This week features three Congressional hearings by three different committees on various aspects of space policy:
- At 10am Wednesday the full House Science Committee is scheduled to meet on the topic of “Perspectives on the President’s Vision for Space Exploration.” The committee’s web site doesn’t offer many details about the hearing, but according to SpaceRef.com the scheduled witnesses include Norman Augustine, Lennard Fisk, Donna Shirley, and Larry Young.
- At 2:30 pm Wednesday the Science, Technology, and Space subcommittee of the Senate Commerce Committee is scheduled to hold a hearing on NASA’s Mars exploration efforts. No witnesses have yet been announced according to the hearing listing on the committee’s web site. This is likely the same hearing that was scheduled for last month but postponed after a ricin scare closed down the three Senate office buildings for several days.
- At 10am Thursday the VA-HUD and Independent Agencies subcommittee of the Senate Appropriations Committee is scheduled to discuss NASA’s budget. The sole witness announced is NASA Administrator Sean O’Keefe.
The first two hearings will be webcast live, according to the web sites of the appropriate committees. There’s no webcast information for the Senate Appropriations Committee hearing, but the audio of many Senate hearings is available live on CapitolHearings.org.
I took a few notes at the Senate hearing concerning Mars on Wednesday afternoon. Senator Brownback announced at the beginning of the hearing that this was going to be a friendly hearing where the Senate could hear about the recent Mars exploration. NASA had three people testifying, including the AA for Space Science, Ed Weiler.
Mostly they talked about what the Mars rovers have found and what it means. Then they talked about what they hope to do next with the rovers. Then they briefly discussed future Mars exploration and finally they discussed the robotic lunar programs that they are considering.
I won’t get into the rovers too much. They discussed the recent findings and the minerology discoveries. Senator Brownback seemed quite interested in the geology issues and asked about specific types of minerals found at Mars. The witnesses also said that the sand on Mars is extremely fine–about 10 times finer than talcum powder, which they said is many times finer than the finest sand on earth. It is for this reason that Mars gets global dust storms; just a little bit of wind easily picks up this dusty powder and blows it all over the place.
They also discussed the temperature range and how that affects the batteries. Right now it is late summer at Mars and the temperatures range from 40 degrees Fahrenheit during the day to 40 below at night. They also said that at the hottest day on Mars it would only get up to 70 degrees F, but that because the atmosphere is so thin there is a huge differential between the ground and only a few feet off the surface. Your feet would be 70 degrees, but your head would be 30-40 degrees F.
One of the speakers referred to the rovers as “robotic Americans.”
They talked about how the temperature affects the batteries and said that they expect a nominal 3 month lifetime for the rovers. But based upon current developments, they think that they might get 5-6 months total. They also said that toward the end of life they may abandon the geology mission and push the rovers as far as they can go. I’m not sure if this is primarily an engineering goal or a scientific/exploration one.
Weiler was really good at explaining the limitations of the rovers compared to a human. This is an explanation that I have seen a lot lately now that we have some capable rovers on the surface of Mars–they allow people to compare what a rover can do in four months and what a human can do in a day. There are a lot of things that a human can do better. For instance, the rovers have a maximum speed of 5 centimeters a second. They then did some crude math and came up with 10 feet in a minute, or a mile in 8 hours of driving. However, they don’t have good sun for that full 8 hours. And the rovers cannot drive in a straight line. They have to avoid obstacles and also zig-zag. As they noted, a human could walk farther in a day than one of these rovers can cover in five months of operation. In addition, the humans can do a better job of assessing the terrain and picking out interesting sites to visit. The rover always has to wait ten minutes for its data to reach earth and another ten minutes to receive a response, whereas a trained geologist on the surface could make instant assessments.
Personally, I think that this is something that NASA should work at quantifying, at least roughly–Try to figure out the cost/benefit ratio for humans and robots (and not only robots of 2004, but the kinds of robots that are likely to be available 20 years from now). I think that what even a crude estimate would demonstrate is that a human might cost 100 times as much as a rover to place on Mars, but might return 1000 times the data. This still does not mean that the cost problem is easy, but it at least allows you to place a value on these efforts.
They said that there is an orbiter launch scheduled for 2005. Then there will be Mars Science Lander in 2009 and a big, nuclear powered rover in 2009. They said that there might be a sample return mission by 2014. (My notes are sketchy on this stuff.)
Towards the end they discussed the lunar exploration plans. They said that there is a plan for a lunar reconnaissance orbiter by 2008 and then possibly a lander by 2009 or 2010. They have not yet decided if the lander should be a rover. Senator Brownback seemed concerned about the 2008 date and asked if it could be done faster. But they were pretty clear that this was as fast as was prudent–NASA had tried to do things faster than that in the past and had run into problems (referring to the Mars failures in 1999, obviously). They also said that the Mars rovers had taken about three years to build, but that a lot of preliminary work had been done before they were launched. Four years sounds about right to me for this vehicle—even low end commercial communications satellites take a year to build, and their blueprints are already drawn up. This would be a new spacecraft with new instruments and all that would have to be designed.
They said that they plan on doing the first solicitation for proposals for the reconnaissance orbiter by May and that the goal of the spacecraft would be to produce a highly detailed digital map of the entire lunar surface, which NASA currently does not have. No new technology development should be necessary for this.