NASA’s announcement that it will be hosting a media teleconference Tuesday afternoon (May 24) “to discuss an agency decision that will define the next transportation system to carry humans into deep space” has prompted speculation that NASA is ready to lay out its heavy-lift launcher plans.

Don’t count on it.

The semi-official word is that NASA’s associate administrator for exploration systems, Doug Cooke, will talk about the agency’s plans for transmuting the Constellation program’s Orion Crew Exploration Vehicle into the Multi-Purpose Crew Vehicle called for in the NASA Authorization Act of 2010.

NASA’s decision, whatever it turns out to be, should help end — for good or ill — some of the uncertainty at Lockheed Martin Space Systems, the Orion prime contractor since 2006.

As for the heavy-lift decision, NASA officials speaking at the National Space Society’s International Space Development Conference in Huntsville, Ala., last week said that a go-forward plan for the so-called Space Launch System will be delivered to Congress in late June or early July.

In the meantime, we are hearing with increasing clarity that the congressionally mandated heavy-lifter will look an awful lot like the Ares 5,  the behemoth NASA began designing in 2006 for manned Moon missions. Ares 5 did not factor into the Obama administration’s flexible-path approach to getting astronauts out of low Earth orbit.

Nevertheless, the Space Launch System likely will feature side-mounted solid rocket boosters and an upper stage design — and contracts — brought over from the defunct Ares 5 program. Its lox-hydrogen-powered core stage would be built by the winner of an open competition.

When Congress demands that you get started right away on a heavy-lift rocket that can lift as much as Ares 5  — and make maximum use of existing infrastructure, hardware, designs and contracts — it should come as no surprise if the new rocket ends up looking a lot like the old rocket.

It’s not exactly rocket science.

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...