On March 9, 2011, the Space Shuttle Discovery landed for the final time at Kennedy Space Center. With 39 flights behind her, she logged a cumulative total of a full year in space. As impressive as it is to marvel at all of her history and that of the entire shuttle program, we are entering a period where America’s future in space is, for lack of a better word, “cloudy.” The ships we have used to enter Earth orbit since April 12, 1981, will ultimately be parked at the Smithsonian and a few other museums around the United States.

As novel as it will be to go and see these multi-million mile machines, museums are not the places in which our nation’s place in space should be heralded. The legacy of the nation’s space program continues to exist on launch pads, in research laboratories, in new, smaller and more versatile ground stations, in the marketplace, in our homes, and ultimately in our own hands.

My 13-year-old daughter and 10-year-old son are both proud owners of Apple’s iPod touch. Each of them has many times more computer power in their hands today than Neil Armstrong and Buzz Aldrin had with them as the lunar module Eagle landed on the moon nearly 42 years ago. As novel and trivial as that might sound, it is worth noting that none of that was by accident. Advances in circuitry, battery power, computer memory and more continue to cascade like falling dominoes, but we cannot take these advances or our achievements in space for granted. To do so would not just put us in a museum, but would lock us inside with no way out.

A day without space puts our daily lives, with all of their monotony and spontaneity, at risk. From the weather report that models approaching storms, to the GPS system that guides us to a weekend destination; from the remote sensing system that detects stressful environmental and soil conditions jeopardizing a crop of soybeans at a farm in Mississippi, to the Skype call that is coming from loved ones on the other side of the planet to tell of news that that really matters to you; from the digital photo that you took of your friends this past weekend, to the post of it on Facebook that has generated at least 23 “likes” …

It would be easy to go on listing examples that show a direct relationship between the lives we live today and the civil, defense and private sector investments in space that have made all of these things and more possible. All are important and essential, but we cannot afford to sit back when it comes to America’s place in space.

For the past two decades I have been fortunate to work within the aerospace and homeland security communities in both the public and the private sectors. While I have learned a lot in navigating those two very different, but also complementary worlds, it has taught me an awful lot about interdependencies and infrastructures.

Interdependencies are the connections that exist from one part to the next, and connect processes, people, operations and networks together.

Infrastructures are those individual elements that make up our country’s operations and economic potential such as government, transportation, financial services, communications, health care and so on. While each may be distinct, with its own workforce, technologies and operational culture, each infrastructure is also related to others.

All too often we have looked at space from a single focus, such as a NASA focus, a military focus, or an intelligence focus. In the new chapter of America’s space history we cannot afford such singular or “silo-ed” approaches.

Our nation, whether we realize it or not, has made space an interdependent infrastructure to life here on Earth.

Here’s a sampling of what space means to homeland security.

Besides the nationwide weather reports DHS Secretary Janet Napolitano gets briefed on every morning to know where Mother Nature may be looking to inflict a bad day, FEMA Administrator Craig Fugate also takes note of the space weather report so as to see how solar storms and flares might affect not just satellite communications but other weather patterns here in the United States. He’s also looking at what is happening around the world – be it in Japan or Haiti – to see if there is a crisis or situation where he and his team might be able to assist.

Satellite monitoring of financial transactions between international terrorist groups, human traffickers, and drug cartels, as well as GPS tagging of them is critically important to intelligence gathering, subsequent prosecution of those criminals and the overall safeguarding of our population.

Space assets give the Coast Guard the vision that clouds, storms and cascading seas often obscure. That’s not just important to the boater who is calling for rescue out in turbulent waters; it is even more important to know what cargo vessel is coming into our ports and what items are in its hold.

The same holds true for the U.S. Border Patrol as well as Customs and ICE agents who often work in environments that require more dynamic and adaptable communications than those offered by existing terrestrial networks.

During my years at DHS, space was a resource that no one appreciated until the unimaginable happened. When Hurricane Katrina slammed into the Gulf Coast at Pass Christian, Miss., bringing with it a 70-foot storm surge of churning water and winds that literally decimated the recording weather instruments, every telephone pole and piece of terrestrial communications equipment was wiped out for hundreds of miles. For the communities that did not have TV crews in their midst to record the carnage they were cut off from the rest of the country.

Mayors, public safety officials and even governors could not connect to their citizens who needed a hand. It was as horrifying as it was unprecedented, but an investment by the State of Mississippi in its Department of Wildlife, Fish and Parks in the form of satellite radios in several hundred of its vehicles made a tremendous difference. Given the rural areas that the so-called “Fish Cops” patrol, terrestrial communications are, shall we say, “spotty,” hence the need to have an adaptable and dynamic system that would allow officers on patrol to remain in communication with their leadership and fellow officers at all times. With all of the terrestrial communications in ruin, Governor Haley Barbour had his Fish and Game Police with their satellite gear deploy around the state, not only gathering information from communities in need but relaying to them what assistance was coming their way.

As positive as this story may be, I sadly saw, firsthand, communities in Louisiana that had similar equipment sitting in boxes, used to prop open storage room doors or stored unopened and unused on bottom shelves. It’s hard to use a lifeline if you don’t first learn what it does or know how to operate it.

In the immediate days after the storm, DHS distributed handheld satellite phones to the various Louisiana parish presidents so that they could stay connected with FEMA, the governor and other public safety response leaders, since there was literally no other means on Earth by which they could communicate with one another.

One of the unheralded heroes of Katrina – Walmart, Fortune Magazine’s number one company in America – used satellite technology that is in each of its stores to collect and relay information that, frankly, federal, state and local government were not able to access, let alone share. This included details such as road closures, public health needs, and the status of public safety operations, as well as fatalities and injuries in decimated communities. Because each of Walmart’s store managers knew how to use satellite phones and what to do under the company’s emergency management procedures, the company’s headquarters in Bentonville, Ark., was able to produce the best situational awareness reports in the opening days of the disaster of conditions on the Gulf Coast. Their peers at Target, Home Depot and Lowe’s were able to do much the same. Satellite communications were the lifeline that reconnected affected communities along the Gulf Coast to their state capitals and every other responder in those very difficult early days.

While it wasn’t a wall of water that struck Kentucky, residents of the state found themselves in a similar situation in early 2009 when they were struck by an unprecedented ice storm. Again, telephone lines and terrestrial communications collapsed because of the ice storm. However, nearly two hundred hospitals and public health outlets in the Commonwealth were connected via satellite communications gear that they had installed the year before, thanks to the use of HHS grant dollars, ensuring that facilities could talk to one another about patient care and a whole lot more.

For all of the talk and money spent on communications interoperability since the Sept. 11, 2001, attacks, the only nationwide interoperable communications network is not on the ground – it’s in space. There are nearly two dozen satellite mutual aid radio talkgroups that exist today that connect federal, state and local law enforcement, public and private sector healthcare operators, national security and emergency management professionals, critical infrastructure owners and operators, regions of the United States, and a whole lot more. Their users include the FBI, the U.S. Marshals Service, FEMA, the National Communications System, and the Central U.S. Earthquake Consortium.

There is further potential to be realized this coming May when the nation undertakes the National Level Exercise, a mandated full-scale disaster preparedness activity, which will for the first time deal with the one component that fails in every disaster – communications. This year’s exercise will simulate an earthquake along the New Madrid fault in the central United States. It was in this exact spot 199 years ago that an earthquake occurred which literally reversed the flow of the Mississippi River for a period of time and caused church bells to ring hundreds of miles away from its epicenter.

In this year’s exercise at least five different states will take their conventional terrestrial communications off-line for the first 24-36 hours of the exercise so as to simulate the probability that all communications would be severely disrupted if an incident like this occurred. In their place, back-up systems will have to be used to direct response and informational activities. Should this event actually occur, it has the potential to become the worst day in American history, surpassing Pearl Harbor, Katrina, the San Francisco Earthquake of 1906, and several other disasters combined.

Giving everyone concern in mid-February was the fact that in Arkansas, where portions of the New Madrid fault lie, a 3.0 earthquake was felt around the state. A New Madrid earthquake could duplicate in the U.S. the devastation that the world has witnessed in Japan following its 8.9 earthquake. In such a scenario, there literally will be no terrestrial network left standing with which to provide the communications necessary to lead response and recovery activities. Satellite technology is just one of the solutions to this problem, and it will be used as part of this exercise for the first time ever.

The ability to stay connected to one another during a disaster or an emergency to hear a voice, share information and take action, is as important to us on the ground as it was to the crew of Apollo 13 when they were on the far side of the moon trying to get their crippled spacecraft home.

From a homeland security perspective, space is an essential part of our overarching critical infrastructure, not just because of overhead connectivity but because of what it allows to happen here on the ground.

While we can and should debate the cost of next generation heavy-lift launch capabilities, what other nations are doing in space, and what the private sector can do to spur more technologies and market opportunities, we cannot underestimate how connected our lives on the ground are to that which happens above. A day without space in this country’s future not only puts our leadership in space at risk; it jeopardizes our economy, innovation, public safety, and much more.

A couple of weeks ago my son was working on a report about the start of NASA. In helping him with the project, we pulled out some books that talked about Sputnik, President Eisenhower and a strange and extinct land called the Soviet Union. As he started to write his report he had lots of questions about the space race and the competition we had with the Soviets to always be the first with each step toward the moon. He discovered that we as a nation weren’t always first. People like Yuri Gagarin beat Alan Shepard to be the first person into space and Alexei Leonov beat Ed White in being the first to walk in space outside of a spacecraft. In sharing with him the lessons of this historical era, I explained to him that second place in sports is a lot like being second as a nation – It’s not particularly fun but there are lessons to learn from wherever you finish the race.

In America’s next chapter in space we not only have to hold the position we have now; we have to go further. Our growth as innovators, explorers, entrepreneurs and more requires that, but, more importantly, our security in infrastructures, operations and the homeland demand it and depend upon it.

A day without space jeopardizes all of those roles, and as my son shared in his report, leadership requires time, energy and investment to succeed, and there is nothing more American than that.