My bet is that I’m not the only one who unplugs his cellphone from the charger and quietly says, “Eject Mercury umbilical…” It was sixty years ago today (February 20, 1962) that launch director Thomas O’Malley gave that order just prior to the launch of Friendship 7. The following is an excerpt from my book, "Growing Up With Spaceflight- Project Mercury." There are some Hollywood myths that have grown upon the history of that flight like warts. The most recent wart was from the movie “Hidden Figures” where it is shown that Glenn is waiting for one of the female “computers” to come up with definitive orbital calculations before he’ll board the spacecraft. Nonsense and dramatic dribble, yet if it was in the movie it has to be true… right? Just like the shot of his stage separation that shows the fin can of a Mercury Redstone dropping away. Both are equally accurate. Likewise, the soap opera “The Right Stuff” TV docudrama from 2020 shows Deke Slayton being informed of his being medically grounded before Glenn’s mission. In fact, his Delta 7 spacecraft was being readied after the Friendship 7 flight when they broke the news to Deke. Someday Hollywood may do a program about project Mercury written by someone who actually knows the history of the program, but don’t hold your breath.
-Wes Oleszewski
As the countdown drew into its final
seconds, Mercury astronaut Scott Carpenter could be heard on the voice loop
saying "Godspeed John Glenn." For Carpenter it was a brief, vocalized
prayer for the well-being of his friend and fellow astronaut. If such were to
occur today, however, sadly the person who spoke the words on a "government"
radio would likely end up being sued by an atheist.
Finally just 39 seconds after 9:47 a.m. the
count reached zero.
The ignition sequence for the Atlas-D booster involved the light off of the two Vernier steering thrusters on the sides of the vehicle followed less than one second later by the ignition of the three main engines. Although official documents state that liftoff occurred "… about T+4 seconds after ignition," examination of historic video appears to show liftoff initiated around 6.7 seconds after ignition. The precise moment of liftoff was probably not a large concern aboard FRIENDSHIP 7 that morning. What John Glenn was focused on was following to-the-letter the procedures that he and his fellow astronauts had written for the launch phase of the Atlas booster.
Glenn was well aware of the concerns
that many engineers had about the Atlas booster itself. One such concern was
his passing through the area of maximum aerodynamic pressure on the vehicle, or
“Max-Q.” It was the area of boosted flight where the previous Mercury Atlas,
MA-2, had failed. Glenn’s dilemma was that Max-Q and the sound barrier are
normally relatively close to one another along the Mercury Atlas flight profile. The
transonic region just happened to be an area where the maximum cabin noise and
vibration took place on the Mercury Atlas. Dutifully, John Glenn reported that
vibration by saying,
"… Have some vibration area coming
up now." Then 28 seconds later he considered what he had just said and
decided to reassure those on the ground, some of whom had their finger on the
command destruct button.
"We’re smoothing out some now, getting
out of the vibration area," he reported.
At 00:02:09 into powered flight the two
outboard booster engines shut down and were jettisoned. This point in the
Atlas’ launch was known as “BECO,” or Booster Engine Cutoff. The remaining
engine, known as the sustainer engine, continued to burn for the remainder of
powered flight. John Glenn then saw some of the plume backflow from the BECO and
mistook it as being his escape tower jettisoning. Some 25 seconds after the
booster engines separated he witnessed the actual automatic jettison of his
escape tower. Overall powered flight lasted for five minutes and one second.
CAPCOM Alan Shepard called FRIENDSHIP 7
and announced,
“You are go for at least seven orbits!”
Although he had been cleared for "…
at least seven orbits," John Glenn's flight duration, according to the
official NASA “News Release” of January 21, 1962 was planned for “… a one, two
or three-orbit mission.” Although many accounts of Glenn’s return after three
orbits rather than seven imply that the mission was cut short due to a problem
with a heat shield indication, the fact is that the mission was planned for
just three orbits. The extra four orbits were simply a contingency in case the
spacecraft could not be brought down on orbit number three due to some
unexpected problem. CAPCOM’s term “at least” was likely just Shepard
misspeaking the clearance which should have been stated as, “a maximum of seven
orbits,” which was actually what was in the flight plan.
Every ear in the free world and
countless ears behind the Iron Curtain were glued to their radios as FRIENDSHIP
7 orbited the Earth. They listened intently as Shorty Powers described the flight
and as radio reporters reinterpreted his words. There was the universal feeling
being that "we" finally have a man up there. Now the distinction
became obvious that the difference between the United States flying an
astronaut and the Soviet Union flying a cosmonaut was that NASA conducted its
flights under the glaring scrutiny of the news media and the full view of the
public, while the Soviets conducted their flights under the shroud of
totalitarian secrecy.
By the beginning of his
second orbit Glenn was dealing with a persistent problem with a yaw thruster
that was becoming something of an annoyance. A potentially more dangerous
problem, however, was being indicated by the telemetry system. The
"segment 51" sensor was indicating that the capsule’s landing bag had
deployed. Folded accordion-style between the heat shield and the capsule’s aft
bulkhead, the landing bag was designed to pop out after reentry and act as both
a cushion and the sea anchor at splashdown. If the indication was valid, John
Glenn's capsule would burn up on reentry. A firestorm of phone calls and loop
communications discussing this issue took place following its initial reception
by the Bermuda "TM" controller. Glenn had not a hint of the problem
until the 02:00:47 point in the mission.
It was then that the
Canton Island CAPCOM simply said "We also have no indication that your
landing bag might be deployed. Over."
To which John Glenn replied "Roger.
Did someone report landing bag could be down? Over."
The CAPCOM then blew it off by replying
with “Negative we had a request to monitor this and to ask if you've heard any
flapping, when you had high capsule rates…"
John Glenn then went on with his very
busy work schedule paying little mind to the landing bag reference. Meanwhile
at Mercury Control the serious debate was being waged between those controllers
who felt that the Segment 51 signal was erroneous and should be ignored and
those in NASA management who thought the best plan of action would be not to
jettison the retro rocket package after retro-fire. The retro rocket package
was held on to the heat shield and the spacecraft by three straps. Management
felt that those straps may hold on just long enough to keep the heat shield in
place.
There are a lot of accounts written by
different individuals who were there at that moment in history when the flight
of FRIENDSHIP 7 appeared to be in jeopardy. There are a lot of documentaries
that have been created about that moment in history as well. Yet in most of
those no one specifically says exactly who it was that came up with the idea to
leave the retro package attached. In the largely fictitious movie "The
Right Stuff." a German rocket scientist is shown holding a Mercury capsule
and discussing the options. Just for the sake of reality and considering how
steeped most of us are in pop culture, it is important to note that aside from
a few launch pad operations there largely were no German rocket scientists
involved with the Mercury capsule itself. In fact, the one individual leading
the charge for the retro package solution was the developer of the
Mercury capsule; Max Faget (pronounced Fah-jay). An original member of the Space Task Group, he
carried tremendous weight in the Mercury Program. According to Gene Kranz’s
terrific book “Failure Is Not an Option,” reentry with the retro package
remaining attached to Glenn’s capsule was Faget’s idea. Considering Faget’s
influence as being the father of the Mercury Capsule, it is fair to conclude
that Kranz’s version of the story is the closest to being factual.
On the third orbit FRIENDSHIP 7 came
into ground contact with the Hawaii station at the 04:21:00 mark of the
mission. Just one minute and 45 seconds later the CAPCOM informed John Glenn of
the full nature of their concern,
"FRIENDSHIP 7, we have been reading
an indication on the ground of Segment 51, which is landing bag deployed. We
suspect this is an erroneous signal. However, Cape would like you to check this
by putting the landing bag switch in auto position, and see if you get a light.
Do you concur with this? Over,"
Glenn replied, "Okay. If that's
what they recommend, will go ahead and try it. Are you ready for that now?"
From that point on John Glenn was
actually brought into the loop concerning the problem the ground controllers
had been studying for more than an hour and a half. Dutifully Glenn moved the switch
into the auto position.
"Negative, in automatic position,” He
then reported, “did not get a light and I'm back in the off position now.
Over."
No one really knew for certain whether FRIENDSHIP
7 would survive reentry. And although contemporary documentaries and movies may
depict an agonizing length of time that John Glenn had to contemplate the
problem, in fact, just 20 minutes and five seconds separated his notification
by ground controllers and reentry blackout. At 04:42:50 into the flight FRIENDSHIP
7 began entry interface. Against the judgment of flight controllers, NASA management
had elected to use an untested procedure based only on the Segment 51 indication.
They ordered the retro package to be left on FRIENDSHIP 7’s heat shield. It was
their hope that the landing bag would remain attached through the majority of
the four minute reentry. In fact, from Glenn’s real-time reports, the retro
pack remained attached for just the first 24 seconds of the reentry.
Following the reentry FRIENDSHIP 7
simply dropped through the atmosphere to a little more than 70,000 feet. It was
kept stable during that time by the constant firing of the reaction control
system jets. Finally, at an altitude of 30,000 feet, the drogue chute
automatically deployed. This small parachute was designed to stabilize the
capsule as it descended into the thicker atmosphere. The final step in the
parachute sequence came passing through 11,000 feet with the release of the
main parachute.
"Chute is out, in reefed condition
at 10,800 feet," Glenn reported and then exclaimed gleefully, "and
beautiful chute!"
Exactly 12 seconds after deployment of
the main parachute the landing bag that had caused so much worry prior to reentry
deployed normally. For the next five minutes and 10 seconds FRIENDSHIP 7
floated gracefully to the surface of the Atlantic Ocean where it splashed down
and was safely recovered later by the Navy destroyer USS NOA.
