28 U.S.C. § 2109: Quorum of Supreme Court justices absent

If a case brought to the Supreme Court by direct appeal from a district court cannot be heard and determined because of the absence of a quorum of qualified justices, the Chief Justice of the United States may order it remitted to the court of appeals for the circuit including the district in which the case arose, to be heard and determined by that court either sitting in banc or specially constituted and composed of the three circuit judges senior in commission who are able to sit, as such order may direct. The decision of such court shall be final and conclusive. In the event of the disqualification or disability of one or more of such circuit judges, such court shall be filled as provided in chapter 15 of this title. In any other case brought to the Supreme Court for review, which cannot be heard and determined because of the absence of a quorum of qualified justices, if a majority of the qualified justices shall be of opinion that the case cannot be heard and determined at the next ensuing term, the court shall enter its order affirming the judgment of the court from which the case was brought for review with the same effect as upon affirmance by an equally divided court.