The Space Reviewin association with SpaceNews

Spacecraft like TacSat-2 show the potential, as yet not fully realized, of Operationally Responsive Space. (credit: USAF)

It’s time to get our ORS in gear

Dwayne Day’s recent article about Operationally Responsive Space (“How to tell your ORS from a hole in the ground”, The Space Review, December 31, 2007) raises four basic issues and asks an interesting rhetorical question which he doesn’t answer. I’ll save the rhetorical answer for last and comment first on his major points:

  • What is ORS supposed to do?
  • Does the technology exist to do it?
  • Why is it better than the big, expensive satellites we now use? Or better than much lower cost UAVs?
  • Can the US overcome bureaucratic wrangling, posturing, and requirements creep long enough to make it happen?

First, a bit of background. ORS officially consists of three tiers:

  • Tier 1: Rapidly exploit existing assets
  • Tier 2: Rapidly launch low-cost satellites from inventory
  • Tier 3: Rapidly and economically develop and build new satellites

For the official definition of what all this means, read the DoD ORS Report to Congress of April 17, 2007. (It can be downloaded from the Responsive Space website, This site also has all of the technical papers from the first five Responsive Space conferences that provide the technical background for most of the ORS work to date.) However, for the purpose of looking at ORS in the broader, non-bureaucratic context, I’ll argue that ORS consists of launching satellites quickly (i.e., within a few hours of a previously unidentified demand) and at low cost (less than $20–$25 million for the launch, payload, spacecraft bus, and one year of operations, but not including the non-recurring development cost). This is Tier 2 in the government terminology, although the government hasn’t yet bought into the cost or time numbers.

Does the technology exist to do ORS?

Clearly, it does and has for over 20 years. The Soviets launched over 50 satellites in direct support of the Falklands War from March to June 1982. The US got valuable imagery on the first or second orbit after launch from many of our systems launched during the 1970s, although at that time the data was returned to the ground by actually dropping a film canister from space. As to cost, Surrey Satellite Technology Limited (SSTL) has been launching both communications and observations satellites for well over a decade that cost less than $10 million. (Initial images of New Orleans after Katrina, published in an Aviation Week article, were taken by NigeriaSat, one of the Disaster Monitoring Constellation satellites built by Surrey.)

Almost certainly, most of those satellites are not as capable as we would like for ORS. But if we can’t do much better for $20–25 million with today’s technology than what the British did a decade ago for $10 million, we certainly can’t claim to be a technology leader in space. If you want more details on proposed ORS systems and missions, many of them are in the papers presented at the first five Responsive Space Conferences and available on the website above. (RS6 will be April 28–May 1 in Los Angeles.)

Are ORS-sats better than traditional satellites or UAVs?

No, they’re just different. It’s like asking, if we have airplanes, why would we want to invent better or cheaper cars? Air travel is faster and safer than highway travel, but it just isn’t the right answer for going to the corner store for milk.

If we can’t do much better for $20–25 million with today’s technology than what the British did a decade ago for $10 million, we certainly can’t claim to be a technology leader in space.

ORS-Sats offer a whole new set of capabilities that complement, but don’t replace, traditional systems. Almost by definition, they are more responsive to a changing world. What’s wrong with a traditional system that takes 10–15 years to build and lasts 15 years on orbit? The problem is that you’re using 25- to 30-year-old technology to address military needs defined in the 1970s when Osama bin Laden was in high school and our main adversary was the Soviet Union.

Traditional satellites have other problems as well. They are clearly vulnerable to ASATs and to other failures, such as orbital debris or sensor failures. If the Chinese choose to take out one or more major US assets in LEO, we can yell and scream, we can hold our breath and turn blue, or we can go to war with China. What we can’t do is to replace those assets in a time frame that matters. Certainly the best safeguard for our large satellites is to be able to launch a replacement (not as capable, but focused on a specific area of interest) tomorrow or, better, this afternoon.

We don’t know where future problems will occur. Therefore, traditional systems are necessarily global, and, consequently, are mostly in near-polar, Sun synchronous orbits. This means that a single satellite sees a given location on the Earth once a day or, depending on how far off track it can look, once every several days. By tuning the orbit to the area of interest, one satellite can see a specific mid-latitude location every 90 minutes from four to six times per day. Three satellites can see that location every 90 minutes, 24 hours a day. (If the problem happens to be near the equator or the poles, we can see it every 90 minutes, 24 hours a day with one satellite.)

“Disposability” is part of what can make ORS so much cheaper than traditional systems. The Hubble Space Telescope, with an aperture of 2.4 meters, initially cost about $2.5 billion in today’s dollars. The ground resolution that Hubble can achieve from 900 kilometers is the same as what can be achieved with a 0.6-meter aperture at 225 kilometers, but the latter system can be bought for a few million dollars, rather than a few billion. Even with lots of stationkeeping propellant and some strategic altitude raising, a system at 225 kilometers won’t last very long. But replacing it with newer technology after a few years may not be a bad thing.

UAVs also have limitations that can be overcome by ORS. Flying UAVs over hostile territory could be considered an act of war and may not be in our best interest. It also means potentially getting the UAV and a ground crew to near the desired location, which takes time and may put American lives at risk.

We’re not arguing that ORS should replace either UAVs or traditional satellites. However, ORS can replace these systems in some roles and can do some tasks that simply aren’t practical with other systems. A broad mix of space assets, just like a mix of aircraft or ships, is what is needed to remain in control of the sea, air, and space.

What is the utility of ORS?

A few items were mentioned above. ORS can rapidly replenish assets lost due to enemy action or “natural causes.” They can bring new technology to bear in weeks or months, rather than decades. (Surrey launches computer technology that is typically less than a year old.)

But what about some specific examples of the potential utility of ORS? They’re not hard to come by. For convenience, let’s take it by broad categories.

Surveillance. Here the example I like best is a non-military one: the tsunami in Southeast Asia on December 26, 2004. No one knew it was coming. There were no advance preparations and no warning. Yet, had we been able to launch a surveillance mission within hours to cover the area, we might have been able to find areas most in need of help or even locate debris fields washed out to sea where people might still be alive.

Knowledge is key to getting help rapidly to where it is needed. The same is true of Hurricane Katrina on the Gulf Coast or wherever the next natural or man-made disaster might occur. We may have advance warning about where the next global disaster will occur, or we may not. Terrorists can strike without warning, anywhere, any time. We need to be able to respond to and track events in a matter of hours. And we could.

As another example, let’s suppose that bin Laden has just been seen in the mountains of western Pakistan. A single satellite could cover that area every 90 minutes during most daylight hours. Three satellites could provide visible and IR coverage every 90 minutes, 24 hours a day—all without putting a single American life in danger or risking a further breakdown in a country that is already more unstable than we would like.

We need to be able to respond to and track events in a matter of hours. And we could.

Communications. Here the rules of the game are different than for surveillance, and the resulting satellites and orbits will be different as well. For a time, it seemed likely that the best approach for achieving the persistence needed for communications would be to use elliptical orbits that are effectively small versions of the Molniya orbit used for many years by Soviet and Russian communications systems that were covering areas too far north for good coverage from GEO. However, recent work suggests that circular medium Earth orbits are probably much better for most applications.

Irrespective of the particular technology or orbit, there are multiple applications for low-cost, possibly short-to-moderate duration communications systems. The Army has a strong need for secure, real-time blue force tracking (BFT) and supplemental communications, often called “comms-on-the-move”. More communications are always needed in any war zone, starting with simple command and control and advancing to sending imagery captured on a soldier’s cell phone camera, and on to color video of events on the battlefield or suspected locations of enemy troops from cameras on the ground or on UAVs.

Returning to the Katrina example, the continental United States is as well positioned as anywhere in the world to provide good aerial surveillance and continuous communications by multiple means. But somehow Katrina managed to eliminate most of them. Supplemental communications and surveillance could have dramatically improved our ability to respond.

Weather. In a study done by the Air Force Space and Missile Command, the top unfulfilled need with high utility to all of the services was better wind data. Clearly this would also be a dramatic help to predicting the path of hurricanes or tracking the dispersion of bioagents, pollutants, or radioactive debris after a major disaster. Here again ORS can help. A traditional spaceborne wind lidar (basically a laser radar) operates from high altitude and is estimated to cost over $400 million. Even more than surveillance, active sensors, such as lidar and SAR, benefit greatly from reduced distances. A one- or two-year low-altitude lidar mission can likely fit within our $20–25 million recurring cost objective and provide great benefit either to the warfighter or in many types of disasters or potential disasters, such as hurricanes.

Space Situational Awareness (SSA). Again, the military has identified a need for much greater SSA in order to defend our assets from both attack and orbital debris. Small, low-cost, responsive satellites are almost ideally suited to this type of task.

Other Applications. To date, NASA has shown very little interest in ORS missions. However, in the case of a problem arising in human space flight, there would seem to be great value in being able to quickly launch additional air, water, peanut butter sandwiches, a left-handed, double-jointed crescent wrench, or whatever the tool of the hour might be. Similarly, it would be great to launch science or technology experiments, evaluate the results, and launch again in a few months. We might even be able to launch student payloads while the student was still a student, or at least before they retire from industry.

It would be great to launch science or technology experiments, evaluate the results, and launch again in a few months. We might even be able to launch student payloads while the student was still a student, or at least before they retire from industry.

These are a few of the potential ORS application areas. In the end, ORS represents a new paradigm for space programs and a new approach to space utilization. Much like GPS or UAVs, many of the applications won’t really become apparent until the systems become available and launch-on-demand becomes a reality. Nonetheless, the applications that we can see today seem more than sufficient to warrant the modest expense of finishing the development of key technologies, such as launch-on-demand, plug-and-play satellites, and reduced-drag, low-altitude spacecraft. But as Dwayne Day points out, a high level of utility doesn’t mean that it will happen.

Can the US overcome bureaucratic impediments in order to make it happen?

Here we would have to say that no one knows. It may or may not occur for all of the reasons that Dwayne Day has clearly pointed out. The need for ORS has been formalized for some years in the Operationally Responsive Spacelift Mission Need Statement (ORS MNS) of December 20, 2001. But that does not mean that it will actually come about. There are a variety of entrenched interests and organizational sandboxes arrayed against ORS, or trying to reshape it in their own image. This is, of course, the same process that has brought us $32 billion in cost overruns in the ten largest DoD space programs according to a 2007 Aviation Week article. We would have to conclude that the odds of success are slim, but not zero. In many past technology developments, it has been Congress that has made things happen. That may or may not occur here.

One thing seems clear: if ORS doesn’t happen in the US, it will certainly happen elsewhere. According to a DoD 2007 assessment, the Chinese have already announced a near-term goal of launching satellites within hours of demand. The Russians have been able to do so for years. The Europeans are well ahead of the US in a formalized process for creating low-cost space missions. The rest of the world will move ahead with the capability to respond rapidly to changing world events, irrespective of whether the US chooses to do so.


I would also like to make two corrections to the historical record in Dr. Day’s article. He quotes an often-cited cost of $11 million for a Minotaur. However, that is only the cost of the vehicle itself bought from Orbital. Minotaur is a solid-fueled rocket that requires substantial on-pad assembly, such that the actual total launch cost is in the range of $25 to $31 million per launch.

A hole in the ground is a pit into which you pour money hoping that in 15 years or so a mighty program will grow straight and tall. Your ORS is what you get moving if you want to use modern technology to get something done today.

Second, clearly many people contribute to the advance of any new way of doing business. Without taking anything away from Gen. Worden (currently the director of NASA Ames Research Center), who is remarkably energetic in trying to change the way business is done in space, much of the original impetus behind ORS came from then Undersecretary of the Air Force, Peter B. Teets, who was largely responsible for instigating the 2001 ORS MNS which, in turn, led to the DARPA FALCON program.

Finally, there’s the question that Dr. Day asked, but didn’t answer, “How to tell your ORS from a hole in the ground?” It’s really pretty straightforward. A hole in the ground is a pit into which you pour money hoping that in 15 years or so a mighty program will grow straight and tall. Your ORS is what you get moving if you want to use modern technology to get something done today. It’s time to get off our collective duff and get our ORS in gear.