Launch on Need Daniel Guiteras (interesting books to read .TXT) đź“–
- Author: Daniel Guiteras
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“The wing area to be inspected,” said the CapCom, “is in the vicinity of RCC panels 6 through 9. This is the point where Jan will go over the payload bay door looking for wing damage and, if necessary, Steve will climb down farther to better view the underside of the wing.”
Jan heard her name. How long had Mission Control been talking, she wondered, and had she missed anything important? Choosing to avoid embarrassment, she did not ask for a re-call from Houston. She knew what to do; she had studied the procedures with Steve and the rest of the crew and, frankly, she did not think it was all that complicated or difficult—she just needed to get out there and do her job.
The EVA procedure seemed simple enough. There was nothing they would have to fix; it was just a wing inspection. No fancy EVA tools would be needed, and there were no satellites they would have to wrestle out of their berths. The astronauts had a mind-numbing list of steps to follow in their final preparations to leave the airlock. Since the preparation for the spacewalk had been done only on paper, and not through countless simulations on Earth, Houston’s reorientation to the payload bay through step-by-step reminders was clearly welcomed.
Jan made eye contact with Steve and nodded.
“Copy that, Houston, we’ll stay up above the payload bay, and thanks for the heads up,” Steve answered for the two of them.
A minute-and-a-half passed in silence. During this time, Columbia’s commander gave Jan and Steve a thumbs-up, then closed the hatch between Columbia’s mid-deck and the airlock. The hatch actuator latches engaged with a click and a thud that resounded on both the flight and mid-decks. The commander then rotated the hatch actuator handle one-and-a-quarter turns to seat the airlock gaskets and to lock the actuator latches. He looked back into the airlock through the small, 4-inch-diameter window in the hatch, and gave another thumbs-up.
The fully suited astronauts floated in Columbia’s airlock, a vertically oriented cylinder mounted between the payload bay and the mid-deck that measured a mere 63 inches in diameter by 83 inches in height. Jan and Steve both gave a thumbs-up back to the commander. All three hatches were closed now, and the process of airlock pressure bleed-down commenced.
FOUR HOURS LATER, the astronauts heard: “One-Oh-Seven, Houston, you’re go for EVA when ready. We show your pre-breathe is complete.”
Nitrogen narcosis, nitrogen sickness, Caisson disease, the bends—all are names for the same problem, a problem with deadly potential. It is as real a phenomenon for astronauts as it is for scuba divers. Venturing out into space exposes astronauts to the same risks and dangers scuba divers face. Both environments are equally harsh. Both environments are equally able to take a life as a result of even simple equipment malfunctions, or careless disrespect.
The atmosphere inside Columbia was of the same composition and pressure as on Earth—roughly 80 percent nitrogen and 20 percent oxygen. To prevent the bends, Columbia’s astronauts had to breathe pure oxygen for at least four hours prior to their spacewalk. This tedious procedure was necessary to prevent the nitrogen, normally dissolved in blood, from transforming into bubbles, deadly bubbles that have a way of lodging in all the wrong places—places like joints, causing crippling pain, or worse, in potentially lethal places like the coronary or carotid arteries.
The pre-breathe procedure followed by astronauts prior to going out into space provided each astronaut’s body the necessary transition from the atmospheric environment of Columbia to that of the spacesuit—from breathing essentially room-air to the marked decrease in pressure and 100 percent oxygen of their spacesuits. Normally, when spacewalks were part of the mission plan, the entire cabin of the orbiter was decompressed at least 24 hours prior to the start of the spacewalk. Then the EVA astronauts need only a 30-40-minute pre-breathe before going out into space. Since NASA needed to know the status of the wing as soon as possible, the fastest way to get astronauts out on the wing was with the four-hour pre-breathe procedure inside Columbia’s airlock.
“Houston, we copy go for EVA, and report air-leak-checks are complete and negative,” Steve responded.
The air-leak-checks showed both spacesuits to be free of air-leaks at the junctions between the pants and torso sections, between the gloves and sleeves, and between the helmets and suit collars.
Jan and Steve then performed a communication check with Columbia’s flight-deck.
“Flight deck, comm check, this is Steve.”
“Steve, flight-deck, we hear you loud and clear.”
“Flight deck, comm check, this is Jan.”
“Jan, flight-deck, we hear you too—good luck out there. We’ll be watching you two from the aft flight-deck windows. Don’t forget to enjoy the view.”
“Roger that,” Jan and Steve said in unison.
“Houston, Columbia, stand by for EVA hatch opening.”
Jan grabbed the hatch actuator handle, braced her legs against the interior of the airlock, and applied the requisite 10 pounds of force to the handle, moving it through 180 degrees. The actuators unlatched. She continued turning the handle another 260 degrees, the amount necessary to fully disengage the actuators. She pulled on the hatch handholds and the D-shaped hatch opened in on its hinges, extending down toward them into the airlock, further crowding their space.
“Not a cloud in the sky, Houston,” Jan remarked as she looked out into space through the 36-inch-wide hatch opening.
“Copy that, Jan… One last reminder for Jan and Steve—don’t forget your SCU disconnect before heading out.”
“Good thought, Houston. We’re both ready to shoot out
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