Comments for UN discussion on Disarmament, Peace, and Security
Dr. Laura Grego, Union of Concerned Scientists
October 21 , 2004
United Nations, New York City
Thank you Jonathan Dean for organizing this panel and thanks to the NGO Committee on Disarmament, Peace and Security for hosting the session, and for all those here who came to discuss the Prospects for Peace and Security in Outer Space.
I happen to believe that the prospects are pretty good, and today I'm going to tell you why. What I hope that you take away from my talk today is how technical considerations put real limits on what space is useful for. They shape what is possible for space security and they show us where we should be putting our energies to realize peace in space. Much of what I'll say today is drawn from a report on space security I'm preparing with two colleagues at UCS. The report is due to appear in early 2005, to be published by American Academy of Arts and Sciences. I invite you to seek it out, or to give me your contact information after the session so that we can get it to you.
As you are all no doubt aware, there has been a longstanding debate about what the appropriate uses for space are. This debate has grown in intensity in recent years first, because more and more countries have investments and aspirations in space and second, because, after about a decade of little apparent interest in space weapons, the U.S. has found itself with an administration that has placed a provocative emphasis on space weapons. This emphasis comes complete with extremely provocative rhetoric, which suggests that the U.S. is at risk of a "Space Pearl Harbor."
Emerging from some military planning circles is an equally provocative answer to this perceived vulnerability: the answer being visions of weapons in space and weapons aimed at space objects. You'll hear more about these plans this afternoon from some of the other panelists.
The debate is complicated but I'm going to give it shape by dividing into three main sets of issues:
First: International and Strategic issues: How do the choices the spacefaring nations make affect security, both nationally and internationally and what is the best way to improve stability?
How would deployment or testing of space weapons by one state cause others to react and would this ultimately lead to more or less security?
What are the guidelines for equitable use and longterm stewardship of space? What is the role, if any, of weapons versus treaties and cooperation?These are questions we must address in order to have peace and stability in space and on the ground. However, I will leave discussion of these topics to the other panelists and to the group, and I'm sure we have some very good ideas here already.
I'm going to focus on the second and third categories of issues:
The second category of issues is: From a narrow point of view of national interests and military capability: What capabilities could some of these new envisioned weapons realistically provide? Would these capabilities be unique, or how might they compare to alternatives?And Third: How should space be used? Space is very well suited to certain kinds of activities and less so for others. What are the concerns for keeping space available for its current peaceful purposes and how does the testing and deployment of these new weapons systems threaten these uses?
The second and third issues have important technical components that inform the debate. The purpose of our study has been to look at these technical questions, and here I will discuss some of the issues and conclusions.
Before beginning the discussions of the utility of space weapons and how space should be used, it will be very useful to remember two physics facts about satellites (and by satellite, I mean anything that is in orbit). Keeping these two facts in mind will help me illustrate why it is useful to do some things from space and not others.
The first is that satellites, by virtue of their great altitude, can see a lot of the earth at once. This is the biggest driver to space—to be able to get a global view. From an airplane, you can see tens of kilometers in your field of view. From the altitude of most weather and intelligence satellites, you can see thousands of kilometers.
The second is that satellites must move very fast to stay in orbit. For a comparison, we will go back to the airplane. A jetliner moves about one-quarter of a kilometer per second. A satellite at the altitude of most weather or intelligence satellites is 7.6 km/s, thirty times faster than a jet! Because satellites move so fast, it takes enormous effort to change their direction. Thus, satellites are not very good at maneuvering.
On to the first set of issues: from the point of view of the U.S. military, what utility do space weapons have, and how do they compare with other alternatives?
To organize the discussion, I will discuss the four missions envisioned by the Pentagon for space weapons:
1. Space-based ground attack—the enticing possibility of being able to attack any part of the world quickly and on-demand.
2. Space-based missile defense—it is not feasible to stage missile defenses from the ground for all potential targets, and the Missile Defense Agency is looking to space for this capability.
3. Defend space capabilities—already the U.S. military relies heavily on space, for communications, reconnaissance, and navigations, and the US.. wants to keep these available. For example, precision guided munitions, which have grown hugely in use over the last ten years, uses all three of these types of space assets.
4. Deny similar capabilities to others—other states have recognized the utility and may want them for themselves
I will briefly discuss the technical issues relevant to these four missions; more detail will be available in our paper. But I will spoil the surprise: from our view, from a technical standpoint, only one of these missions has a useful reason to be carried out in space at all. And this capability is unlikely to be unique or decisive.
FIRST MILITARY GOAL Attacking targets on the ground can be done as well or better from the ground than from space, and at much lower cost.
At first it seems like a good idea, since as I mentioned, you can see a lot of the ground from space. However, the second physics fact is the kicker. Satellites that are close to earth move quickly with respect to the ground. For example, to a person on the ground, a satellite in a low-altitude orbit will appear to go from horizon to horizon in about ten minutes.
So, soon after a satellite comes over a target, it is gone again, and may not return for hours or days. If the response time necessary for a military mission is hours or days, a satellite could be used, but then there are a number of other military options besides satellites. For the more strict military mission that is envisioned for space-based weapons the time scale is shorter, i.e. a response time of about 90 minutes.
For this, one would need a number of satellites, so that as one left position, another would arrive in position to attack. The "absentee ratio" is the number of satellites needed in orbit to assure there is one in position when needed. It expresses how large a constellation of satellites need be for a particular mission.
In addition to needing multiple satellites, there is another important consideration for basing weapons in space: launch.
To get a satellite to the high speeds of orbit, it requires an enormous amount of energy—witness space launch rockets. For a space-based ground attack weapon, the satellites must be orbited first, and then deorbited to come back to the ground. This action is enormously costly.
Any mission being considered for space must be analyzed for feasibility and compared to ground-based alternatives. Particularly when viewed in comparison with attacks by conventionally armed ballistic missiles, the high cost of space launch limits the amount of mass that can practically be put into orbit and drives up the cost of those objects that are.
These projects are so costly and, I would argue, without a compelling military mission to meet. I just don't see them as happening in the near future. Efforts to reduce launch costs are continuing, but will not significantly change this situation for the foreseeable future.
SECOND military mission envisioned for space weapons: missile defense and denying space access to others.
Neither missile defense nor denying access to space by other nations is not a mission suited to space-basing.
Ballistic missile defense is a mission that in principle benefits from space-basing since it allows global coverage. However, that advantage is more than offset by the practical difficulties of the system, especially its vulnerability to attack and high cost. I just mentioned the "absentee ratio," which is the number of satellites needed to ensure one is in a position to do the job it's intended for. For boost-phase missile defense, the defense only has a few minutes to detect the launch and destroy the missile. Such a demanding task would require many hundreds to thousands of satellites.
Also, there are inherent vulnerabilities to a space-based missile defense. To frustrate the defense, the targeted country just needs to be able to "punch a hole" in the system. A space-based missile defense consists of observable satellites with predictable coverage. An attacker can use a smaller and less valuable missile to attack the missile defense satellite and destroy it or get it to expend its interceptor; and then send its ICBM through the "hole." The defense will always be imperfect. If your reaction to this scenario is just to "Make sure there are two interceptors in place!," I note that because of the motion of satellites, making sure there are two in place requires doubling the size of the entire constellation.
Attacking a space launcher while launching is a virtually identical operation to attacking a ballistic missile while launching. And so the same analysis holds. One cannot reliably deny another country access to space using space weapons.
THIRD MILITARY MISSION: SPACE BASED WEAPONS TO DEFEND SATELLITES:
Using space-based weapons to defend satellites is also subject to the imperfect defense scenario. It is very unlikely that a "bodyguard" satellite will be able to reliably and sufficiently protect a satellite. We just discussed how space weapons cannot be used to deny another country space launch, and this includes denying them launch of an anti-satellite weapon.
The best defense is to have a robust satellite system, which has planned redundancy and spares at the ready. And to have other assets that can provide the lost capability (like having UAV-based imagery, like laying sufficient fiber optics for communications).
In fact, the country with the most dependence on satellites, the United States, is also the best prepared to use other capabilities in the face of their loss. Making the systems robust has the added advantage of making the satellites less attractive targets, because their loss won't pack as big a punch. The commercial satellite industry offers an important example of dealing with component vulnerabilities.
The operators of satellite systems must deal with a relatively high rate of failures of space components and minimize the disruption of service to customers.
FOURTH: using space-based weapons to attack other satellites.
This is the only mission we see as having use for space-basing—attacking other satellites. While many ground-based antisatellite weapons would be useful for attacking satellites in those orbits a few hundred kilometers above the earth, there are many fewer options for attacking the valuable satellites in geostationary orbits from the ground. Geostationary orbit is 36,000 km above the earth and is where the orbital period equals an earth day—so the satellite appears to hover over a spot on earth. It is where a large number of high value commercial and military satellites are stationed.
Ok, so although there are opportunities to damage satellites using ground-based anti-satellite weapons and one cannot reliably defend against them, there are more opportunities to damage a satellite using another satellite.
However, this is why I think our prospects are good. If of all these potential uses of space the US military has identified, the only mission that has some advantages to space-basing is attacking other satellites, then there is perhaps room for useful discussion and negotiation. The countries that are best able to attack satellites are also those with interest in using space safely themselves. Not to put too fine a point on it, but the United States has more to lose than to gain by opening up space to ASATs and space weapons.
Now, I have been intentionally a bit provocative here. We all do know that the U.S. does not always make strategic choices according to good fiscal sense or technical reality—witness the missile defense program, which is enormously costly and has no demonstrated capability. However, there are a number of reasons why space weapons could take a different course from missile defense, and I will leave those to the discussion period.
Also, I hope that these comments serve to focus our efforts. The initial move to put weapons in space will likely to be ASAT weapons, or test assets for other programs, like missile defense, test assets which will have a latent but provocative ASAT capability.
Now, just a few comments about the third group of issues I presented:
What constitutes proper use of space and how do the presence of space weapons and anti-satellite weapons affect the proper use?
There are some missions especially well suited to space, and largely these are what is already there in space: satellites perform missions like monitoring the environment and tracking the weather, reconnaissance and surveying, providing global navigation systems like GPS and the EU Galileo system, broadcasting information to a large audience, long-distance rapid communications for everything from credit card authorization to long-distance education to secure military communications. (Astronomical satellites operate in space not because they can see the earth—which is a nuisance!—but because they can only access some parts of the spectrum from up above the earth's atmosphere.) Our lives are more convenient and prosperous and secure because of these uses of space.
What effects could introducing weapons into space have on these largely benign uses of space?
Debris is paramount—because of the high speeds in orbit, a collision with even a tiny particle can devastate a satellite. Both destructions of satellites and missiles in space can create lots of little particles that would have a negative impact on other users. Especially for space-based ballistic missile defense cluttering up space at valuable altitudes are problems. I remind you that space-based BMD would require deployment hundreds or thousands of satellites in orbits near earth. Such clutter would have an impact on other users, but requiring a more complicated space traffic system to make sure satellites did not collide during launches and while orbiting. Drastically increasing the number of satellites in low-earth orbit would increase interference on communications systems. We want to be very sure that we want to go down this road. There is a lot to lose.
To leave you with my main point:
The missions best-suited to space are already in space. Even from a strictly military utility point of view, there is very little to be gained and much to be lost from introducing weapons into space. And from the point of view of those of us who would like to see everyone benefit from what satellites can add to our lives and who desire long-term stability and security, there is nothing to be gained from putting weapons in space.
