Mercury-Redstone 4, July 21, 1961 — NASA Audio
During the recovery of the fourth launch and second crewed spaceflight of Project Mercury, Mercury-Redstone 4 (MR-4) Liberty Bell 7, the recovery team discusses a dye pack in the water that did not activate.
Incident Overview
Mercury-Redstone 4, designated Liberty Bell 7, was flown by Virgil “Gus” Grissom on July 21, 1961 — making him the second American in space after Alan Shepard’s flight eleven weeks earlier. Grissom’s sixteen-minute suborbital arc took Liberty Bell 7 to 118 miles altitude before reentry and splashdown in the North Atlantic. The mission itself was largely successful, but the recovery was not. Within minutes of splashdown, the capsule’s explosive hatch blew prematurely while the spacecraft was still in the water. Grissom escaped into the ocean, but the capsule flooded rapidly and sank before recovery helicopters could lift it clear. Liberty Bell 7 descended approximately 15,000 feet beneath the Atlantic surface, where it remained until a private salvage expedition recovered it in 1999.
The audio recording preserved in the PURSUE release captures communications from the recovery operations phase, in which the recovery team discusses a dye pack in the water that failed to activate. Dye packs were deployed by early NASA to mark the landing zone in open ocean, aiding visual acquisition by helicopter and ship recovery crews. The content of this specific excerpt is routine recovery communications rather than a UAP observation. AARO’s preservation of this recording reflects the agency’s mandate to archive the complete audio record of early crewed spaceflight operations, with PURSUE serving as the vehicle for releasing that record publicly. The mission is documented here as part of the government’s commitment to transparency about its aerospace archives, even when — as in this case — the released content does not describe an anomalous phenomenon directly.
What the government released
During the recovery of the fourth launch and second crewed spaceflight of Project Mercury, Mercury-Redstone 4 (MR-4) Liberty Bell 7, the recovery team discusses a dye pack in the water that did not activate.
Status of the case
Records released under the PURSUE program are designated unresolved by the All-domain Anomaly Resolution Office, which means the federal government has not concluded the events were anomalous, has not concluded they were conventional, and has not ruled out either possibility. Where AARO has offered a likely source for an item — an infrared sensor aboard a military aircraft, a commercial camera, or a known optical effect — that attribution is the agency’s working assessment rather than a final determination. Conventional candidates such as drones, balloons, flares, satellites, parallax and forced-perspective artifacts, and ordinary aircraft remain on the table for any unresolved case absent better data than a single sensor pass or a witness recollection.