The Apollo program, which sent a dozen men to the Moon, ended in 1972. It’s so long ago that fewer than half of all Americans are old enough to have watched one of its missions on live TV. Yet some of the technology behind Apollo is about to be brought out of retirement for NASA’s return to the Moon, scheduled for 2020.
The agency’s new system for traveling to Earth orbit, and later to the Moon and Mars, dubbed The Constellation Program, essentially duplicates the Moon mission technologies proposed by Wernher von Braun in the late 1950s and used in the Apollo program. For instance, it includes a multistage rocket similar to Apollo’s Saturn V, a crew vehicle similar to the Apollo command module, and a lunar lander directly based on the Apollo lander.
Last month, NASA chose aerospace giant Lockheed Martin to build the crew vehicle, called Orion. The craft’s cone-shaped crew module and cylindrical service module might have just arrived from the Smithsonian Air and Space Museum–except they’re a bit larger than the Apollo versions, carrying four to six crew members instead of three.
Yet, according to Lockheed Martin officials, Orion will make the Apollo craft look like a Model T. Orion’s reentry system, for example, will incorporate knowledge gleaned from Lockheed’s recent Genesis and Stardust missions, which retrieved materials from comets. What’s more, the avionics software and equipment will be based on systems used in the newest passenger jets; and a new abort system will carry astronauts away from the main rockets in case of a Challenger-like launch disaster.
Patrick McKenzie is business development manager for the Orion project at Lockheed Martin Space Systems in Denver, CO. He talked with Technology Review on September 7 about the technologies–old and new–going into Orion.
Technology Review: What did aerospace engineers learn from Apollo that can be applied in the Orion project? And why does your design look so similar, at least superficially, to the Apollo command module and service module?
Patrick McKenzie: One of the most enduring things that Apollo got right was the aerodynamic shape of the capsule–which also happens to be the most visible element. One of the reasons NASA chose to go with the Apollo-type shape is the proven safety database that goes along with that. When you look at alternatives like lifting-body designs–space airplanes like the Shuttle–they provide things like additional cross-range [the ability to steer to different landing sites], but you are not able to fly them safely in the event that a control system goes offline. A ballistic reentry system like a capsule can return the crew safely in the event of a fault. But virtually everything else about this capsule is new technology–not necessarily bleeding-edge, but developed after Apollo.
TR: What are some of the most important new technologies, in your opinion?
PM: One of the major technology applications that is clearly going to be different with Orion is the automated rendezvous and docking capability. Orion will need to dock with the International Space Station and with the Earth Departure Stage [the rocket that will accelerate Orion out of Earth orbit to the Moon]. The Shuttle is manually docked, and Apollo obviously wasn’t automated. Orion will have manual override capability, but the vast majority of the time, there should be no need for a crew member to intervene.
TR: I understand that Orion will have a new type of heat shield for reentry into Earth’s atmosphere.
PM: The idea is pretty much the same as with Apollo, but there will be a new design and new materials that provide more robust protection. That’s important because with vehicles coming back from the Moon, or particularly from Mars, the reentry velocities are going to be a lot higher [than with spacecraft in low-Earth orbit]. We are looking at heat-shield materials like PICA [phenolic impregnated carbon ablator] and SLA [a cork-based ablative material] that Lockheed has proven on the Genesis and Stardust deep-space sample return missions.
Another thing that’s going to be new is “skip reentry,” which we are going to be doing routinely. That’s where you bounce off the atmosphere and come back in again, which gives you the ability to touch down on land, as opposed to the Apollo landings in the ocean. That provides an extra measure of safety and enhances the reusability of the system. Of course, we’re also looking at upgraded landing-impact systems. You still come down on parachutes, like Apollo did, then you deploy airbags or fire retrorockets, similar to what the Russian Soyuz vehicle does, to slow down the vehicle for a safe landing.
TR: What will conditions be like inside the crew module?
PM: Apollo could carry only three people, and they had very tight living conditions. The Orion crew module will have twice the volume: 361 cubic feet per crew member. Four crew can go back and forth to the Moon, and on flights to the International Space Station we could accommodate up to six crew. Also, the crew module will be able to stay in orbit around the Moon in a fully autonomous mode, so all four crew members could go down to the surface, for potentially long-duration stays.
TR: For Apollo, NASA designed an abort system to carry the command module away from the Saturn V rocket in the event of a launch emergency. Such an abort system might have saved the Challenger astronauts, but unfortunately the Space Shuttle doesn’t have one. What’s being planned for Orion?
PM: It’s the same kind of idea as with Apollo. One of the particular advantages of the capsule configuration over the Space Shuttle is the fact that we aren’t side-mounted. On the Shuttle, both the solid rocket boosters and the external fuel tank are right up against the belly of the vehicle, and there is no way to separate the crew from those in an emergency. Orion will sit on top of the Ares I launch vehicle in the same fashion as Apollo, so that if there’s any kind of issue with the rocket below, the advanced launch abort rockets on the tower above the crew module are fully capable of accelerating away from the Ares and getting the crew into a safe situation, with parachutes for landing.
TR: The old mechanical cockpit systems in the Space Shuttle were recently replaced with a modern “glass cockpit” design, with fully electronic displays and controls. I assume that technology will go into Orion as well?
PM: The avionics systems on board are going to be light-years ahead of where Apollo was. Not only will we have what you called the glass cockpit, but the other key element is “dual fault tolerance.” That means that with the critical systems being built into Orion, you could have two failures in the same system and still fly safely. The system that our teammate Honeywell is working on is based on the avionics architecture of the Boeing 787, which is also dual-fault tolerant. The systems constantly monitor one another, and if one system has a problem, another one automatically takes over. It adds some additional weight and complexity to the vehicle, but it provides a much greater margin of safety on these very dangerous space missions.
TR: The Space Shuttle is due to be retired in 2010, and the first crewed test flights for the Constellation Program–or at least the Ares rocket with Orion on top–are planned for 2014. What will be the hardest technology challenges as you try to hold to that schedule?
PM: Typically, the avionics software development ends up being a critical path element. The RCS engines, derivatives of the Shuttle’s RCS engines, are another [Reaction Control System–the small side-mounted rockets used for attitude control and steering. The Shuttle’s RCS engines were themselves derived from Apollo. -eds.] So it comes down to software and propulsion. We’re aware of those critical-path issues and working with NASA to address them early. We’d like to close the gap after the Shuttle’s retirement and skinny the schedule down to test launches in 2012 or even sooner. But the Ares I launch vehicle development process has to come together along with Orion.
TR: From President Kennedy’s May 1961 speech announcing the goal of landing on the Moon to the actual Apollo 11 landing in July 1969, a little more than eight years passed. Today NASA says it’s going to take at least 14 years to do the same thing. Why?
PM: The Orion part of the project would probably be capable of lunar missions sooner than 2020. That being said, you’re also going to need to develop a lunar lander, an Earth-departure stage, and a lift vehicle [the Ares I and Ares V]. Because NASA’s budget in this day and age is a much smaller percentage of the budget of the nation than it was in the Apollo era, we have to “go as you can pay,” as NASA administrator [Michael] Griffin puts it. The initial budget priority is on developing Ares I and Orion. We will not be able to do development on the lunar lander, the EDS, and all the elements of Ares V in parallel.
TR: Why do you think Lockheed Martin’s proposal for the Orion contract won out over Northrop Grumman’s? Was Lockheed offering superior technology?
PM: I’m extremely proud of the team and what they accomplished with the technical concept we delivered to NASA. But the requirements are still in the process of changing, and all of the bidders actually had to deal with a diameter change [in the Orion capsule] halfway through the process, from 5.5 meters down to 5 meters. With NASA delivering so many things to us as requirements, the playing field was leveled somewhat.
When it gets right down to it, NASA is signing up for a relationship with an industrial partner that’s going to last a couple of decades. They wanted to know that it would be a happy marriage, where the spirit of partnership was in real evidence. During Phase I [when NASA paid several bidders to develop designs for Orion], we took the initiative to make sure our project office was co-located in Houston, which made it easy for them to participate in all of our control board meetings and other important events over and above the typical bimonthly reviews. We’ve got a significant workforce at the Michoud Assembly Facility in New Orleans [where the Shuttle’s external tanks are put together]; we made a decision early on to do final assembly and checkout at Kennedy Space Center; we’re going to be doing engine testing at Stennis Space Center in Mississippi [NASA’s primary rocket propulsion test site]. I think NASA has appreciated that.