women of Chilean Astronomy - National Air and Space Museum - April 5th, 2021
- If Astronomers see Isoprene in the Atmosphere of an Alien World, Theres a Good Chance Theres Life There - Universe Today - April 5th, 2021
- Astronomers see a ghostly 'radio jellyfish' rise from the dead in the southern sky - Livescience.com - April 5th, 2021
- Astronomers Have Captured the Most Detailed Photo of a Black Hole EverSee the Magnetic Fields That Power It Here - artnet News - April 5th, 2021
- Terrascope: The Whole Earth Telescope - SYFY WIRE - April 5th, 2021
- Astronomy: The Moon, the most romantic object in the sky - RTL Today - April 5th, 2021
- An astronomer's animation shows how Earth and the moon both orbit a spot 3,000 miles from the true center of the planet - Yahoo News - April 5th, 2021
- What is the Milky Way? | Astronomy Essentials - EarthSky - February 20th, 2021
- Mysterious Origins of Super-Earths Uncovered by Astronomers - SciTechDaily - February 20th, 2021
- 7 reasons Astronomy Club deserves its flowers for being the future of comedy - REVOLT TV - February 20th, 2021
- Pune, this week: From an art exhibition to an astronomy course and a lot more - The Indian Express - February 20th, 2021
- Astronomers figure out why some galaxies are missing dark matter - Big Think - February 20th, 2021
- Astronomers Mapped The Spectacular Accelerating Outflows of a Stellar Explosion - ScienceAlert - February 20th, 2021
- The case for, and against, the still-unseen Planet 9 Astronomy Now - Astronomy Now Online - February 17th, 2021
- 'Farfarout' confirmed to be really, seriously far out Astronomy Now - Astronomy Now Online - February 17th, 2021
- What the Heavens Declared to a Young Astronomer - ChristianityToday.com - February 17th, 2021
- BYU Department of Physics and Astronomy hosts Three Minute Thesis competition - The Daily Universe - Universe.byu.edu - February 17th, 2021
- DST astronomers trace huge optical flare from supermassive black hole discovered in the 1960s - Firstpost - February 17th, 2021
- Black-sky thinking - A distinguished astronomer sees evidence of extraterrestrial life | Books & arts - The Economist - February 17th, 2021
- Farthest known object in the solar system identified - EarthSky - February 17th, 2021
- Homan: Surge at border will be 'astronomical' without Title 42 in Mexico - Yahoo News - February 17th, 2021
- Radio Astronomer F. Peter Schloerb Named to ARCS Foundation Alumni Hall of Fame - UMass News and Media Relations - February 17th, 2021
- Harvard astronomer argues that alien vessel paid us a visit - The Hindu - February 7th, 2021
- View On Astronomy: Observing the Winter Circle is quite the seasonal sight - The Independent - February 7th, 2021
- How Astronomer Anton Pannekoek Planned To Storm the Heavens - The Wire Science - February 7th, 2021
- Astronomers are Starting to Understand the Quasar Lifecycle - Universe Today - February 7th, 2021
- Astronomy surveys aim to up the pace with army of tiny robots - Science Magazine - February 6th, 2021
- Astronomers are now Finding Planetary Disks Around the Smallest, Least Massive Stars - Universe Today - February 6th, 2021
- Astronomers identified a piece of the Milky Ways missing matter - Tech Explorist - February 6th, 2021
- Astronomers find origins of "galactic cannibalism" with discovery of ancient dark matter halo - CBS News - February 6th, 2021
- Astronomy on Maunakea and in Hawaii will be put at significant risk, UH says of request for new governance - KHON2 - February 6th, 2021
- Astronomers Think They've Found Another Trojan Asteroid Lurking in Earth's Orbit - ScienceAlert - February 6th, 2021
- Explore Scientific, the Explore Alliance, and Astronomy Magazine Team Up for Global Star Party Celebrating Pluto - Yahoo Finance - February 6th, 2021
- A blue bolt out of the blue: On the edge of space, lightning leaps *upward* - SYFY WIRE - February 6th, 2021
- Astronomers Can Predict When a Galaxys Star Formation Ends Based on the Shape and Size of its Disk - Universe Today - February 6th, 2021
- A Warp in the Milky Way Linked to Galactic Collision - University of Virginia - February 6th, 2021
- UPDATES: Phosphineless Venus and dustless Betelgeuse? - SYFY WIRE - February 6th, 2021
- South African astronomy has a long, rich history of discovery and a promising future - Space.com - January 27th, 2021
- 2021: What Astronomical and Space Events Await Us This Year? - EcoWatch - January 27th, 2021
- Astronomers discover a bizarre string of five planets that "dance" in perfect resonance - Salon - January 27th, 2021
- Astronomers Have Discovered a Star That Survived Nearly Being Swallowed by a Black Hole - ScienceAlert - January 27th, 2021
- Students fascination with astronomy inspires first completed Immersion Vanderbilt project - Vanderbilt University News - January 27th, 2021
- Asteroid naming contest sparks discussion of women in astronomy - SpaceFlight Insider - January 27th, 2021
- Astronomers discover huge exoplanet has the density of cotton candy - CBC.ca - January 27th, 2021
- Astronomers Detect a Surprisingly Huge Galactic Birthplace in The Early Universe - ScienceAlert - January 27th, 2021
- Sextuply-eclipsing Astronomers discover a six-star system that eclipses one another - ThePrint - January 27th, 2021
- International Astronomical Union's OAD selects eight projects from Africa to receive funding - Space in Africa - January 27th, 2021
- 'Great Conjunction' brings 'astronomical event of the year' to Cincinnati's sky - WLWT Cincinnati - December 12th, 2020
- Amateur Astronomers Over the Moon for Chang'e 5 Mission - Sixth Tone - December 12th, 2020
- ESO and Microsoft will work with artificial intelligence to boost astronomy - News Center Latinoamrica - Microsoft - December 12th, 2020
- Assistant Professor of Physics and Astronomy in Muncie, IN for Ball State University - Physics - December 12th, 2020
- Ghostly blobs in space are the new exciting thing in astronomy. Could these be linked to wormholes? - Scroll.in - December 12th, 2020
- Star gazing with astronomers of the past - The Hindu - December 12th, 2020
- Astronomer Andrea Ghez on the responsibility that comes with a Nobel Prize - UChicago News - December 12th, 2020
- Tiger Woods rookie card grabs an astronomical fee and it can still be yours (we think) - Golf Digest - December 12th, 2020
- The Conversation: I'm an astronomer and I think aliens may be out there but UFO sightings aren't persuasive - New Zealand Herald - December 12th, 2020
- How Ice Shelf Loss Will Change the Antarctic Ecosystem - The Scientist - October 10th, 2020
- Emphasis on robust ecosystem of research and innovation at VIT convocation - The Hindu - October 10th, 2020
- Live by the plant, die by the plant - carniverous plants have a haunting place in ecosystem - The Virginian-Pilot - Virginian-Pilot - October 10th, 2020
- Horseshoe crab blood key to COVID-19 vaccine despite negative impact it could have on ecosystem - NationofChange - October 10th, 2020
- How DevOps adoption - and its ecosystem - has increased during Covid: The VC perspective - Cloud Tech - October 10th, 2020
- Microdisplays Industry: an Explosive Ecosystem Mixing Technical Innovations, Strategy Games and Attractive Applications - Display Daily - October 10th, 2020
- How one woman revived the citys most impressive natural ecosystem - Chicago Reader - October 10th, 2020
- COVID-19 and beyond: Confidence and resilience in vaccine ecosystem - EURACTIV - October 10th, 2020
- Defining Trends in the Indian Gaming Ecosystem and the Impact of COVID-19 - CNBCTV18 - October 10th, 2020
- GameStop Partners with Microsoft to Bolster Its Digital Ecosystem - Wccftech - October 10th, 2020
- AFWERX Announces NXM Labs Among Top Teams Selected to Revolutionize Space Ecosystem - I-Connect007 - October 10th, 2020
- iConnections Announces Partnership With The Investment Institute to Build Transformational Ecosystem For the Investment Industry - Business Wire - October 10th, 2020
- Secure Technology Alliance Webinar to Explore Challenges to Robust Growth of the Mobile Driver's License Ecosystem - GlobeNewswire - October 10th, 2020
- 'It just sounds like a thud': astronomers hear biggest cosmic event since big bang - The Guardian - September 4th, 2020
- The Sky This Week from September 4 to 11 - Astronomy Magazine - September 4th, 2020
- A nearby supernova could have caused the Devonian mass extinction - Astronomy Magazine - September 4th, 2020
- Great Basin National Park astronomy festival to be held mostly virtually this month - FOX5 Las Vegas - September 4th, 2020
- Indian astronomers discover one of the farthest galaxies in the universe - Moneycontrol - September 4th, 2020
- Breaking down the astronomical number of mail-in ballot requests in NC - CBS17.com - September 4th, 2020
- Meet The Woman Behind Ninjas Astronomical Success: Jessica Blevins - Forbes - September 4th, 2020
- Tesla To Cash in on Astronomical Stock Price With $5 Billion Capital Raise - The Drive - September 4th, 2020