The Last Water Launched Sounding Rocket

The Long Night

There it was in the middle of the night, a sounding rocket and launcher, bobbing up and down in the ocean, hundreds of miles off the Southern California coast. The first Hydra-Sandhawk water launched sounding rocket was finally ready for launch. The sounding rocket had been deeply submerged in seawater for about 10 hours. The rocket, its launch control system and a sensitive payload were being tossed around from the waves of a heavy sea state two, while attached to its launcher.

Scientists, engineers and technicians from the Lawrence Radiation Laboratory and the Naval Missile Center stood huddled in the portable launch control hut that was securely attached to the fantail of the USS Norton Sound (AVM-1. The short countdown had begun.

The ship’s personnel were hoping for quite a pyrotechnic show as they kept the ship a mile or two from the Hydra-Sandhawk. The midnight ocean was pitch black and the floating launcher’s two bright strobe lights were all but invisible. Five… four… three… two… one… launch! The launch command was given to the launcher. But wait, no brilliant white light from the booster. Nothing happened!

The last thing the designers wanted was for this sounding rocket to be launched 20 degrees off vertical. So, some launch delay was expected. It took time for the rocking launcher’s  gyro’s pitch rate and position data to indicate that the rocket and launcher were positioned properly in both axes. Vacuum tubes in the launcher’s fire control system should then start the ignition sequence of the big NOTS 401A booster as the sounding rocket was rotating into the vertical of both its axes.

30 seconds went by. Damn! Still nothing happened and nothing could be seen for miles out on the black horizon. It should have gone by now if it was ever going to go. Eyes strained to see the booster’s bright exhaust, or at least see the distant strobe lights. Waves had been increasing all evening. Maybe the strobe lights couldn’t be seen because of the wave height, but there was no way that anyone would miss seeing hundreds of pounds of solid propellant burn in two seconds of booster motor operation.

Maybe the heavy sounding rocket had broken free of its delicate launch restraint mechanism due to hours of wave caused banging and pulling. That restraint mechanism had never been real world tested. Maybe the big, two-stage rocket and its sensitive X-Ray astronomy payload were now a mile deep at the bottom of the Pacific Ocean.

A minute went by, then two. Ocean waves can do unpredictable things. After several minutes, many on board began thinking that the sounding rocket had probably broken free and was at the bottom of the Pacific. Even worse, if the rocket’s booster had a “misfire” it would be a very time consuming and risky process to try to retrieve the two stage rocket and launcher. Anyway, it was going to be a long, sleepless night, talking about what may have gone wrong and organizing a retrieval effort, even if retrieval was for just an empty launcher.

A long five minutes had gone by and in total amazement to everyone, a blinding white light was seen from the big NOTS 401A booster’s bright exhaust plume boiling seawater as it came off the launcher. The booster silently clawed its way off the ocean surface as it lifted the heavy Sandhawk and payload to the clouds. The sounding rocket should now be beginning its 175 mile trip up to the edges of space! But, would the staging ignition system and release band mechanism work to properly ignite the Sandhawk? Had 10 hours of saltwater waves shorted out igniters and explosive bolts?

The big NOTS motor created a tall column of white light as it did its job and pushed the sounding rocket a couple of miles up. At several hundred miles an hour, the booster burned out. After that, there was nothing but blackness for what seemed an eternity! Then, as booster motor sounds hit the USS Norton Sound, the Sandhawk ignited and was properly released from its booster. Its long burning, solid propellant motor’s plume stood like a tall white column in the night. The Sandhawk illuminated its way through the clouds and rumbled on to take an X-Ray astronomy payload to the edges of space.