Tag: Orion

NASA’s refurbishment plans for the mobile launcher and SLS launchpad suggest that the first manned flight of SLS is increasingly likely to be delayed from its present 2021 launch date.

The situation is complicated. The SLS configuration that will launch an unmanned capsule in December 2018 will use a Delta rocket upper stage, and will only have the capability of launching about 70 metric tons into low Earth orbit. After this one flight NASA wants to begin using SLS’s own upper stage, which it calls the Exploration Upper Stage and which will raise the rocket’s payload capacity to 105 metric tons. Because these changes will make SLS taller, however, they have to refurbish both the mobile launcher that brings the rocket to the launchpad as well as the launch tower used to fuel the rocket during countdown. These changes, now scheduled, will shut down the launchpad from January 2019 until the end of 2020.

The problem with doing this is that SLS’s second flight, presently scheduled in 2021, is supposed to be manned. To use the Exploration Upper Stage untested on this manned flight is something NASA doesn’t really want to do. Flying another unmanned flight to test that upper stage however will require NASA to delay the first manned flight again, probably to 2023.

Based on the article at the link above, those delays now seem almost certain. Because NASA is moving to refurbish the launchpad right after that first unmanned flight in December 2018, this means all later SLS launches will use the Exploration Upper Stage. Since Congress has also ordered NASA to fly its upcoming Europa orbiter mission on SLS, it seems to me that NASA is now quietly moving to add a second unmanned SLS test flight between the rocket’s first flight in 2018 and the first manned flight and will use it to launch the Europa orbiter some time in 2021. This will in turn delay the launch of that first manned flight, probably until 2023, a date that is presently listed in many NASA documents as the latest SLS’s first manned mission will fly.

If this is the case, it means that it will have literally taken NASA two decades to build and fly a single manned Orion capsule, beginning when George Bush ordered the construction of the Crew Exploration Vehicle in January 2004.

Does no one but me see something wrong here?

Link here. The article gives an excellent and detailed overview of where construction of SLS presently sits, what the problems are that still remain, and what they have done to overcome them.

What struck me most however in reading the article was how long it takes them to do anything. For example, it appears they will assemble the rocket in the spring of 2018 for a December launch. In fact, the description of this assembly in this article partly explains to me why SLS will have the ungodly slow launch rate of at best once every two years.

In addition, the article describes how NASA has handled a number of engineering issues that have come up, and for each the approach seems to me to be more complicated than necessary. However, I am not an engineer and have never been part of this kind of work. Maybe everyone does it this way.