When space shuttle Atlantis fired up its engines on July 8, beginning the STS-135 mission to resupply the space station one last time, the bittersweet tears for the end of an era had barely dried when the question: “So, what's next?" was asked.

Well, sadly, the answer is: “We're not sure."

But if you were to listen to NASA Administrator Charles Bolden, you'd think there's a super-secret replacement spaceship ready to be rolled out to the launch pad. In an upbeat statement to mark Atlantis's final touchdown on Wednesday, Bolden said:

The future is bright for human spaceflight and for NASA. American ingenuity is alive and well. And it will fire up our economy and help us win the future, but only if we dream big and imagine endless possibilities. That future begins today.

But how “bright" is the future for human spaceflight, really? Internationally, human spaceflight is the buzzword for technological prowess. Sadly, for NASA, it's become a political punch bag.

Perhaps it's to be expected that the former NASA Administrator Mike Griffin is at odds with Bolden's enthusiasm: “When you push aside all the puffery and high-flying political announcements, with the landing of Atlantis, the human spaceflight programme of the US will come to an end for the indefinite future," Griffin told the BBC on Thursday.

How can two administrators, from two different administrations, have polar-opposite opinions on NASA's human spaceflight program? Is it purely political? Or is there a genuine confusion as to where NASA is going?

One thing's for certain, for the thousands of highly skilled space shuttle workers who are now without jobs, the future is anything but rosy.

The Situation

The facts are as follows:

1) The shuttle fleet is now retired. No more shuttle launches; no more Hubble servicing missions; no more human spaceflight capability for NASA. No rocket on U.S. soil is currently human rated.

2) NASA must depend on Russia for access to the International Space Station, a project NASA is heavily invested in. NASA will pay Russia over $60 million per astronaut for the privilege of accessing space via the Soyuz spacecraft.

3) NASA has no concrete plans in place for the next heavy lift vehicle to launch next-generation spaceships beyond low-Earth orbit. Congress (not the Executive Branch) is setting guidelines as to what kind of vehicle this should be — a situation some commentators see as “ill-advised." A decision on the next launch vehicle is expected later this year.

4) A spaceship is currently being developed; a variant of the Orion capsule from the canceled Constellation Program. The “Multi-Purpose Crew Vehicle," however, doesn't have a rocket to launch it yet (see #3).

5) Commercial spaceflight will be heavily relied on for access to low-Earth orbit.

Now, the only real glimmer of hope for U.S. manned spaceflight in the near-term is #5; the commercial spaceflight wildcard.

Companies are seeing a profitable avenue into the spaceflight sector and many — like Elon Musk's ever impressive Space Exploration Technologies, a.k.a. SpaceX — are vying for the contracts provided by the US space agency to, initially, send supplies for the space station. Within a couple of years, they hope to deliver astronauts to the space station. Some of the long-term goals of the private sector are, well, exciting to say the least.

Unfortunately, depending on the burgeoning private spaceflight sector to build a viable low-Earth orbit space infrastructure seems like a gamble to many critics.

A Crossroads?

So where does the U.S. stand in the human spaceflight arena?

Due to decisions made in previous administrations, a timeline for the retirement of the shuttle was set without planning a suitable replacement program. Granted, the Constellation Program underwent a short period of development, but had to be canceled after the Augustine Commission advised it was too expensive and “not very do-able," according to commission member Leroy Chiao in a 2009 Discovery News interview.

Now we wait for the private spaceflight industry to take over as NASA continues to send astronauts to the space station (just because the shuttle is finished, it doesn't mean NASA's human spaceflight program is dead, it's just running at a reduced capacity) on board the Soyuz, rather than the shuttle.

As I've pondered before, this could mark a crossroads in U.S. human spaceflight; where expensive government space agencies are surpassed by commercial entities. But it could also mark an era where the U.S. lost its only manned access to space, lacked the political cohesion to build a replacement and the private sector failed to live up to expectations.

Although President Obama set the ambitious goal for NASA to develop new technologies and send astronauts to an asteroid by the “mid-2020′s," it seems hard to imagine it can be achieved when NASA is being tugged in every direction by conflicting politicians who would rather score points than understand the huge scientific advantages the space shuttle brought to the U.S. as a nation.

Yes, the shuttle was expensive and wasn't as sustainable as it promised, but it has forged 30 years of incredible science, international collaboration and kept the U.S. at the apex of human endeavors in space.

Rockets for Air-Conditioned Tents

With tough economic times and conflict down here on Earth, space exploration is considered a luxury, whereas dumping $20 billion into air-conditioned U.S. military tents each year is considered essential. NASA's entire annual budget is $19 billion.

Congressional attitudes toward science, for now, don't seem to be changing.

Case and point being the current struggle to keep the James Webb Space Telescope from being cut by Congress. It may be over budget, but the last time I checked, no one was questioning the Hubble Space Telescope's worth after it has changed our understanding of the Universe through 21 years of incredible scientific discoveries. (Yes, even the Great Hubble was more expensive than managers reckoned.)

Human spaceflight programs and space telescopes are, of course, two separate entities, but the outcome is the same. The shuttle doesn't have a replacement because of political hesitation, and we could soon lose the most powerful — half-built — telescope ever conceived through political ineptitude.

Whichever way you look at it, the spirit of exploration and discovery is being eroded and we're left wondering how NASA can possibly dream for a manned mission to an asteroid if the agency is constantly being short-changed.

Image: Workers measured and marked in bright red the letters “MLG" at the spot where space shuttle Atlantis' main landing gear came to rest after the vehicle's final return from space. Credit: NASA