Launch Window

Two Mars-bound spacecraft have been just loitering about. They were launched a year ago. But the timing wasn’t right for them to reach Mars. So they were sent to a point in space where the gravity of Earth and the Sun are balanced – a place where they could “loiter.” But now, their time has come. They’ll leave that spot in a few days, beginning their trip to the Red Planet. Escapade consists of two small spacecraft, called Blue and Gold. After they enter orbit around Mars, they’ll measure its magnetic field and its interactions with the solar wind – a flow of particles from the Sun. That will help scientists understand how Mars lost much of its atmosphere. Escapade was supposed to launch several years ago. But there were problems with its potential rides to space, so it kept getting delayed. And if you miss a launch window, it’s a long time until the next one opens. You can’t send a craft to Mars anytime you want. You have to wait for the proper alignment – when Earth and Mars are going to be close together. Otherwise, the distance between them is so great that you just can’t get there. That alignment comes about every 26 months. NASA decided to go ahead and launch Escapade a year early and have the two craft wait in space. They’ll soon fire their engines to nudge them toward Earth. They’ll use Earth’s gravity to kick them toward Mars, with arrival at the Red Planet in September. Script by Damond Benningfield