Q&A with Guglielmo Aglietti, RemoveDebris principal investigator (members only)

Don’t miss riveting slow-motion video of Thursday’s blastoff of four European navigation satellite satellites captured by high-speed cameras at the Ariane 5 rocket’s jungle launch pad, plus dramatic up-close snapshots showing the launcher’s climb into the sky on 2.9 million pounds of ground-shaking thrust.

Video from the SpaceX webcast, featuring the launch of the SES 10 satellite atop a previously-flown Falcon 9 rocket, followed by a successful barge landing by the first stage.

With the flagship-class ExoMars program nearing the finish line after a decade in development, European Space Agency officials want to complete negotiations with the mission’s industrial teams before committing to a 2018 launch date for a European-built Mars rover.