For the last five years, a spacecraft named Juno has traveled across 1.8 billion miles (2.8 billion kilometers) to arrive at the planet Jupiter. It will be a historic arrival that culminates in a critical sequence of events designed to insert Juno safely into Jupiter’s orbit. As JPL notes: “If the Jupiter Orbit Insertion burn fails to insert the spacecraft into orbit around Jupiter, there will be no science mission.” From The New York Times:

On July 4, as the main engine on the spacecraft fires, in the control room at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., there will be nothing to control, and all anyone there will be able to do is wait and watch.

If anything goes wrong, there is no way for anyone to intercede. The radio signals take 48 minutes to travel from Jupiter to Earth. By the time engineers receive word the engine firing has begun, the engine should have already switched off, with the spacecraft in orbit.

If the engine shuts off prematurely, Juno might still end up in orbit, albeit in the wrong orbit. If the engine fails, “we don’t end up in a very exciting spot…”

Why study Jupiter? When we learn more about Jupiter, we may have a better understanding of how planetary systems form. From Juno principal investigator Scott Bolton, via NYT:

What particularly piques scientists’ interest are the small amounts of heavier elements like lithium, carbon and nitrogen.

“Jupiter is enriched with these elements compared to the sun… We don’t know exactly how that happened. But we know it’s really important. And the reason it’s important is the stuff that Jupiter has more of is what we’re all made out of. It’s what the Earth is made out of. It is what life comes from.”

For context of our technological advancements, watch some Raw Footage of Jupiter from Voyager 1 from 1979. Plus: Take a 360 degree animated virtual tour of our Solar System from Crash Course.