Here’s what we’re reading and watching Friday:

1) The Solar Impulse flight began Friday. The team is offering a live video feed of mission control, so you can track the flight as it makes its way across the country:

The plane, piloted by Bertrand Piccard, is powered by solar energy and will fly the first leg of its trip from Moffett Airfield in California to Sky Harbor International Airport in Phoenix. A clean-energy promotion initiative called “Clean Generation” is coordinating the start of the mission. The takeoff, scheduled for 9 a.m. Eastern time (6 a.m. Pacific time) was slightly delayed when air traffic controllers determined a new flight plan was needed. Solar impulse has a live map of the flight as well.

Update 10:41 a.m.: If you missed the takeoff, Solar Impulse has posted the video:

2) “Iron Man 3” comes out Friday. According to our colleagues over at Comic Riffs the film is a loud, flashy good time — and, no, there is no “Iron Man” fatigue.

3) The folks over at PSFK have a fun gallery chronicling the design evolution of some of the world’s most popular Web sites.

4) In more serious news, the U.S. economy added 165,000 jobs in April, with the unemployment rate falling to a four-year low of 7.5 percent.

5) And, in other aeronautics news, yes, a helicopter can land on a guardrail. One did in this video, at least:

Have a great weekend!