From: Johnson Space Center
Posted: Monday, November 13, 2006
From: Hanley, Jeffrey M. (JSC-ZA)
Sent: Monday, November 13, 2006 3:54 PM
Subject: FW: NASA Encounters Problems With Ares 1 Launch Vehicle Design
All, between articles like this one (see below) and the wave of 'better ideas' for architecture that have waded into recent notoriety, I thought it was time to level set folks on where things stand - and - dispel these rumors and hearsay surrounding the "issue" of the Ares 1 performance and overall implications to the architecture.
In summary, many who carp from the sidelines do not seem to understand the systems engineering process. They instead want to sensationalize any issue to whatever end or preferred outcome they wish. So be it, that is the world we live in.
So where are we today, specifically on the issue of what the launch vehicle can lift and what the Orion is allowed to weigh?
First, the latest set of analyses indicate that the Ares I can lift 58 klbm to the program-specified injection point of -30 x 100 nmi. This number PROTECTS worst case propulsion performance on the first and second stage.
This compares favorably to the requirement that we specified for the Ares I to inject 52.1 klbm.
The Orion team is working to a control mass of NGT 48.4 klbm. They in turn carry margin within that allocation ranging between approximately 10-20% for mass growth as the design process proceeds.
Further, we have been fairly conservative on the amount of propellant we will load in the Orion Service Module for the lunar missions.
Both the Ares I performance and the Orion control mass are 'watch items' on our list of top program risks. This is NORMAL for any such development effort ... mass delivered to space has been and will always be a source of risk for any spaceflight project or program.
The Ares and Orion design teams are systematically addressing these challenges as part of the normal systems engineering cycle. For example, the Ares team made some early design assumptions for the upper stage that, if workable from a mass perspective, could have reduced the complexity of the stage making it easier to manufacture. Their findings through their recent analysis cycle indicated otherwise, and the team set out to modify the design to bring the mass down to within our targets.
Architecturally speaking, we have improved our performance projections over the past year for the amount of mass we can launch to TLI on a Lunar mission by more than 2 mT. We have a highly synergistic launch vehicle approach for Ares I and Ares V that gains high leverage off of our early investments in the 5-segment motor and J2X engine. Our selection of the RS68 engine for the Ares V core stage reduced our outyear costs by billions. And most significantly, our strategy is within our budgetary means for developing the associated launch infrastructure - something that most 'alternative' architectures largely ignore.
We will continue to get these faux expressions of concern from those who wish to see us fail.
They will be disappointed.
Constellation Program Office Houston, Texas 77058
NASA Encounters Problems With Ares 1 Launch Vehicle Design Keith Cowing
Saturday, November 11, 2006
Sources inside the development of the Ares 1 launch vehicle (aka Crew Launch Vehicle or "The Stick") have reported that the current design is underpowered to the tune of a metric ton or more. As currently designed, Ares 1 would not be able to put the present Orion spacecraft design (Crew Exploration Vehicle) into the orbit NASA desires for missions to the ISS. This issue is more pronounced for CEV missions to the moon.
The Ares 1 SRR (System Requirements Review) was held last week at MSFC. Mike Griffin was in attendance. Others participated off-site via webex.com.
It is widely known that both Mike Griffin and Scott Horowitz are reluctant (to say the least) about abandoning their current launch vehicle concept. Alternate approaches such as using EELVs are not welcome solutions by either Griffin or Horowitz.
One possible solution to the Stick's current design problems is to add side-mounted solid rocket motors. Many inside the program are not so sure that this solution is worth the effort. Others suggest that starting from a clean sheet of paper may be the only prudent course of action.
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