lable at ScienceDirect

Space Policy 29 (2013) 229e230

Contents lists avai

Space Policy

journal homepage: www.elsevier .com/locate/spacepol

Viewpoint

Response: Against manned space flight programs

Steven Weinberg 1

University of Texas at Austin, USA

a r t i c l e i n f o

Article history:Received 20 October 2013Accepted 20 October 2013Available online 16 November 2013

Keywords:Manned space flight

E-mail address: weinberg@physics.utexas.edu.1 Nobel Prize in Physics, 1979.

0265-9646/$ e see front matter � 2013 Elsevier Ltd.http://dx.doi.org/10.1016/j.spacepol.2013.10.005

a b s t r a c t

Richard Rovetto has done a good job of assembling various arguments that are commonly advanced for aprogram of manned space flight. I will take them up one by one, and explain why I find them allunconvincing.

� 2013 Elsevier Ltd. All rights reserved.

1. Science

It is argued that “Scientific discoveries extending the frontiers ofhuman knowledge are both a focus and a benefit of human spaceexploration”. It is certainly true that observatories based in spacehave enormously extended our knowledge of the universe. TheCOBE, WMAP, and Planck radio observatories have studied smallfluctuations in the cosmicmicrowave radiation, which give detailedinformation about physical processes in the first 380,000 years ofthe Big Bang, and that mark seeds from which the galaxies of thepresent universe grew. Observations at the Hubble Space Telescopein conjunction with ground based observatories have revealed thatthe expansion of the universe is speeding up, presumably becauseof a mysterious dark energy inherent in space. Other spaced-basedobservatories havemade historic studies of astronomical sources ofX-rays, gamma rays, and charged particles, and the Kepler obser-vatory has found over a hundred confirmed planets around distantstars, and thousands of other possible planets.

All brilliant work, but with the single exception of a singleHubble repair mission, none of it has involved humans in space. It isunlikely that such a repair mission will be repeated. The newerobservatories like WMAP and Planck are at L2, a point a millionmiles from Earth that is now inaccessible to humans, and whererepair missions will probably never be cost-effective. The plannedJames Webb space telescope will also be at L2.

So what are the benefits to science of human space exploration?Rovetto can point only to studies of the effects of a microgravityenvironment. These studies have been frequently cited as a justi-fication for the enormous cost of the International Space Station,but I have not heard of anything of scientific importance that they

All rights reserved.

have revealed. In any case, with one exception, if microgravitystudies had any value they could all be carried out more cheaplyand probably more reliably on unmanned satellites.

The one kind of microgravity study that does require humanparticipation is the study of the effects of microgravity on humans.As far as I can see, the only possible importance of this research is asan adjunct to a program of human space flight. But this justificationdisappears if human space flight is notworth pursuing for any otherreason.

2. International cooperation

It is argued that “Space exploration affords cooperation on theglobal scale”. Manned space flight certainly has involved a grati-fying level of international cooperation, but so have many otherprograms of science and technology. The CERN laboratory nearGeneva is Europe’s first collaborative effort, and now is run by 20different European states, with active participation by physicistsfrom many other countries, especially the United States. Greattelescopes in Chile, Hawaii, and the Canary Islands are mostly builtand operated by international consortia. There is ITER, an interna-tional collaboration aimed at developing usable thermonuclearpower. Many other examples could be given. The special feature ofmanned space flight is not that it offers an opportunity for inter-national cooperation, but that it is cooperation for no good purpose.

3. Exploration

It is argued that “there is something significant and positive tobe said about reaching a summit, or diving to unknowndepthsdabout exploration in generaldbecause we can, andbecause it is there”. Some people do make a heroic effort to climbmountains, but they generally do not expect their expeditions to be

S. Weinberg / Space Policy 29 (2013) 229e230230

funded by governments, certainly not at the level of many billionsof dollars. For the foreseeable future, only a tiny fraction of hu-manity can ever go into space (not even all those in astronautprograms get into orbit), sowhy should the public in general pay fortheir thrills? As far as the thrill of new knowledge is concerned, thepublic gets that better from robotic explorers, like Spirit and Op-portunity on Mars, or from astronomical discoveries, like thewonderful photos sent from Hubble.

4. Inspiration

It is argued that manned space flight “provides a source of in-tellectual curiosity” and that “To remove an inspirational source ofthat imagination e human spaceflight e is to deprive present andfuture generations of a certain potential for greatness”. As a phys-icist who had been around for a long while, I have met many youngphysicists just beginning their careers, but I have never met onewho went into physics because they were excited about mannedspaceflight. Most were motivated by reading about real science.Though I can’t prove it, I suspect the same is true of most scientists.Manned space flight is a spectator sport, which like football can beexciting for spectators, but this is not the sort of excitement thatseems to lead to anything serious.

5. Spinoffs

It is argued that “Technological advancements and their publicspinoffs, such as artificial hearts and other applications to terrestrialneeds, are perhaps the most concrete benefits of spaceflight pro-grams”. Any large technological program is likely to produce some

useful spinoffs. We have seen examples of this in elementary par-ticle physics: the World WideWebwas developed at CERN to makeit possible for experimental physicists to share large volumes ofdata, and the synchrotron radiation that was originally an un-wanted byproduct of elementary particle accelerators is nowwidely used for the study of materials. But if I wanted to choose atechnological program that was least cost-effective in yieldinguseful new technology, I would choose manned space flight. Thegreat technological challenge of manned space flight is to keeppeople alive on space missions, a goal that has no value on Earth. Incontrast, unmanned space exploration makes severe demands onrobotics and computer programming, which have obvious terres-trial applications.

6. Human survival

It is argued that “The most pertinent long-term reason for hu-man spaceflight is survival as a species”. I don’t disagree with this,but it is a task for the distant future. In order to give humanity achance to survive a global catastrophe such as a large meteor strikeor an all-out nuclear war, an extraterrestrial colony would have tobe permanently self-supporting. The colony would have to possessthe industrial capacity to replace its equipment e solar panels, airsynthesizers, water mining machinery, hydroponics, etc. e when itwears out. We do not now have the capability to establish such apermanently self-supporting colony on Antarctica, a far morebenign environment than Mars or an asteroid. This is the realchallenge: not to get people toMars, but to free them from the needof support from Earth. Perhaps we should start with Antarctica.