As United Launch Alliance (ULA) counts right down to a revised No Earlier Than (NET) goal of 4:43 p.m. EDT Tuesday, 21 Could for the long-awaited Crew Flight Take a look at (CFT) of Boeing’s CST-100 Starliner, NASA veterans Barry “Butch” Wilmore and Suni Williams are primed to turn into the primary people to launch atop a Mighty Atlas rocket since “Authentic Seven” Mercury astronaut Gordon Cooper flew his day-long Religion 7 mission in Could 1963. Following launch from Cape Canaveral House Pressure Station’s storied House Launch Complicated (SLC)-41, Wilmore and Williams will spend at the least eight “docked” days aboard the Worldwide House Station (ISS) conducting a spread of flight check goals earlier than returning to a parachute-and-airbag-aided touchdown within the southwestern United States.
In turning into the primary individuals to experience an Atlas rocket in additional than six many years, Wilmore and Williams will add their names alongside Venture Mercury luminaries John Glenn, Scott Carpenter, Wally Schirra and Gordon Cooper. And however for a slight accident, two others—fellow “Authentic Seven” veterans Deke Slayton and Al Shepard—additionally got here tantalizingly near flying an Atlas themselves.
As is likely to be anticipated, the Atlas-D of the Venture Mercury period was a far cry from the mammoth Atlas V of at the moment. Standing 94.3 ft (28.7 meters) tall, the rocket that lofted Glenn, Carpenter, Schirra and Cooper had a mass of 260,000 kilos (120,000 kilograms) and a liftoff thrust of barely over 360,000 kilos (163,000 kilograms). Examine that to at the moment’s Atlas V—with its Widespread Core Booster (CCB), Twin-Engine Centaur (DEC) higher stage and pair of Aerojet Rocketdyne-furnished AJ-60 strap-on solid-fueled boosters—and a completely totally different beast emerges: a beast that stands 172 ft (52.4 meters) tall, weighs 1.3 million kilos (590,000 kilograms) and rises from Earth beneath a ground-shaking 1.5 million kilos (725,750 kilograms) of thrust.
Atlas originated in 1946 as an Air Pressure-led idea for America’s first Intercontinental Ballistic Missile (ICBM) and preliminary research have been awarded to Convair Corp. of San Diego, Calif., which led to Venture MX-774, described as “a form of Americanized” model of Nazi Germany’s notorious V-2 missile. Its novel design would management the rocket by swiveling its engines, utilizing hydraulic actuators that responded to instructions issued by gyroscopes and an autopilot operate.
Positioned on a again burner for a number of years by President Harry S. Truman, the ICBM effort earned the moniker “Atlas” in 1951 and by the center of the last decade Convair was deeply entrenched within the particulars of the brand new missile. Its airframe (nicknamed “gasoline bag”) utilized stainless-steel sections thinner than paper and rigidized by helium pressurization.
The outcome was a pointy discount within the ratio between the Atlas’ construction and weight: its “empty” weight was lower than two % that of its propellant weight and but the airframe as an entire remained able to withstanding excessive aerodynamic masses. In the meantime, a three-engine design for the missile—with two boosters and one “sustainer”, along with small verniers—was developed by the Rocketdyne Division of North American Aviation.
In its Venture Mercury incarnation, the Atlas-D, the rocket’s airframe benefitted from a thicker, sturdier pores and skin and employed radio-inertial steering programs to detect aerodynamic forces and calculate and alter its positioning, velocity and route. And in December 1958, the House Process Group (STG) at NASA’s Langley Analysis Middle (LaRC) in Hampton, Va., formally chosen Atlas as its launch automobile of alternative for Venture Mercury’s manned orbital missions and ordered 9 flight models.
Its maiden suborbital flight with an uncrewed Mercury capsule hooked up—often called Mercury-Atlas (MA)-1—took flight from Cape Canaveral’s Launch Complicated 14 at 9:13 a.m. EST on 29 July 1960. The early a part of ascent proceeded with out incident, however a minute after liftoff the strain differential between the rocket’s liquid oxygen and gasoline tanks instantly ran to zero and get in touch with was misplaced.
Cloud cowl over the Cape that morning was so thick that visible and photographic proof was virtually unattainable, however telemetry knowledge indicated that the Atlas’ partitions had ruptured because of vibrations arrange by mechanical resonance within the adapter linking the rocket and the Mercury capsule. The stack reached an altitude of 8.1 miles (13 kilometers) earlier than descending to influence the Atlantic Ocean; astonishingly, the Mercury capsule maintained its structural integrity and was recovered (although crumpled) from the water.
A stainless-steel reinforcing “belly-band” was applied and the adapter stiffened as a part of corrective steps and MA-2 obtained underway at 9:12 a.m. EST on 21 February 1961. It ascended to 114 miles (183 kilometers), after which the uncrewed Mercury capsule separated and carried out a ballistic re-entry and splashdown within the Atlantic Ocean.
9 weeks later, at 11:15 a.m. EST on 25 April 1961, MA-3 rose from Earth carrying an digital model able to “inhaling” and “exhaling” man-like portions of gasoline, warmth and water vapor. However the Atlas suffered a transient voltage challenge throughout ascent, which prompted it to fail to correctly execute its pitch and roll program maneuvers.
“The roll and pitch program usually modified the preliminary vertical trajectory of the launch right into a extra horizontal one that might take the Atlas out over the Atlantic,” wrote legendary NASA flight director Gene Kranz in his memoir, Failure Is Not An Possibility. “The Atlas was nonetheless inexplicably flying straight up, threatening the Cape and the encompassing communities.” The booster was remotely destroyed by the vary security officer at 43 seconds after liftoff, however astonishingly the MA-3 capsule survived and splashed into the Atlantic Ocean in such good situation that it was reused for the subsequent mission, MA-4.
In readiness for MA-4, the flight-proven capsule was meticulously cleaned, repaired and its warmth protect was changed. At 9:04 a.m. EST on 13 September, the Atlas delivered MA-4 to orbit and succeeded the place its predecessor had so dismally failed.
And on 29 November, the chimpanzee Enos was blasted into orbit aboard MA-5 to guage the Mercury capsule’s life-support programs and the Atlas’ personal efficiency with a dwelling passenger aboard. Enos, who owed his title to the Hebrew phrase for “man”, had undergone 1,250 hours of coaching, together with psychomotor preparations and parabolic plane flights, to prepared him for his mission. Talking shortly after liftoff, President John F. Kennedy drew laughs from the Senate when he introduced that the just-launched Enos “experiences that every little thing is ideal and dealing effectively”.
The Atlas efficiently positioned MA-5 and Enos right into a exact orbit with an apogee of 147 miles (237 kilometers) and a perigee of 98.8 miles (159 kilometers). Initially supposed to finish three orbits of Earth—the identical as was deliberate for astronaut John Glenn on MA-6, the Atlas’ first manned mission—MA-5 skilled issues with its attitude-control system and compelled flight controllers to terminate the flight after two orbits.
Enos’ flight was removed from wrinkle-free, nonetheless, and the beleaguered chimp weathered failures along with his ship’s environmental management system and the temperature of his strain go well with climbed to an uncomfortable 38.1 levels Celsius (100.6 levels Fahnreheit). On-board tools failures additionally meant that poor Enos was “rewarded” for working the proper controls not with banana pellets, however with electrical shocks…
Blooded and described as “excitable” when he was rescued, the flight of Enos quickly pale as NASA ready to launch Glenn as early as 19 December on the primary manned Atlas mission. Sadly, a collection of technical points pertaining to the MA-6 capsule pushed the launch into January 1962 on the earliest.
However the issues remained and few have been beneath any illusions that Glenn’s flight can be problem-free. “John Glenn goes to experience on that contraption?” famed rocket engineer Wernher von Braun remarked. “He must be getting a medal only for sitting on prime of it earlier than he takes off!”
The second a part of this three-piece story will seem tomorrow.
