It was September 2005, and NASA administrator Michael Griffin faced down a room of reporters at NASA Headquarters in Washington, D.C.

Griffin had only been in charge of the agency for five months, having been nominated by President George W. Bush to succeed Sean O'Keefe, who resigned in December 2004.

In part one of our new Horizon Goal series, we examined how the president laid out a bold new vision for NASA in the wake of the Columbia accident that would retire the space shuttles in 2010, build and fly a new deep space crew vehicle by 2014 and land humans on the moon by 2020. The new program was called Constellation.

At the time, the space shuttle was America's only means for shipping crew and cargo to the International Space Station, which was scheduled to be completed in 2010 and de-orbited in 2016. NASA's potential alternatives included relying on foreign partners, outsourcing ISS runs to the private sector, using the yet-to-be-built crew vehicle, or some combination of all three.

To Griffin, this was untenable: NASA needed an in-house shuttle successor, and a plan to kick Constellation into high gear.

He commissioned an agency-wide tiger team which produced a report called the Exploration Systems Architecture Study, or ESAS. The report concluded NASA should build two new rocket systems and make the crew vehicle a gumdrop-shaped capsule similar to the Apollo vessels that first carried humans to the moon.

Constellation had a new look, and this press conference was the big reveal. In response to a reporter's question about the crew vehicle, Griffin made a remark that came to define the program.

"Think of it as Apollo on steroids," he said.

During the Apollo years, in 1966, NASA's budget peaked at $44 billion (all costs in this article have been converted to 2016 dollars for ease of comparison). But in 2005, the agency's budget was less than half of that, and that continues to be the case today.

Could NASA really do Apollo on steroids with one-half the funding?