Micrometeorite debris is a very real threat to the safety of any astronaut. Since the orbiter is designed to spend an indefinite time in space, it is probable that it could be hit by such debris. In turn, the vehicle needs to be able to survive a substantial impact to any location of the orbiter and still be able to carry out its mission objectives.

    Two scenarios are likely to occur due to a micrometeorite impact - depressurization or fatal damage to the thermal protection system. Damage to the TPS has been resolved by the use of the new ARMOR plating as opposed to the ceramic tiles used on the shuttle, but for extra security two layers of ARMOR is used so that an impact to the outer layer would not compromise the inner layer's integrity. The details of the TPS and ARMOR can be found in the TPS Subsystem Report.

    Depressurization is a very real possibility as well, and in turn the inner layer of the vehicle airframe is lined with Kevlar and Teflon. This, while not maintaining pressure, prevents internals from being damaged by the impact and keeps an "exit wound" from forming, or two breeches in the hull by the same piece of debris. The Kevlar and Teflon will slow the depressurization, allowing the astronauts to enter their pressure suits, or if docked to exit the vehicle and seal the hatch.

    Not all debris impacts during spaceflight are detected when they occur, and such impacts should be known before any reentry. In turn, several small robots, spheres the size of a basketball, are available inside the crew cabin. These robots, can be powered via either umbilical or internal batteries and propellant tanks depending on the circumstances. These robots can venture through the orbiters airlock or via the Quest airlock on the International Space Station. With the use of high resolution video and still cameras, the astronauts and Mission Control can teleoperate the robots and inspect the vehicle skin for any damage. This teleoperation and data transmission is provided by the same 802.11a wireless network that serves as a redundant communications channel between the orbiter and the station, as indicated in the Communications Subsystems Report. While the orbiter is in a docked configuration, these inspections would be done on a weekly or biweekly basis and could be autonomously controlled via the orbiters computers, sending the images to Mission Control for inspection at their convince.

    In the event that damage is believed to be to great to allow reentry, another orbiter can be sent to retrieve the crew, leaving the original orbiter unmanned to reenter autonomously for repairs if it is able to service reentry. The transfer of crew person will will be conducted in a manner similar to a Shuttle Rescue mission. However, a true hard dock would be preferred in this configuration, and is possible with the rescue orbiter facing the aft of the original orbiter. Again, the rescue orbiter would be unmanned to start, but given the autonomous nature and the watchful eye of Mission Control, this does not present a problem.