It was yesterday’s afternoon in the USA when NASA’s Juno spacecraft did a flyby being within 500 km (350 miles) of Earth. This maneuver is part of the complex trajectory that will bring Juno to Jupiter and had the purpose of using the Earth’s gravity to increase its speed enough to reach Jupiter. During that operation, it went unexpectedly into “safe mode” but it seems that it actually has no real problems.

The Juno spacecraft was launched on 5 August 2011 on an Atlas V rocket. The purpose of its mission is to study Jupiter’s magnetic field and the atmosphere. To do all that it was equipped with nine instruments that will measure in various ways many the many electromagnetic emissions of the biggest planet in the solar system and will take photographs.

The probes sent beyond the orbit of Mars must follow convoluted trajectories because they need to make at least a flyby with a planet to exploit the effect of a gravitational slingshot to gain enough speed to reach deep space.

Juno is the first space probe sent to Jupiter to use solar panels instead of radioisotopes generators. The enormous advances in solar energy technologies made this solution possible  despite the fact that Juno will receive only a small fraction os much sunlight as it’s available on Earth.

The environment near Jupiter is really inhospitable also because of the planet’s very strong magnetic field. To protect its electronic circuits, the Juno space probe is equipped with a shield of titanium about a centimeter thick. Despite those protections, it will enter a polar orbit that will allow it to avoid continuous contacts with Jupiter’s magnetosphere.

During the Earth’s flyby, Juno went into “safe mode”, a precaution that occurs when a space probe detects a possible problem. The closure of federal operations in the U.S.A. has also crippled NASA’s activities so there are no official announcements about the event. However, the reduced staff still at work established a contact with Juno making sure that it’s working.

The flyby has produced the desired effects on the trajectory of the Juno spacecraft. Since this is a stressful maneuver, it’s possible that some sensor has detected a potential danger triggering the activation of the “safe mode”. This, however, didn’t affect the maneuver.

Now Juno started the last stage of its journey into deep space. The entrance into Jupiter’s orbit is scheduled for July 2016.

[ad name=”eBayUSUKAstronomy”]