The text of Program Element C.18, Laboratory Analysis of Returned Samples, has been corrected to remove an ambiguity in the text regarding the Step-1 proposals. Proposals to this program will be taken by a two-step process in which the Notice of Intent is replaced by a required Step-1 proposal submitted by an organization Authorized Organizational Representative. However, this year no PDF upload is required for the Step-1 proposals in this or any program in Appendix C. Step-1 proposers merely must fill in the Proposal Summary text box on the NSPIRES cover pages. Only proposers who submit a Step-1 proposal are eligible to submit a Step-2 (full) proposal. See Section 6 for details. New text is in bold and deleted text is struck through. The due dates remain unchanged: Step-1 proposals are due April 24, 2015 and Step-2 proposals are due June 26, 2015.