Sasha’s Story. Part 3: History

“Let's see." Sasha's father said, "How did we come this far so quickly? To some extent it’s simply down to good luck, but I guess it all started back in 2010 when some people at NASA made some very smart decisions. That's only fifteen years ago, just before you were born. There wasn't much public enthusiasm for human spaceflight or space research back then. NASA hadn't done anything really exciting for nearly 40 years. They had built the International Space Station of course, and repaired the Hubble Space Telescope, but nothing that sparked the public imagination the way the moon landings had.

“The Space Shuttle was being retired, and the new White House administration had invited suggestions on how the space program might evolve, and what goals it could realistically set for NASA.

“Scientists were generally agreed that Mars was a very interesting place in the Solar System, mainly because we thought we might find evidence of life there, but also because Mars is a world that’s undergone catastrophic climate change. We knew there would be valuable lessons for us here on Earth. The idea of a manned mission to Mars had been discussed since the Apollo days, but no plans had ever made it off the drawing board.”

“What’s a drawing board?” asked Sasha.

“Um, it’s like a tablet computer without the computer... It doesn’t really matter. As you know we had sent several simple robot Rovers to Mars by 2010, which were a scientific success, but quite limited in range and capability, especially when you consider we were exploring an entire planet. The fact is there are big challenges with operating rovers remotely, and the biggest one is due to Einstein."

Sasha's eyes brightened, "you mean the speed of light problem?"

"That's exactly right. Mars is very far away, so it can take up to 40 minutes for a radio command to travel from Earth to a Mars rover and for a response to come back. It’s a tedious process. The rovers NASA launched in 2003 worked this way, and ended up covering only about two miles every year. As you know I love robots, but today most people agree that if we'd continued with just robots it would have been decades before we discovered those Martian fossils.

“People who wanted a manned mission to Mars said a human geologist could accomplish everything the NASA rovers achieved in just a week or two! But plans for manned missions to Mars always assumed we'd land and stay on the surface. They were immensely expensive, complicated and dangerous, and since they were making plans when money was tight – just like now – most people had given up hope of ever getting scientists onto the surface. My robotics friends would also point out that manned lander missions would always be less capable than theirs because robots didn’t need to take food, water – or toilets – so you’d always be able to send more rovers to more sites for the same cost.

“There was also a third idea that people looked at: a ‘sample return mission.’ While we were sending ever more capable rovers, such as the Mars Science Laboratory, nicknamed Curiosity, they were always going to be limited in the kind of analysis they could do. So, instead of sending robot geologists to Mars, the idea with ‘sample return’ was to bring Mars back to the geologists here on Earth. The trouble is this type of mission required a very large, complex, and therefore expensive rover. It needed to be able to find an interesting sample, load it into an on-board rocket that could launch from the surface, enter Mars orbit, head back to Earth, and then a year or so later re-enter our atmosphere where the geologists would be patiently waiting. That’s a lot of hardware to carry to the Mars surface, and a lot that can go wrong. Plus it’s only one sample. What if you picked a boring rock by mistake?

“That’s when they hit on the idea that we now know worked so well, a way to get most of the advantages of all three approaches, while avoiding their biggest problems. Public enthusiasm for the plan snowballed, the money was found, and here we are today.

“The original plan for the Mars Orbital Laboratory was a simple rover control room, where geologists would operate multiple rovers on the surface in real-time from the safety and comfort of Mars orbit. That’s how my company got involved. The astronauts used our helmets – like the one you tried in the exhibit – to see through the Rover’s camera eyes. For them it was like actually being on the surface, but of course since they were actually in the orbiting lab they didn’t have to deal with the freezing temperatures, or worry about dust. Plus they could work at a rover site in the northern hemisphere in the morning and switch to the south in the afternoon! I should also say the Mars Sample Geochemistry Module was added pretty quickly after planning started, and it’s these guys we have to thank for finding life on Mars.

“Until they came up with the MOL plan there were two competing camps within NASA that could never agree. On the one hand you had the remote science and robotics fans, which the astronauts criticized for being ineffective and boring, and on the other side was the astronaut corps, which the science and robotics teams dismissed as simply grandstanding Buck Rogers wannabe’s who sapped funds from their serious work.

“With the MOL proposal, the Mars remote rover drivers could see the value of being an astronaut geologist ‘on-site.’ They were now all on one side.

“Plus there was an economics argument that persuaded many. Come to think of it, I bet you’ll approve of it too.

“We had planned to continue sending orbiters and rovers to Mars every twenty-six months – just as we’d done since the late 1990s – with some missions scheduled decades out. With the MOL plan, we could vastly accelerate how quickly the research was done. The idea was to spend all the money in one go. Rather than spend 200 million a year for 16 years, put the whole 3.2 billion into the MOL pot. It was a gamble, of course, but the idea of an intensive research program that brought in the data decades earlier was very compelling.

“NASA also decided to hand over nearly all Moon missions to the private sector. That freed up money for MOL, and led to the startup of many of today's commercial space companies. They make a nice profit doing sample return projects for NASA and other space agencies. This also marked the real beginning of the space tourism industry.

“The value of knowledge gained from MOL is really hard to judge in financial terms. If we’d not found the fossils, I’m sure you’d find more people who’d say it was a waste of money. But we were lucky enough to have a series of governments who saw the value of the program, and the money kept flowing. But I guess my point is the MOL mission was approved because of the science return it promised, and because it explicitly didn’t need the expense of a human base on Mars.”

Sasha was unconvinced. “OK. I can see the advantages of operating rovers from orbit, and the virtual reality stuff was cool, but surely it would be better to be there in person. You haven’t explained why it’s so hard to do that. What’s so easy about landing on Phobos and hard about landing on Mars?”

“Well, with Phobos you have no atmosphere and essentially no gravity, so ‘landing’ there is a matter of moving your spacecraft close enough to touch it.

“As for Mars... I already mentioned that Einstein makes life difficult for us. It turns out that Newton and Maxwell cause us headaches too. The basic problem is the atmosphere on Mars is very thin, less than 1% as thick as it is here on Earth. When we send spacecraft on their way to Mars they are going very fast since they’ve got such a long way to go. The trouble is when you get there you need to slow down.”

“Sure,” said Sasha. “So you have a heat-shield and a parachute. Just like Apollo, and just like the Mars Rovers.”

“That works for smaller spacecraft that have a fairly small amount of momentum to shed. But if you do the math for a spacecraft the size of a manned ship and habitat, the atmosphere isn’t thick enough to slow you down to a speed where you can safely open the parachutes. There are ways around the problem of course, like using an enormous heat-shield, or firing the engines to slow you down ahead of time, but both of these require a ship much larger than the MOL. Plus a manned ship that lands in just one place can’t do anywhere near as much science as we can today with multiple rovers. But it’s the guys who figured out we could fit small rock-sample rockets on the rovers that really made this option a winner. Once we had the orbiting lab in place, the rockets only had to launch the samples into low orbit where a tug could capture them and bring them back to the geologists in the MOL. There they ran tests, and directed the other rovers to promising sites, and ultimately found the fossil."

Sasha wrinkled her nose. “So how many samples did they look at in the Mars Lab before finding the fossil?”

“Seven. From six different sites. And the Geochemistry Module onboard is far more sophisticated – and by that I mean larger and heavier – than anything we could reasonably fit into a manned lander.

"So basically, we got this far so quickly by arguing we didn't need the expense of a manned Mars landing, so it's hard to convince the people who control the money we want to do one now.”

He had overdone it. Sasha was looking at her feet.

“Of course, there are plenty of people who think a manned landing is the next logical step, and if we don’t do it first someone else will. I don’t want sound too discouraging! It’s just that it might not happen for a few years yet, while we wait for those rocket scientists to work their magic. I just don’t want you to be disappointed!”

“It’s OK, Dad,” she said. “I can be patient. But in the meantime I’m going to walk on Deimos instead.”

“That’s my girl.”

Email link | Printer-friendly | Feedback | Contributed by: Adrian Wyard