42 U.S. Code § 18323 - Multi-purpose crew vehicle
(a) Initiation of development
(1) In general
The Administrator shall continue the development of a multi-purpose crew vehicle to be available as soon as practicable, and no later than for use with the Space Launch System. The vehicle shall continue to advance development of the human safety features, designs, and systems in the Orion project.
(2) Goal for operational capability
It shall be the goal to achieve full operational capability for the transportation vehicle developed pursuant to this subsection by not later than December 31, 2016. For purposes of meeting such goal, the Administrator may undertake a test of the transportation vehicle at the ISS before that date.
(b) Minimum capability requirements
The multi-purpose crew vehicle developed pursuant to subsection (a) shall be designed to have, at a minimum, the following:
(2) The capability to conduct regular in-space operations, such as rendezvous, docking, and extra-vehicular activities, in conjunction with payloads delivered by the Space Launch System developed pursuant to section 18322 of this title, or other vehicles, in preparation for missions beyond low-Earth orbit or servicing of assets described in section 18383 of this title, or other assets in cis-lunar space.
(3) The capability to provide an alternative means of delivery of crew and cargo to the ISS, in the event other vehicles, whether commercial vehicles or partner-supplied vehicles, are unable to perform that function.