When I think of all the dreams I had as a teenager, the one I recall best is the dream I had of human exploration of the Moon and Mars. I was visiting my cousin in Ventnor City, New Jersey in 1969, that fateful evening when Neil Armstrong took the first steps of any human on the surface of the Moon.
What is it that President Kennedy said about such an effort? He said that such a “space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish.” He also had said in that 1961 speech that “in a very real sense, it will not be one man going to the Moon; it will be an entire nation.”
From that day in 1969 until the 1980’s, I firmly believed that humans would not only have colonies on the Moon, but we would also see humans step foot on Mars. My higher education path was not a straight one, but in the end, I worked on a graduate degree in astronomy, and I was involved in the original effort to build a space station at Grumman Aerospace Corporation, and efforts to design missions to go to Mars and return samples to Earth. In the end, however, there were never any bases established on the Moon, or any Mars sample return missions.
In 1976, the first soft landing on the surface of Mars took place with the successful landing of the Viking Lander. In fact, this occurred almost exactly seven years after that landing by Armstrong and Aldrin.
In November of 2011, the Mars Science Laboratory was launched on an Atlas V-541 expendable launch vehicle.
In August 2012, the Mars Science Laboratory reached its destination. This was a very well equipped science laboratory that was sent to Mars. It contained three different cameras: the Mast Camera (MastCam); the Mars Hand Lens Imager (MAHLI); and the Mars Descent Imager (MARDI). It also contained four spectrometers, instruments that allow scientists to determine chemical composition. These included the Alpha Particle X-Ray Spectrometer (APXS); the Chemistry and Camera (ChemCam); the Chemistry and Mineralogy X-Ray Diffraction/X-Ray Fluorescence Instrument (CheMin); and the Sample Analysis at Mars (SAM) instrument Suite. There are also two radiation detectors: the Radiation Assessment Detector (RAD) and the Dynamic Albedo of Neutrons (DAN) detector. Finally, there were two environmental sensors: the Rover Environmental Monitoring Station (REMS) and the Mars Science Laboratory Entry Descent and Landing Instrument (MEDLI). Naturally, the instruments associated with the actual descent of the rover are no longer functioning; however, the Curiosity Rover maintains functioning of the remainder of the instruments.
The Mars Science Laboratory spacecraft spent over eight months on its voyage to Mars. This was not a straight line trajectory. It travelled a total of 354 million miles before reaching Mars. Why did it have to travel so many miles, when Mars itself is only about 50% further from the Sun than the Earth? This is due to the Mars transfer orbit which is used as the trajectory for spacecraft, a minimal fuel use approach to getting to Mars.
Now to get to Mars safely, the Curiosity Rover traveled safely tucked inside a protective shell. It was targeting a landing site on Mars within reach of Gale Crater. Gale Crater is about 96 miles wide. One of the reasons that this was chosen as the landing site for the Curiosity Rover was because of the rock layers that would be available for exploration by the rover, and the many formations it could explore, from canyons to channels, all in one place.
The Curiosity Rover is much larger than the much smaller rovers, Spirit and Opportunity, sent in 2003. Those rovers only weighed about 384 pounds with 11 pounds of instrumentation. Curiosity Rover weighs about 1,982 pounds and has instruments that weigh about 165 pounds. That’s about the weight of a classic VW Beetle with instruments of my own total weight.
The Mar Science Laboratory entered the Martian atmosphere at about 78 miles above the planet’s surface and took about seven minutes to reach the ground. It entered the atmosphere travelling at about 13,000 miles per hour and the Martian atmospheric friction itself slowed the craft to about 900 miles per hour. This friction of the atmosphere heated the spacecraft heat shield to about 3,000 degrees Fahrenheit. A parachute slowed the spacecraft from its 900 miles per hour velocity to about 180 miles per hour, or about the speed that a Formula One race car achieves. During this time period the heat shield was released and the Curiosity Rover was exposed to the atmosphere itself. There was a descent camera which began taking video of the remaining 5-mile flight to the ground. The engines on the descent stage were fired and the rover was powered down to the last mile before the surface. The descent stage lowered the rover down on three nylon ropes called the bridle. At this point electronics and communications cables were also unspooled, leading to what was called the sky crane configuration. Radar was used to determine the altitude and help safely land the rover. In the end, the craft had decelerated from its initial entry speed to resting on the surface in seven minutes. Upon touchdown, the sky crane was flown a safe distance away from the rover before crashing on the surface itself.
Immediately after touchdown, the Curiosity Rover was ready to go. The first things done were to raise its mast with camera and perform a systems self-check. Once all instruments were checked out, it was decided what the rover would do next. After scanning the Martian panorama, it was decided to have the rover first go over to a rock known as N165 and test out some of its scientific instrumentation. Dutifully, Curiosity moseyed over to N165 and used a laser to slough off some its surface material so that the chemical laboratory onboard could do an analysis.
The first images of the surrounding surface features were quite reminiscent of so many images from the Viking Lander. For me, it was indeed déjà vu. There were also images taken of the rover itself, as the rover has two different cameras that could be maneuvered easily allowing engineers to see all portions of the rover, even the underbelly.
The ultimate goal is to get to the base of the crater rim, also known as Mount Sharp. The targeted location is about 11 kilometers from the actual landing site. Since its landing in August 2012, Curiosity has traveled only about 7.5 kilometers. Yes it is going very slowly, but it has also stopped along the way to take pictures and analyze soil and rocks. Besides, any miss-step can kill the mission, so slow and steady she goes.
In December of 2012, the first chemical studies of soils were released, and there was a big media blitz with rumors that the rover had discovered organic compounds in the soil. As it turned out, by time of the announcement at the fall meeting of the American Geophysical Union (AGU) in San Francisco, it was determined that the organics discovered by the chemical laboratory was actually derived from the cleaning solution used to sanitize the rover itself. As of this date, no organic material native to Mars has been discovered. This was in agreement with the data from the Viking Landers so many years ago.
In March of 2013, the Rover experienced a loss of memory, probably due to gamma ray or other cosmic radiation sources. This issue was overcome by switching to the backup memory. However, it has concerned mission operators about the viability of the computer memory for the remainder of the mission. More recently, this year it was noted that the rough Martian terrain has put some holes in the tires of the rover. This too must be watched carefully so that the rover can reach its destination.
Now that I’ve reviewed what is currently taking place on Mars via the Curiosity Rover, what about the future of Mars with respect to human exploration.
Not long ago I uncovered an essay I wrote addressing the exploration of space in answer to a question posed by an English professor. This essay was written over thirty years ago just prior to the first Space Shuttle mission in 1981. I titled my essay “The Next 25 Years in Space: What, Where and Why.” At that time, NASA had big plans for the Space Shuttle program. As most of you reading this will know, the Space Shuttle program is now dead. It ended three years ago, and the United States still has no way of taking humans to space, whether low Earth orbit or deep space. At the time I wrote that essay, I noted that the future of the American space program was hinged on the success of the space shuttle. NASA had planned flights for telecommunications satellites, space telescopes, classified military payloads and, miscellaneous satellites for experiments in everything from astronomy to zoology. So much for strategic plans for human space exploration.
I expressed my concerns that the future of the space program could lead to anything from a future of hope and promise to one of self destruction. Three decades ago, it was hoped that the Space Shuttle program would be like the wagon trains of the old west, opening up a frontier and a future in for humans throughout the Solar System. Obviously, this did not occur. Over thirty years ago I spoke about the feasibility of using the natural resources of the Moon, Mars and asteroids. I talked about the possibility of building factories on other planets that would not pollute the Earth. In fact, I talked about the feasibility of using solar energy as a major energy source, one that won’t disappear for a few billion years.
A major reference that I used in that time period was a study entitled “Space Settlements: A Design Study.” This report summarized the efforts of engineers and scientists at a workshop held at Stanford University and NASA Ames Research Center. In that analysis from 1977, it was believed that a space colony, in orbit about the Earth, could be established for 200 billion dollars. Is that a lot of money? Well, there are those who feel we should not spend any government money on such an effort.
I continued by addressing what I called the benefits of space exploration. To my credit, I first talked about how such an effort would provide jobs for many thousands of employees. Then, addressing the requirements of a space colony, I noted that all types of professionals would be required. These included farmers, policemen, firemen, sanitation engineers, teachers, doctors and many more.
I believed that human space exploration helped produce technological advancements which allowed the USA to push ahead of the Europeans in many disciplines including computer technology. Necessity is indeed the mother of invention, and I believed that a sagging economy then, as now, could use an infusion of new inventions.
As I mentioned above, many people ask why we should bother with space exploration. Some, including an economics professor at my institution, don’t believe the government should be in the space exploration business at all. He believes only private enterprise should drive space exploration. He calls such efforts as the space program and the science funding of our National Science Foundation as “little more than a flashy scam, a horns waggling of the public.” I disagree.
Astronomers have taught us that all of the chemical elements other than hydrogen and helium were formed in the death of earlier generations of stars. Human beings have evolved from simpler life forms that in turn have evolved from complex elements. Thus, as Sagan was often fond of reminding us, we are made of the stuff of stars. Being made of the stuff of the cosmos, are we not a part of the cosmos itself? Do we not have an obligation to survive, and explore, the entire universe around us? Is this not a good enough reason to reach for the stars?
Our future in space can lead our species in many directions. We need to choose as a species between survival of our species beyond the Earth, or destruction of our species and our planet. Which path shall we take?