Space Shuttle mid-deck, it doesn't look like there is much for the astronauts there to do.

I recognize this photo was not taken during a mission. enter image description here I couldn't find an image of the mid-deck during reentry.

This diagram seems to indicate the astronauts on the mid-deck were facing the avionics bay. enter image description here

If they did have responsibilities, what were they?

  • $\begingroup$ Sit down, hold on, and shut up is my guess. $\endgroup$
    – GdD
    Mar 9, 2020 at 23:13
  • 35
    $\begingroup$ For such an amazing trip, that is one lousy view. $\endgroup$
    – Bob516
    Mar 10, 2020 at 0:51

1 Answer 1


There were no nominal activities for the middeck crew related to flying the vehicle. There were no switches or controls on the middeck accessible to seated crewmembers in the ascent/entry seats. The rectangular objects in the photo are middeck lockers which are located external to the avionics bays.

enter image description here

Mission Specialist 3 (MS-3) did have responsibility over side hatch jettison, an action that would be taken only in the case of the Orbiter not being able to reach a runway, and which was never taken in the real world. MS-3 would also extend the escape pole through the hatch opening, after which the crew would use it to bail out.

Accordingly, there are two nominal callouts for MS-3 in the Entry Checklist, both related to the side hatch:

  1. Just before the deorbit burn, MS-3 unsafes the side hatch in case jettison is needed.

Remove and stow Side Hatch UV Filter and Locking Device, and Pyro Box Safing Pin

  1. After wheel stop, MS-3 safes the side hatch, since jettison is no longer required.


That is it for the nominal case. The timeline below shows the MS-3 actions for jettisoning the side hatch and deploying the escape pole during an Orbiter bailout contingency case.

enter image description here

MS-3 had one instrument visible to them, an pressure-operated altimeter mounted on the locker immediately in front of them. This allowed them to monitor the progress of the cabin being vented to ambient, an action that was taken prior to side hatch jettison.

enter image description here

(Images credit NASA, annotation and editing mine)

Source 1: Tom Jones described ascent and entry on the middeck in Chapter 7 of his memoir Sky Walking.

Source 2: Generic Entry Checklist

Source 3: Crew Escape Systems handbook

Middeck image source: Shuttle Crew Operations Manual


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