|Dyna-Soar spaceplane. Image credit: U.S. Air Force|
Though Bono's Mars glider was impressively large, it was part of a Mars expedition plan that was in fact stripped-down and bare-bones by early 1960s standards. It lacked redundancy and provided few abort modes. For those familiar with Wernher von Braun's 1950s plans for Mars expeditions, some of which included 10 or more cargo and crew spacecraft, Bono's plan must have seemed daring, even reckless.
Bono himself acknowledged that his study did not "present the solution to many major problem areas." He nevertheless assured his readers that it was "restricted to the realm of practicality and reflect[ed] a moderate degree of conservatism."
|A large crane hoists into place the forward section of Bono's Mars glider. Final assembly occurs on the launch pad. Image credit: Boeing Airplane Company|
Six tall outboard booster rockets would surround and hide the short booster, living module/rocket stage, and most of the aft section of the glider. Fully assembled, loaded with liquid hydrogen and liquid oxygen propellants, and ready for launch, Bono's massive Mars stack would stand 248 feet tall and weigh in at 4150 tons.
|Abort: the forward section of the Mars glider (upper right) blasts free of a malfunctioning booster rocket during first-stage ascent. Image credit: Boeing Aircraft Company|
During first-stage operation, four of the outboard boosters would supply propellants to all seven engines. The rocket would climb to an altitude of 200,000 feet, where it would cast off the four expended boosters. These would fall to Earth 60 nautical miles downrange of the launch site.
|Bono's Mars spacecraft begins second-stage flight by casting off four outer boosters (lower left). Image credit: Boeing Aircraft Company|
Safely on course for Mars, the astronauts would crawl through a tunnel in the glider's aft section to reach the 45-foot-long, 18-foot-diameter living module. They would deploy an inflatable 50-foot dish-shaped antenna for radio communication with Earth (the dish might have been a late addition to Bono's plan, for it is not depicted in any of the illustrations for this post). During the 259-day voyage to Mars, the crew would breathe a 40% oxygen/60% helium air mix, so in their radio reports to Earth they would sound like Donald Duck.
|Its job done, the short central booster stage shuts down and fires thrusters to separate from the Mars spacecraft. Image credit: Boeing Aircraft Company|
After deploying the antenna, the crew would point the glider's nose - which would contain a nuclear reactor for generating the Mars expedition's electricity - at the Sun. This would place the living module in shadow, and would shield the liquid hydrogen/liquid oxygen propellants in the small rocket stage from solar heating. Bono assumed that no course corrections would be necessary so that his spacecraft could maintain its nose-toward-Sun attitude throughout the journey to Mars.
The glider, meanwhile, would carry the eight-man crew directly into Mars's atmosphere with no stop in orbit. If conditions on Mars were not suitable for an immediate landing - for example, if a planet-wide dust storm were raging - then the crew would have no way of aborting atmosphere entry and descent to the martian surface. (Such a storm did in fact occur in late 1971, though by January 1972 it had mostly abated.)
|The Mars glider casts off its drag parachute as it steers toward a smooth area of martian desert. Image credit: Boeing Aircraft Company|
|Vertical descent and touchdown. The artist depicts Mars as smooth and dusty, with no obvious rocks on its surface. Image credit: Boeing Aircraft Company|
Bono's description of the glider's aerodynamic performance was based on an estimated martian surface air pressure equal to about 8% of Earth's. The true value is, however, less than 1% of Earth's surface pressure. In the actual martian atmosphere, a single 42-foot parachute would not be adequate to slow the heavy glider's descent. In addition, the glider's wing design would not produce sufficient lift to enable effective gliding. In short, Bono's glider would reach the surface while still moving at supersonic speed. Some call this "lithobraking."
|Mars Outpost: members of the eight-man crew lower the glider's nose-mounted nuclear reactor onto the expedition truck. In the background (right) stand radio antenna masts and the inflatable dome-shaped shelter. Image credit: Boeing Aircraft Company|
Near the end of their stay on Mars, the astronauts would reconfigure their glider for launch by moving its landing engines so that they could serve as ascent engines and by returning the reactor to its place on its nose. They would also anchor the aft section of the glider to the surface using stakes and cables. The glider's forward section would then blast off at a 15° angle using the aft portion as its launch pad.
|Liftoff from Mars: the forward part of Bono's Mars glider begins the climb to Mars orbit. Image credit: Boeing Aircraft Company|
The crew would dock the glider forward section tail-first with the waiting living module which would have loitered in Mars orbit throughout their surface stay. Several astronauts would spacewalk to join together the glider and living module and detach the empty torus-shaped propellant tanks on the living module's small rocket stage. The tanks would have been retained after the Mars orbit capture maneuver emptied them so that they could protect the small rocket stage and the precious Earth-return propellants it contained from meteoroid punctures.
|Members of Bono's Mars crew cast off empty torus-shaped propellant tanks on the small rocket stage (upper right) attached to the aft end of the living module (center) in preparation for Mars orbit departure. Image credit: Boeing Aircraft Company|
|The forward section of Bono's Mars glider separates from the living module ahead of Earth atmosphere reentry. Image credit: Boeing Aircraft Company|
|24 January 1974: the forward section of Bono's Mars glider returns to Earth. Image credit: Boeing Aircraft Company|
"A Conceptual Design for a Manned Mars Vehicle," Philip Bono, Advances in the Astronautical Sciences, Vol. 7, pp. 25-42; paper presented at the Third Annual West Coast Meeting of the American Astronautical Society, Seattle, Washington, 4-5 August 1960
Space Race: The Notorious 1962 Proposal to Launch an Astronaut on a One-Way Trip to the Moon
A Forgotten Pioneer of Mars Resource Utilization (1962-1963)
A 1964 Proposal for a Small Lifting-Body Shuttle with "Staged Reentry"
NASA Marshall's 1966 NERVA-Electric Piloted Mars Mission