Also , during his stay at General Dynamics , he participated on Project Orion ( nuclear propulsion ) .
The NEXUS reusable rocket was a 1960s concept design by a group at General Dynamics led by Krafft Ehricke .
Also , during Krafft Ehricke 's stay General Dynamics   Dynamics , Krafft Ehricke participated on Project Orion ( nuclear propulsion ) .
The NEXUS reusable rocket was a 1960s concept design by a group at General Dynamics led by Krafft Ehricke .