Three things you need to know today.
Hatch closed - At 9:19 a.m. ET on Monday, the hatch between the space shuttle Atlantis and the International Space Station will be closed for the final time and the shuttle will prepare for a return to Earth.
Tomorrow, the shuttle will undock from the station and fly around it so visual inspections of both the space station and the shuttle's thermal protection system can be performed.
Atlantis is scheduled to land at Kennedy Space Center in Florida at 7:06 a.m. on Wednesday, bringing an end to three decades of space shuttle flight.
Hot temperatures - A heat wave will continue to roast the country's midsection even as it spreads to the east, according to the National Weather Service.
The hottest spots from Oklahoma through South Dakota should see highs of more than 100 degrees Fahrenheit, and top temperatures are forecast in the 90s for most of the rest of the country - with the exception of some mountain and coastal regions, according to the weather service.
On Sunday, daily temperature records were broken from Alpena, Michigan, south to Miami, Florida.
"Heat index values" - how hot it feels outside - have been running over 125 degrees Fahrenheit in the worst-hit areas, the National Weather Service said. The scale designed to describe how intense heat feels also includes factors such as humidity.
Japan typhoon - Workers in Japan scrambled Monday to build a protective covering over a damaged nuclear reactor ahead of an approaching powerful typhoon, an energy company spokesman said.
Typhoon Ma-on¬† should strike Japan well south of the damaged No. 3 reactor at the crippled Fukushima Daiichi nuclear power plant.
But the Tokyo Power Company, which is responsible for the plant wracked by the March 11 tsunami that struck northeast Japan, is constructing a "roof-like structure to prevent rain from entering holes on the turbine building," spokesman Satoshi Watanabe said.
The energy company says it aims to complete construction late Monday.