The next Explorer spacecraft is designed, Explorer 7! This spacecraft was designed as a lower cost spacecraft that would require fewer launches to prepare. Previous Explorer spacecraft required two launches: one for the spacecraft and another to deliver crew.
This was largely due to the nuclear fuel component that was part of the Pathfinder-derived vehicles.
The new design features a new Mk10 crew module at the top, which allows emergency escape options on launch. Once in orbit, the crew fires a transfer burn to Duna, then exits the vehicle and climbs from a ladder into the cryogenic stasis chamber. They’ll reverse the procedure once they arrive at Duna Spaceport!
Explorer 7 costs less than 1/10th the cost of the much more versatile and longer range Deep Space Vehicle Discovery, and is more suited to visiting Duna (and possibly Eve) than further flung missions such as Jool and beyond!
The next Duna Mission won’t be for another year – once the launch is closer, a crew will be chosen and a new mission patch will be released!