Project Stairstep (Part One)

Project “Stairstep” came into being in 1956 as a child of the McDonnell-Goodyear “Meteor” spaceplane project, but quickly subsumed its parent and several other space related projects then current in the United States.

“Stairstep” was the ambitious plan to build a manned space station (or “satellite,” as the earlier phases of the project termed it) capable of sustaining a large population in space, a population who would (amongst pure research projects) be available to build interplanetary spacecraft to explore the rest of the solar system.

Space City spine The project initially sprang out of Darrell C. Romick's designs for a “space city.” To Romick, the “Meteor” project, as technically complex as it was, was only phase one of a larger plan. Using the three-stage space plane as both transportation and raw materials, he created a plan where hundreds of flights would deliver, piece by piece, a floating city, holding perhaps twenty-thousand inhabitants. Modified versions of the “Meteor's” third stage would be connected together to form the backbone of a structure over half-a-mile long. Then frameworks would be constructed, outer skins attached, resulting in a final structure that would be a thousand feet in diameter!

“Stairstep,” while created to develop Romick's grand plan, quickly scaled back as the political, financial – and practical – realities of this space city began to become obvious.

Space City In 1956, the longest any one had been in space was still Forrest Petersen's fifteen orbit flight in 1952. The “Meteor” project's “Crew Capsule Test Vehicles” (otherwise known as “the Wingless Wonders”1) had flown four flights in 1954/55, but none of them lasted more than three orbits.

It occurred to “Stairstep's” planners that maybe it might be good to see if man could live in space for long periods of time before they built a city for twenty-thousand of them.

Downsizing dramatically Romick's plan, “Stairstep” designed a “satellite” composed of just five of the modified third stages, with minimal external frameworks (just enough to support the antennas, docking supports, airlock, and thermal solar power unit) and spartan living conditions. Still, it would support up to ten men at a time, with long-term studies using a five or six man crew. Initial plans had the first components being launched in mid-1959, with the “satellite” completed and operational by mid-1960.

Original Meteor Design However, by 1958, it was becoming obvious that the Meteor project was going to take much longer than originally planned. Under initial scheduling, it should have been getting ready for its first launch of a “Meteor Jr.” sub-scale test vehicle. But designing wings that could work for all stages of the flight was proving to be far, far harder than anyone had dreamed. From the first stage's twenty-four miles up to ground glide, to the second's from forty-two, to the third's critical reentry and landing from actual space, in spite of Romick's original design of three sets of similar delta wings, it was becoming obvious that each stage needed a separate design, with those for the third being particularly difficult. Thus, projects dependent on the “Meteor” were being delayed across the board, and some of the more pessimistic were saying even the “Meteor Jr.” wouldn't fly until 1964 or '65.

Indeed, the Air Force – originally, an early adopter of the “Meteor” plan – had already build the “MBF-101” capsule, launched by an Atlas B-m,2 designed to be their “space fighter” should the Soviet Union succeed in their program of manned flight and try to deny access to overflights by U.S. spacecraft. While they would have much preferred the versatility of the Meteor system, they weren't prepared to delay their space program for it.

Naturally, “Stairstep” was another project hit by this delay...and by the Air Force's successful space program. Some Congressmen were wondering why the United States needed separate civilian and military space programs3 and “separate programs” that weren't actually launching anything were being looked at specifically.

“Stairstep” project leaders realized that they needed to get something flying – soon – to show that they were a worthwhile (of funding) program. Scott Crossfield, one of the engineers on loan to the project from the Air Force, had worked on the “Atlas III” program and knew that the Air Force had over eight-five of the older “Atlas Bs” mothballed since they had been decommissioned in 1955. Essentially the same as the “Aphrodite LV-1Cs” that the program managers had had experience with on “BROOM,” this would give the project a ready-made source of boosters on which to launch that “something.”

The modified “Meteor” third stages were to be 4.6 meters in diameter (15.1 feet), just two tenths of a meter bigger than the “Atlas B2C” (the new designation for the refurbished “Atlas Bs”). However, the length (38.6 meters – 126 feet) and weight of such a payload meant that even with the “Meteor 3rd” using its engines, the “Atlas B2C” could not boost it into orbit.

Weight reduction was the next obvious step. Under this modified plan, the stage would never have to return to Earth, so anything associated with reentry and/or landing could be stripped – including the as yet undesigned wings. Nor did it need to carry fifteen men, so the much smaller compartment of the “CCTVs” could be used. And since they'd already shortened the crew section, shortening the entire stage was the obvious next step.

Atlas/M32A The final result was essentially a third-stage for the “Atlas B2C,” 13 meters (42.6 feet) long, with a two-man crew compartment at one end and two “CR-05” engines at the other. On top of one of the refurbished “Atlas B2Cs” (along with four added solid boosters, which would later be regularly used on the “Atlas IIIb”) the three-stage vehicle was capable of lifting the final stage plus 1,200 kilograms (2,640 pounds) of additional men and payload into a 270 kilometer (168 mile) circular LEO. An unmanned “tanker/freighter” version could manage almost 1,500 kilograms (3,300 pounds) into the same orbit, though the automatic flight controls proved unreliable during the early part of the program, resulting in the loss of nine payloads.

The first “Atlas/M32A”4 vehicle launched from White Sands on October 5th, 1958 carrying a small test payload of tools and an equally small thermal-solar generator, pilot Dave Stephens and copilot Rick Marsh. Two orbits later, they rendezvoused with a previously launched three-seat version of the “MBF-101” carrying only Conrad Harvey. After ensuring the “M32A” was stable and under full control of White Sands and the solar generator was providing power, the two transferred to the “MBF-101”5 for the flight home.

Over the next eight months, eleven more “M32As”6 were launched to rendezvous with the original one plus five of the cargo versions (two of them entered incorrect orbits and were lost). The tanks on all the vehicles had been vented and the whole assemblage was tethered together, ready for the first stage of assembly.

On July 5th, 1959, two two-man “MBF-101's” and one of the new “MBV-300 Conestoga's” with a full six-man compliment launched serially from White Sands to begin the actual “satellite”7 construction. The larger size of the “MBV-300” required the use of a much larger version of the “MBF-101's” “transtage” - a fuel and engine pack that increased the “fighter's” maneuverability and “range” while in orbit. On the “MBV-300/Aphrodite LV-2A” combo, this much enlarged transtage effectively operated as a small, but necessary, third stage to get the vehicle into orbit.

At stage separation, though, the engines of the transtage did not light and the craft could not achieve orbit. Normal abort procedures would have them reenter and land as normal after their shortened ballistic flight, but not only did the transtage not light, it refused to separated.

Too heavy for its chutes and loaded with hypergolic fuel, the vehicle hit the Gulf of Mexico at Ship Shoal, a 140 kilometers (87 miles) south of New Orleans at almost 120 k/h (75 mph). It is believed the crew died instantly, but the explosion of the transtage fuel tanks seconds later would have assured that in any event.

The crews of the two “MBF-101s” didn't learn of the disaster until their craft were in orbit, White Sands feeling that letting them know of the loss during the delicate orbital maneuvers would only add more burden to their jobs.

The loss of over half the construction crew caused the planned assembly to be drastically cut-back. Initial plans had the full crew in orbit for eight days, and for the “32As” making up central core to be connected together, if not fully integrated. Later experience with construction in space proved that this was an overly ambitious schedule even had the full ten-man crew made orbit,8 but with only four men in orbit to do the work, White Sands was wondering if anything could be completed at all.

M32A The mission immediately had to be shortened from eight days to four, as the loss of the consumables carried by the 'Conestoga' put firm limits on just how long they could stay. Then the steep learning curve for space construction began shrinking even their modified, cut-down plans.

In the end, the two ships left the station site and returned to Earth with just two modules attached together and, Major Mason later admitted, “the bolts could have been a lot tighter.”

It was September before the next flight while the project researched what happened with the “MBV-300.” Finally they decided to go ahead with the construction using the “MBF-101s.”

From September 27th, 1959 until July 14th of 1960, the project launched two “MBFs” roughly every two weeks.9 In July, the “MBVs” were cleared for use again and both the number of men per flight – and the construction speed – doubled. In early August, all the structural sections had been separated from their launching components, drained, and connected together to form the basis of “Outpost One.” Work now continued on the interior crew accommodations and on the exterior sensors, radar booms, and the five and twelve inch scopes for the “Goddard Memorial Observatory.”10

With the basic structure complete, plans were made to move the new “Outpost One” into a higher orbit. During construction, it had been in a low, 150 mile orbit at a modest inclination to reduce launch costs and increase the number of launch windows. However, it was recognized that this was low enough that atmosphere drag would eventually deorbit the station.

While initially it was thought to put the station in a geostationary orbit, positioned such as to maximize it's launch window from White Sands, recent discoveries of the limits of Earth's radiation belts placed such an orbit right in the middle of the outer belt. Much discussion eventually settled on a 450 mile equatorial orbit with an inclination as close to zero as possible to ensure the station never actually passed over Soviet territory.

Two of the “engine racks” from the launched “M32As” had been retained in orbit.11 These had been attached to the rear booms of the station and a test flight of the new “Aphrodite LV-3 Heavy” brought up both fuel and tanks that were also mounted there.12

So on August 3rd, 1960, Lt. Colonel Wyatt Jefferys, nominal “Captain” of the station (and only crew-member aboard) slowly throttled up the four “CR-05” engines and began the long slow burn to move the station into its new orbit. Three days and multiple other burns followed until “Outpost One” finally entered its new home, somewhere over Borneo.

(to be cont.)