Missions of NASA's Mercury Program, Astronauts, and Spacecraft

Missions of NASA's Mercury Program, Astronauts, and Spacecraft
Page content

From Baby Steps to Record Breakers

Before the U.S. could make a suborbital flight, the Soviets leapfrogged us and put a man into orbit. Uri Gagarin, in Vostok, became the first man in space. He orbited the Earth once, in a spacecraft that weighed more than 10,000 lbs, two and a half times that of Mercury.

There was now a greater urgency to get a man into space.

Finally, NASA was ready. Alan Shepard was picked to be the first to ride the Mercury Redstone-MR-3–on a suborbital jaunt. He named his spacecraft Freedom 7.

On May 5, 1961, MR-3 lifted off, and Navy Commander Alan Shepard became the first American in space. He experienced 5 minutes of weightlessness, and was able to perform every task, including controlling his spacecraft in space.

Freedom 7 reentered and splashed down right on target, with helicopters waiting.

At least the U.S. was on its way.

NASA planned three suborbital flights. The next was flown by Gus Grissom in Liberty Bell 7. A number of modifications had been made to the Mercury spacecraft as a result of Shepard’s experience. The two porthole windows were replaced with a large trapezoidal window that provided a better view for the astronaut. The egress hatch, which had been through the top of the craft, was replaced with an explosive hatch on the side. For Liberty Bell 7, this would prove disastrous.

The explosive egress hatch had blown, and the opening was allowing sea water to pour in. Grissom quickly exited the capsule, but then his

Liberty Bell 7 sinks

suit began filling with water. Heroic efforts by the helicopter pilots saved Grissom, but they could not save Liberty Bell 7. It sank to Davy Jones locker.

Despite the loss of the spacecraft, NASA was satisfied that man could function in space at least for short periods. Then the Soviets kicked us again. Gherman Titov rode Vostok II around the Earth for 17.5 orbits—more than 25 hours.

NASA decided a third suborbital flight was not needed. We needed a man in orbit. Marine test pilot Lt. Col. John Glenn was selected for the honor.

John Glenn as the First American in Orbit

The attempts began on Jan. 27, 1962. Bad weather forced that attempt to be scrubbed. That was only the first of many occasions when Glenn would climb into his Friendship 7 spacecraft, only to have to climb out because of malfunctions or weather.

Glenn enters Friendship 7

Then, finally, on Feb. 20, after further delays to replace a faulty unit, MA-6’s three engines ignited, and the Atlas booster lifted Glenn in Friendship 7 towards space.

“The clock has started,” Glenn reported to Cap Com (capsule communications), as the Atlas soared upwards. The flight proceeded nominally to BECO (booster engine cutoff). As the MA-6 pitched over to orbital insertion angle, Glenn could see the Earth through the big window.

“Oh, what a beautiful view,” he exclaimed.

The spacecraft performed flawlessly until midway through the first orbit. Then a yaw control thruster began sticking, causing Friendship 7 to drift away from its nominal orbital attitude. There was only one solution. The pilot in the cockpit had to take control of his craft. Glenn did, and for the remainder of his three orbits, he flew the spacecraft, proving conclusively that a great pilot is a great pilot whether he’s flying an aircraft or a spacecraft, and man had to be in control of a spacecraft.

But that was not the only problem ground control saw indicated. An indicator on the ground was showing that the heatshield was no longer locked to the craft. If that was actually the case, the heatshield would come off when the retro package was jettisoned, and the spacecraft and Glenn would burn up on reentry.

Ground control told Glenn not to jettison the retro rockets after they were fired. They wouldn’t tell him why, but he had no problem figuring out why. He had no indication in the spacecraft that anything was amiss, but he kept the package on.

As he reentered the atmosphere at 12,000 mph, the plasma fireball we’re all now familiar with enveloped the capsule.

“That’s a real fireball outside,” he reported.

The craft ran out of fuel for the control jets on the way down, but the drogue chute deployed early and stabilized the craft. The capsule splashed down 40 miles short of the pickup ship, but it took the carrier only 17 minutes to reach him.

Glenn had performed flawlessly under great stress, and showed no ill effects from the flight.

Now it was an all out push to learn how to fly in space.

Aurora 7

The next flight scheduled was another three orbit swing. But this one, with Glenn’s experience in controlling the spacecraft, would test the pilot’s ability to put the craft through its paces. Scott Carpenter was selected to fly the mission, and dubbed his craft Aurora 7.

This time the countdown went smoothly, and the flight to orbit was nominal. Carpenter put the capsule through all kinds of gyrations, using both the ‘fly-by-wire’ system and the manual control system. He stood it on end, rolled it over and over, and proved conclusively that a pilot could fly a spacecraft with absolute control.

But he did make one mistake. During his control tests he accidentally activated the automatic control system, so he was using both fuel tanks. He did the same thing when he fired the retro rockets. This would cause some difficulty on reentry.

With both control systems operating at the same time, the spacecraft had the incorrect attitude when the retros fired. The result was that the capsule splashed down 50 miles away from the nearest pickup aircraft. Still, both astronaut and capsule were recovered safely within 3-1/2 hours.

An Extended Tour for Sigma 7

MA-8 would build on the knowledge gained from the first two orbital flights, and orbit the Earth six times. Wally Schirra would pilot his Sigma 7 craft during those nine plus hours, the longest any American had been in space.

MA-8 was a textbook flight. The launch was flawless, and the space craft performed without a glitch.

So did the pilot. Schirra managed his orbital fuel supply superbly. At retro fire, he had 78 percent of his fuel remaining. When the drogue deployed he still had 52 percent in the automatic system.

Splashdown was within sight of the pickup carrier. Wally Schirra did not have to wait.

Gordon Cooper’s Faith 7 Spacecraft

Gordon ‘Gordo’ Cooper had always wanted to fly ‘higher, faster, and farther’ than anyone. He was about to get his chance.

MA-9, once scheduled for 18 orbits, had been upgraded to a 22 orbit 34 hour mission. That would eclipse Titov’s record.

Cooper named his spacecraft Faith 7. On May 5, 1963, the final flight of the Mercury program lifted off from pad 14. Once again, the Atlas booster performed flawlessly.

As did Faith 7—until the 18th orbit. About halfway through that orbit, an indicator light on Cooper’s control panel showed that G forces were building up. This would mean the craft was imperceptibly reentering the atmosphere.

Cooper discounted the light, because everything in the craft was still floating weightlessly. However, on the 21st orbit, a short circuit occurred in a main inverter and all power to the automatic control system was lost. This meant Cooper would have to manually fire the retros, and manually control Faith 7 during reentry.

‘Gordo’ was blasé about that. He was after all flying higher, farther and faster than any pilot ever had.

And under manual control, he splashed down in sight of the pickup carrier.

The Mercury program was at an end. It had proven man was an integral part of spaceflight, and that he could function and survive in weightlessness.

Now, under direct orders from the President of the United States, NASA had to prepare to go to the moon.

Credits

Shepard in Freedom 7: NASA

Liberty Bell 7 sinks: NASA

Glenn entering Friendship 7: NASA

.

This post is part of the series: The Mercury Manned Spacecraft Program

The U.S.’s first manned space program was Project Mercury. Seven Astronauts were chosen to fly the craft, six actualy did. John Glenn was the first American to orbit the Earth. Gordon Cooper was the last to fly in Mercury, orbiting for 22 orbits

  1. NASA’s First Project: The Mercury Redstone Program
  2. Rocket Science - On the Job Training
  3. The Mercury Missions