On Wednesday, one of the Republican space policy leaders most consistently opposed to commercial heavy lift rockets over the last decade—as an alternative to NASA's large SLS rocket—has ...

Nasa says the SLS is "the only rocket that can send Orion, astronauts, and cargo directly to the moon in a single launch." But its expense has been criticized: each SLS launch is estimated to cost ...

Plus as Kip explains, solid rocket motors offer a higher propellant density, meaning you can get more energy into a smaller vehicle. For MESOS, Kip says he used a propellant known as ammonium ...