Q&A with Keith Gendreau, principal investigator of the first X-ray space communications experiment (members only)

SpaceX’s Falcon 9 rocket is set for liftoff from Cape Canaveral early Tuesday, heading due east over the Atlantic Ocean to deliver the EchoStar 23 communications satellite into orbit 34 minutes later.

Watch the launch of a commercial Falcon 9 rocket carrying a Dragon cargo ship bound for the International Space Station, as seen live on NASA Television.

Russian ground crews working in starkly different environments on the barren steppes of Kazakhstan and in the lush jungles of South America are readying a pair of Soyuz rockets for two launches Thursday, one to resupply the International Space Station, and another to broaden the capacity of SES’s O3b Internet network.