There’s a race between the future and the past boiling between a space upstart and an aerospace giant—Elon Musk’s 13-year-old SpaceX and Lockheed Martin, a company whose roots go back 103 years. At the heart of the matter is a potential competition for a future in deep space between two spacecraft, SpaceX’s Dragon 2 versus Lockheed Martin’s Orion.
The Dragon 2 has been contracted by NASA for short runs only—to take astronauts to the International Space Station and back. The Orion, on the other hand, has been contracted for something far more audacious—missions to deep space: the Moon, asteroids, and ultimately Mars. But is the Orion actually capable of handling deep space missions? And why is a mere “space taxi,” the Dragon 2, relevant to America’s deep space goals?
It all comes down to how the Dragon and the Orion shape up in a one-on-one deep-space comparison.
Let’s start with a device that SpaceX will test sometime in the next few months, the emergency escape system. What’s an emergency escape system? It’s hardware designed to whisk American astronauts to safety in the event that the massive launch rocket on which their capsule is riding fails.
The Dragon 2’s emergency escape system uses rocket engines built into the sidewalls of the capsule. Those engines are designed to allow the Dragon 2 to make a rocket-powered landing at a predetermined point with helicopter-like accuracy on either land or sea. However, in an emergency these engines will rocket the human crew a safe distance to protect them from an exploding booster. This new, dual-use approach to emergency escape is called a “pusher”1 system.
The escape mechanism on Orion2 is an upsized version of the 50-year-old Apollo-style “puller” or “tractor” type system used by NASA in the 1960s. At launch, the Orion spacecraft is covered by a shroud, above which is mounted a solid rocket booster. In case of an emergency abort, the solid rocket booster accelerates the Orion away from the booster at high speed. Successful boost to orbit or not, the shroud and solid rocket booster are a danger. They need to separate after the spacecraft is a safe distance away from the rocket. If they do not separate, they can imperil the crew by preventing a safe atmospheric reentry, a life-threatening crisis that cannot occur with the Dragon 2.
After separation, the Orion’s launch abort system—its shroud and solid rocket booster– is dead weight. It’s thrown away, never to be used again. That’s an expensive waste of valuable equipment. What’s more, the Orion is designed to make an old Apollo-style splashdown at sea, a strategy that requires an expensive open-sea recovery by a large ship with a full crew plus planes and helicopters to search for the Orion’s chancy landing location. The Dragon 2 takes a far less expensive approach: retro-rocket touchdown at a landing and service facility—a spaceport or launch pad–conveniently located on shore.
The key difference between the Dragon 2 and the Orion is reusability. Though NASA insists on a new Dragon 2 spacecraft on each NASA-sponsored flight, SpaceX has designed the Dragon 2 so it can be relaunched with little or no refurbishment between flights.1 Thus, SpaceX could use a second-hand Dragon 2 spacecraft for private industry missions to orbit and beyond for a low price since the spacecraft’s development and manufacturing costs will have already been paid. This could cut the cost of future space launches of humans into space by 90%. On the other hand there’s the ultra-expensive alternative, Lockheed Martin’s Orion. All of the Orion is designed to be thrown away after each flight.
You might well argue that this is really not a fair comparison. After all, Orion is advertised as a vehicle capable of going to the Moon, an asteroid, or Mars. And the Dragon 2 is only equipped to reach the orbit of the International Space Station. But is that true?
SpaceX designed the Dragon 2 to go to Mars and back. The Dragon 2’s heat shield is crafted to withstand the extreme high heat and stresses associated with an atmospheric reentry during a return to Earth from the red planet3 To accomplish this feat the Dragon relies on a modern heat shield substance called PICA that was developed by NASA and improved by SpaceX. Orion, on the other hand, uses the 50-year-old AVCOAT heat shield material (often referred to as Thermal Protection System or TPS) that was used on the Apollo capsules in the 1960s.4 AVCOAT was only designed to withstand the lower reentry temperatures and stresses associated with a return from the Moon.
AVCOAT doesn’t cut it for Orion’s new role as a spacecraft to go beyond the Moon. Even Lockheed-Martin is unsure that Orion’s old-style AVCOAT TPS can withstand the harsher conditions of a faster reentry from deeper space without a significant “enhancement” to the heat shield. In Lockheed-Martin’s words5:
“Reentry velocities are 11.05 to 11.25 km/s for asteroid missions, vs 11.0 km/s for lunar return. TPS [thermal protection system] enhancement may be required depending on the ultimate capability of Orion lunar TPS.”
In other words, the Orion is not ready for prime time. For example, it could not handle the round trip to and from a deep-space asteroid beyond the Moon. And it could not handle the trip to Mars and back.
There’s another argument to be made on behalf of the Orion. With the addition of a European-built service module, a traveling pantry and storage closet, the Orion can support a crew far longer than a Dragon 2. In theory, SpaceX could develop a service module that would equal or better the capabilities of anything Orion can do. But that’s only in theory. The service module that would support an Orion crew on long voyages is already being assembled. A SpaceX service module is not.
However, neither Orion nor Dragon 2 can be used on an interplanetary mission to a near Earth asteroid or Mars by themselves. Each would require an additional habitat7 to provide the extra living space, life support systems and radiation protection needed for deep spaceflight. There is no money in Orion’s budget for such a habitat and currently no firm plans for one.
Meanwhile, the Dragon 2 is being readied for deep space. SpaceX CEO Elon Musk says8 he plans to execute a flight around the Moon and back in the near future.
In addition, SpaceX is preparing a new rocket, the Falcon Heavy, for a test launch this year. The Falcon Heavy will be the most powerful launch vehicle since the Saturn V moon rocket of the 1960s and more than capable of sending a crewed Dragon 2 on a moon-circling flight.
Billions of dollars9 have been spent on the Orion. A tiny fraction 10 of that amount has been spent on the Dragon 2. Yet the capabilities of the Dragon 2 are much more impressive. Why the huge difference in price and capabilities? Says Space Development Steering Committee member and author of The Plundering of NASA R.D. Boozer, “The Orion gives pork-loving politicians bring-home-the-bacon billions. The Dragon 2 does not. As long as short-term regional advantages are given precedence over the best deal for the country at large, the Orion will continue to be an expensive and obsolete fiscal black hole.”
References
1 http://www.spacex.com/news/2014/05/30/dragon- 2-spacexs-next-generation-manned-spacecraft
2 http://www.nasa.gov/sites/default/files/files/orion_las_fact_sheet.pdf
3 http://www.spacex.com/news/2013/04/04/pica-heat-shield
4 http://spaceflightnow.com/2014/11/05/engineers-recommend-changes-to-orion-heat-shield/
5 http://www.lpi.usra.edu/sbag/meetings/sbag2/presentations/PlymouthRockasteroidmission.pdf
6 http://www.nasa.gov/content/what-is-nasa-s-asteroid-redirect-mission/#.VRms4OFVrMs
8 https://www.youtube.com/watch?v=U44geuM6iQ0&feature=player_embedded
9 http://www.nasa.gov/pdf/740427main_NASAFY2014SummaryBriefFinal.pdf
10 http://spaceflightnow.com/news/n1405/29dragon 2/#.VRrKsuFVqio