each case of a contract for a service into which the Secretary enters under subsection (a) that would result in the Department incurring an obligation of more than $2,000,000,000, not later than 20 days after the date of the contract award, the Secretary shall submit to the Committee on Veterans’ Affairs of the Senate and the Committee on Veterans’ Affairs of the House of Representatives— (1) a justification of the need for the contract, including an explanation of why the Department is unable to perform the service