Lucy Mission to the Trojans Mission
The Lucy mission is a NASA spacecraft that will orbit the Lagrange point of the Earth-Sun system. This mission aims to explore Jupiter's Trojan asteroids, which are located 60 degrees ahead of and behind the planet in its orbit. This is an ambitious project with many goals, including learning more about these objects and their origins and studying how solar winds affect them.
One goal of the LUCY mission is to study these asteroids in greater detail than ever before. The Trojans are grouped into two swarms, known as the Greek camp and the Trojan camp. They probably exist as loose collections of as many as 350 individual bodies per swarm. It is believed that these asteroids were initially part of a larger body called the Didymos asteroid, but at some point, they came together to form their separate groupings.
Mission scientists hope to use LUCY's instruments to answer questions such as:
- What are they made of?
- How many objects per swarm exist, and what is their size distribution?
- What is the nature of dusty material that covers some of the asteroids' surfaces?
- Do Trojan asteroids have rotational periods and influence one another by collisions or mutual forces when close to each other in orbit around Jupiter?
- What is their dynamical relationship with Jupiter, and what role did they play in determining the current orbital architecture of this extensive planet system?
- What can we learn about solar winds from our observations of them at such a great distance from Earth?
- Is there life on any of these bodies, either past or present?
Technology It Uses
Lucy will carry a state-of-the-art ion propulsion system, which is used to thrust the spacecraft through space at a much lower fuel cost than conventional propulsion. The solar-powered ion engine allows for a longer mission duration and can achieve an incredible velocity of up to 90,000 miles per hour or 14 kilometers per second.
This technology has been used on other NASA missions such as Dawn, Deep Space 1, and Stardust, but LUCY's instrumentation makes it possible for the Trojans to be observed more closely than ever before. This new knowledge may lead to an even greater understanding of these objects' origins and possibly even that of our own planet Earth.
Since Lucy will orbit one of the Lagrange points, this orbit has many unique ways of observing the Trojan asteroids. The Trojans are small bodies that remain relatively close to Jupiter. Still, they move slightly out of their orbital plane over time because of their gravitational interactions with Jupiter and the Sun. Lucy will be able to observe these Trojans bypassing behind them as they orbit in front of Jupiter's disk. This allows for a spacecraft-based view free from any atmospheric effects or turbulence caused by Earth's atmosphere.
Additionally, this mission will allow scientists to study solar winds at distances greater than achieved during previous space missions. Solar wind particles impact these Trojan asteroids at speeds 100 times faster than those impacting Mars' surface. The spacecraft will be able to acquire detailed information on the intensity and direction of these solar winds, which may help scientists answer questions such as:
- Is this effect driven by interactions with Jupiter's powerful magnetosphere?
- What is the nature of dust coming from the asteroid surfaces, and how does it compare to other objects in our Solar System?
- How do these dust grains interact with water molecules contained within the solar wind plasma?
- How do these observations compare to observations made by other missions (such as Galileo, Cassini-Huygens, Mars Global Surveyor Mars Orbiter Camera (MOC), Mars Observer, or even Earth-based telescopic studies)?
These questions could lead to a greater understanding of solar wind processes in this region, similar to those occurring on other Solar System bodies.
Will the Mission Be a Success?
Lucy will orbit around Jupiter's Lagrange point L2 using its ion propulsion system to maintain its orbit there for the mission's duration. This location is ideal because it lies along Jupiter's magnetotail, allowing scientists to study how solar particles interact with Jupiter's magnetic field.
At the same time, however, Juno orbits inside this radiation belt to shield all instruments from these harmful conditions at Europa L1 or Ganymede L5. The spacecraft baseline design for Europa has always included shielding around sensitive parts of the spacecraft. Still, Juno's designers had no such luxury, given that Juno must orbit inside the radiation belts.
In Greenbelt, Maryland, NASA's Goddard Space Flight Center will provide overall mission management, systems engineering, and safety and mission assurance. The Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Maryland, will build and operate NASA's Science Mission Directorate in Washington.
APL designed and built the New Horizons spacecraft and operates it now en route to Pluto. Lockheed Martin Space Systems of Denver will build the Lucy orbiter around a modified New Frontiers class spacecraft bus used previously on Juno. In Huntsville, Alabama, NASA's Marshall Space Space Flight Center manages the In-Space Propulsion Technology Program Office for Solar System Exploration within the Human Exploration and Operations Mission Directorate at NASA Headquarters in Washington.