Solely days now stay earlier than a United Launch Alliance (ULA) Atlas V rises from Cape Canaveral Area Pressure Station’s storied Area Launch Advanced (SLC)-41, carrying NASA astronauts Barry “Butch” Wilmore and Suni Williams for the long-awaited Crew Flight Take a look at (CFT) of Boeing’s CST-100 Starliner spacecraft. The pair will spend a minimum of eight “docked” days aboard the Worldwide Area Station (ISS) conducting a variety of flight take a look at targets earlier than returning to a parachute-and-airbag-aided touchdown within the southwestern United States.
After being scrubbed two hours previous to launch—with Wilmore and Williams already aboard the Starliner—on the night of 6 Might, following observations of a defective oxygen aid valve on the Atlas V’s Twin-Engine Centaur (DEC) higher stage, the mission was realigned to fly as quickly as 6:16 p.m. EDT on the seventeenth, earlier than slipping once more to No Earlier Than (NET) 4:43 p.m. EDT on the twenty first, as a consequence of a helium leak in Starliner’s service module that was subsequently traced to a flange on a single response management thruster. When launch does happen, Wilmore and Williams will grow to be the primary people to journey a member of the “Mighty Atlas” rocket household since Undertaking Mercury astronaut Gordon Cooper flew his day-long Religion 7 mission method again in Might 1963.
And they’ll add their names alongside “Unique Seven” luminaries John Glenn, Scott Carpenter, Wally Schirra and Cooper himself to grow to be solely the fifth and sixth folks in historical past to launch atop this most exceptional of rockets. But for a slight accident, two others— Unique Seven veterans Deke Slayton and Al Shepard—additionally got here tantalizingly near flying an Atlas themselves.
As described in yesterday’s AmericaSpace story, 5 Mercury-Atlas missions had been launched with blended success between July 1960 and November 1961, the final of which ferried the chimpanzee Enos on a three-hour, two-orbit mission to trial the skills of the Atlas-D rocket and the Mercury capsule to fly a residing passenger. Within the days after Enos’ protected return to Earth, NASA entered excessive gear for Mercury-Atlas (MA)-6, carrying John Glenn on the US’ first manned orbital flight.
Early on 20 February 1962, after a number of days as a consequence of technical points pertaining to the rocket’s gas tanks and poor climate in Florida, John Glenn boarded the Mercury capsule he had nicknamed “Friendship 7” for the primary historic launch of a person atop an Atlas. Nonetheless, the climate round Launch Advanced 14 at Cape Canaveral that morning proved dicey, promising solely a 50-50 likelihood of acceptability.
Clouds rolled overhead by the point Glenn arrived on the capsule at 6 a.m. EST, however regardless of a handful of points together with a damaged microphone bracket contained in the astronaut’s helmet and a sheared hatch bolt, Friendship 7’s hatch was secured at 7:10 a.m. By the point the pad crew departed the neighborhood of the rocket and blue skies started to appear overhead, Glenn’s pulse various from 60-80 beats per minute and he later mirrored upon the eerie sensation of sitting atop the teetering 94.3-foot-tall (28.7-meter) behemoth.
“I might hear the sound of pipes whining under me because the liquid oxygen flowed into the tanks and heard a vibrant hissing noise,” he mentioned later. “The Atlas is so tall that it sways barely in heavy gusts of wind and, in actual fact, I might set the entire construction to rocking a bit by transferring forwards and backwards within the sofa!”
Lastly, after one other maintain attributable to a caught gas pump outlet valve and {an electrical} energy failure at a monitoring station in Bermuda, the countdown continued. At T-18 seconds, the rely reverted to automated and at T-4 seconds Glenn “felt, moderately than heard” the Atlas-D’s engines ignite, far under.
At 9:47:39 a.m. EST, with a thunderous roar that overwhelmed Capcom Scott Carpenter’s radioed name of “Godspeed, John Glenn”, the Atlas-D’s hold-down posts had been severed and the large rocket started to climb away from Earth. That climb appeared cumbersome, because the 260,000-pound (120,000-kilogram) rocket rose underneath its liftoff thrust of barely greater than 360,000 kilos (163,000 kilograms) from its two boosters and sustainer engine.
“Liftoff was gradual,” Glenn recalled in his 1999 memoir, John Glenn: A Memoir. “The Atlas’ thrust was barely sufficient to beat its weight. I wasn’t actually off till the umbilical wire that took electrical communications to the bottom of the rocket pulled unfastened. That was my final reference to Earth.
“It took the 2 boosters and the sustainer engine three seconds of fireside and thunder to carry the factor that far,” he continued. “From the place I sat, the rise appeared ponderous and stately, as if the rocket had been an elephant making an attempt to grow to be a ballerina.”
For the primary seconds of ascent, the Atlas-D climbed vertically, earlier than its automated steerage system positioned it onto a northeasterly heading, a transition which Glenn discovered noticeably “bumpy”. Forty-five seconds after liftoff, the rocket handed by means of “Max Q”, the interval of most excessive aerodynamic forces—a degree at which the uncrewed MA-1 had catastrophically failed in July 1960.
“It lasted about 30 seconds,” remembered Glenn. “The vibrations had been extra pronounced at this level. I didn’t count on any hassle, however we knew there have been sure limits past which the Atlas and capsule shouldn’t be allowed to go…Since it’s tough for the human physique to evaluate the precise frequency and amplitude of vibrations like this, I used to be unsure whether or not we had been approaching the bounds or not.
“I noticed what regarded like a contrail float by the window and I went on reporting gas and oxygen and amperes,” the astronaut added. “The G forces had been build up now. I strained towards them, simply to verify I used to be in fine condition.”
Efficiently launching and passing by means of the turbulence of Max Q ticked off two of the mission’s 4 main targets. A 3rd was accomplished shortly afterwards when the Atlas-D’s outboard boosters shut down on time, and the central sustainer engine wrapped up Friendship 7’s push to orbit. “There was no sensation of velocity,” Glenn wrote later, “as a result of there was nothing exterior to take a look at as a reference level.”
Two and a half minutes after leaving Earth, at 9:50 a.m. EST, the Atlas-D’s Launch Escape System (LES) tower was discarded, “accelerating [away],” wrote Glenn, “at an amazing clip”. And two minutes after that, the mission’s fourth hurdle—reaching orbit for the primary time with a U.S. human crew—was triumphantly achieved.
“Zero-G,” breathed Glenn as the primary vestiges of weightlessness made themselves obvious to him. “And I really feel effective!”
The ultimate a part of this story will seem tomorrow.
