WEEKLY WHINE

Continuing the commitment to space

The final report of the Review of US Human Spaceflight Plans Committee was released last week, and its contents did not come as a significant surprise. The committee believed that there were several meaningful options for human exploration of space, all of which require more money than NASA is currently allocated.

Planning for human spaceflight, the committee reasoned, should begin with the goals to be achieved. At this point, it should be obvious that the goals of NASA’s human spaceflight efforts should be to establish a permanent, sustainable human presence in space with maximum scientific gain. These are precisely the areas in which NASA’s position and expertise are valuable.

The committee evaluated a few representative options, all of which followed from the answers to five questions that the committee identified as framing questions. The committee argued that the answers to these questions would determine how to proceed.

So, as a public service, we here at GoobNet are now going to answer those questions for you.

WHAT SHOULD BE THE FUTURE OF THE SPACE SHUTTLE?

The Space Shuttle has met its goals, but it is approaching time for retirement. Under US president George W Bush, NASA planning called for retiring the Shuttle in 2010, and extending the programme significantly would incur additional costs of recertifying it. Therefore, the Space Shuttle should be retired once the International Space Station is completed.

WHAT SHOULD BE THE FUTURE OF THE INTERNATIONAL SPACE STATION?

Currently, the ISS is planned to be closed down in 2015. This would be a grave mistake. The ISS has only just reached a capacity of six residents, and to allow only six years of full operation would be a gross underuse of this resource. There is considerable demand for experiments on the ISS from universities and research organisations. In addition, extending the ISS provides the opportunity to test hardware in low Earth orbit, as well as the chance to simulate solar system exploration [perhaps by introducing an artificial delay in ground communications]. Finally, were the US to withdraw from the ISS after only six years of full operation, the ISS’s other partners would surely question the US’s reliability as a mission partner.

Therefore, the ISS should be extended, with scientific experiments to be provided by an international user base as well as by NASA itself, to make use of its unique capabilities. NASA should also examine the possibility of turning the ISS over to the private sector rather than deorbiting it.

ON WHAT SHOULD THE NEXT HEAVY LIFT LAUNCH VEHICLE BE BASED?

The next heavy lift launch vehicle should be based on the Ares system that is already in development; there is no reason to abandon the technical work that has been completed so far. We also concur with the committee’s recommendation to emphasise lifecycle cost – the cost of a system over its entire mission life – rather than development cost.

HOW SHOULD CREWS BE CARRIED TO LOW EARTH ORBIT?

NASA should accelerate development of the Ares 1 in hopes of closing the gap between the end of the Space Shuttle programme and the first Ares 1 launch. It should also maintain the option of human rating the Delta 4 or Atlas 5.

WHAT IS THE MOST PRACTICABLE STRATEGY FOR EXPLORATION BEYOND LOW EARTH ORBIT?

The committee proposed what it calls the Flexible Path, wherein manned missions can visit any of several possible destinations, including Lagrange points, near Earth asteroids, lunar orbit, Mars orbit, and Mars’s moons. Another alternative would be to conduct long duration missions to the Moon as preparatory work for Mars landings.

Each of these approaches has its drawbacks. With the Flexible Path, many of the possible destinations have little scientific interest. With the Moon first plan, there is no opportunity to test long term missions away from Earth’s sphere of influence.

Therefore, the best approach is a combination of these methods, which we call the Simultaneous Path. Under this approach, several simultaneous missions are conducted. For instance, the first round of missions could include trips to Earth-Moon Lagrange points and the lunar surface. Each of these missions would be up to several weeks in duration. The second round could include trips to Earth-Sun Lagrange points, near Earth asteroids, and the lunar surface, all up to a year in duration. The third round could include trips to more distant near Earth asteroids, the lunar surface, and Mars orbit.

This approach maximises scientific interest by ensuring that a variety of destinations are visited at the same time. It maximises public interest by providing a new set of destinations with each round of exploration. It maximises cost efficiency by building up to longer and more complex missions one step at a time.

We have now told you what humans should do in space over the next twenty or so years, and how they should do it. All that remains at this point is for US president Barack Obama and the US Congress to allocate sufficient funds to NASA to complete these clearly worthy objectives.