NASA and ESA team up for world-saving mission
NASA joined forces with its European counterpart, ESA, to build a probe for an asteroid deflection test. The Asteroid Impact & Deflection Assessment (AIDA) mission will test our ability to impact a spacecraft on what could be a hazardous near-Earth asteroid. The target chosen by scientists, nicknamed “Didymoon”, is the natural satellite orbiting the asteroid Didymos.
AIDA will be made up of two “sub-missions”: the ESA-led Asteroid Impact Mission (AIM) and the NASA-led Double Asteroid Redirection Test (DART). DART will impact with Didymoon, AIM meanwhile will assess the mission’s effectiveness in diverting the moon’s orbit around Didymos.
“AIDA will help us gain important knowledge regarding [asteroid] hazard mitigation,” Patrick Michel of the Côte d’Azur Observatory (OCA), the lead of the AIM Investigation Team, told astrowatch.net.
The team carefully selected the target – and is developing the design of the spacecraft that will be sent out to carry out the mission.
“Once we validate our understanding of the impact physics and the kinetic impactor techniques, we can design the next kinetic impactor with a more reliable way,” he added.
The AIM probe is scheduled to be launched in October of 2020 atop a Russian Soyuz 2.1b launch vehicle from the European spaceport located in Kourou, French Guiana. After the launch, followed by a course adjustment deep-space maneuver, AIM will arrive at Didymos in June 2022, some months before DART impact.
After its arrival, the AIM spacecraft will transition into a heliocentric co-flying orbit, from which it will observe the binary system to derive a high-resolution, 3D model of the asteroid, to determine its mass and dynamical state. Scientists will also characterize its surface and shallow sub-surface properties by utilizing an infrared thermal imager and high-frequency radar.
“AIM will provide [the] first direct measurement of the internal structure of a small asteroid. The internal structure of such small bodies is a great source of debates [as] is the outcome of their collisional history, as most bodies [of] this size are fragments of bigger ones. We have various internal structure models but none is complete and has been validated yet, and they all tell us a different story on the formation of binary asteroids and on the Solar System collisional evolution,” Michel said.
This first characterization phase will likely last for approximately two months and should be conducted from a distance between 6 to 22 miles from the asteroid. Following this, the AIM spacecraft will release a number of CubeSats and a lander that is based on the German Aerospace Center’s (DLR) MASCOT lander.
“It will be the first direct interaction of a small lander with a surface in a very low gravitational environment, much lower than comet 67P/Churyumov–Gerasimenko [ESA’s Rosetta spacecraft target],” Michel noted. “This will make us improve drastically our understanding of the mechanical response of a surface in low-g, with implications on our interpretation of surface images and great relevance for a good design of tools aimed at interacting with a small asteroid’s surface.”
The landing of the MASCOT-2 spacecraft on Didymoon will be one of the most difficult tasks that the mission has to complete. The lander should allow for a detailed characterization of the deep interior structure of the asteroid by means of a low-frequency bistatic radar.
“One difficulty with AIM is landing the MASCOT-2 on the small [moon] and Didymoon’s low gravity. It will require the AIM spacecraft getting close, about 650 ft., to the surface of the secondary body,” Michael Küppers, ESA’s Project Scientist for the AIDA/AIM mission, told SpaceFlight Insider.
The CubeSats will assist with observations and will test new science and technology capabilities, including intersatellite communications links in deep space.
The impact of the approximately 700 lbs. (318 kg) DART spacecraft at 6.25 km/s will produce a velocity change on the order of 0.4 mm/s. This will lead to a significant change in the mutual orbit of these two objects, but only a minimal change in the heliocentric orbit of the system.
Approximately two weeks before DART’s impact, the AIM spacecraft will be placed at 60 miles (97 kilometers) from the asteroid for impact observation. According to Michel, AIM will go to a “safe” position during the impact, observing the ejecta curtain and then come closer once the environment is safe to measure the outcome of the collision. It’s also possible that some CubeSats that AIM will deploy before DART impact will observe the event from close range. After the impact, a second characterization phase will close the mission.
“Having such a fully documented experiment, which requires the measurements of the initial conditions with AIM, including both the DART impact conditions and target’s structure, and the outcome, is priceless. It will definitely allow us to either validate our understanding or revise it according to what will happen,” Michel concluded.
The AIDA mission is a joint international collaboration of ESA, DLR, OCA, NASA, and the John Hopkins University Applied Physics Laboratory (JHU/APL).
“The cooperation works excellent on project level as well, with participation of the NASA side in all relevant ESA meetings and vice versa,” Küppers said.
The AIDA collaboration was discussed last week at the European Planetary Science Congress (EPSC) 2015 in Nantes, France. The mission is currently in its conceptual phase.
This is not the first time that NASA and ESA have carried out a joint mission. From their cooperation on the International Space Station (which has 16 partner nations working together) to Cassini, to Hubble and beyond, the duo have partnered on an array of efforts to explore the universe and increase humanity’s understanding of the cosmos.
Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.