If NASA returns to the moon in 2020 as planned, astronauts will step out in a brand-new space suit. It will give them new mobility and flexibility on the lunar surface while still protecting them from its harsh atmosphere. The suit will also be able to sustain life for up to 120 hours and will even be equipped with a computer that links directly back to Earth.
Credit: Brittany Sauser
The new design will also let astronauts work outside of the International Space Station (ISS) and will be suitable for trips to Mars, as outlined in NASA's program for exploration, called Constellation. "The current suits just cannot do everything we need them to do," says Terry Hill, the Constellation space suit engineering project manager at NASA's Johnson Space Center in Houston. "We have a completely new design, something that has never been done before."
NASA has proposed a plug-in-play design, so that the same arms, legs, boots, and helmets can be used with different suit torsos. "It's one reconfigurable suit that can do the job of three specialized suits," says Hill. The space agency has awarded a $500 million, 6.5-year contract for the design and development of the Constellation space suit to Houston-based Oceaneering International, which primarily makes equipment for deep-sea exploration. Oceaneering has partnered with the Worchester, MA-based David Clark Company, which has been developing space suits for the U.S. space agency since the 1960s.
The space shuttle astronauts currently wear two difference types of space suits. The Advanced Crew Escape Suit (ACES) is worn during the launch and ascent phases of flight. It is soft, fabric-based, and protects against the loss of atmospheric pressure or cold-water exposure in case of an ocean landing, and provides water cooling to regulate an astronaut's body temperature. The full assembly includes a survival pack, an emergency oxygen system, and a personal parachute so that astronauts can abort the shuttle during the landing phase.
Astronauts wear a second suit, called the Extravehicular Mobility Unit (EMU), when they perform tasks outside the confines of the shuttle or the ISS, such as adding solar panels to the space station or performing repairs. It has a hard upper torso, layers of material to protect astronauts from micrometeoroids and radiation, a temperature-regulation system, and its own life support and communication systems. The EMU weighs over 300 pounds and has limited leg mobility--astronauts' feet are normally locked in place on foot restraints while performing extravehicular tasks, and during Apollo missions, astronauts were forced to develop a bunny hop to traverse the lunar surface."When we went to the moon the first time, we were just trying to get there. Now astronauts need to be able to explore the surface, harvest resources, and do science," says Daniel Barry, vice president and director of research and development at David Clark Company, and head of the Constellation space suits project.
The new space suit will consist of two configurations. The first is similar to the current space shuttle escape suit, and it is designed for launch, reentry, and emergency operations in zero gravity. It's soft and allows for mobility in the event of pressure loss or in case crew members need to abort.
When existing space suits are pressurized, they tend to stiffen. For the Constellation suits, Barry's team has built in panels of material at the joints--shoulders, elbows, and knees--that keep the volume inside the suit constant, allowing astronauts to easily move. David Clark engineers are also developing breathable materials for the suit, making them more comfortable than the conventional urethane- or neoprene-coated nylon fabrics.
The second configuration of the Constellation space suit, which will be used for lunar excursions, uses the same arms, legs, boots, and helmet. These are snapped onto a new reinforced torso equipped with life support, electronics, and communication systems. Astronauts will also put on an outer garment to protect them from the harsh lunar atmosphere, including micrometeorites. Engineers are also working on enhanced materials to combat the very fine lunar dust, which, as NASA learned from the Apollo missions, can be problematic and hazardous to the crew.
The new design will eliminate many of the hard elements that add weight to current space suits and can injure the crew in the event of a rough landing. Instead, engineers are using lightweight composite structures. Furthermore, astronauts will be able to get in and out of the suit more quickly through a rear zippered entrance. The current suits are made of two pieces that take three hours and a helping hand to put together.
Barry says that a single modular suit will be cheaper to manufacture and will reduce launch mass and logistical complexity. David Clark Company has built an early prototype that will undergo testing next week at NASA with the new crew exploration vehicle, called Orion, which is also being developed for the Constellation program.
Hill says the first completed suit will be ready for testing in September, and the final suit design will be ready by 2013 and ready for flight in 2015. The lunar suit will incorporate OLED displays and a computer, and will act like a node on the Internet, relaying data back to Earth.
In the coming weeks, the Obama administration will make a decision on the future of U.S. human spaceflight, which could significantly change the direction of the Constellation program. "The bottom line is that if we are going to do manned missions, we need a new space suit," says Hill. And, he adds, "we have made the suit modular for that reason; if they decide to skip the moon and go to Mars, it does not change our architecture."
By Brittany Sauser
From Technology Review