1. Critical Timeline for Flight Phase Operations
2. Submission of the Flight Safety Review and Flight Configuration Forms
3. Preparing the RhFET-01 for Flight
4. Planning for Return Shipping
5. Shipping the RhFET-01 to Rhodium
6. Transport of the SSEP Payload from Houston to the International Space Station
7. Operations Aboard the International Space Station
8. Conducting the Ground Truth Experiments
9. Receiving the RhFET-01 After the Flight

1. Critical Timeline for Flight Phase Operations

Given the complexity of transporting science payloads to the International Space Station and the discretionary ability of the agencies involved with spacecraft launch and landing to make schedule changes, all student teams are asked to remain flexible. This page will be updated by the SSEP Flight Operations Team when any new information on launch and landing dates is made public. All flight experiment teams are advised to regularly monitor this page.

Nomenclature: During flight phase operations, milestones on the Critical Timeline below are stated in terms of:

• Handover + XYZ Days/Weeks, counted from the time the student teams hand over their flight ready RhFET-01s to Rhodium for incorporation into the SSEP payload, or Launch Minus XYZ days/hours.
• After landing, the milestones are given in terms of Return to Earth + XYZ Hours/Days.

The Critical Timeline for flight phase operations for SSEP Mission 21 to the International Space Station is provided below. All SSEP student experiment teams are required to abide by the these milestones. These milestones are subject to the very fluid nature of launch operations, and should be viewed as a nominal operations profile that is subject to significant change.

T=0, Handover: Deadline for Rhodium to Receive Flight RhFET-01s from Student Flight Experiment Teams
(RhFET-01s must be loaded with the final fluid/solid concentrations and volumes, and shipped according to the thermal control requirements as defined on the signed Flight Configuration Agreement) 
Once received, Rhodium will log receipt of shipment and photograph each RhFET-01, before loading the RhFET-01s into the SSEP Mission 21 Payload Boxes.
Current Target: TBD

• NO RhFET-01s WILL BE ACCEPTED AFTER THIS DEADLINE 
• The Handover Window (period of time during which Rhodium will accept delivery of flight mini-labs in Houston) is approximately XX weeks. The Handover Window for an October 13, 2026 launch date is XX.
• NET (No Earlier Than) date for RhFET-01s to arrive at Rhodium in Houston is T=0 MINUS XX
  Current Target: XX
• While FedEx can drop off a package on Saturday there will be no Rhodium staff at the office at this time. If the RhFET-01 requires special handling on arrival, e.g., placed in refrigeration, the team should ensure that the it does not arrive on a Saturday (see Section 5 below).

T + XX Days:  NASA Conducts Human Factors Review of the SSEP Mission 21 Payload
Current Target: TBD (Launch Minus Approximately X Days)

T + XX Days: SSEP Mission 21 Payload turned over by Rhodim to NASA for Vehicle Integration
Current Target:TBD (Launch Minus Approximately X Days) 

T +XX Days: SSEP Mission 21 Payload Loaded into Ferry Vehicle
Ferry Vehicle: SpaceX CRS-35 (also known as SpX-35) to the ISS
Current Target:TBD(Launch Minus X Days or Less)

T +XX Days: Launch of SSEP Mission 21 Payload to ISS
Ferry Vehicle: SpaceX CRS-35
Current Target: October 13, 2026

T +XX Days (XX weeks): SSEP Mission 21 Payload Transferred from Ferry Vehicle to ISS
Current Target: TBD

T +XX Days (XX weeks): Ferry Vehicle with SSEP Mission 21 Payload Returns to Earth
Ferry Vehicle: SpaceX CRS-35
Current Target: TBD

Return to Earth + (XX) Hours:SSEP Mission 21 Payload Received and Processed by Rhodium in Houston and RhFET-01 Shipped Directly to Flight Experiment Teams
Flight RhFET-01s are retrieved from Dragon and handed over to Rhodium for processing. As soon as intake processing is complete, Rhodium staff prepares the flight RhFET-01s for shipping per handling requirements specified by each flight experiment team, e.g., thermal control requirements, shipping speed. Note: International experimenters will need to work with NCESSE in advance of return to ensure proper arrangements have been made to meet customs requirements.
Current Target: TBD

2. Submission of the Flight Safety Review Forms and Flight Configuration Agreement

The details regarding the fluids and solids to be used, crew interaction activities aboard ISS, and thermal control requirements during RhFET-01 transport are assessed for each SSEP flight experiment at three milestones during the flight operations phase:

1^st milestone (COMPLETE): immediately after tentative selection of the flight experiment by the Step 2 Review Board, the experiment details from the proposal undergo an internal safety review by Rhodium. Upon completion of that review, Rhodium provides an official ‘go’ for the formal selection of the experiment pending the outcome of NASA’s Toxicology and Flight Safety Review.

2^nd milestone (COMPLETE): after the ‘go’ for formal selection of the flight experiment, students are given an approximate 6-week period to run trials and refine and optimize the experiment details based on the outcomes.   There are no limitations on modifications that can be proposed at this time: samples can be added and/or removed, volumes and concentrations can be increased and/or decreased; and changes to the requested thermal controls during transportation and the crew interaction timeline and interactions are allowed. Upon submission of modification requests, Rhodium’ safety team completes a more in-depth review of the experiment details and the proposed modifications before forwarding them to NASA for Toxicology and Flight Safety Review. NASA Toxicology requires experiment details to be submitted at least 90 days in advance of the projected launch date.

At the completion of this milestone, the fluids and solids to be flown and the maximum volumes/ concentrations of each must be fully determined, and any required safety documents must be submitted.

IMPORTANT NOTE: after submission to NASA Toxicology there are limitations on modifications to experiment samples:
1) there is no ability to add NEW fluids and solids,
2) volumes/concentrations of fluids and solids CAN NOT be increased. Modifications to experiment samples are limited to REDUCING concentrations and volumes (even to 0 thus removing the sample entirely),

In order for Rhodium to meet the deadline for submitting experiment details to NASA for Toxicology and Flight Safety Review the Final Flight Safety Review Forms were completed in March 2026. 

3^rd milestone (COMPLETE): locked to the launch date, this third assessment typically takes place 1.5-2 months before launch and provides the student flight experiment team one final opportunity to propose modifications that may have resulted from continued refinement of the experiment since the 2^nd milestone.  Only minimal modifications, critical to experiment success, are expected at this milestone and all limitations imposed at the 2^nd milestone are still in effect.

Schedule for Submission and Approval of Flight Configuration Agreements

August 4, 2026: Flight Configuration Agreements (FCA) sent to the Teacher Facilitator and Community Program Director(s) for each student flight team.

August 13, 2026: deadline for NCESSE to receive Flight Configuration Agreements with: 1) confirmation that all details are accurate and final; or 2) an email detailing any modification requests. The FCA or a request for modification is to be emailed to the Senior Flight Operations Manager, Stacy Hamel at: stacyhamel@ncesse.org

TBD, 2026:  Rhodium reviews requests for modification and signs the FCAs approving the final flight experiment details.

TBD, 2026: DEADLINE for Flight Configuration Agreements to be signed by the Teacher Facilitator, NCESSE, and Rhodium.

3. Preparing the RhFET-01 for Flight

RhFET-01s Shipped to the M21 Communities

In October 2025 a single RhFET-01 per flight slot (not certified for flight) was shipped to each Mission 21 community. This RhFET-01 was to be used during the experiment design and proposal writing phase as a demonstration of the mini-labs size and operation.

In January 2026 a package of six (flight certified) RhFET-01s per flight slot were shipped to each Mission 21 community.  In addition to the six RhFET-01s, the package contained a small plastic bag containing the valve turn key for opening and closing the mini-lab valves, and four extra )-rings to be used if needed. Each package of 6 RhFET-01s is to be used by the flight experiment team:
– 2 RhFET-01s can be used by the flight experiment team for testing, refining and optimizing their flight experiment;
– 2 RhFET-01s must be set-aside in a safe place to be used , 1 for the actual flight experiment and 1 as a back-up to the flight RhFET-01;
– and 2 RhFET-01s are to be used by the student flight experiment team to conduct their ground control experiments at the same time the flight experiment is conducted by the astronauts on ISS.

• Student flight teams must not load experiment samples into the flight and ground truth RhFET-01s until the Flight Configuration Agreement is approved and signed by all parties AND a “GO” to load is received. The reason, proposed modifications could be rejected, and what is loaded into the RhFET-01 must precisely reflect what is specified on the approved and signed Flight Configuration Agreement or Rhodium will not accept the RhFET-01s for flight, and the flight opportunity will be forfeited. Also, a copy of the signed Flight Configuration Agreement must be included in the box with the flight RhFET-01s that is shipped to Rhodium.  For safety reasons, Rhodium will not handle RhFET-01s that are sent without a copy of the signed Flight Configuration Agreement.
• Student flight teams must ship the complete, flight-ready RhFET-01. Rhodium will not add any samples to the RhFET-01. Shipping of samples that are not inside the flight-ready RhFET-01 will lead to forfeit of the flight opportunity.

4. Planning for Return Shipping

Before a student flight experiment team ships their flight-ready RhFET-01 to Nanoracks, they need to formulate the plan for the return of their RhFET-01 after flight.

Supplies for Special Handling During Return Shipping

If refrigeration is requested during return shipping, Rhodium will provide the materials needed, e.g., cold packs and insulated envelopes. (NOTE: if refrigeration is requested during shipping to Rhodium for Handover in advance of launch, the flight experiment team must provide those materials.)

Return Shipping via Fed Ex

If the flight experiment team wants the RhFET-01 shipped back to them after return to Earth (which has been the case for nearly every SSEP experiment since program inception) a FedEx shipping label must be completed and paid for by the community. FedEx requirements for creating the labels are very time sensitive, so NCESSE will request completion of the return shipping label close to return Earth and while the flight experiment is still onboard the ISS. Rhodium cannot ship the flight RhFET-01s to the student flight experiment team if the FedEx return shipping label is not provided to NCESSE in advance of return to Earth.

Do not complete the return shipping label before it is requested (labels are only valid for a certain amount of time)  and do not include a pre-paid return label with your flight mini-lab shipment to Rhodium in Houston. 

5. Shipping the RhFET-01 to Rhodium

Your flight-ready RhFET-01 must be sent to Rhodium in Houston and must NOT request a signature for delivery. Rhodium will only accept delivery of flight mini-labs during the Handover Window (detailed above). If your flight RhFET-01 is not delivered by the Handover Deadline it will lead to the loss of the experiment slot and flight opportunity.

Handover Window, Current Target: XX-XX
Handover Deadline, Current Target: XX

Rhodium staff will not be on site to accept the package if it arrives on Saturday. Note that the package is being dropped off at a secure facility, so that Saturday delivery is fine if there are no impacted special handling requirements. For example, if you have need for refrigeration, and the package arrives on Saturday, cold packs you shipped with the mini-lab will most likely be exhausted before staff return on Monday. Also note that if you accidentally request signature on delivery, and the package arrives on a Saturday, the package will be placed back on the FedEx truck and might not be re-delivered for a few days. Also note that FedEx does not deliver on Sunday. Work with FedEx so that your package is delivered in compliance with these requirements and constraints.

Other Important Shipping Requirements:

• The Flight Configuration Agreement must be complete and signed by all parties before shipping the flight RhFET-01 to Rhodium. A copy of the Flight Configuration Agreement must be included in the box with the RhFET-01 when shipping to Rhodium.
• All packages must be shipped with tracking and the tracking number must be provided to NCESSE. Tracking numbers should be emailed to John Hamel, johnhamel@ncesse.org. Note: If you use the FedEx website to print your shipping label, in the “E-mail Notifications” section you can specify that emails tracking the progress of the package along the route are automatically sent to you, and you can specify that these emails should also be sent to John Hamel.
• Please note, if the team is shipping to Rhodium with cold packs a special container must be used. Placing cold packs in a box or other non-insulated container will not maintain refrigeration during shipping and your RhFET-01 will arrive warm in Houston.

Ship your flight Mini-Laboratory to:
Rhodium Scientific
c/o XX
XX
XX
XX

Incorporating the Flight RhFET-01s into the SSEP Payload

Once Rhodium receives your RhFET-01, they will log receipt of the shipment, and store the RhFET-01s in their payload processing facility until it is incorporated into the SSEP experiments payload.

While at Rhodum awaiting payload integration and handover to NASA, there are two options for temperature control:
1) storage at room temperature (21-24ºC; 70-74ºF), or,
2) storage in a standard refrigerator temperature (2-4°C; 36-39°F).

Rhodiium will follow the Thermal Control requirements specified by the student flight experiment team on the Flight Configuration Agreement. Rhodium staff will compare their electronic copy of the Flight Configuration Agreement to the hardcopy shipped with the flight RhFET-01, and store flight RhFET-01s accordingly. NOTE: Any written instructions on the shipping box or enclosed documents will be ignored.

6. Transport of the SSEP Payload from Houston to the International Space Station

After the individual flight RhFET-01s are incorporated into the SSEP Mission 21 experiments payload, the entire payload is handed over to NASA. The SSEP Mission 21 experiments payload, designated SSEP23 – Discovery, named for NASA’s Space Shuttle orbiter Discovery.

7. Operations Aboard the International Space Station

The SSEP Mission 21 experiments payload is expected to be delivered to the International Space Station 2-3 days after launch. The payload will return to Earth on SpaceX CRS-35, which is scheduled to undock from the station and return to Earth on TBD.

Experiment Timeline on the International Space Station

The timeline aboard ISS for handling each team’s RhFET-01 is defined in the Flight Configuration Agreement (see Section 2 above). Rhodium will incorporate the Crew Interaction Days and specific crew interactions, as specified on the approved Agreement for each flight experiment, into a master schedule to be followed by astronauts on orbit. The student flight team can only ask for crew interactions with their experiment during the five scheduled Crew Interaction Days. For more information about the way the student teams can specify handling of their experiment aboard ISS, see the section titled: “4. Mixing the Experiment Samples in the FME Once in Orbit, and Astronaut Handling” on the SSEP Mission 21 to ISS: Mini-Laboratory Operation page. Note that the timeline for each experiment will be reassessed once the exact dates for arrival at and departure from ISS, as well as the overall ISS crew schedule, are known. Therefore, the timelines for all experiments remain tentative until they are incorporated into the final ISS work schedule.

Updates to Student Teams on the Progress of Their Experiment

Astronauts will work with the SSEP payload at times of the day that fit best in their overall work schedule. Even though crew interactions with the experiments are to take place on pre-specified Crew Interaction Days, the time of interaction can vary from one Crew Interaction day to the next. While the SSEP flight operations team may know the astronauts’ planned work schedule a few days in advance, we’ll not know exactly when the payload is handled until the task is complete. After the astronauts have completed handling of the SSEP payload, Rhodium will forward a report on the activity to the SSEP program team at NCESSE, and we will then post the details – including the time at which the payload was handled – on the SSEP Mission 21 to ISS: Experiment Log page to make the information available to all student teams as quickly as possible. The report will be posted as soon as it is received, but it may take up to 24 hours for the information from the International Space Station to make its way to the Log. That means, for example, that the details of an activity conducted by the astronauts on the afternoon of a specified Crew Interaction Day will be posted on the Experiment Log no later than the afternoon of the following day (and likely far sooner than that).

8. Conducting the Ground Truth Experiments

Ground truth experiments – the control versions of the experiment conducted on Earth while the microgravity experiment is being conducted in orbit – are an essential part of analyzing the results of the flight experiment. Once the flight experiment returns to Earth, simultaneous harvesting and analysis of both the flight experiment and the ground truth experiments allows the research team to assess the role of gravity in the physical, chemical, or biological system under study. It is hard to imagine how the role of gravity can be determined without ground truth experiments conducted at the same time as the flight experiment.

However, given that it may take up to a day to receive a report on exactly what time of day a specific activity was conducted with an experiment aboard the ISS, the student team may want to shift activities with their ground truth experiments by 1 day (24 hours). That will allow teams to ensure that the timing of activities they carry out on their ground truth experiments accurately reflects the timing of activities with their experiment aboard the station. This is especially important for experiments that are sensitive to exact timing. For example, if a microbiological experiment is likely to produce different results depending on whether it is active for 40 or 50 hours, the teams will want to match the exact timing of the experiment aboard the station with their ground truth experiment.

9. Receiving the RhFET-01 After the Flight

The SSEP payload is scheduled to return to Earth aboard SpaceX CRS-35 on TBD. Dragon splashes down in the Atlantic off the coast of Florida and is then transported by ship back to land where the payload is removed and turned over to Rhodium. Rhodium will then transport the payload back to Houston. Rhodium will process the payload as quickly as possible, so that mini-labs will be ready for shipping to the student flight teams 24-72 hours after landing.