Monday, August 22, 2005

What The Satellites See Of Earth.

Fourmilab's webpage for viewing Earth from the satellites is here. There are a lot of satellites up there.

-tdr

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Thursday, August 11, 2005

The Mars Society Convention: To The Moon And Mars.

The morning plenary session at the Mars Society Convention (website here) began with a speech by Robert Zubrin, the President of the Mars Society and its founder. His talk was entitled “Moon by 2012, Mars by 2016.” Much of his talk was a surprisingly basic presentation of the Mars Direct plan for sending humans to Mars. Surprising because the audience was filled with Mars Society members who most likely know the plan very well. That plan was developed long ago by Zubrin and his colleagues and has long been promoted by the Mars Society as an affordable program for doing sustained human exploration of the planet Mars. When he first proposed Mars Direct the goal was to have humans walking on Mars by 1999. As Zubrin put it this morning, that schedule has slipped a bit. But the goal of landing humans on Mars within 10 years of program start remains.

Zubrin tailored some of his speech to the current political situation. He described how the opportunity finally exists to start a humans to Mars programs in the US. We have a President whose goal for the space program is to send humans to Mars. The President’s party controls both houses of Congress. And, most important, in Zubrin’s opinion, we have Michael Griffin, whom Zubrin described as “the first real NASA Administrator since Thomas Paine” served in 1969-1970.

Griffin’s value to NASA is his technical expertise and his willingness to confront risk. Zubrin cited as an example the decision to launch Discovery even though the problem with the fuel sensor that delayed the launch briefly was not discovered. Griffin gave the order to launch anyway proving to Zubrin that the current Administrator “has guts.”

Although the current political situation is positive for a human Mars exploration program, the situation won’t last. A new president takes office in 2009, Griffin’s term will come to an end, and politics changes. To ensure the survival of the Moon, Mars and Beyond initiative, certain key things must happen before 2009. Zubrin listed them as:

1. A heavy lift vehicle program must be in place and making progress;
2. The CEV program must be in place and making progress, as well;
3. There must be technical momentum for human exploration; and
4. There must be a plan in hand.

Thus, when a new President, who is not necessarily invested in the Moon, Mars and Beyond program, NASA will be able to show the technology it has developed with the programs in place and rolling, and with a plan to use them.

Confronted with a temporary political situation that provides an opportunity for progress to Mars, the President of the Mars Society argued in favor of returning to the Moon. Zubrin’s outline for a return to the Moon is as a subset of a larger exploration program geared towards sending humans to Mars.

The wrong approach for this would be to develop hardware for the Moon that cannot be used for a Mars mission. The right way is to use technologies and procedures that can be used for missions to either destination. Zubrin’s preferred outline for a Moon mission would be to send several Mars habitats to the Moon empty. And then send humans to the Moon in a crew vehicle using a single heavy lift launcher to get them there. The crew vehicle should be usable in both a Moon and Mars mission. For a Moon mission it relies on a single stage to return to Earth; for a Mars mission it adds a booster stage to launch it from Mars back to Earth. But the crew vehicle itself is the same for either mission.

A vitally important component of Zubrin’s recommendation is a heavy lift launcher derived from existing shuttle systems. The heavy lift launcher is needed to keep the mission architecture simple. A single launch to destination rather than multiple launches to orbit using smaller boosters, with orbital assembly, and departure for destination from orbit. Using a single launch avoids the complexity and increased risk of failure from trying to launch multiple times in a short time and assembling the vehicles in space.

Another key to the simple and robust single-launch system is keeping the size of the crew exploration vehicle down to a small size. Designing a vehicle that can replace the shuttle by carrying 7 people to orbit will put off sending that vehicle to farther distances. Thus, the size of the vehicle would have to be limited.

Zubrin’s description of a manned Moon program envisions using the Moon as a stepping stone to Mars, not as a base to launch from or as a fuel depot but as a laboratory and test bed site. In that sense, Zubrin’s vision of bypassing the Moon and heading to Mars still drives his ambition. It’s a vision for the space program that is driven by a desire to explore space and push back the frontier. It’s not a vision for exploiting space for commercial purposes or filling in behind the frontier with civilization. Where some see commercialism and the profit motive as the forces that will open space from lower Earth orbit to the Moon so that humanity can expand incrementally into the Solar System, Zubrin sees the goal of a human space program as moving on to Mars and setting there.

That vision is what appears to motivate Zubrin to lobby for a government program rather than a private sector program. Indeed, in answer to an audience question he stated his belief that only government at this time can afford to do a Mars exploration program and that there is no profit for the private sector in funding a Mars mission.

In my view, Zubrin is correct that government’s role in space should be pushing back the frontier. The private sector is not well suited to that task. However, another role of government in space should be to help fill in the area behind the frontier and bring civilization to that region. When the US government pushed back the western frontier it did not then abandon the areas behind the frontier. The forts that dotted the west were testament to government’s continuing presence in the west.

Similarly, government has a role on the Moon and from there back to Earth. When it comes to the Moon, we have not “been there and done that.” We went to the Moon and explored a few areas on a world with a surface area the size of Africa. There is still a lot of territory left to explore there and the Moon holds the promise of commercial exploitation as well.

By all means, let’s go to Mars. But let’s not put all of our eggs into that one basket. We did that with Apollo and when the program was finished we pulled back and had to start all over again with something else. The risk we run with a Mars-only program is that we’ll go there for a few missions and not go back because we’ve already “done that.” Unless we are simultaneously developing Terra-Luna Space we could be left once again without a real space program if the Mars program ends. The space program should have as its goal the creation of a true space faring civilization that inhabits the entire Solar System, not just Earth and its most Earth-like neighbor, Mars. Part of that mission must take place in Terra-Luna Space.

-tdr

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Wednesday, August 10, 2005

Looking For Signs Of Water On Mars Today So Humans Can Survive There Tomorrow.

The search for water on Mars to date has concentrated on determining whether Mars once had flowing water on its surface millions or even billions of years ago. The scientific missions were not designed to look for the presence of water on Mars today.

But with the recent deployment of MARSIS on Europe's Mars Express in orbit around Mars and the pending launch of the Mars Reconnaisance Orbiter (MRO) on Thursday, the search for water on Mars today begins in earnest. MARSIS is a radar instrument on the Mars Express that is capable of probing and mapping up to five kilometers below the surface of Mars. NASA's MRO will carry its own instrument that will be capable of mapping up to a kilometer below the surface. Enrico Flamini, an Italian scientist involved with both projects, says,
"With MARSIS we are going to have the broad picture of the distribution of water on Mars, while with SHARAD we are going to have the defined picture. We will be able to provide the position, the depth, and the extension of the possible ice and water layers that are under the Martian surface at a depth that can be reached by future Mars exploration."
(See story here.)

Although it is interesting to learn about the ancient history of the geology and climate of Mars, and the rovers have been incredibly helpful in that regard. It is even more important for planning human exploration of Mars to understand the current condition of Mars. Knowing where water is below the surface of Mars is vital if human exploration of Mars is to be successful. The money being spent on these two projects is more than just funding for science; it is an investment in humanity's future. All upcoming robotic missions to Mars should focus more on understanding Mars today in order to pave the way for human exploration of the Red Planet.

-tdr

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At The Mars Society Conference

I have arrived in Boulder for the Mars Society's Annual Conference from Thursday until Sunday. More information on the conference is available at the Mars Society's website.

-tdr

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