Inspiration4 (stylized as Inspirati④n) was a 2021 human spaceflight operated by SpaceX on behalf of Shift4 Payments CEO Jared Isaacman.

The trip was the first orbital spaceflight with only private citizens aboard and was part of a charitable effort on behalf of St. Jude Children's Research Hospital in Memphis, Tennessee.

The hospital selected two commercial astronauts: cancer survivor Hayley Arceneaux and military veteran Christopher Sembroski.

The mission overlapped with the 55th anniversary of Gemini 11, which in September 1966 had an apogee of approximately 1,368 km (850 mi), the highest Earth orbit ever reached on a crewed flight until Polaris Dawn in 2024, which was also operated by SpaceX on behalf of Isaacman.

[16][17][18][19] Entrepreneur Sian Proctor was selected by Shift4 Payments to board the flight through a competition modeled after Shark Tank that rewarded the best business idea to make use of Shift4's commerce solutions.

[20] The panelists in the competition included Salesforce CEO Marc Benioff, Fast Company editor Stephanie Mehta, former NASA engineer Mark Rober and Bar Rescue host Jon Taffer.

[27] The cupola was protected during launch and re-entry by the spacecraft's retractable nosecone, which also housed a custom camera, enabling photography of the vehicle's interior and exterior during flight.

[28] Four Draco thrusters on the spacecraft's nose necessitated the installation of four heat shield tiles on the cupola's exterior, which protected the plexiglass dome from engine exhaust during propulsive maneuvers.

The toy, attached to a tether, began to float above Arceneaux's head and in doing so fulfilled its purpose as the Inspiration4 mission's "zero-g indicator".

Hanging in the air, it provided a visual signal to Arceneaux and her three crewmates that they were now in the microgravity environment of outer space after reaching Earth orbit on 16 September 2021.

[34] The mission planned to include ultrasounds, microbe samples and a variety of in-flight health experiments (measure fluid shifts, record ECG activity, blood oxygen levels, heart rates, etc.)

[38] On 18 September 2021, at 23:06:49 UTC, Resilience splashed down in the Atlantic Ocean north of Cape Canaveral and was picked up by recovery ship GO Searcher roughly forty minutes afterward.