Mr. Pritchett finally has sent back some recommendations on my draft.  Amongst other things, he recommended not using the X-38 airframe, but the X-33, as the X-33 has accommodations for ascent rocket engines, where the X-38 does not.  In my opinion, this is not a big deal, and the X-33 airframe will serve me well.  The X-33 is very large, originally designed to be a reusable unmanned vehicle to carry payloads into orbit that the Shuttle usually would.  With this in mind, I will use the X-33 airframe with X-38 systems, most notably keeping the parafoil.

I was to get together with Mr. Peters this past weekend, but unfortunately he was called out of town at the last minute.  We haven’t yet decided when we will reschedule to, but the sooner the better.  He still wonders about the maximum altitude this launch system can reach, and that’s something I am not yet able to answer.  I will remind Mr. Pritchett that I need to determine this and hopefully he can ask one of his colleagues.

I also worked with Dave Bottrill, a fellow senior, on ways we can get more altitude, velocity, and payload out of the An-225 heavy cargo lift plane.  Turns out that the An-225’s engines are not nearly as powerful as what is available today, and they have a habit of being unreliable.  So the obvious room for improvement is the engines, and General Electric has just the thing.  One of their engines, used on the 777 passenger aircraft, has a thrust of 115,000 pounds of thrust.  The An-225’s engines only have 53,000 pounds of thrust.  By replacing all six engines with the ones from General Electric and by increasing the An-225’s wing surface area, we can get more payload, velocity, and altitude, each trading off with the other.  I hope to get equations to quantify these improvements in the near future so I can determine the optimal launch point, but at first glance I think that increased payload will probably be the most important, so more fuel can be carried if the original 240,000 kilograms of fuel in the second stage is insufficient to attain ISS orbit.

I have also compiled a binder with my research up to date on the X-38, MAKS, RD-261, RD-701, and these various propellant types I have reviewed.  I still need to add more data on the An-225, including its original and replacement engines, and the X-33, but it’s a good start.

I did not get to review the launch system this weekend due to the loss of Columbia.  This obviously changes my Senior Project, but how it changes it I am not sure.  Everybody who sees my presentation will be thinking about its loss.  I assume that I will have to consider the Thermal Protection System and the aerodynamic structure and demonstrate how these are better and more rugged than the Shuttle.  Originally I intended to use additional sensor and health monitoring technologies that SLI has created in order to increase safety and reliability.  After this incident, it is obvious that this is a necessity.