Solicitation Number: NNH19ZDA010O

NASA’s Science Mission Directorate (SMD) is releasing the 2019 Announcement of Opportunity (AO) for Discovery Program mission investigations. The Discovery Program conducts Principal Investigator
(PI)-led space science investigations in SMD’s planetary programs under a not-to-exceed cost cap for the PI-Managed Mission Cost (PMMC). Discovery Program investigations must address NASA’s planetary science objectives as described in the 2018 NASA Strategic Plan and the 2014 NASA Science Plan. Both documents are available at:

The full text can be found at

The time frame for the solicitation is intended to be:

Release of final AO: April 1, 2019
Preproposal Conference (target): April 26, 2019
Electronic Proposal Submittal Deadline: July 1, 2019, 11:59 p.m. EDT
Step-1 Selections Announced (target): January 2020
Phase A Concept Study Reports due (target): November 2020
Downselection of Investigation for Flight (target): April 2021

Launch Readiness Date: July 1, 2025 through Dec. 31, 2026 and/or July 1, 2028 through Dec. 31, 2029

Questions/comments to Dr. Thomas Wagner (
Indicate in the email’s subject line: “Discovery AO 2019”.

Visit the 2019 Discovery Program Acquisition Website at: