Earth Orbit to Lunar Surface
Home Tour Join! Contents Team News Catalog Search Comm

Risks to the Ascent Stage During Descent to the Lunar Surface

The original reference mission called for using one of the descent engines for ascent, which raises the question of what happens if we subject the ascent stage to a very rough landing. If the spacecraft stack lands so hard that collapses the landing gear, impact with the lunar surface could damage the ascent engine. In fact, depending on how the gear collapsed, other equipment in the ascent stage could be damaged, stranding the crew on the surface.

This is a serious concern that has only come up recently. If the reusable engine remains part of the design, we will need more detailed analysis as the overall spacecraft develops. There may not be a plausible scenario for the crew to survive a crash landing that does extensive damage to the descent stage.

There is another, known risk to this approach to the ascent stage: no abort during descent. The Apollo spacecraft had the ability to separate the ascent stage from the descent stage and fly back to lunar orbit as a last-minute abort scenario in the terminal landing. The Artemis spacecraft, however, designed to leave as much equipment as it can on the lunar surface, loses that safety feature.

Initial Lunar Base Deployed on the Moon These concerns added to the decision to move the Ascent Stage to a position alongside the Descent Stage, as shown in the picture at the right, rather than sandwiched in between the Habitat and the Descent Stage. The exploration base habitat has been rotated from its vertical landing position in this illustration by Vik Olliver. The Ascent Stage, seen at the left side of the picture, is shown where it will be throughout the flight, until the crew is ready to come home from the moon.

The sidesaddle orientation of the Ascent Stage also alleviates the problem of the crew falling below the Dead Man's Curve. With its engine clear below and the crew already aboard, they will be able to abort back to lunar orbit at any time almost all the way down to the surface.

See section 4.2 of the Artemis Data Book for more information on the spacecraft design.

Earth Orbit to Lunar Surface

Home Tour Join! Contents Team News Catalog Search Comm
ASI W9600319r1.1. Copyright © 2007 Artemis Society International, for the contributors. All rights reserved.
This web site contains many trade names and copyrighted articles and images. Refer to the copyright page for terms of use.
Author: Gregory Bennett. Maintained by Jeremy Kraemer .
Submit update to this page. Maintained with WebSite Director. Updated Sat, Jul 12, 1997.