Friday 8 March 2024

Axiom-3 mission launch – 18 Jan 2024

Title: Axom-3 Mission launched to ISS on 18 January 2024. Title: Axom-3 Mission launched to ISS on 18 January 2024.


The Axiom 3 mission (Ax-3) to the International Space Station (ISS) launched on 18 January 2024 from Pad 39A of Kennedy Space Centre (KSC) in Florida, USA.

Ax-3 was the third Private Astronaut Mission (PAM) and the product of a collaboration between the National Aeronautics and Space Administration (NASA) and the private company Axiom Space.

After a successful launch and insertion into orbit, the Dragon Freedom capsule carrying the astronauts docked into the ISS on Saturday 20 January. The crew were greeted by fellow astronauts living at the station.

The crew returned to Earth on 09 February 2024 having completed a successful mission.



UPDATE



Ax-3 mission returns to Earth: Re-entry and Splashdown – 09feb2024

After a 47-hour journey back to Earth from the International Space Station (ISS), the Axiom Mission 3 (Ax-3) crew splashed down off the coast of Daytona, Florida on 09 February 2024.

The Ax-3 crew spent 18 days (435 hours) onboard the ISS, which orbits the Earth at a speed of 28,000 km/h. They lived and worked at the stations during 288 orbits, covering the equivalent length of 12.2 million kilometres on the surface of our planet.

Having completed their mission successfully, the astronauts were exhilarated and proud. All the stages of their journey went well and “nominally”, and they were able to achieve their goal of performing more than 30 experiments during their stay at ISS.

Ax-3 Mission concluded with a successful splash down off the coast of Florida on 09 February 2024. Axiom, 2024. Ax-3 Mission concluded with a successful splash down off the coast of Florida on 09 February 2024. Axiom, 2024.


After undocking on 07 February, the Dragon capsule gradually approached our planet following a carefully choreographed set of events:

  1. Departure burn: After separation from the ISS, the Dragon capsule fired its forward-facing Draco Thrusters to adjust its trajectory and speed in preparation for re-entry.
  2. Trunk detachment: The crew then jettisoned the unpressurised Trunk, the cylindrical section attached to the bottom of the capsule.
  3. Deorbit burn: Running entirely on batteries, the Dragon capsule performed a 9-minute deorbit burn before closing the cone.
  4. Re-entry: Once the Dragon entered the atmosphere there was an expected 7-minute loss of communication, known as Loss of Signal (LOS), caused by friction of the spacecraft as it pushed through increasing amounts of air particles, which cause the formation of super-heated plasma around the vehicle. As the capsule slowed down, the plasma dissipated, and communications resumed. To prevent the astronauts from heating up, Nitrox gas is circulated in the cabin and their suits.
  5. Parachutes deployment: First, two small Drogue parachutes were released to stabilise the spacecraft. A minute later, the 4 main parachutes were released to slow down the vehicle from 560 km/h to 28 km/h.
Graphic showing the stages of the return flight from departure burn to splashdown. NASA, Axiom 2024. Graphic showing the stages of the return flight from departure burn to splashdown. NASA, Axiom 2024.


  1. Splashdown: The Dragon capsule splashed down on the calm waters of the Atlantic Ocean off the coast of Daytona, Florida.
Composite image of the moment of splash down on the Atlantic Ocean, off the coast of Daytona, Florida, USA. NASA, Axiom 2024. Composite image of the moment of splash down on the Atlantic Ocean, off the coast of Daytona, Florida, USA. NASA, Axiom 2024.


  1. Recovery: The recovery teams approached the capsule within 30 minutes of splashdown and towed the spacecraft to the recovery vessel, which winched the Dragon onto a soft nest and aligned the side hatch with a platform.
    Ater opening the hatch, the medical personnel were the first to greet the astronauts inside the capsule and after verifying that everyone was fit to continue, they helped the astronauts exit the capsule one at a time. Coming out last was Commander Michael Lopez-Alegria, who gave a triumphant smile at the end of the mission.
Commander Michael Lopez-Alegria smiles outside the Dragon Freedom capsule marking the end of the Ax-3 mission. 09 February 2024. NASA, Axiom 2024. Commander Michael Lopez-Alegria smiles outside the Dragon Freedom capsule marking the end of the Ax-3 mission. 09 February 2024. NASA, Axiom 2024.


Watch the Ax-3 Return video by NASA (2hr).


Axiom-3 mission return, from Departure Burn to Recovery. Broadcast live on 09 February 2024. NASA, Axiom, 2024.







UPDATE



Ax-3 says goodbye after completing mission at ISS – 02feb2024

On 02 February 2024, the members of Expedition 70, living at ISS, said goodbye to Mission Axiom-3, who successfully achieved their research objectives in their 2-week stay at the station.

Expedition 70 included Commander and ESA’s Danish astronaut Andreas Mogensen (depicted in the centre of the image wearing a red polo shirt).

Axiom-3 astronauts took turn to give their message of appreciation to their hosts, their ground team, and in their own language, to their country teams.

Axiom-3 astronauts thanking their hosts, Expedition 70 at ISS at the end of their stay at the station. NASA 02 February 2024. Axiom-3 astronauts thanking their hosts, Expedition 70 at ISS at the end of their stay at the station. NASA 02 February 2024.


Watch the farewell video by NASA (9min).


Axiom-3 mission saying goodbye to Mission 70 as they finish their time at ISS. NASA 02 February 2024.







AXIOM 3 CREW

This is the first all-European crew on this programme and also the first time to include an ESA sponsored astronaut, Marcus Wandt.

Commander Michael López-Alegría (Spain/USA). Commander Michael López-Alegría (Spain/USA).


Commander Michael López-Alegría (Spain/USA, Axiom Space, 6th flight): A former aviator and NASA astronaut who completed 3 space shuttle flights and a Soyuz mission. He made a record number of space walks and the longest accumulating time outside a spacecraft. Inducted into the US Astronaut Hall of Fame in 2020. In Axiom Space, he is the chief astronaut and served as commander of the Axion-1 mission, which flew to ISS in April 2022.

Pilot Walter Villadei (Italy). Pilot Walter Villadei (Italy).


Pilot Walter Villadei (Italy, MDD, 2nd flight): A flight engineer of the Italian Air Force who represents his institution in the USA, he was the first Italian to qualify as a Cosmonaut and Space Engineer. This is his first flight to lower orbit as the first Italian to take up the post of Dragon Pilot.





Mission Specialist Marcus Wandt (Sweden). Mission Specialist Marcus Wandt (Sweden).


Mission Specialist Marcus Wandt (Sweden, SNSA/ESA, 1st flight): A Lieutenant Colonel of the Swedish Airforce, who flew 9 years as a fighter pilot and graduate from the US test-pilot school. He was selected as Astronaut Reserve by ESA in 2022 and he is the first ESA representative in an Axiom flight.





Mission Specialists Alper Gezeravcı (Türkiye). Mission Specialists Alper Gezeravcı (Türkiye).


Mission Specialists Alper Gezeravcı (Türkiye, TSA, 1st flight): An experienced aircraft pilot who flew the F-16 aircraft and the commercial B-737 as Captain. He has a Master’s degree from the US Airforce Institute of Technology.







ABOUT AXIOM SPACE


In 2019, NASA opened up the International Space Station for commercial activity and since then they have worked with many private industries to prepare for the future of Low Earth Orbit. NASA’s plan is to no longer remain a provider of Low Earth Orbit destinations but to become a customer that purchases commercially owned and operated services. To reach that goal ISS began to enable private astronaut missions that will help refine and mature the processes needed for a future when NASA and private astronauts will work together.

Axiom Space is one of those companies.


Michael T. Suffredini and Kam Ghaffarian, funders of Axiom Space Inc. Michael T. Suffredini and Kam Ghaffarian, funders of Axiom Space Inc.

Axiom Space Inc. or Axiom Space, is a privately funded space infrastructure developer company based in Houston, Texas, USA. It was founded in 2016 by NASA-retired programme manager for ISS Michael T. Suffredini, and Iranian-born American engineer and businessman Kam Ghaffarian. The company aims to own and operate the first commercial space station in the late 2020s and they are interested in research, manufacturing and exploration in space.

Axiom Space has very tight commercial links with NASA, employing some key former NASA personnel, e.g., former administrator Charles Bolden and astronauts Michael Lopez-Alegria and Brent W. Jett. NASA selected Axiom Space to provide the first commercial destination module (Hab one or Ax-H1) to attach to the Harmony forward port on ISS.

The first Axiom mission to the ISS (Ax-1) launched on 08 April 2022, Ax-2 on 23 May 2023 and now Ax-3 on 18 January 2024.

Modules will later be added to start the development of the Axiom Station (Ax-H2, Research and manufacturing module and Power thermal module), once it is detached from ISS. The latter is due to retire by 2030, dismantled and disposed via Atmospheric Re-entry.

Axiom Station of the future in orbit. Axiom Space, 2024. Axiom Station of the future in orbit. Axiom Space, 2024.






AX-3 PATCH



Axiom mission patches: Ax-1 flew in 2022; Ax-2 in 2023, and Ax-3 in 2024. Axiom mission patches: Ax-1 flew in 2022; Ax-2 in 2023, and Ax-3 in 2024.

The design of the mission’s patch is a tradition that started with NASA’s Gemini programme in the 1960s. All those who worked in the mission can wear the patch proudly as a symbol of their contribution and ownership.

The Axiom-3 patch is shaped as a shield to illustrate strength and courage and features the ISS in gold in perspective to emulate wings because all the crew members are aviator pilots and also symbolising piloting to orbit tough the spirit of exploration and collaboration.

The 4 stars represent the 4 European nations and at the top there are the flags of 5 nations: Türkiye, Spain, USA, Italy, and Sweden.

The Earth in wireframe represents bridging cultural divides to advance human knowledge and prosperity.

The number 100 celebrates the centennial for Italy and Türkiye, and the number 500 celebrates the fifth centennial (jubilee) for Sweden.

The Latin “PLVS VLTRA” is the mission’s motto, meaning “Further, Beyond”.

Axiom 3 mission patch. Axiom.com.

The official Patch was added to the collection of mission patches in a celebration that took place at Building 9 of Johnson Space Centre in Huston, Texas.

Ax-3 Patch added to the collection of mission patches at Johnson Space Centre, Texas. Axion.com. Ax-3 Patch added to the collection of mission patches at Johnson Space Centre, Texas. Axion.com.






ZERO GRAVITY

GiGi the Zero-gravity indicator bear. Yahoo.com, 2022. GiGi the Zero-gravity indicator bear. Yahoo.com, 2022.


Following the astronaut tradition of bringing a “Zero-gravity indicator” to celebrate their insertion into orbit, Ax-3 Mission carried a teddy bear named GiGi.

GiGi wears a black and blue “Next generation lunar spacesuit” with orange highlights.

More about GiGi at CollectSpace (link open in new tab/window).













A RESEARCH MISSION


Dr Lucie Low from Axiom Space on research. NASA, 2024. Dr Lucie Low from Axiom Space on research. NASA, 2024.


Axiom-3 was a 14-day privately funded research mission to conduct 36 experiments in over 350hr of research on human health, wellbeing, radiation exposure, genetic expression and Earth observations.

Dr Lucie Low from Axiom Space expanded on the research aims of a sample of topics:


The Italian experiments were led by the Italian Air Force (ItAF) and the Italian Space Agency (ASI).

  1. Space object cataloguing: The Italian Space Operations Centre (ISOC) of ItAF is a service that uses software to locate objects in space to manage space objects safely, avoid collisions and protect instruments from severe solar events. Their Space Weather Forecasting will follow solar flares, for example, that damage human cells and electronics in a spacecraft, therefore it is important to know when to take precautions.
  2. Amyloid aggregation upgrade: This continues the study of the effects of microgravity on the structural changes of protein formation, in particular Amyloid Beta, which is related to the formation of amyloid plaques in neurodegenerative diseases like Alzheimer’s.
  3. Light Ion Detector Hardware: This is LIDAL (Light Ion Detector for ALTEA, Anomalous Long-Term Effects on Astronauts), an instrument that will use 2 LIDAL Detector Units (LDU) analyse real-time radiation risk for companies developing materials to shield against radiation in the future.
  4. Evaluation of endothelial function in personnel exposed to microgravity during orbital flight activity: A comparative study of vascular health measured before, during and after spaceflight using non-orbital flight personnel as a reference to learn more about vascular changes in preparation for long-duration spaceflight missions.
Italian experiments: 1. ISOC. 2. βAmyloid aggregation in Alzheimer’s. 3. LIDAL. NASA, MDPI.com, 2024. Italian experiments: 1. ISOC. 2. β-Amyloid aggregation in Alzheimer’s. 3. LIDAL. NASA, MDPI.com, 2024.


The European Space Agency (ESA) experiments were represented by Sweden’s participation.

  1. Orbital Architecture: This project studies the effects of architectural settings on physical and social wellbeing, measuring cognitive performance, stress levels and recovery from stress in isolated environments. Testing the crew in different sections of the space station will reveal if those environments influence their biology and psychology while they work.
  2. Crew Interactive Mobile Companion (CIMON): This is an AI guided robot that is free flying on the station that can help the crew with tasks, e.g. help Marcus do a physical science investigation.
  3. The Analyzing Interferometer for Ambient Air-2 (ANITA-2): The analysis of air samples from ISS in search of contaminants. This experiment uses infrared light to detect traces of 33 gases; unknown substances can be brought back to Earth for analysis.
  4. Multi-Avatar and Robots Collaborating with Intuitive Interface (Surface Avatar): A project to develop robots for space exploration and building on extra-terrestrial environments and for communications as data relays. This knowledge can also be used for arctic exploration, search and rescue and submarine applications.

ESA/Sweden’s experiments: 1. Orbital architecture. 2. CIMON. 3. ANITA-2. NASA, ESA, 2024. ESA/Sweden’s experiments: 1. Orbital architecture. 2. CIMON. 3. ANITA-2. NASA, ESA, 2024.


The Turkish experiments were led by the Scientific and Technical Research Council of Türkiye (TUBITAK) and Turkish Space Agency (TUA).

  1. Vokalkord: An easy-to-use telemedicine application that analyses the sound produced in the respiratory system, including breathing, speaking and coughing for the detection of disease using artificial intelligence trained on 71 diseases. The application can be loaded on a smart phone The goal is to help with the diagnosis of respiratory, infectious, cardiovascular and other diseases for telemedicine, which would be applicable in space missions and space tourism.
  2. Innovative Research on Novel Space Alloys (UYNA): In partnership with the Japanese Space Agency (JACSA), TUA used JACSA’s electromagnetic levitating facility to melt and re-solidify metal alloys while they float in space. This metallurgic experiment focused on Medium Entropy Alloys (MEA) and High Entropy Alloys (HEA), to understand how their molecular structure changes to give them high strength, toughness and corrosion resistance. that will have applications in space, aviation, automotive and energy industries, and medicine.
  3. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR-Gem): An agricultural experiment on extremophytes modifying the structure of plant genes that will help understand plant adaptation to extreme environments for the creation of more resilient crops.
  4. UzMan: Microalgal life support systems for space missions. Investigates the use of algae as a nutritional source for long duration flights. Algae convert carbon dioxide into oxygen for spacecraft environment; help regulate temperature, recycle certain waste and maybe used as fuel and fertiliser for agriculture.

Türkiye experiments: 1. CRISPR-Gem exremophytes . 2. UzMan microalgae. 3. Vokalkord software. NASA, ESA, 2024. Türkiye experiments: 1. CRISPR-Gem exremophytes . 2. UzMan microalgae. 3. Vokalkord software. NASA, ESA, 2024.


Other Axiom Space scientific partners lead health-related experiments.

  1. Cosmic Brain Organoids project from the National Stem Cell Foundation (NSCF): An experiment that will use organoids derived from stem cells of patients with neurodegenerative diseases (Parkinson’s and Primary progressive multiple sclerosis) and study how they are affected by microgravity.
  2. Cancer in LEO project from the Sanford Stem Cell Institute (SSCI): A study of tumour organoids in microgravity to identify early signs of cancer to prevent disease. This is part of the Space Stem Cell Orbital Research (ISSCOR) project with collaboration of SSCI, JM foundation and Axiom Space to understand stem cell role in cancer, ageing and exposure to space.
  3. Translational Research Institute for Space Health (TRISH) Essential Measures: This project started in Ax-1 and continues to gather physiological, behavioural, and biological data of spaceflight participants to study adaptation to space. This will add to knowledge on movement disorders and the impact of isolation, confinement and stressful environments on participants.
  4. Bodewell Skincare Study: This study focuses on the moisturising effect of Bodewell cream on the skin of astronauts exposed to microgravity and artificially controlled environments. Results will help develop skin-care products for normal skin and skin conditions like eczema and psoriasis.

Other experiments: 1. NSCF Brain organoids. 2. TRISH Space health. 3. Bodewell skin care. Axiom, Bodewell, 2024. Other experiments: 1. NSCF Brain organoids. 2. TRISH Space health. 3. Bodewell skin care. Axiom, Bodewell, 2024.








AX-3 LAUNCH

On 18 January 2024, Axiom-3 launched from Pad 39A at Florida’s Kennedy Space Center (KSC) on board of the Crew Dragon Freedom capsule propelled by a Space-X Falcon 9 rocket. Their destination was the International Space Station (ISS).

Launch sequence:


  1. Lift off (0sec): Took place after all checks were approved, propellent was loaded (liquid Oxygen and RP-1 rocket-grade Kerosene), and countdown reached 0.
  2. Stage 1 Throttle Down: 43seconds into the flight the Falcon 9 engines throttled down to help the ship pass through Max-Q.
  3. MAX Q: This is the period of Maximum Dynamic Pressure sustained by the rocket while it ascended to reaches supersonic speeds.
  4. Throttle up: The Merlin engines increased burning again to continue ascending to reach 3.5 minutes into the flight.
  5. MECO: Main Engine Cut Off, was when the 9 Merlin engines stopped firing in preparation for stage separation.
  6. Stage Separation: The first stage or propulsion unit separated from the top section of the rocket (second stage) and began returning to the ground.

Flight stages: Ax-3 launch onboard a Space-X Falcon 9 rocket. From lift off to stage separation. Axiom, 2024. Flight stages: Ax-3 launch onboard a Space-X Falcon 9 rocket. From lift off to stage separation. Axiom, 2024.


  1. Second Engine Ignition: The engine on Stage 2 called Second Engine Star-1 (SCS1), is a Merlin Vacuum Engine that ignited to propel this section into orbit.
  2. Stage 1 Boost-back Burn: 3 of the 9 Merlin engines ignited and shut down to propel the first stage away from the ascending route towards Cape Canaveral, Florida.
  3. Stage 1 Entry Burn: This burn slowed the first stage down to prepare for re-entry into the atmosphere. Descent was steered by grid fins located close to the bottom of Stage 1.
  4. Stage 1 Landing Burn: This burn rapidly slowed down Stage 1 to perform a soft landing on the landing pad. This happened 90 seconds after the delivery of Stege 2 into orbit and 8 minutes into the mission.
  5. Orbital Insertion: The second stage continued to ascend into orbit and cut off its engine.
  6. Dragon Separation: 3 minutes after reaching orbit, the Dragon Freedom Capsule separated from Stage 2 and checked its Graco manoeuvring thrusters.
  7. Nosecone deployment: 12 minutes into the flight, the capsule’s nose-cone was deployed to expose the mechanism that allowed it to dock into the ISS.

Flight stages: Ax-3 launch onboard a Space-X Falcon 9 rocket. From second engine ignition to nosecone deployment. Axiom, 2024. Flight stages: Ax-3 launch onboard a Space-X Falcon 9 rocket. From second engine ignition to nosecone deployment. Axiom, 2024.


The event was broadcast via ISS live at (links open in new tab/window):
axiomspace.com, spacex.com/launches, x.com/@SpaceX, NASA Television, and the NASA app.







AX-3 DOCKING INTO ISS

It took around 12 minutes to ascend to lower orbit and enter space by crossing the boundary area known as the Kármán Line at an altitude of 100km above sea level.

The Dragon capsule and the second stage of the Falcon 9 rocket continued in orbit slowly gaining altitude and speed to catch up with the ISS at an altitude of around 420km.

There were 5 major burns of the Draco Thrusters on Dragon while in orbit during this approach:

  1. Following insertion into orbit Dragon Freedom performed an initial Phase Burn to gain altitude and reach 400km above sea level, which placed it at 20 km from ISS.
  2. A Boost Burn advanced the spacecraft to 10km from the ISS, and a Close Co-elliptical Burn provided it with more speed to keep the Dragon below the ISS.
  3. 8 hours later, the Transfer Burn raised the Dragon to 2.5km from the ISS, yet still around 60km behind it, the Final Co-elliptical Burn helped the spacecraft get even closer.
  4. Approach initiated when Dragon was 7km behind the ISS, moving the capsule through 2 checkpoints. The first one, when entering the Approach Ellipsoid (AE) zone, which is a 3-dimensional ellipsoid that measures 4x2x2km. This is a “24hr safe trajectory area”, which means if Dragon lost all control of its thrusters, it would take at least 24hr before reaching the innermost boundary of the AE.
  5. After receiving permission to continue, Dragon arrived at Waypoint 0, 400km from the ISS, for another check of all functions before being authorised to approach the Keep out sphere, which is a 200 m radius area around the station. This is a “6hr safe trajectory zone”.
  6. Waypoint 1 was at 220m from ISS and directly in front of the docking point or Docking Axis position. This mission headed to the Node 2 Forward Port which has an International Docking Adaptor (IDA).
  7. Waypoint 2 was 20m away from ISS, and it was where Dragon focused on aligning with the docking adaptor.
  8. After final checks at that point, the call out Crew Hands Off Point (CHOP) indicated that there were 30 seconds before docking and all manoeuvres were controlled autonomously by Dragon.
  9. The initial contact of Dragon to the IDA is known as Soft Capture. The adaptor pulled the capsule closer until 12 hooks drove into place, securing the capsule to the ISS, a crucial step known as Hard Capture.
  10. NASA astronauts Loral O'Hara and Jasmin Moghbeli manually pressurised the vestibule area in between Dragon’s hatch and the ISS’ hatch. Meanwhile, umbilical cables provided power, data and audio for communications with Dragon.
  11. Less than 2 hours later, the hatches were opened to allow access to the ISS.

In this manner, after a 36-hour journey, the Dragon capsule matched the speed of the ISS (28,000 km/h) and docked into the Harmony module of the ISS on 20 January 2024.

Orbital journey diagram showing the 5 major burns that propelled the Dragon Capsule to approach and successful dock into ISS. 20 January 2024. Axiom, 2024. Orbital journey diagram showing the 5 major burns that propelled the Dragon Capsule to approach and successful dock into ISS. 20 January 2024. Axiom, 2024.


SpaceX Dragon spacecraft successfully docked into the ISS Harmony module on 20 January 2024 (Left: model. Right: actual photo). Axiom, 2024. SpaceX Dragon spacecraft successfully docked into the ISS Harmony module on 20 January 2024 (Left: model. Right: actual photo). Axiom, 2024.








AX-3 WELCOME TO ISS

Axiom-3 crew salute viewers after the welcome ceremony at their arrival to ISS. Station crew on the background. 20 January 2024. Axiom, 2024. Axiom-3 crew salute viewers after the welcome ceremony at their arrival to ISS. Station crew on the background. 20 January 2024. Axiom, 2024.


On 20 January 2024 the Axiom Mission 3 (Ax-3) crew that arrived on board Dragon Freedom were welcomed into the ISS by the residing Crew 7 Dragon spacecraft or Dragon Endurance (docked on 27 Aug 2023 for a 6-month stay).

Commander Michael Lopez-Alegria formally presented the Astronaut Pins to his crewmates Col. Walter Villadei (astronaut 609), Alper Gezeravci (610) and MarcusWandt (611).

Commander Lopez-Alegria awards new astronauts with their pins: Walter Villadei (609), Alper Gezeravci (610) and MarcusWandt (611). 20 January 2024. Axiom, 2024. Commander Lopez-Alegria awards new astronauts with their pins: Walter Villadei (609), Alper Gezeravci (610) and MarcusWandt (611). 20 January 2024. Axiom, 2024.








AX-3 WORKING AT ISS

During their time at the ISS, the Ax-3 crew took part of more than 30 experiments that occupied them fully. Their daily activities were logged on Axiom’s website starting on 20 January 2024 (opens in a new tab/window).

The Axiom-3 crew training at Axiom and finally living and working at ISS. 18 January to 09 February 2024. Axiom, 2024. The Axiom-3 crew training at Axiom and finally living and working at ISS. 18 January to 09 February 2024. Axiom, 2024.







 



REFERENCES


» Axiom Space (2023) Ax-3 mission to expand government-sponsored research in low-earth orbit. 12 October 2023 [Online article]. Available at axiomspace.com. Accessed: 18 January 2024.
» Axiom Space (2024) Ax-3 mission update flight day #16. 02 February 2024 [Online article]. Available at axiomspace.com. Accessed: 02 February 2024.
» Axiom Space (2024) Ax-3 mission to enable important technological advancements for Türkiye. [Online article]. Available at axiomspace.com. Accessed: 8 February 2024.
» Axiom Space (2023) Ax-3 mission to prioritize government-sponsored research in low-Earth orbit. [Online article]. Available at axiomspace.com. Accessed: 18 January 2024.
» Axiom Space (2024) Axiom Space News. [Online article]. Available at axiomspace.com. Accessed: 18 January 2024.
» Axiom Space (2023) Axiom Space releases Ax-3 Mission Patch. [Online article]. Available at axiomspace.com. Accessed: 18 January 2024.
» Axiom Space (2024) Axiom Station. [Online article]. Available at axiomspace.com. Accessed: 18 January 2024.
» Barilla (2023) Barilla pasta lands on astronauts’ menus. Barilla, 14 Dec. 2023. [Online article]. Available at barillagroup.com. Accessed: 06 March 2024.
» Collect Space (2024) GiGi, Axiom's spacesuit-clad Build-A-Bear, returning to orbit on Ax-3. [Online article]. Available at axiomspace.com. Accessed: 18 January 2024.
» Evans B (2024) Ax-3 crew primed for science, technology, educational outreach mission. America Space, 17 January 2024. [Online article]. Available at americaspace.com. Accessed: 18 January 2024.
» Evans B (2023) Falcon Heavy launches USSF-67, Readies for Busy 2023. America Space, 17 January 2024. [Online article]. Available at americaspace.com. Accessed: 18 January 2024.
» NASA (2024) Axiom Mission 3 launches to the International Space Station (Official NASA Broadcast), 18 January 2024. [Online video]. Available at YouTube. Accessed: 18 Jan. 2024.
» Romoli G (2023) LIDAL, a time-of-flight radiation detector for the International Space Station: Description and ground calibration. sensors 2023, 23(7), 3559; https://doi.org/10.3390/s23073559. [Journal article] Available at www.mdpi.com. Accessed: 07 February 2024.
» Wikipedia (2024) Axiom Mission 3. [Online article]. Available at wikipedia.org. Accessed: 18 Jan. 2024.
» Wikipedia (2024) Axiom Space. [Online article]. Available at wikipedia.org. Accessed: 18 Jan. 2024.


=== END ===

Wednesday 13 September 2023

DART redirects an asteroid - 26 SEP 2022

Title: The Double Asteroid Redirection Test (DART) is NASA’s probe to redirect asteroids. Successful contact with the target asteroid took place on 26 September 2022. NASA, 2022. Title: The Double Asteroid Redirection Test (DART) is NASA’s probe to redirect asteroids.
Successful contact with the target asteroid took place on 26 September 2022. NASA, 2022.


The Double Asteroid Redirection Test (DART) is the first mission aimed at demonstrating a method of asteroid deflection through kinetic impact. In 2021, NASA launched a spacecraft to travel and collide with an asteroid system. Contact with the target took place on 26 September 2022.



UPDATES



First anniversary of DART’s impact on Dimorphos – 26sep2023

A year ago, on 26 September 2023, the Double Asteroid Redirection Test (DART) mission culminated in a precise intentional impact of the spacecraft onto its target, the moonlet Dimprphos, of the binary asteroid system Didymos, located 11 million kilometres away.

On the first NASA interplanetary defence test mission, DART travelled almost a year through space to demonstrate the capability of a kinetic impactor in changing the trajectory of an asteroid.

Although the Dymorphos system orbit around the sun does not intercept that of the earth, on that date, it was the closest to our planet to perform a test.

Now we know that a kinetic impactor is a viable option should an asteroid be discovered in the future that appears to be a threat to our planet.


First anniversary of success of NASA’s DART mission that reached its on 26 Sep 2022. APL/NASA, 2023.







Boulders ejected by DART’s impact on Dimorphos – 08aug2023

Particle Swarm ejecta resulting from the impact of DART on Dimorphos was a predicted event when the mission was planned as the small moon has a small gravitational power that loosely attaches rocks to its surface.

Attention-seeking media exaggerated the report with alarming headlines like “Nasa asteroid blunder unleashes boulder storm as deadly as Hiroshima” (Yahoo! News, 08 Aug 2023), and “NASA’s voyager-2 alien invasion, a human error” (Telegraph, 03 Aug 2023), but thy were bound to include factual information: “although the impact succeeded in knocking Dimorphos slightly off course, it also dislodged 37 boulders, which are currently zipping through space at 20,900 km/h.

Prof David Jewitt, UCLA. About boulders ejected by DART’s impact on Dimorphos (2023, ApJL, 952 L12).Prof David Jewitt, UCLA.
About boulders ejected by DART’s impact on Dimorphos (2023, ApJL, 952 L12).

In the original study published on 20 July 2023, David Jewitt, a professor of Earth and planetary sciences at UCLA, and his co-authors, examined images of the Near-Earth asteroid 65803 Didymos and its small companion Dimorphos taken by the Hubble Space Telescope in 2022 (26 Sep “impact”, and 19 Dec), and 2023 (04 Feb and 10 Apr). “Impact” on the first date refers to the deliberate crash of the DART spacecraft on the surface of the asteroid Dimorphos of the Didymos–Dimorphos binary system, with the purpose of changing its course as an experiment for the planetary defence programme.

The Hubble Space Telescope captured images of the Didymos asteroid before, during and after DART’s impact on 26 September 2022. NASA, 2010.The Hubble Space Telescope captured images of the Didymos asteroid before, during and after DART’s impact on 26 September 2022. NASA, 2010.

The authors analysed images taken by the 2.4m Hubble Space Telescope, which uses a camera (WFC3) with two 2015x4096 px Charged Couple Device (CCD) sensors.

The impact of DART on 26 Sep. 2022, resulted in the ejection of debris that formed a long, comet-like tail, directed away from the sun as it was swept by solar radiation pressure. This cloud of debris provides the opportunity to learn more about the mission and its effects.

Images were enhanced to separate them from the cosmic background, re-oriented to bring the celestial north to the top and composited from a series of similar images taken on that date (24 images taken in 5hr on 19 Dec). The team identified 37 boulders circled in the image below. The spikes emanating from the Didymos system resulted from telescope diffraction and rotation of superimposed images.

Identified boulders surrounding the Didymos-Dimorphos binary system after the impact of DART in Sep. 2022. Image from Hubble Space Telescope. Jewitt D (2023) ApJL, 952 L12). Identified boulders surrounding the Didymos-Dimorphos binary system after the impact of DART in Sep. 2022.
Enhanced image from Hubble Space Telescope. Jewitt D (2023) ApJL, 952 L12).

The comparison of Hubble’s images from December 2022 and February 2023 provided more detail about positional changes and acceleration of visible boulders.

Theoretical calculations suggested that boulders that were launched at less than 0.09m/s were not able to surpass the binary system’s escape speed of 0.24 m/s and fell back onto the surface of Dimorphos within hours, while those that gained faster speeds were able to escape the system but remained close.

Comparison of position of the boulders ejected by DART between 19 Dec 2022 and 04 Feb 2023. Images by Hubble Space Telescope. Jewitt D (2023) ApJL, 952 L12).
Comparison of position of the boulders ejected by DART between 19 Dec 2022 and 04 Feb 2023.
Images by Hubble Space Telescope. Jewitt D (2023) ApJL, 952 L12).

Some of the boulders not included in the count, were embedded in the particle trail (marked with T in the enlarged image), which left 37 identifiable boulders circled around the binary system.

Close up of boulders embedded in the tail. Images by Hubble Space Telescope. Jewitt D (2023) ApJL, 952 L12).
Close up of boulders embedded in the tail.
Images by Hubble Space Telescope. Jewitt D (2023) ApJL, 952 L12).

The analysis of DART’s penultimate photo of the surface of Dimorphos before impact provided with vast information on the features of the surface. Taken from 12 m from the surface and covering 30x30m or 1% or the surface of Dimorphos. The impact site is marked on the photo with a yellow dot, located next to the largest boulder named Atabaque (5m wide). Measuring the boulders and building a simulation of an impact provided an estimation of the size of the crater resulting from the impact of DART (40-60m).

Image of the surface of Dimorphos taken by DART before impact. The crash point marked by a yellow spot. DART 26 Sep. 2022. NASA, Jewitt D (2023) ApJL, 952 L12). Image of the surface of Dimorphos taken by DART before impact.
The crash point marked by a yellow spot. DART 26 Sep. 2022. NASA, Jewitt D (2023) ApJL, 952 L12).

The main mechanism of ejection was cratering, by which particles are displaced in a hollow cone configuration and seismic shaking resulting from the propagation of the impact shock that launched boulders that were sitting on the surface with sufficient speed to overcome the escape speed.

The team of researchers reported the following:

  1. They identified approximately 40 boulders that are now moving with the asteroid within a region spreading 10,000 km. The largest has a diameter of 7m and the smallest 4m.
  2. They calculated that the combined mass of the boulders is 5,000 tonnes, which corresponds to 0.1% of the total mass of Dimorphos (4 million tonnes).
  3. The projected speed of the boulders relative to Dimorphos is comparable to the gravitational scape speed from the system. The boulders carry 0.00003 parts of the kinetic energy delivered by the DART impactor.
  4. The number, sizes and shapes of those objects appear to be those of objects dislodged from 2% of the surface of the asteroid that correspond to a circular patch of at least 50m in diameter (Jewitt D (2023) ApJL, 952 L12).

Prof Jewitt said: “The boulder swarm is like a cloud of shrapnel expanding from a hand grenade. Because those big boulders basically share the speed of the targeted asteroid, they’re capable of doing their own damage.” Because DART was an experimental mission to learn the effects of redirecting an asteroid, this new evaluation suggests that in a real scenario of an asteroid redirected after approaching our planet, the dislodged particles would still be able to cause damage if they were to impact our planet. According to the Professor, given the high speed of a typical impact, a 4.5m boulder hitting Earth would deliver as much energy as the atomic bomb that was dropped on Hiroshima, Japan, during the Second World War (Kanapton S (2023) Yahoo! News).







Hubble’s photos of DART’s impact analysed - 01mar2023

The NASA/ESA Hubble Space Telescope captured a series of photos of rapid changes to the asteroid Dimorphos when it was deliberately hit by a 545-kilogram spacecraft on 26 September 2022. The primary objective of the NASA mission, called DART (Double Asteroid Redirection Test), was to test our ability to alter the asteroid’s trajectory as it orbits its larger companion asteroid, Didymos. Though Dimorphos poses no threat to Earth, data from the mission could help inform researchers how to potentially change an asteroid’s path away from Earth, if ever necessary.

Debris were flung into space as the DART impactor spacecraft crashed into Dimorphos at 21,000 Km/h. It is estimated that the blast ejected over 900,000 kg of dust off the asteroid.

The images show an Ejecta Cone with spiral swirls of debris caught up along the Dimorpho's orbit around Didymos.

Superimposed yellow lines show the direction of the ejecta cone, the curved ejecta stream and the double tail formation on photos after the impact of DART on Dimorphos. Images between 27 Sep. and 08 Oct 2022. Hubble ST/ESA, 01 March 2023. Superimposed yellow lines show the direction of the ejecta cone, the curved ejecta stream and the double tail formation on photos after the impact of DART on Dimorphos. Images between 27 Sep. and 08 Oct 2022. Hubble ST/ESA, 01 March 2023.

The movie starts 1.3 hours before impact when the binary asteroid system is at the centre, although they look like one spot as they are close together. Hubble's optics produce artefacts that appear as straight spikes coming from the centre.

The next image, 2 hours after the crash, shows debris flying away faster than 6.5km/h and forming a hollow cone with long stringy filaments.

By 17 hours post-collision the interaction of the binary system affects the ejecta pattern producing a pinwheel shape caused by the gravitational pull of the larger Didymos. Later, the pressure of sunlight on the dust gave the ejecta a comet-tail-like shape, which split into 2 for a few days.

Images joined into a video before and after DART impacted on Dimorphos, the orbiting asteroid of the Didymos binary system.
Note development of ejecta patterns over time. Hubble Space Telescope. NASA/ESA, 26 September to 08 October 2022.







NASA confirmed change in Asteroid’s orbit – 11 Oct 2022

The DART mission was a success!

Scientists confirmed a significant change in the orbit of the moonlet Dimorphos following the purposeful impact of a spacecraft on 26 September 2022.

The goal of the mission was to crash the spacecraft in the opposite direction of the orbital movement of the asteroid so that it would lose some of its kinetic energy and deflect to a lower orbit, closer to Didymos than the original one. Success was defined at NASA by a change in orbital period of 73 seconds or a shorter time to complete its new orbit.

Graphic of DART planned impact with Dimorphos changing its orbit to a lower one around Didymos. Note the accompanying imaging spacecraft LICIACube. NASA, 2022. Graphic of DART planned impact with Dimorphos changing its orbit to a lower one around Didymos.
Note the accompanying imaging spacecraft LICIACube. NASA, 2022.

Before the impact, Dimorphos completed its orbit around the parent asteroid Didymos in 11 hours and 55 minutes. Using the same methods of measurement via Earth telescopes, astronomers measured an orbit of 11hr, 23 minutes after the impact, which confirms that the crash of the spacecraft altered the speed of rotation of the asteroid by 32 minutes (margin of uncertainty of 2 minutes).

The full effect of the impact is still being studied as the focus shifts towards measuring the efficiency of momentum transfer, calculated as 22,530 km per hour collision with its target. Analysis includes the tons of asteroidal rock displaced by the impact. This material, known as “ejecta” exits the asteroid at high speed creating a blast that further pushes the asteroid in the opposite direction, enhancing the effect of DART’s push against Dimorphos.

Hubble observed debris around Dimorphos, known as ejecta, still present on 08 October 2022. NASA, 2022. Hubble observed debris around Dimorphos, known as ejecta, still present on 08 October 2022. NASA, 2022.

Telescopic facilities contributing to the observations used by the DART team to determine this result include: Goldstone, Green Bank Observatory, Swope Telescope at the Las Campanas Observatory in Chile, the Danish Telescope at the La Silla Observatory in Chile, and the Las Cumbres Observatory global telescope network facilities in Chile and in South Africa.







Hubble captures DART’s impact – 29 Sep 2022



Hubble captures DART’s impact. NASA, 2022.Hubble captures DART’s impact.
NASA/ESA/JWST, 29 September 2022.

The impact of DART on Dimorphos was observed and recorded by two space telescopes.

This is the first time both telescopes, the Hubble Space Telescope and the James Webb Space Telescope observe the same object simultaneously.

Coordinating Hubble and Webb was an operational milestone. The combination of both observatories demonstrated the capability of the technical and scientific teams, opening more opportunities for research.


Webb captures DART’s impact. NASA, 2022.Webb captures DART’s impact.
NASA/ESA/CSA/JWST, 29 September 2022.

The analysis of images by Webb and Hubble together will provide information about the characteristics of the surface of Dimorphos as the collision produced an ejection of material that can be studied using the various wavelengths.

Hubble’s image is in the visible spectrum of light, while Webb’s image is in the infrared range. Webb took one observation of the impact location before the collision took place, then several observations over the next few hours. Images from Webb’s Near-Infrared Camera (NIRCam) show a tight, compact core, with plumes of material appearing as wisps streaming away from the center of where the impact took place (NASA/ESA/CSA/DART/JWST, 2022).

Planning and developing methods to track asteroids moving very fast took several years and intensified in the weeks leading to the impact. Webb obtained 10 images during an observation of five hours, while Hubble took 45 images from before to hours after the impact.

Hubble’s Wide Field Camera 3 showed material ejected as rays stretching out from the body of the asteroid. In the following series of images in visible light, the border on the left that fans out more prominently corresponds to the side that Dart hit the asteroid (left side of the asteroid on the image below). Brightness of the asteroid system increased threefold, lasting more than eight hours after impact.

Hubble’s images taken 22 minutes, 5 and 8 hours after the impact show material ejected into space, more evident on the left, where DART impacted. NSA/ESA, 2022. Hubble’s images taken 22 minutes, 5 and 8 hours after the impact show material ejected into space, more evident on the left, where DART impacted. NSA/ESA, 2022.

Hubble will monitor the Didymos asteroid system 10 more times in the weeks following the impact, to observe how the cloud of particles expand and fade away.

“This is an unprecedented view of an unprecedented event,” summarized Andy Rivkin, DART investigation team lead of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland (NASA/ESA/CSA/DART/JWST, 2022).







About the DART mission


The asteroid Didymos as a target.

The target of this mission was carefully selected from known asteroids that are visible but do not come close the Earth in their paths.

While there are no known asteroids larger than 140 metres in size that shows a significant chance of hitting Earth in the next 100 years, only around 40% of those asteroids have been found as of August 2023.

One of the early candidates visible to most astronomic instruments was the Didymos binary asteroid system imaged by the Arecibo Radio Telescope in 2003.

Didymos binary asteroid: 14 sequential radio-telescope original images on the left; enhanced on the right. NASA/Arecibo Radio-Telescope. 2003.Didymos binary asteroid: 14 sequential radio-telescope original images on the left; enhanced on the right. NASA/Arecibo Radio-Telescope. 2003.

The radio-telescope images above show the smaller Dimorphos at different stages of its orbit around the larger asteroid Didymos.

The target was the Asteroid Dimorphos, photographed here by DART’s camera shortly before the spacecraft impacted on its surface. NASA/DART, 26 September 2022. The target was the Asteroid Dimorphos, photographed here by DART’s camera shortly before the spacecraft impacted on its surface. NASA/DART, 26 September 2022.

This binary celestial object coded “Asteroid 65803”, was composed of a 780 metre-diameter large asteroid called Didymos and its moonlet, a 160 m-diameter small asteroid named Dimorphos

Dimorphos orbits Didymos at 1.18 km from its centre at an orbital period of 11.9 hr. The latter rotates rapidly with a rotation period of 2.26 hr, while Dimorphos seems to have a rotation synchronous with the orbit, therefore always showing the same face to the larger asteroid.

The name of the asteroid derives from the Greek word Didymos meaning Twin.

Greek twins Artemis and Apollo and their mother Leto.Greek twins Artemis and Apollo
and their mother Leto.

The DART mission.

The Double Asteroid Redirection Test (DART) is the first NASA interplanetary defence test mission. This successful test opens the possibility of saving the planet from a strike by an asteroid in the future, provided it is discovered early giving time to deploy a reaction.

The DART mission had two goals:

  • Strike the moonlet Dimorphos at a speed of 6.4 km per second.
  • Slow down its orbit by 10 minutes from its known regular orbit of 11hr 55min.

The initial goal was achieved successfully, and it was an unprecedented achievement, considering the size of the target and that the asteroid system is 11 million kilometres away.

The second goal was determined weeks after the impact. Teams of astronomers from all over the world analysed the orbit of Dimorphos to find differences compared with the data obtained before the impact.


DART, impactor spacecraft

The main structure of DART is a box of width/height/length (depth): 1.2 x 1.3 x 1.3 metres. Considering the extensions, it reaches the size w/h/l: 1.3 x 2.6 x 1.9 m. In addition, the spacecraft has 2 solar arrays that extend 8.5 m each.

DART’s weight was 610 kg at launch, including 50 kg of Hydrazine propellant for manoeuvres, and 60 kg of Xenon for the Ion Propulsion Engine. After using some of the fuel, the spacecraft was approximately 580 kg at impact.

The interaction between the spacecraft and the asteroid in space followed the universal laws of physics and therefore, in theory, it could be predicted mathematically.

One of the physical concepts involved in this transaction of energy is momentum. When DART crashed into Dimorphos, the spacecraft transferred its Momentum to the asteroid’s, resulting in a change of velocity, orbital rotation and possibly altitude around Didymos.


Momentum

Momentum of a pool cue ball is transferred to the racked balls after collision. Wikipedia, 2023. Momentum of a pool cue ball is transferred
to the racked balls after collision. Wikipedia, 2023.

Momentum is a property of physical objects that results from the product of the object’s mass and velocity. Momentum is also a Vector and has a Magnitude and a Direction.

Still objects have a mass but because they are not in motion, they have no velocity, therefore no momentum. The physical symbol for Momentum is “p” (from the Latin “pellere”, meaning "push” or “drive"). Consequently, a standing object has “0” momentum, or p = 0.

To calculate the momentum of an object, follow the equation:
momentum = mass x velocity.         p = m v

By convention, the units are:

  • Momentum (p) is measured in kilograms metres per second (kg m/s), equivalent to newton-second.
  • Mass (m) is measured in kilograms (kg).
  • Velocity (v) is measured in metres per second (m/s).

For example, if a skater has a mass of 60 kg and travels at a speed of 15 m/s, the formula would be:
      p = 60 x 15       or       p = 900 kg m/s.

Vector analysis in the collision of 2 objects in one plane. Wikipedia, 2023.Vector analysis in the collision of 2 objects on a flat plane.
Wikipedia, 2023.

Considering the multiple variables involved in a collision of two objects in space the complexity of these calculation rapidly increases.

Some of the experts conducting research in this area work at the Impact Simulation Working Group at Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. The NASA article “Predicting the unpredictable” (Rehm J, 2020), explains the essential thinking that took place during the planning of the DART mission.



Simulation of a projectile colliding with the surface of a rubble-pile asteroid. Resulting ejecta in opposite direction of the impact. JHUAPL/ Angela Stickle, 2020. Simulation of a projectile colliding with the surface of a rubble-pile asteroid. Resulting ejecta in opposite direction of the impact. JHUAPL/ Angela Stickle, 2020.

Researchers at APL calculated the change of direction after the collision and also theorised about the dispersion of particles following the impact of a small object onto a loose conglomerate of rocks, which is the case of the surface of Dimorphos.

It was predicted that the crater created by DART would displace between 9 tons (the mass of 2 elephants) and 100 tons (the mass of a whale) of surface rocks into space, creating what is know as “Ejecta” in all directions, some of it visible through telescopes.

Images that followed the impact of DART (see updates above) demonstrated multiple size particles that continue in relative proximity to the asteroid from which they originated as their resulting momentum dictates their direction of travel.

Another factor the plays a role is the gravitational force of the large objects, which was the reason that kept the smaller rocks on their surface to begin with.







DART’s Payload



DRACO camera

The DRACO camera, a high magnification imager onboard DART. DART, 2023. The DRACO camera, a high magnification imager onboard DART.
DART, 2023.

DART carries a single instrument, the Didymos Reconnaissance and Asteroid Camera for Optical Navigation (DRACO), which consists of a high-resolution camera of the Long Range Reconnaissance Imager (LORRI) type, originally developed by the Johns Hopkins University Applied Physics Laboratory (JHUAPL) for the New Horizons mission that went past Pluto in 2015.

This is a panchromatic high-magnification imager with a 20.8 cm aperture telescope that focuses visible light onto a Complementary Metal-Oxide Semiconductor (CMOS) light detector, a cheaper version of the original and expensive Charged-Coupled Device (CCD) used in New Horizons. This camera helped locate Dimorphos to support the SMART Nav Autonomous Navigation system (see below). DRACO captured the closest images of the asteroid’s surface just before impact.



Autonomous navigation system

DART featured a Guidance, Navigation and Control (GNC) system based on mathematical algorithms known as Small-body Manoeuvring Autonomous Real Time Navigation (SMART Nav), which allowed for autonomous navigation to solve the problem of aiming for a 160-metre target located at 11 million kilometres from Earth. Once the two objects were identified, about one hour before impact, the GNC elements guided the spacecraft towards the smaller one. The system was the result of decades of research on missile guidance.

The RLSA planar high-gain antenna onboard DART provided outstanding communications. DART, 2023.The RLSA planar high-gain antenna onboard DART
provided outstanding communications. DART, 2023.

In addition, DART demonstrated the use of a single-board computer and an interface module to control the advance avionics system. The CORE Small Avionics suiTe (CORESAT) also provided imaging processing, communications, and propulsion system management.

An improved communications system was provided by the Radial Line Slot Array (RLSA) low-cost high-gain antenna, which has a planar configuration and the shape or a disk with slots and able to send and receive data accurately and efficiently.

Advanced Ion propulsion.

The NEXT-C advanced Ion propulsion took DART to its destination. DART, 2023. The NEXT-C advanced Ion propulsion took DART to its destination.
DART, 2023.

DART demonstrated the NASA’s Evolutionary Xenon Thruster-Commercial (NEXT-C) engine, developed at NASA Glenn Research Center and Aerojet Rocktdyne. This electric engine is solar-powered and uses a Gridded Ion propulsion that produces thrust by electrostatic acceleration of ions (electronically charged atoms) formed from the Xenon propellent. An improved and more efficient version of the system used in the Dawn mission (2007-2018) and the Deep Space 1 mission (1998-2001).



Roll-out solar arrays

Electrical power for DART was provided by the Roll-Out Solar Array (ROSA) that consisted of two large arrays launched as compacted rolls at both sides of the main body. Each system rolled out to reach 8.5 m in length. This technology was tested at the International Space Station (ISS) in 2017. An improved version developed by Redwire’s Deployable Space systems in California, USA, was installed on the spacecraft.

The NEXT-C advanced Ion propulsion took DART to its destination. DART, 2023. The NEXT-C advanced Ion propulsion took DART
to its destination. DART, 2023.

A new technology, Transformational Solar Array was demonstrated on the panels, which contains reflective concentrators that provide 3 times more power than regular arrays. An important advancement that will reduce the need of heavy fuels in future missions.




DART’s companion, LICIACube.

The Light Italian CubeSat for Imaging of Asteroids (LICIACube) is a CubeSat constructed by the Italian Space Agency (ASI). Its mission was to observe and analyse the Didymos asteroid binary system during and after DART’s impact. The satellite bypassed the asteroids at 56.7km and took pictures of its target.

The small satellite, measuring 20x30x10cm travelled attached to the DART spacecraft and was ejected from its spring-loaded box 15 days before DART’s impact, on 11 September 2022. After release, as part of the testing process to calibrate the miniature spacecraft and its cameras, LICIACube captured images of a crescent Earth and the Pleiades star cluster, also known as the Seven Sisters.

LICIACube attached to DART in the lab. Artist impression of DART and LUCIACube as they approach the moonlet Dimorphos of the Didymos asteroid binary system. NASA/ASI, 2022. Insert: LICIACube attached to DART in the lab.
Background: Artist impression of DART and LUCIACube as they approach the moonlet Dimorphos of the Didymos asteroid binary system. NASA/ASI, 2022.

LICIACube’s image of DART impacting Dimorphos shows the “ejecta” or particles emitted by the collision.

Image taken by LICIACube as DART crashed onto the moonlet Dimorphos, ejecting particles into space. The large object at the bottom is the main asteroid Didymos. NASA/ASI, 26 September 2022. Image taken by LICIACube as DART crashed onto the moonlet Dimorphos, ejecting particles into space.
The large object at the bottom is the main asteroid Didymos. NASA/ASI, 26 September 2022.







DART’s journey


DART launched onboard the SpaceX Falcon 9 rocket from California, USA on 24 November 2021. NASA, 2021.DART launched onboard the SpaceX Falcon 9 rocket
on 24 November 2021. NASA, 2021.

DART was launched on 24 November 2021 onboard a Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Space Force Base in Santa Barbara County, California, USA. The rocket carried a 624kg payload and after launch, the primary booster successfully landed autonomously on a drone ship stationed on the Pacific Ocean and was re-used in subsequent flights.

Falcon 9 is a partially reusable medium lift launch vehicle that can carry cargo and crew into Earth orbit, produced by American aerospace company Space Exploration Technologies Corporation (SpaceX), funded by Elon Musk in 2002.

Since June 2010, rockets from the Falcon 9 family have been launched 191 times, with 189 full mission successes, one partial failure and one total loss of the spacecraft. In addition, one rocket and its payload were destroyed on the launch pad during the fuelling process before a static fire test was set to occur.

After 10 months, 2 days and 17 hours of travel through space at a speed of approximately 6.1 km per second, the mission concluded with the spacecraft crashing onto the asteroid Dimorphos on 26 September 2022.







Missions related to DART



ESA’s Hera mission 2024.


Hera is a Space Safety programme mission led by the European Space Agency (ESA) to study the impact of DART on the Didymos binary asteroid system on 27 Sep. 2022. It will measure the size and characteristics of the crater allowing to measure the efficiency of deflection produced by a calculated impact on an asteroid.

Planned to launch in October 2024, Hera will carry cameras, an altimeter, a spectrometer, and will deploy two CubeSats or nano-satellites called Milani and Juventas. In addition to studying physical properties, it will record measurements of the sub-surface and internal structures of the asteroid.

Scientific exploration will depend on gathering data using Hera’s advanced instruments:

Surface features of the asteroids and the crater will be captured by two Asteroid Framing Cameras (AFC) developed by JenaOptronik, each with a 1020x1020 pixel sensor (FaintStar panchromatic) and a telephoto lens. They can resolve 1 metre at 10 km.

Images in visible and infrared light will be captured by the Hyperspectral imager Hyperscout-H, an instrument that detects that type of light in 25 bands between 665 and 975 nanometres (visible to near infrared light).

Distance to the asteroids will be measured with a Planetary Altimeter (PALT) that uses and infrared laser to track the ground with an accuracy of 50cm of altitude.

Temperatures will be tested with a Thermal Infrared Imager (TIRI) developed by the Japanese Space Agency, capable to resolve 2.3 metres at 10 km.

The asteroids’ gravity field, rotational speed and orbits will be measured by detecting radio wave disturbances using the X-Band Radio Science (X-DST) instrument based on the Doppler effect that measures the change in wave frequency resulting from movement of an object in relation to the observer.

Image of DART taken by LICIACube as the spacecraft crashed on the moonlet Dimorphos. Notice the emitted particles known as ejecta. The large object at the bottom is the main asteroid Didymos. NASA/ASI, 26 September 2022. Image of DART taken by LICIACube as the spacecraft crashed on the moonlet Dimorphos. Notice the emitted particles known as ejecta.
The large object at the bottom is the main asteroid Didymos. NASA/ASI, 26 September 2022.

NASA's DART and ESA's Hera missions are the result of an international collaboration called "The Asteroid Impact and Deflection Assessment (AIDA)", in a similar fashion to Hubble and James Webb space telescope missions.

The asteroid monitoring system was developed by NASA and ESA in early 2000s and despite a temporary dip in funding the project revived in 2017 with a new name, Hera, inspired by the ancient Greek goddess of marriage, women and family, and the protector of women during birth.

According to Homeric Greek, Hera is the queen of the 12 Olympians and Mount Olympus, sister and jealous wife of Zeus, daughter of the Titans Cronus and Rhea. Her vengeful nature was fuelled by Zeus’ infidelities that included a mortal woman Alcmene, who became pregnant with his child. Zeus announced that this child would become the new ruler, therefore Hera did her best to prevent Alcmene from delivering, but eventually she gave birth to Heracles.

The new-born was hated by his stepmother Hera, who sent two serpents to kill him in his cot, but he played with them instead. Zeus then decided to trick Hera into nursing infant Heracles, but when she discovered who he was, she pulled the infant from her breast and a spurt of her milk formed a smear across the sky, called since then “The Milky Way”. Her milk also created a white flower, the Lily.

“The origin of the Milky Way” from Hera’s breast milk spilt after she pulled away infant stepson Heracles, the illegitimate son of Zeus. Oil artwork by Venetian painter Jacopo Tintoretto from 1575. “The origin of the Milky Way” from Hera’s breast milk spilt after she pulled away infant stepson Heracles, the illegitimate son of Zeus.
Oil artwork by Venetian painter Jacopo Tintoretto from 1575.







Live broadcast of the impact – 26 Sep 2022

On Monday 26th September 2022, millions of people around the world tuned to NASA’s live broadcast of DART’s impact onto the asteroid Dimorphos. The spacecraft followed a series of programmed events autonomously all the way to its destination. The last minutes of DART’s journey were followed closely from the Mission Control Centre at Johns Hopkins Applied Physics Laboratory in Maryland, USA. This research laboratory serves as a technical resource for the Department of Defence, NASA, and other government agencies.

The last moments of the mission were tense but full of jubilation as consecutive milestones confirmed the precision of the plans and calculations conducted by countless teams involved in constructing, flying and processing data sent by the spacecraft as it travelled through space. The last step called “Precision lock” was confirmed 17 minutes before the expected impact, indicating that DART had a lock on Dimorphos from 100 km away, and was invariably aiming at her target.

As the spacecraft approached her destination, she flew past Didymos heading for Dimorphos at 6.6 km/sec. The onboard camera sent progressively more detailed images of the small asteroid’s surface, showing an untidy conglomerate of rocks before transmission was lost. The last image was mostly a red screen that signalled the end of the mission as the spacecraft crashed successfully on the surface of the asteroid.


DART mission's success – 26 Sep 2022



Confirmation of success

Following DART’s impact, astronomers from all over the world focused on measuring the orbiting speed of the moonlet Dimorphos around the asteroid Didymos. As both asteroids are cold and do not emit light, the largest is only visible by the light it reflects from nearby objects. The moonlet can be detectable when it eclipses the larger one as it crosses in front during its orbit. From Earth, it looks like a decrease in brightness the duration and frequency of which, allows astronomers determine the orbital speed.







Asteroids, a potential threat

Redirection of potential threats to Earth

DART is a demonstration of the potential redirection of a celestial body should an Earth-threatening asteroid be discovered in the future. To date, there is no known asteroid larger than 140 metres that threatens our planet for the next 100 years, but it is thought that only 40% of those asteroids have been detected. This means that there are tens of thousands near-Earth asteroids, big enough to cause damage to Earth that we do not know about and maybe detected at any point in the future.

In an interview with the BBC in 2014, Jonathan R. Tate, Director of the National Near Earth Objects Information Centre (NNEOIC), also known as the Spaceguard Centre in Knighton, Powys, UK, showed a fragment of the meteorite that fell over Chelyabinsk in 2013.

Video evidence of the undetected asteroid that exploded over Chelyabinsk, Russia on 15 February 2013, causing a shockwave that struck six cities across the country. It was estimated that the asteroid had a diameter of 18 metres and broke down in smaller particles as it travelled at high speed, causing shockwaves that caused extensive damage to nearby towns.


Coverage of a meteor that exploded over Chelyabinsk, Russia on 15 February 2013. Renart 2022.



 



REFERENCES


» APL (2023) From impact to innovation: A year of science and triumph for historic DART mission. [Online video]. Available at APL’s YouTube channel. Accessed: 26 Sep. 2023.
» BBC (2014) Watching the skies for asteroids that could threaten Earth. BBC News. [Online video]. Available at BBC’s YouTube channel. Accessed: 20 Dec. 2021.
» DART (2022) Didymos: The ideal target for DART's mission. DART. [Online article]. Available at DART’s website. Accessed: 26 September 2022.
» DART (2023) Impactor Spacecraft. [Online article]. Available at DART’s website. Accessed: 04 September 2023.
» DART (2022) NASA Confirms DART Mission Impact Changed Asteroid’s Motion in Space. DART. [Online article]. Available at DART’s website. Accessed: 14 October 2022.
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