Wired has an article on an Apollo lunar orbit rescue concept from 1965.

The idea was to have a specially outfitted Apollo Command Service Module, with a single pilot, standing by on the launch pad. If something went wrong with the ship in lunar orbit, the rescue ship would be launched.

The problem with the concept is obvious. The crew in lunar orbit would likely run out of oxygen before the rescue ship arrived.  Because of that limitation, as well as the cost, the rescue project was never pursued. Apollo was left with no rescue capability in lunar orbit.

The Orion “Apollo on Steroids” architecture, pursued during the George W. Bush Administration, had the same safety vulnerabilities as Apollo, plus one additional failure mode. Instead of leaving a command module pilot in lunar orbit, the Orion architecture proposed to have all the astronauts descend to the surface, leaving the command module on autopilot for several weeks. At the end of their lunar stay, the astronauts would return to the Orion command service module and ask the computer to “open the pod bay doors,” as Arthur C. Clarke famously put it.

The fact is, the Apollo architecture was not really designed with safety in mind. Its mission was to “land a man on the Moon and return him safely to the Earth.” A man, singular, was all Kennedy required, but it had to be done quickly to beat the Soviets. Although safety was part of the stated requirement, no one expected Apollo to fly very often, so NASA could afford to take chances and trust that improbable events would never occur.

On Apollo 13, however, an improbable event did occur, and NASA nearly lost a crew as a result. What few people remember today is that the Apollo program very nearly came to an immediate end after Apollo 13. It was not considered NASA’s finest hour, as filmmaker Ron Howard later famously called it. There was serious consideration to canceling the remaining Apollo flights, which were due to end soon, anyway. NASA had already achieved the Kennedy goal of landing a man on the Moon. What did the remaining Apollo flights offer that could be worth the risk to human life? A few more Moon rocks? The decision was made to continue the program with four more flights, but it could easily have gone the other way. (Ironically, Richard Nixon, who courageously allowed the landings to continue, is considered a villain by many space buffs because he “killed Apollo.”)

If the Moon landings had been canceled after Apollo 13, NASA might have moved quickly on to Skylab or directly into Shuttle development. Or, perhaps, the United States would have closed down the Manned Space program. It was a near thing, and there were voices in the media calling for just that.

The Bush Vision of Space Exploration gave NASA a chance to address some of Apollo’s vulnerabilities, but NASA failed to do so. There was a lot of talk about the importance of a launch escape system for the Orion capsule, but no provision for in-space rescue. Orion would be just as vulnerable to an Apollo 13-style mishap as the original Moon capsule. The potential consequences for the program, though, would be greater. NASA was now planning to establish a lunar base, and Orion would be the key link in its supply chain. After Apollo 13, NASA could afford to halt Apollo flights for a while to fix the problem. After the Columbia accident, NASA could afford to halt Shuttle flights temporarily, because it had Russian partners providing Soyuz and Progress capsules as a backup. But if Orion failed, there would be no backup. If Orion was grounded for a protracted period because of an accident, the results would be very serious for a lunar base. In the best case, NASA would have to temporarily abandon the base. In the worst case, a crew on the Moon might die waiting for supplies that would never come, with no ride to take them home.

How might NASA have addressed the vulnerabilities in the Apollo/Orion architecture?

One obvious answer would be to have two or more capsule designs in operation. That is the approach NASA appears to be pursuing with commercial crew and cargo services for the International Space Station. If NASA employed the SpaceX Dragon and Boeing CST-100 capsules for lunar missions, a failure which grounded either capsule would not bring the entire program to a halt. Redundant designs are a good idea. The US military has seen that on many occasions when it had to ground one of its major fighter or transport planes due to mechanical problems. Fortunately, it has always had other aircraft, which were not affected, that could carry on the mission. (That may not always be the case in the future, as current procurement policy seeks to drastically reduce the number of aircraft types in military service. NASA is not the only organization that fails to learn from past lessons.)

Redundant capsule designs would enable the program to continue after a fatal accident, but that would be small comfort to the families and friends of those who perished in the accident. What could be done to improve the chances of crew survival in the event of a mishap?

Having a rescue ship standing by might help, but it may not be practical. For lunar missions, a rescue ship is not always going to arrive in time. For deep-space missions beyond the Moon, a rescue ship is never going to arrive in time. The laws of orbital mechanics preclude it.

So, if something goes wrong, the astronauts are most likely going to have to save themselves. For this reason, mission design should incorporate a concept called buddy operations.

Buddy operations, or buddy ops, refers to two or more units undertaking a mission together and providing mutual support. The importance of buddy ops is drilled into anyone who undertakes hazardous or potentially hazardous activities. Boy Scouts are taught to take a hiking buddy when they leave camp. Scuba divers don’t venture out into deep water without a dive buddy. Combat pilots always fly with a wingman. Soldiers and policemen have partners. In each case, the concept is the same: if something goes wrong, there’s someone there to take care of you.

Unfortunately, that concept has rarely been employed in space. The Air Force never sends a fighter out on a solo mission, but nearly every US spaceflight has been a single-ship mission. (The single exception was Gemini 6 and 7.)

In Orion, NASA sought a capsule that could carry four to six astronauts. If something went wrong on the way to the Moon, the entire crew would be at risk.

If NASA had incorporated the concept of buddy ops, Orion would not have been a single capsule but a flotilla, or mission group, of smaller capsules. Suppose, for example, the capsule was designed to carry three astronauts. For a lunar mission, it could be launched with two astronauts and an assortment of supplies intended for the lunar base. Capsules would operate in mission groups of three. If one capsule became disabled on the way to the Moon, its crew could transfer to the two buddy capsules, which would discard the non-essential supplies to make room for them. Each mission group would have its own inherent rescue capability.

The importance of this capability has been demonstrated in terrestrial exploration missions of the past. On his first expedition to the New World, Columbus had to abandon one of his three ships and transfer the crew to the remaining crew. We must develop similar capabilities and operating modes, if we’re serious about deep-space exploration.

Evacuating a crippled ship or capsule is the most dramatic example of buddy operations, but there are many types of emergency support a buddy could provide short of evacuation. A buddy ship could perform fly around inspections; transfer propellant, food, supplies, or spare parts; assist with repairs; provide backup for failed communication or navigation systems; etc. And we should not underestimate the psychological value of simply knowing someone else is nearby .

Buddy operations can be valuable in non-emergency situations as well. There are many operational and scientific tasks which can be performed more effectively by a mission group rather than a single ship. Space construction, imaging with widely separated sensors, and deploying instrument packages are just a few of the possible applications.

The routine use of buddy ops was an important part of the operations concept for the Space Cruiser concept studied by DARPA in the 1980’s. A declassified report titled Spaceplane Technology and Research (STAR) states, “Rendezvous and docking for refueling and transfer of payload, crew, or equipment between two Space Cruisers is a buddy operation. For example, two Cruisers could each inject into the same transfer orbit. One Cruiser carries the payload and therefore consumes more propellants. After the injection burn is complete, the Cruiser with the payload is refueled by the other in a buddy operation and will arrive at its apogee with full tanks. This procedure is analogous to upper-staging in terms of performance but no stage is used or expended and no space debris results…. The previously discussed buddy type operations can be considered modular configurations, adapting the spaceplane to more missions and increasing without the development or purchase of new equipment, requiring a larger [launch vehicle], etc.” All of these considerations are still valid.

Another advantage of designing for buddy operations is reduced cost. A capsule or ship designed for three astronauts will be cheaper to design and build than one designed for six. Because of its smaller size, it might eliminate the requirement to develop a new, expensive heavy lift rocket (as noted by DARPA in the 1980’s). And because more capsules would be built, there would be mass-production and learning-curve effects helping to hold down costs as well.

Buddy operations have been essential to successful exploration in the past. They will be essential to successful space exploration in the future.


Written by Astro1 on June 13th, 2012 , Innovation, Space Exploration (General), Space Medicine and Safety

Leave a Reply

Your email address will not be published. Required fields are marked *