No, I have no idea why Horowitz is leaving the agency. I do know, though, that the story about "spending more time with the family" is usually code for something else. He obviously knows things about The Shaft that the rest of us don't, but it's not obvious that he's a rat leaving a sinking ship. On the other hand, it's certainly possible.

Also, I've heard rumors that one of the names in the DC madam's little black book was a high-ranking NASA official, but again, no particular reason to believe that it's him, even if they're true.

Either way, as Thomas James notes, it would be nice if he'd take his toy with him, but it's unlikely.

[Update a few minutes later]

Chair Force Engineer, who has been speculating about Orion's mass issues, has further thoughts.

The fact that Scotty is leaving at this time is significant. The engineering team at MSFC at this time has an intractable problem and Scotty was not helping. The problem is that the upper stage of Ares 1 simply can't do the job of lifting the Orion at its current weight which is not dropping due to Scotty and his former co workers demanding space inside the capsule.

MSFC has been seriously looking at a two J2X upper stage but that opens a huge can of worms aerodynamically with basically a hammerhead design. The engineers have been looking longingly at the facilities a few miles away in Decatur where the EELV's are built. There is a possible solution to their problem in using a modified EELV design, one that is designed by NASA with part of the production done at the EELV plant and part at NASA.

What most are too young to remember is that the first Saturn's were built on site in building 4705 at MSFC which is where a lot of the ISS hardware was also built. A situation can easily be envisioned where the booster stage of a liquid Ares 1 could be built in Decatur (which also barges its hardware to the cape using the same locks at Wheeler, Wilson, and Pickwick dams that were built for the Saturn) and the upper stage built by contractors in 4705.

This would accomplish two positive things. If the EELV by the name of Ares 1 was built in Decatur it would help cover the ongoing overhead of the facility (that big fat check from the USAF every year) and reduce the size of that big check so the USAF is likely to like this.

The Upper stage, built at MSFC would help to cover some of the ongoing overhead there and help to reconsitute some of the manufacturing knowledge base there. It would not tax any of the facilities so MSFC could easily make the case further down the road for the construction of the LSAM. There is still a lot of ISS manufacturing assets at MSFC and the upper stage qualification test flights could easily be done there as well.

The performance of a "NASA" Ares/EELV system would be adequate to do the job for Ares 1 and if the idea from Lockmart to resurrect the liquid flyback booster (and overdesign Ares 1 for that task with two RD-180's on the booster) for the Ares 5 and now all objections from Mike could be overcome (Mike likes his big stick) and he could say that he is actually listening to some of the objections out there.

A flyback first stage for the Ares 1 would shake address the huge cost problem that the lunar outpost has, because it has been found that the current Ares 5 is about 13t shy of the performance that it needs as well and no matter what is done with the LSAM design, the Tony Lavoie architected outpost buildup scenario of mixing cargo and humans is not workable. The flyback booster (whether it is flyback or not) solves the weight problem for the Ares 5 as well as the total impluse for the Atlas (excuse me Ares 1) style booster is much better than (and specific impluse) then Thiokol solution.

Can't happen?

With Scotty out of the way this could easily happen. It solves a lot of problems and keeps those pesky DIRECT guys from being able to say that they did anything to influence the design as in reality this goes back to some of the ideas from the early days of SEI, updated.

Interesting comments.

MSFC has been seriously looking at a two J2X upper stage but that opens a huge can of worms aerodynamically with basically a hammerhead design.

It also creates a new failure mode--single engine out could be uncontrollable without a lot of gimbal (this caused a loss of at least one Centaur). With a single engine, it either lights or it doesn't. If it doesn't you abort. But a tumble caused by a single-engine ignition on a two-engine stage could be nasty.

In those comments it was not meant that the qualification "flights" be at MSFC, just the ground qualification. For those who don't remember, each Saturn flight stage was test fired on the test stands at Michoud. This could happen there or at MSFC.

There is still a strong possibility also of a stealth effort to do a truly STS derived design rather than the total screw up that has been Ares 1. A sidemount Shuttle C would be much cheaper than an Ares 5 development program and this would be a way to keep STS flying through FY 12 or 13 while integrating higher performance upgrades into the Shuttle stack. The Ares 1 program office has recently adopted one of the major pre Columbia STS upgrade ideas, which is to abandon the existing SRB TVC system and go with the Thermal Battery/EMA gimbaling system. This saves a lot of weight and problems with SRB refurb and could be integrated into the STS system as part a human rating/ flight qualification program.

The direction will be strongly influenced by the lunar mission cost (now that the LSAM cargo vehicle is coming back into the baseline architecture, along with the cost of a separate dedicated cargo mission), and congressionally mandated STS workforce retention. in the end the workforce issues may be the deciding factor to drive toward a true STS derived system (which brings some other Lockmart derived STS dual SRB booster designs back into play.

There are two problems with a flyback booster. First, building a flyback boostefor a huge rocket with a tiny market makes no sense (the Shuttle mistake). Although that might not stop NASA from proposing it.

Second, NASA's official line is that reusable vehicles are impossible. If they admit otherwise, the wbole architecture is in question. Why an expendable capsule instrad of a reusable spacecraft? Why heavy lift instead of orbital assembly? Why does NASA need to own a other space transportation system instead of obeying the Launch Service Purchase Act?

I've already posted a comment about Horowitz's departure here:

http://www.transterrestrial.com/archives/009365.html

however, I think you can find the TRUE reason on Wikipedia:

http://en.wikipedia.org/wiki/Scapegoat

it's easy to understand why he will(must?) leave NASA...

his Ares-I can't work as expected nor carry an (heavy) Orion

the Horowitz's rocket (or the entire ESAS plan) needs DEEP changes

but they can't do that changes with the same guys that failed

then, they need a person that accepts to take all guilts on himself

clearly, if Horowitz has made some mistakes on the Ares-I design HE is the right person for this job

so, when they will change something (or everything) in the plan, they will say:

"sorry People/Press/Congress/President... it was an Horowitz's mistake..."

mixing cargo and humans is not workable.

Proven by the failure of Fed Ex, UPS, and every other land, sea, and air cargo operation -- none of whom have ever separated humans from cargo???

The "unmanned" religion has never produced a safe, affordable transportation system in space or on Earth.