By MICHAEL BENSON
Human space flight is at a tipping point. Next September, after 29 years of flights, the Space Shuttle is scheduled to be launched for the last time. The future of U.S. crewed missions is currently being reviewed at the highest levels of the Obama administration, with a decision expected early next month.
This follows the delivery in October of a rather bleak reassessment of the activity by an expert commission led by Norman Augustine, the former Lockheed Martin CEO. Its verdict was that without an increase in funding, U.S. crewed space flight “appears to be on an unsustainable trajectory.”
It is inconceivable that the United States, the leading spacefaring nation, will stop sending astronauts into space. But if flagging public interest in their work is ever to be revived, the Obama administration needs to articulate a bold vision capable of relegitimizing crewed missions, and then back it with real money.
The only credible reason to continue is to make astronauts true explorers again. A revivified program would send them on missions into deep space for the first time in decades, and it should include substantial international participation, allowing the sharing of costs.
In the nearly 40 years since Apollo 17 returned from the Moon in December 1972, no human being has traveled further from Earth than a car can drive on its surface in only a few hours. For all its virtues, the highest the Shuttle ever flew is about 385 miles.
By contrast even the comparatively primitive two-person Gemini spacecraft of the mid-60s achieved a maximum altitude of 850 miles — more than twice as high.
As for the International Space Station (ISS), at about 210 miles above Earth it’s so low that it has to be periodically boosted higher because its orbit is perpetually decaying due to residual atmospheric drag. And it flies, of course, in circles — with no destination.
For all the engineering genius and astronaut skill involved, it is hard to label missions that never leave the mouth of their harbor true exploration, and public interest in the activities of the astronaut corps has largely waned since Apollo.
While altitude records and hard destinations don’t necessarily need to be the goals — the space station is arguably useful both to rehearse international cooperation in space and to research long-duration space flight in preparation for actually going somewhere — the end of the shuttle program presents a clear opportunity for a new human mission beyond Earth.
Of the three options seriously considered by the Augustine Committee, the one that makes the most sense involves charting what it calls a “flexible path” to Mars.
In this scenario, a series of increasingly daring deep space missions to intermediate destinations, such as near-Earth asteroids, will allow the development of technologies and capabilities necessary for an eventual crewed landing on Mars later in the century. A return to the Moon is not excluded — spacecraft intended to explore Mars could eventually be tested there, for example — but the Moon would not be the main destination.
As long as the eventual exploration of Mars remains a firm goal, this graduated approach has a number of virtues. It initially avoids the great expense associated with the development of a landing system for the Moon or Mars, thereby staying within a comparatively low annual budget boost for NASA of about $3 billion.
It permits the incremental development of increasingly sophisticated technologies, rather than the construction of a full-blown Moon or Mars trip architecture from the ground up. It potentially benefits from a deepening of existing international space cooperation, as demonstrated in the ISS project — which, apart from the United States, includes Canada, Europe, Russia and Japan. Most critically, it allows astronauts to boldly go where no one has gone before — a prerequisite for capturing the popular imagination, as the Star Trek franchise has always understood, but not necessarily NASA.
Apart from the excitement sure to be generated by long-duration crewed missions, there are excellent reasons to commit astronauts to the exploration of near-Earth asteroids.
In recent decades awareness has grown of the real danger these objects pose. As the dinosaurs discovered 65 million years ago, the impact on Earth of an asteroid of a diameter of one kilometer or greater would produce catastrophic effects. To date, almost a thousand such asteroids have been found — a figure thought to be a very low percentage of the total.
A crewed investigation of one or more asteroids would represent a significant advancement in our understanding of such objects, with one goal being to determine potential ways to deflect them from a dangerous trajectory.
Because asteroids have such slight gravity fields, their investigation wouldn’t require expensive landing craft. Instead, space-suited astronauts with rocket-propelled backpacks such as NASA has already tested could easily conduct detailed surveys.
Asteroids may be a worthwhile intermediate step on the way to Mars for another reason: they’re quite literally gold mines. For example, 433 Eros, the first asteroid ever discovered, is thought to have more gold, silver, zinc and other exploitable metals than could ever be mined from the Earth’s crust — all in a package only 34.4 × 11.2 × 11.2 kilometers in size.
The comity that such international missions could establish would be considerable. China, which has only recently demonstrated an ability to send people into space, has repeatedly expressed an interest in being included in the ISS program. (Its approaches were rebuffed by the Bush administration.)
A series of U.S.-led deep space missions that might included the Chinese as well as Canadians, Europeans and Japanese would be a truly meaningful expression of international cooperation and a significant antidote to centrifugal political forces back on Earth. They would also make it far easier to fund an ambitious Mars landing and exploration program later in the century.
The path to the planets, it seems, contains both dangers and opportunities. We should take it for both those reasons.
Michael Benson is the author, most recently, of “Far Out: A Space-Time Chronicle.”