An enclosed volume is provided for performing operations in space, or on any astronomical object, in a manner separated from aspects of the external environment. The enclosed volume can be a flexible container for a satellite. The enclosed volume can include a membrane having a fluid barrier layer and being configured to contain a propellant gas or fluid; and an expulsion device configured to expel material from the membrane. In a stowed configuration, the flexible container is contained within the satellite, and in a deployed configuration, the flexible container extends away from the satellite. The flexible container can inflate from one shape, in the undeployed configuration, to another shape, in a deployed configuration. The other shape can be toroidal or other appropriate shapes. The flexible container can provide bipropellant, blowdown, and gas/fluid metering functionality. Entertainment and game play can be enabled by the enclosed volume involving robots and other devices.

A robotic vehicle is provided with a novel wheel design and a virtual differential transmission. The novel wheels are generally rounded with scallops along the outer periphery permitting secure engagement of irregular terrain structures, such as the rungs of an inclined ladder. The virtual differential transmission employs rotational sensors in independently driven wheels to maintain information on the relative rotational position of left- and right-side wheels. When necessary, the relative rotational position information is used to selectively drive the left- or right-side wheel until the scallops in a left-side wheel are horizontally aligned with the scallops in a right-side wheel. Thus, the virtual differential transmission can realign the scallops in left- and right-side wheels to facilitate their mutual engagement with a terrain structure, such as a ladder rung.

A drill rig with a steering system may include a substructure having a wheelhouse, a drill floor arranged atop the substructure, a mast extending upwardly and above the drill floor, and a steering system arranged within the wheelhouse. The steering system may include a wheel assembly comprising an electric motor configured for driving rotational motion of a wheel, a deployment device configuring for deploying the wheel assembly to carry the drill rig, and a steering mechanism configured for selective engagement with the wheel assembly and rotating the wheel assembly.

The wheel is all-metal, and is suitable for use on the moon. The wheel includes tread-plates mounted on leaf-springs, which deflect to permit suspension movement. The leaf-springs are flexible, light, and thin, yet are made strong enough to cope with heavy traction forces by the provision of hoop-cables, which link all the tread-plates together.