Create a free profile to get unlimited access to exclusive videos, sweepstakes, and more!
NASA’s Lucy mission launched on Saturday, October 16 — and SYFY WIRE was there to see it blast off (check out the video below) on a ULA Atlas V rocket from Kennedy Space Center in Cape Canveral, Florida. It flashed in the sky like a scene out of Thor and is now headed towards Jupiter’s orbit to explore the primordial Trojan asteroids.
Lucy was able to pull off the launch on the very first day of its 23-day window, but what now? The spacecraft will not get close enough to perform a series of flybys on one main-belt asteroid until 2025 and seven Trojans until 2027, and distance is not the only reason, though to give you an idea of around how far from Earth they are, Jupiter itself is about 419 million miles from us. That kind of journey isn’t so easily achievable without a warp drive.
“What makes the Trojans so compelling is that they are fairly easily accessible with a spacecraft,” Lucy Principal Investigator Hal Levison told SYFY WIRE. “If all these ideas we have about solar system formation are true, the most interesting thing that could come out of Lucy is proof.”
Say you’re along for a ride that will end up being at least 4 billion miles until you reach the Trojans. Humans cannot survive the vacuum of space unprotected, but for the sake of a virtual reality experience, imagine being able to take it like a tardigrade. You are now cruising along at about 39,000 mph on a trajectory that will take you around the Sun three and a half times. Eventually, you’ll need a boost, but since no one outside of the Star Trek universe has actually invented a warp drive yet, Lucy will be relying on three gravity assists from Earth.
For about the next year, you’ll find yourself trying to kill boredom as Lucy orbits the Sun, until you realize you’re flying towards Mars. The Martian orbit will accelerate the spacecraft and shift its trajectory towards Earth. Wait — what? No, Lucy won’t exactly be returning to the home planet to hang out. Brace yourself for a sudden turn. Earth’s gravity will change the direction of Lucy’s velocity, though you will still be going about as fast as you were for a while until you find yourself holding on in terror as it speeds ahead, but don’t worry because that won’t last long.
What you just went through was a gravity assist. You won’t have to worry about another one of those for two more years, but after the second assist, you’ll finally be on a legit path to the Trojans by 2024. A year later, the main belt asteroid Donaldjohanson will come into view.
“Donaldjohnason is simply a rehearsal,” said Levison. “We will be passing it between 3.7-6.2 miles per second, and as a result, the upcoming encounters have to work. We have new tech and particularly want to test our ability to have the spacecraft figure out the target it’s flying by to have the imaging stuff pointed at it.”
Named after Donald Johanson, the paleoanthropologist who discovered the hominid fossil Lucy is named for, since the Trojans are considered the “fossils” of the solar system, Donaldjohanson is the smallest object you will encounter on the journey. You’re going to have to wait two more years after that flyby to set eyes on your first Trojan. There are thought to be over a million of these objects in each swarm, and Lucy will be arriving at the swarm trailing Jupiter first. You will be closing in on a grayish hunk of rock. This is Eurybates, orbited by the satellite Queta.
Lucy will gather data from Eurybates and beam it back to Earth before heading onward. It will glimpse one more asteroid in 2027, Polymele. This asteroid is the first one you’ll fly by in the swarm orbiting in front of Jupiter. While Eurybates was chosen because of how much it stands out from the other Trojans, Lucy almost wasn’t scheduled to fly by Polymele or Leucus (which you’ll see half a year later in 2028). Levison and his team added them because they could.
“Leucus and Polymele were added late, but we added them because we had enough fuel to get to them,” he said. “So they weren’t chosen in any real way, but they’re interesting in and of themselves.”
Around seven months after you zoom by Leucus, you will approach a reddish-gray object that is about the same size as Eurybates and also rotating backwards (at least what we perceive as backwards because it rotates in retrograde). This is Orus. It may or may not have a satellite, something that was suspected when it was first imaged by Hubble. Unfortunately, the Trojans are so faint that even Hubble’s unreal telescopic vision cannot really see them as much more than blurry specks in the sky. Keep in mind you might see a smaller object orbiting Orus.
Though they are both fascinating in their own right, and Lucy will have already passed enough tests by making it this far, the Lucy team had decided Eurybates and the darker Orus were the best bet for making sure the spacecraft would pick up the scientific data they expected when it reached the Trojans. Being so similar to each other means that these asteroids will tell scientists back on Earth whether the spacecraft is gathering and processing the same types of data in the same ways. Meaning, its instruments are consistently working and not glitching in space.
“Eurybates and Orus were the first two objects that we decided to study because we wanted to run a control science experiment,” Levison said. “Orus and Eurybates are approximately the same size, and because they are similar in size, that was the idea — we know they’re in the same orbit with same sun exposure, impact, and things like that.”
Bad news. After that, you’re going to have to hold on for another Earth flyby and gravitational assist. At least this won’t happen for another two years after the Orus encounter and is going to the very last one before you’re flung back out towards Jupiter’s orbit one last time. It’s going to be three years until you see anything of interest to NASA, but when you do, this is a target that the Earthbound team is especially anxious to observe. On March 3, 2033, you will pass an orbiting pair of asteroids, Patroclus and Menoetius. That is the grand finale — or is it?
Lucy will probably keep going so long as it has enough fuel to maintain flight. The team is already thinking of proposing a mission extension to NASA, so it could possibly fly by other Trojans that might be keeping secrets of the early solar system we could never imagine. It’s like finding out you get to ride a monster roller coaster again and again without waiting in line. If the timing for the planned targets is right on, others could be added.
“We need to make the best use of every second that we have as we fly by these objects,” Lucy Deputy Principal Investigator Cathy Olkin also told SYFY WIRE. “We made sure we could gather data simultaneously with all three instruments, because time is a precious commodity.”
Too bad Lucy can’t actually take us with it in VR (how awesome out that be?). Maybe someday, we really will be able to virtually ride along with a mission just by putting on a headset.