- Historic Sites
The Recovery Of ‘aurora’
FLYING TO THE AID OF SCOTT CARPENTER WHEN HE SPLASHED DOWN 240 MILES OFF TARGET
April 2001 | Volume 52, Issue 2
At 7:45 A.M. on May 24, 1962, Aurora 7 blasted off Launch Pad 14 at Cape Canaveral, Florida. The prelaunch countdown had been the smoothest of any American space mission to that date. While some 40 million people watched on television, Lt. Cmdr. M. Scott Carpenter—the fourth American (and sixth human being) in space—began a three-orbit flight.
At the same time, two 12-man crews were preparing to take off in P2V-7 aircraft from the naval station at Roosevelt Roads in eastern Puerto Rico. Their mission was to pinpoint Carpenter’s location when Aurora 7 splashed down in the Atlantic. The scheduled landing point, about 75 miles north of San Juan, was at the center of a 200-mile ellipse running from northwest to southeast along the flight path of the returning capsule. I was the pilot in command of the plane assigned to await the recovery about 50 miles from the northwest end; Lt. Jimmy Hickman’s P2V would wait the same distance from the southeast end. We were at our posts about 90 minutes before the expected time of the splashdown.
While waiting for Carpenter’s arrival, our crews settled into a familiar routine, keeping the coffeepots going and checking out our equipment, chief among it a specially installed SARAH system and our standard APS-20 radar. SARAH (search and rescue and homing) had been developed by the British for rescuing downed airmen. It was a small radio transmitter, about the size of a deck of cards, for Project Mercury flights, placed outside the astronaut’s capsule but inside the re-entry heat shield, while a highly sensitive receiving system had been installed in the P2Vs assigned to recovery missions. APS-20 radar had been designed to seek very small targets on the ocean’s surface, specifically submarine snorkels and periscopes. If SARAH failed, this radar would be used to search for the capsule, the astronaut in a raft, or, in the worst case, debris.
“Until Aurora 7 reached the communication range of the Hawaiian station on the third pass,” the NASA official history tells us, “Christopher Kraft, directing the flight from the Florida control center, considered this mission the most successful to date; everything had gone perfectly except for some overexpenditure of hydrogen peroxide fuel.” This fuel powered the thrusters used to adjust the spacecraft’s attitude with respect to the earth and flight direction. The desired attitude for firing retro-rockets (reverse thrust) to start re-entry into the atmosphere was a 34-degree pitch angle and zero-degree yaw angle—that is, the capsule aligned exactly along the flight path. Aurora 7’s gauges showed 40 percent of its fuel remaining when things started to go seriously wrong.
Carpenter began aligning his spacecraft for re-entry by shifting to automatic mode, but the automatic stabilization system refused to hold the proper re-entry attitude. He frantically tried to determine what was wrong and discovered that he had forgotten to turn off the manual attitude control system, which had needlessly burned thruster fuel for some 10 minutes.
After he got the capsule aligned at what he thought was the right attitude, ground controllers told him to bypass the automatic retro-attitude switch, since the automatic controls were causing trouble. From his seat in Arguello, California, Alan Shepard ordered, “Mark! Fire one.” Carpenter pushed the button to fire the solid-fuel retro-rockets strapped to the heat shield, normally controlled by the automatic stabilization system. Three seconds later, the first rocket ignited, successfully followed by the second and third retros.
The capsule alignment was less accurate than Carpenter had hoped. At close to 25 degrees yaw angle, Aurora 7’s trajectory was severely miscalculated. The craft was set on a landing course 175 miles beyond its planned touchdown point. Moreover, the three-second delay in firing the first retro-rocket added 15 miles, and, although not discovered until later, three retro-rockets had been putting out only about 97 percent of their expected force, thereby adding another 60 miles. Altogether, Aurora 7 was going to land about 240 miles downrange from where the carrier Intrepid was waiting at the center of the ellipse.
A few minutes later, Walter Cronkite told the world about the worrisome situation. “Everyone following the flight by radio or television knew that the spacecraft must be down,” says the NASA history. “But was the pilot safe? What the public did not know was that one P2V airplane [Hickman’s] had received the spacecraft’s beacon signal from a distance of only 50 miles, while another plane [mine] had picked up the signal from 250 miles. Aurora 7’s position was well known to the recovery forces in the area.”
When the SARAH signal came in, we knew that the capsule’s parachutes had opened. Deployment of the parachutes released the heat shield, which in turn allowed SARAH to begin transmitting. So we knew that the capsule had survived re-entry and it was very likely that Scott Carpenter was O.K.
I headed my aircraft toward the spot where Carpenter would splash down, only 4 hours and 56 minutes after he had taken off that morning. We reported receipt of the SARAH signal to the Intrepid , went to full power on our two reciprocating and two jet engines, and flew straight to the capsule.