Commercial Spaceflight Companies Take Different Approaches to Seat Egress Safety

4

An artist's rendition of passengers free floating in SpaceShip Two (Credits: Virgin Galactic).

Commercial Spaceflight operators such as Virgin Galactic and Armadillo Aerospace aim to provide tourist spacefarers with a view of Earth and a true experience of weightlessness – including the opportunity to float free of seat restraints. As Air & Space Smithsonian reports, however, there may be some safety concerns associated with such a free float.

 “Unstrapping and re-strapping in such a short time frame would be a risky endeavor,” says Mike Masse, communications representative of spaceflight operator XCor. He believes that passengers will be so engrossed by the spectacular view that they won’t mind being confined to their couches, as they would be on an XCor Lynx suborbital flight, designed to carry a single strapped-in passenger.

Veteran astronauts are warning that reseating passengers may be more complicated than suborbital providers are anticipating, estimating anywhere from 30 seconds up to 2 minutes will be needed for each passenger to be reseated at the end of a microgravity experience – and that’s only if they do not become spacesick from the additional motion.

Virgin Galactic however, isn’t concerned. “We’re confident that our customers will be both ready and eager to get up out of their seats once they reach space,” says James Vanderploeg, the company’s chief medical officer. With SpaceShip Two’s smoother G transitions relative to parabolic flights such as those provided by ZeroG, Vanderploeg doesn’t think maneuvering into and out of seats will be a problem for passengers. Neither does Neil Milburn, vice president of program management at Armadillo Aerospace. “Audible and visual cues will signal that weightlessness is about to end, and of course, training will be provided prior to flight,” says Milburn. He estimates only 10-20 seconds will be needed for passengers to resume their seats.

Adequate passenger restraint is a flight qualification requirement by the United States in order for a spaceflight provider to received authorization to operate. 5 or 6 point seat belts are now the standard in order to provide protection from G forces in 3 axes. Helmets that integrate into either seats or seat belts protect the head and neck from directional injury such as whiplash. Space tourists will need to be trained in the use of all these elements prior to any suborbital flight.

Virgin Galactic’s promotional video envisions passengers unstrapping to enjoy 4 minutes of microgravity:

 

Bookmark and Share
Did you enjoy this article?
Share
It!
Subscribe to our Weekly Newsletter

4 Responses

  1. Doug Jones

    Six minutes seems a bit high, that’s 360 seconds, so the fall time from apogee is 180 s, making the re-entry speed nearly 1800 m/s, and the fall distance about 160 km. If the only deceleration is via drag without any modulation of the drag area, it takes less than two scale heights of the atmosphere (H=kT/Mg, ~8km) to come to a near-halt. If you fall 160 km at one gee downward, it will take about 11 gee to decelerate in 1/10th the distance. I think VG’s numbers got garbled in translation; the video shows a countdown timer running from 3:57 back.

    I’m pretty sure that a bit under four minutes arcing over the top will be a memorable experience, though! I know I’m looking forward to it, myself.

    Reply
    • Merryl Azriel
      Merryl Azriel

      Thank you for your analysis – you are absolutely right. SpaceShip Two is expected to average 3-4.5 minutes of microgravity per flight according to Virgin Galactic’s payload guide.

      Reply

Leave a Reply

Your email address will not be published. Required fields are marked *