You’ve all seen the iconic photo of an American astronaut riding gracefully in his NASA-designed MODOK chair. This astronaut was Bruce McCandless II, Houston’s capsule communicator during the lunar landing mission. Challenger crew member and driving force behind America’s ability to conduct operations beyond the sweltering confines of space shuttles and international stations. Without McCandless, there is no guarantee that the United States will have the ability to go into outer space today. Miracles aroundExhaustively researched and written by McCandless’s son Bruce III, explores the trials and tribulations of McCandless Sr. during NASA’s formative years and his laser focus on allowing astronauts to navigate space unencumbered by the mass of their ships.
Copyright @ 20201 Bruce McCandless III. Published by Greenleaf Book Group Press. Distributed by the Greenleaf Book Group. Design and composition: Greenleaf Book Group and Kimberly Lance. Cover design: Greenleaf Book Group, Sean Venish and Kimberly Lance. Cover image courtesy of NASA, photographed by Robert L. “Hoot” Gibson.
In his long, hard days of waiting for space flight, my father found a path to redemption on the back of an aging cartoon character. On the afternoon of December 1966, when he first experienced maneuver maneuvering on the Martin Marietta simulator, he was hooked on a vision of a gas-powered jetpack that would allow astronauts to work outside of their spacecraft. This vision had obvious precursors to pop culture. In the 1920s, a comic book character named Buck Rogers – an American, stone-jawed World War I veteran – succumbed to a mysterious gas he encountered while working as a mine inspector. He fell into a deep sleep and woke up after five centuries of sleep in a strange new world of spaceships, ray cannons and Asian rulers. Although he originally traveled through this new world with the anti-gravity belt, a device that allowed him and his best girlfriend, Wilma, to jump long distances at the same time, Buck eventually acquired a sleek and apparently omnidirectional jetpack. He eventually went into space on an adventure called Tiger people from Mars, and his exploits in space forever changed America’s vision of the future. Millions of people followed Buck’s adventures in comics, radio, and TV series. Buck’s imitators and spiritual heirs include Flash Gordon, Brick Bradford, John Carter of Mars, and Han Solo.
A lot of talented men and women have spent a lot of time and money to get this jetpack out of funny newspapers and get into the space shuttle. However, no one worked harder than Bruce McCandless and his chief officer, an engineer and chestnut-trained Air Force officer named Charles Edward (“Ed”) Whitsett Jr., a pale, bespectacled man with gentle manners but tenacious. He had an advantage over my father. He thought and wrote about jetpack technology back in 1962. In a sense, he was trying to solve a problem that did not yet exist: namely, how could an astronaut go beyond the confines of his spacecraft and carry out constructive tasks in it? an oxygen-free environment, extreme temperature fluctuations and orbital “free fall” that would leave the astronaut idle in the practical equivalent of zero gravity? Alexei Leonov from the Soviet Union and American Ed White proved that spacewalk is possible, that people can survive outside their space capsule, but basically all they did was float. How could a person move from one part of a spaceship to another, or from one spaceship to another, or from a spaceship to a satellite to carry out checks or repairs? None of these needs actually existed in the early sixties, when both countries’ programs were still trying to get cans into low Earth orbit and more or less predict where they would return. But it is clear that needs will eventually arise, and various methods have been proposed to address them.
In the mid-1960s, the US Air Force assigned NASA’s Whitsett to lead the development of the Air Force Astronaut Maneuvering Unit. Gene Cernan’s failed test flight on the Gemini 9 in 1966 – the “spacewalk from hell,” as Cernan called it – threw the jetpack project back, but it never ended. McCandless, Whitsett and a NASA engineer named Dave Schultz worked quietly but hard to keep the dream alive. They increased and improved the CAM throughout the second half of the decade and up to the seventies. In the Forgotten Astronauts telegram portraying him as a failure in 1973, my father mentioned the reason why he wanted to stay in a manned space program despite not winning a trip to Apollo or Skylab. “McCandless,” the article says, “helped develop the experimental M509 maneuverable rig. Skylab’s astronauts strap it on like a backpack and move themselves with Buck Rogers – like inside Skylab. [He] wants to build a larger operating unit to carry out space work outside the shuttle. ” This is exactly what he did.
Although the Skylab M509 trials in 1973 and 1974 were resounding success, leading to the jetpack concept triumphant over rocket boots and a portable maneuvering device, Whitsett and McCandless did not rest on their laurels. Over the next few years, using all the time and funds they could muster together, the team made several updates – eleven, by one count – of what was now called the “manned maneuvering unit” or MMU. The ASMU’s nitrogen gas canister has been replaced by two streamlined aluminum tanks at the rear of the unit, each wrapped in Kevlar. The number of nozzles has been increased from fourteen to twenty-four, located around the jetpack to allow precise maneuvering with six degrees of freedom. Smaller gyroscopes replaced those used on the ASMU and, as space historian Andrew Chaikin observed, “ASMU pistol grip hand controllers, which are tiresome to operate in sealed spacesuit gloves, were replaced by small T-shaped handles that only needed a push with the tips fingers “. The new MMUs have been made adjustable to accommodate astronauts of all sizes. Painted white for maximum reflectivity, the device was designed to withstand the 500-degree fluctuations in temperature (from a maximum of 250 degrees F to a minimum of minus 250 F!) That an astronaut can encounter in space.
By 1980, the car weighed 326 pounds. Like the AMU and ASMU before it, the MMU was designed to fit or “over” an astronaut’s spacesuit. The shuttle astronauts wore a newly developed suit called the Extravehicular Maneuvering Unit, or EMU, a marvel of textile engineering composed of fourteen layers of nylon, ripstop, gore-tex, kevlar, mylar, and other materials. The jetpack electrical equipment was supplied with two 16.8 volt zinc-silver batteries. Two motion control knobs – a manual forward motion controller and a rotary arm controller – were mounted on the left and right armrests of the unit, respectively, and a button activated a “hold position” mode that used motion-sensitive gyroscopes to control the firing. engines to maintain the position of the astronaut in space.
The car has gone through all kinds of tests that designers could imagine. A local shooting club representative visited Martin Marietta and fired a 50-caliber bullet at the MMU nitrogen fuel tank to see if the tank would explode if pierced. (It is not.) The jetpack was launched over hundreds of hours of simulations. At my father’s insistence, a gifted and energetic project manager Martin Marietta named Bill Bollendonk subjected the device to near-space conditions in the company’s thermal vacuum facility. The MMU was no longer a “distant” experiment, as Mike Collins once called it. It was now a promising space instrument. Unfortunately, at the moment, it was an unused space instrument. American astronauts stayed on Earth as NASA struggled to build its next-generation orbiting workhorse, the space shuttle.
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