The NASA Human Space Flight program is interested in projects where humans, beyond low-Earth orbit (LEO), can make an important and unique contribution that cannot be reasonably accomplished purely by robotic means, and is commensurate with the effort and cost associated with human spaceflight.

An artist’s rendering of the Shirtsleeves Assembly Hangar. At the lower right is a cutaway of the inflated fabric sphere that houses astronauts in oxygen masks and backpacks. The humans would work with a robot to accomplish the final telescope assembly.
Robotic space telescope missions have been conceived and launched as completed assemblies (e.g., Hubble) or as “jack-in-the-box” one-time deployments (e.g., James Webb). If it were possible to assemble components of a very large telescope from one or two launches into a telescope that was vastly greater in light-gathering power and resolution, that would constitute a breakthrough. Large telescopes on Earth, like all one-off precision assembly tasks, are done by humans. Humans in shirtsleeves (or cleanroom “bunny suits”) can perform tasks of remarkable dexterity and precision. Unfortunately, astronauts in pressure suits cannot perform such dexterous and precise tasks because of the limitations of the pressurized gloves.

If a large, inflatable “hangar” were placed in high orbit, along with all the components needed for a large assembly such as a large telescope, then humans in bunny suits could perform the same sorts of extremely precise and dexterous assembly that they could be expected to perform on Earth. Calculations show that such an inflatable hangar, and the necessary gas to make it safe to occupy by shirtsleeves humans wearing oxygen masks, fits within the mass and volume limitations of the proposed “Space Launch System” heavy-lift rocket. A second launch could bring up all the components of a ≈100- meter-diameter or larger telescope.

A large [200 ft (≈61 m) in diameter] inflated fabric sphere (or hangar) would contain four humans in bunny suits. The sphere would contain sufficient atmospheric pressure so that spacesuits would not be necessary [about 3.2 psi (≈22 kPa)]. The humans would require only oxygen masks and small backpacks similar to SCUBA tanks. The oxygen content of the gas would be about 35%, low enough to reduce fire risk but high enough to sustain life in the event of a failure of an oxygen mask. The bunny-suited astronauts could ride on long “cherry-picker” robots with foot restraints somewhat similar to the arm on the International Space Station. Other astronauts would maneuver freely with small propeller fans on their backpacks to provide thrust in the zero-g environment.

This work was done by Brian H. Wilcox of Caltech for NASA’s Jet Propulsion Laboratory. NPO-48441