Unless the USA comes to its senses, and includes its partners from the start, its new space exploration vision is doomed to fail

So the countries behind the International Space Station (ISS) have agreed what will be the final configuration of mankind's only outpost in Earth orbit. That is the easy part. Deciding how cargo and crew will get to and from the ISS is proving to be much more problematic.

Ever since NASA's Space Shuttle was grounded following last year's Columbia disaster, Russia has borne the burden of cargo resupply and crew transfer flights to the ISS. Russia will fulfil its commitment under the original international agreement when it launches the 11th manned Soyuz mission to the ISS next year.

What happens then will be the subject of tough bargaining over the coming months - negotiations in which the Russians would seem to hold the upper hand over the Americans, and in which the Europeans could play a key role in brokering any deal.

NASA is in a mess over the ISS. While US President George Bush's new space-exploration vision has given the agency a much-needed goal, the formidable challenge of implementing a sustainable "Moon, Mars and beyond" exploration programme within an essentially flat budget is forcing difficult choices.

To make such a programme possible, NASA plans to free up a large part of its budget by retiring the Shuttle upon completion of ISS assembly, scheduled for 2010, and to stop funding ISS operations around the time it launches its first manned mission to the Moon, planned for 2015 at the earliest and at the latest 2020.

For this plan to work, first NASA has to get the Shuttle flying again. If this takes longer or costs more than expected, then the space-exploration initiative could be off to a rocky start. And, even when NASA gets the Shuttle back in orbit, almost all the flights will be dedicated to completing assembly of the ISS - in particular to launching and attaching the modules that NASA's European, Japanese and Russian partners have waited so long to see fly.

In this situation only Russia can provide the bulk of the cargo resupply and crew transfer flights to keep the ISS operational. But with its original commitments to be fulfilled in 2005, the Russian space agency is playing hard ball: launch its modules and pay hard cash for additional Progress and Soyuz flights or there is no deal - and no ISS.

The USA has already tied its negotiators' hands behind their backs, first by passing legislation that bars NASA from buying Russian spacecraft, and then by cancelling its X-38 crew return vehicle. If the ISS is to continue operating, there is no alternative to using Russian vehicles. It will be interesting to see how a deal can be struck.

Talks over future access to the ISS come as the USA begins defining its space exploration programme architecture - a task restricted by law to US entities despite NASA's public pronouncements that its exploration vision can only be achieved through international co-operation. This is not the only example of NASA double-think. The agency's space exploration chief has said that the ISS is necessary for his long-range plans. Yet the NASA budget foresees a decline in US involvement in the ISS after assembly is completed. So the ISS partners would probably disagree with that view.

The reality is that maintaining a presence in orbit and exploring the Solar System will become mutually exclusive because NASA cannot afford to do both. Or, more accurately, because the USA chooses not to pay for both at the same time. This leads to questionable claims by US industry that NASA must first define its space exploration architecture then decide what role, if any, the ISS can play. Contrast this with European studies that point to an orbital hub as the logical jumping-off point for space exploration.

The flaw in NASA's approach is that its space exploration plan must first be something the USA can accomplish alone. Only then can international participation be considered. Unless the US government is prepared to be pragmatic, and not dogmatic, its "go as you pay" approach will fail. If nothing else, the growing conviction that only a new heavylift launch vehicle will make missions to the Moon and Mars possible could kill the programme before it begins. Paying to develop such a vehicle would empty NASA's coffers.

But there is an answer. Listen to the European, Japanese and Russian partners. Recognise the long-term value of a base in Earth orbit. Buy what can be bought and only develop what does not exist. And do not carry the territorial boundaries and technological barriers that divide the Earth into deep space.

Source: Flight International