Solar-Powered Plane Making 24-hour Flight 85
After technical glitches threw a kink in its schedule, Solar Impulse, the solar-powered plane first mentioned here in June, has finally taken off. Reader asukasoryu writes "An experimental solar-powered plane took off from western Switzerland on Wednesday for a 24-hour test flight — a key step in a historic effort to one day circle the globe using only energy collected from the sun. The plane left Payerne airfield shortly before 7 a.m. after overcoming an equipment problem that delayed a previous attempt. Although the goal is to show that emissions-free air travel is possible, the team says it doesn't see solar technology replacing conventional jet propulsion any time soon. Instead, the project is designed to test and promote new energy-efficient technologies." You can follow the flight's progress at the project's site.
re: Only collected from the sun (Score:3, Interesting)
ReNothing new here. (Score:3, Interesting)
The reason I am not impressed is that there is no new technology in the aircraft. We already have solars cells, electric motors,ultralight construction and high aspect ratio sailplanes. A competent aeronautical engineer could have done the design and shown that it could easily work. Sure it is cool but it does not advance technology.
Analysis (Score:3, Interesting)
Now that the flight is over, lets take a look at a few of the numbers from http://www.solarimpulse.com/nightFlights/charts.php [solarimpulse.com].
1. They need a more accurate speed and altitude sensor. There are quite a few spikes in the charts. Some of them have "disappeared". They were probably fixed in the data by averaging.
2. They started with the battery 69% charged.
3. The low point in battery level was 46%
4. It took 7.5 hours to get to full charge.
5. When air temp decreased below 0 the efficiency of the solar cells also decreased dramatically.
6. For a 2.5 hour period when the engine power was at 4% with 0% solar charging the battery charge did not decrease; strange.
7. When the battery was used, it drained at about 10% per hour.
8. The airspeed was about 23kmph most of the time.