The International Space Station had its 20th birthday on November 2, The New York Times reported. Since 2000, it has been a symbol of global cooperation in humanity’s endeavors to reach for the stars. Unfortunately, space exploration is expensive and slow.
As The New York Times pointed out, the International Space Station has had an exciting 20-year history. “Humanity has never built anything like the outpost that orbits Earth about 240 miles above the planet,” the article said. “These are some moments that have defined the two decades it has been our home in space.”
The article then features a timeline that includes “move-in day” on November 2, 2000; Peggy Whitson becoming its first female commander in 2007; and its first received delivery from SpaceX in 2012. If all this sounds like a lot, it is. Space travel is a complex feat of science and mathematics that features a hefty price tag and a long wait.
A Budget of Astronomical Proportions
Space travel is a noble endeavor, but one that asks a lot of a nation’s wallet.
“Space is expensive, particularly human space flight,” said Dr. David M. Meyer, Professor of Physics and Astronomy at Northwestern University, where he is also Director of the Dearborn Observatory and Co-Director of the Center for Interdisciplinary Exploration and Research in Astrophysics.
“In order to send humans into space, they need air to breathe, they need water to drink, and they need protection from the radiation in space—the high energy radiation in the form of high energy protons and charged particles from the Sun.”
Additionally, the political landscape of space exploration is different than in the 1950s and 1960s. Dr. Meyer pointed out that during the Cold War, there was considerable political motivation to fund NASA in hopes of beating Russia in the “Space Race.” At that time, he said, NASA made up over 4% of the federal budget, whereas today, it only constitutes about one-eighth of that.
So what happens next as we set our national sights on sending a space exploration program to Mars?
One problem that involves the expense of continued space exploration is the time it takes to get to Mars.
“It would be a six-month journey each way, and that raises all kinds of issues,” Dr. Meyer said. “Specifically, how could we protect astronauts from radiation for such a long time? And when you add up all the weight you need in the supplies and in the protection for radiation and everything put together, the realistic cost of a round-trip mission sending people to Mars and bringing them back would be well in excess of $50 billion.”
A one-way trip would be less expensive, but as Dr. Meyer mentioned, NASA doesn’t like to do that. Another way to reduce the expense of going to Mars is to continue exploring it with unmanned spacecraft.
“The factor that comes in is the amount of time it takes light, in the form of radio, TV, and optic signals, to get from Mars to Earth,” Dr. Meyer said. “At its closest, the distance between Earth and Mars is 80 million kilometers—because both planets orbit the Sun, they’re at different distances at different times, but when they’re closest, they’re 80 million kilometers apart.
“The speed of light is about 300,000 kilometers per second, and what that means is, when Earth and Mars are closest, it takes light four and a half minutes to get from Mars to Earth.”
In other words, once a Mars rover captures a picture to send to Earth, the image begins a nine-minute, round-trip journey, at minimum, for scientists to see what the rover sees, before they can tell the rover where to go next. When all is said and done, it’s a strain of time and money. However, the scientific interest in Mars replaces the political interest in the Moon, and more rovers are on their way to the “Red Planet.”
Dr. David M. Meyer contributed to this article. Dr. Meyer is Professor of Physics and Astronomy at Northwestern University, where he is also Director of the Dearborn Observatory and Co-Director of the Center for Interdisciplinary Exploration and Research in Astrophysics. He earned his BS in Astrophysics from the University of Wisconsin, and his MA and PhD in Astronomy from the University of California, Los Angeles.