Information to be determined is in RED TEXT below.
Information that is subject to change is in GREEN TEXT below.
Last update of this page: October 22, 2026 at 11:57 am ET
Payload Ferry Flights and ISS Crew Data
Ferry Vehicle to ISS: SpaceX CRS-35
Current Launch Date: October 13, 2026 at 6:33 am ET (useful reference NASA Consolidated Launch Schedule at nasa.gov)
Crew: none
Launch Site: Space Launch Complex (SLC) 40, Cape Canaveral Space Force Station, FL
Berthing at ISS: October 15, 2026 at 10:27 am ET
Launch Date History:
Initial Launch Date: August 2026
Rescheduled to: NET October 2026
Ferry Vehicle for Return to Earth: SpaceX CRS-35
Crew: none
Unberth/Landing Date: TBD
Landing Site: splashdown likely off Florida coast
Payload Duration on ISS: nominally 4-6 weeks; expectation 4 weeks
Notable: visit the NASA ISS website for a comprehensive overview of ISS construction, on-orbit research, operations, crews, and multimedia galleries; read about the SpaceX Falcon 9 rocket and Dragon spacecraft
ISS Crew for SSEP Mission 21 Payload Operations: Expedition 75 (see Expeditions Schedule at nasa.gov)
Commander Pyotr Dubrov (Russia); Flight Engineer Anil Menon (USA; X: @astro_anil); Flight Engineer Anna Kikina (Russia); Flight Engineer Jessica Watkins (USA; Instagram: astro_watkins; X: @astro_watkins); Flight Engineer Luke Delaney (USA); Flight Engineer Joshua Kutryk (Canada; Instagram: astro_kutryk); Flight Engineer Sergey Teteryatnikov (Russia)
SSEP Mission 21 to ISS: Payload and Program Data
Payload Designation: SSEP23 – Discovery, named for NASA’s Space Shuttle orbiter Discovery. Starting with Mission 19 to ISS, SSEP experiment payloads are named for the orbiter vehicles from the NASA Space Shuttle Program. (For SSEP Mission 16-18, experiment payloads were named for NASA’s robotic lunar exploration programs in advance of the Apollo missions; for SSEP Missions 12 to 15, experiment payloads were named for NASA human spaceflight programs; for SSEP Missions 5 to 11, experiment payloads were named for Apollo Command Modules; prior to Mission 5, payloads were named for Apollo Lunar Modules.)
Number of Student Team Flight Experiments: 17
20 communities are participating in SSEP Mission 21 to ISS
20 flight experiments were selected, with 20 communities each flying 1 experiment
Payload: Suite of Flight Certified Rhodium RhFET-01 mini-laboratories
History:
The 23rd SSEP flight opportunity—SSEP Mission 21 to the International Space Station—was announced by the National Center for Earth and Space Science Education (NCESSE) and the Arthur C. Clarke Institute for Space Education on May 14, 2025, with accompanying Video Clips describing SSEP by Center Director, Dr. Jeff Goldstein: Clip 1 (NASA), Clip 2 (NASA)
Current Status:
Flight experiments are currently being conducted on the ISS.
A List of Important SSEP Mission 21 to ISS Subpages:
SSEP Mission 21 to ISS: Critical Timeline
SSEP Mission 21 to ISS: Mini-Laboratory Operation
SSEP Mission 21 to ISS: Mission Patch Art and Design Competition
SSEP Mission 21 to ISS: Flight Operations