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Sixty-years ago this month, a live biological payload consisting of a primate and a colony of mice was lofted to an altitude of 236,000 feet by a two-stage Aerobee X-8 sounding rocket.  The mission marked the first recorded instance where a mamallian payload survived the rigors of high altitude rocket flight.

The post-World War II period saw a rapid expansion in America’s efforts to explore space.  Emphasis was placed on flying faster and higher.  Rocket power led the way.  First, into the upper atmosphere, and ultimately into the lower reaches of space.

Early post-war flight research capitalized on using V-2 rockets captured from the defeated Third Reich.  These vehicles were brought to America and adapted to boost instruments to high altitude.  While servicable in this new role, the V-2 was less than ideal from the standpoints of launch, performance and payload recovery.

In light of the above, a variety of purpose-built rocket systems rapidly came into being during the post-war years.  Prominent among these was the Aerobee high altitude sounding rocket.  Aerojet General initiated development of the system in 1946.  The first Aerobee test vehicle was flown in November of 1947 at White Sands proving Grounds (WSPG).

The first Aerobee configuration was about known as the X-8.  It consisted of a solid propellant booster and a liquid sustainer.  The booster generated 18,000 lbs of thrust for 2.5 seconds.  Sustainer propellants included aniline and furfuryl-alcohol (fuel) and red fuming nitric acid (oxidizer).  The sustainer rocket engine produced 2,600 lbs of thrust for 40 seconds.

The X-8 launch vehicle measured 26.4-feet in the length with a launch weight of about 1,100 lbs (including 150-lb payload).  The sustainer stage was a little more than 20-feet in length and 15-inches in diameter.  The launch weight of the booster was roughly 50 lbs more than that of the sustainer.

The X-8 was launched from a 143-foot tower which was typically canted 3-degrees off of the vertical.  Booster burnout occurred at 950 ft/sec and 1,000 feet above the ground.  Sustainer burnout took place at 4,420 ft/sec and an altitude of 17-nm.  Apogee was on the order of 66-nm.

The Aerobee carried a variety of scientific instruments to probe the atmospheric and space environments.  Measurements were made of high altitude thermodynamic properties, winds, radiation and magnetic fields.  The Aerobee Program also provided a wealth of information regarding vehicle aerodynamics, flight dynamics and dispersion.

The Aerobee was also used to loft live biological payloads into near space.  At the time this flight research began in the late 1940’s/early 1950’s, very little was known about the effects of high altitude rocket flight on living organisms.  A variety of small animals were used as test subjects including primates, mice, and insects.  The data obtained from these animal flights were ultimately used to safely launch men into space.

History records that it was not all that easy to rocket animals into space and have them survive the experience.  Animals died either due to the rigors of rocket flight, launch vehicle failure or recovery system malfunction.  Sometimes everything worked, but an animal died due to heat exhaustion when recovery crews could not extract it from the downed payload section soon enough.  It would take over 3-years of flight experience before success was achieved.

The great day came on Thursday, 20 September 1951.  An Aerobee X-8 RTV-A1 served as the launch platform.  The live biological payload consisted of a monkey named Yorick and a colony of eleven (11) mice.  The launch took place at 15:31 UTC from Holloman Air Force Base, New Mexico.  The X-8 carried the monkey and mice payload to an apogee of 236,000 feet.  The parachute recovery system finally worked.  Recovery was also successful.

Many more successful Aerobee animal flights took place in the ensuing years.  Even as Aerobee rocket performance increased significantly as numerous variants of the X-8 were developed over the life of the program.  Indeed, almost 1,100 payloads were lofted into the realms above by the time the Aerobee was taken out of active service in 1985.

Posted in Aerospace, History

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