STS-114 and Science on the ISS
Space Shuttle Discovery succesfully launched from NASA’s Kennedy Space Center on Cape Canaveral this morning at 10:39 EDT. This marks NASA’s first shuttle mission since the loss of Columbia in 2003, hence its designation as the “Return to Flight.”
STS-114 will be primarily a resupply mission to the International Space Station, carrying a new gyroscope to replace a malfunctioning one on the ISS as well as a stowage platform for the Quest airlock to aid in future spacewalks. The astronauts will also be testing out various new repair techniques on several sections of test ceramic tiles in the shuttle payload bay, to see if structural damage like that suffered by Columbia can be repaired during a shuttle mission.
NASA’s human spaceflight is often criticized by scientists as a money pit that diverts funds from scientifically useful projects such as interplanetary probes and data-collecting satellites. The amount of science conducted by the human spaceflight program has significantly decreased since the Columbia accident. Since Russia’s Soyuz and Progress resupply vehicle carry much less payload than the Shuttle, NASA and her sister agencies decided to reduce the permanent crew aboard the ISS to two shortly after the Columbia accident. Science aboard the ISS has always been dependent upon having a large crew, since day-to-day maintenance operations require at least two astronauts. Therefore, the successful return to flight status of the space shuttle is crucial to useful science being conducted aboard the ISS. While critics often cite the lack of science being conducted on the ISS as a reason to cut its funding, it is worthwhile to note that sustained or increased funding could drastically increase the amount of science being conducted on the station by reducing the time until the station reaches its full capacity (probably six) of astronauts and cosmonauts.
Hormones are the new diet magic
This one’s from the “completely unsurprising” department. Oxyntomodulin injections prevent people from overreating by promoting a feeling of fullness. Oxyntomodulin is the hormone that tells your brain that your stomach is full.
Typically when one eats, it takes approximately 20 minutes for the feeling of fullness to propagate to the brain and tell you to put your fork. This is the reason that if you’re like me and you house your food, you can eat more than you could if you ate slowly. Researchers found that by artificially stimulating the feeling of fullness, people ate less, and tended to lose weight.
This makes me wonder if slower eating is just another reason that our European cousins tend to be less obese than Americans. Slower eating, smaller portions, less fast food.
It should come as no surprise then, that pharmaceutical companies are already working on an oral dosage form that will likely be available in a few years. It should be noted before one is tempted to hate on obese people for eating too much and being too lazy to lose weight themselves that there is a medical condition where the patient is naturally deficient in oxyntomodulin and always feels hungry as a result. However… I also think that the drug should be available to those who are unable to conquer obesity on their own for whatever reason. Obesity is a huge killer in the United States and much of the rest of the first world.
<Insert obigatory, generic diet and exercise exhortation here.>
A look at Lance Armstrong
And now for something largely fluff, but cool nonetheless… The NYT is running a piece on Lance Armstrong, and what sets him apart from the rest. Some have called him a genetic freak, which is actually sort of true. I thought I’d run through it briefly in honor of his record-breaking 7th straight Tour de France victory. (Yay Lance!)
But is Lance Armstrong that unusual? It depends on whom you compare him with.
Mr. Armstrong, for example, can maintain a power output of about 6.8 watts per kilogram of body weight for 20 minutes. “I would say there are probably no more than 20 people on earth with that ability, and probably at least 10 of them rode or are riding in the Tour de France,” Dr. Coyle said.
This doesn’t explain why he’s won so many times:
“When you look at elite athletes, cyclists or marathoners, you have to have the physiology to get to that point,” he said. “But then, if you looked at the top half-dozen, you really couldn’t tell the difference.”
Mr. Armstrong’s numbers may not be much different from other elite racers, but he has the average cyclist beat by a mile. A good recreational rider could generate about 4 watts per kilogram, which would translate to a speed of about 20 miles an hour on a flat road. Mr. Armstrong, Dr. Coyle said, would be traveling at 34 miles an hour.
I find that hard to believe. I can easily ride 20mph on my bike (a mountain bike, even), without much trouble, and I’m not in especially good shape. But maybe that’s just because I’m relatively young?
Mr. Armstrong’s VO2 max is 85 milliliters of oxygen per kilogram of body weight per minute. An average untrained person has a VO2 max of 45 and with training can get it to 60.
“Lance would be 60 if he was a couch potato and never trained,” Dr. Coyle said. “For the average person, their ceiling is Lance’s basement.”
But wait, there’s more!
“I’m sure there are other Lances out there who have the same potential,” he added. But they may not know it because they never tried to train. “They could get on a bicycle right now,” he said, “and if they were willing to suffer they could ride with the average person who’s been training for two years.”
Training can make a huge difference to those who are genetically gifted. Mr. Armstrong, for example, had a lactic acid test after he had recuperated from cancer and had just begun to train again. He had 8 millimoles of lactate per liter of blood. The average person has a value of 12. But after Mr. Armstrong trained, his levels were 6, an astonishingly low number. “He has to train hard to have those very, very low levels,” Dr. Coyle said.
This is one instance where I’m disappointed that I’m not a genetic freak.
Biologists observe speciation in butterflies
While I wouldn’t exactly call recent observations “unlocking evolution’s secret,” they do offer some interesting insight into speciation in action. Speciation, of course, is when one species diverges into two, usually because of geographic isolation.
Recent observations, however, have keenly shown that geographic barriers need not exist. And in fact may be a sort of barrier to speciation, particularly with one species of butterfly, Agrodiaetus.
In the case of Agrodiaetus, the butterflies with geographic boundaries tended to show no evidence of speciation, whereas those without boundaries tended to show speciation, which flies in the face of conventional thought. In this case, butterflies with no boundaries living in close proximity to one another tended to breed with those that looked like themselves, thereby having offspring that also had similar markings. But butterflies with geographic boundaries showed no special attraction to mates that looked like themselves.
More interestingly, it has been found that if a rogue member of the butterflies coming from the more isolated genetic pool mated with a butterfly that looked different from itself, produced less viable offspring than those that chose to mate with genetically-similar butterflies. That is, if those butterflies with no geographic boundaries chose to procreate with dissimilar mates, their offspring were less likely to survive. This further suggests a slow divergence of the Agrodiaetus species: natural selection is lending a helping hand.
I think a simple explanation exists: when there are many potential mates around, creatures tend to be more choosey, and this is slowly causing speciation among these butterflies. Picking mates that look similar occurs frequently in the human world as well.
Possible evidence of life on Titan
There is some speculation that there is life on Titan, Saturn’s largest moon. The source of this speculation is Chris McKay of NASA’s Ames Research Center and Heather Smith of the International Space University in France.
Titan’s atmosphere is about 5% methane, and Dr. McKay thinks that it could be due to methanogens — strict anaerobes that produce methane as a byproduct of their cellular metabolism. These methanogens would breathe hydrogen from Titan’s atmosphere, and consume organic molecules descending from Titan’s atmosphere as food. The three substances considered as a food source were ethane, tholins, and the most promising, acetylene which yields six time the energy per mole as either ethane or tholins.
Whether or not methanogens exist on Titan remains to be seen. The proof will be when the raw Huygens data is re-analyzed to determine the levels of hydrogen on the surface of the moon. If they are 1/1000th the levels that they are in the atmosphere, there’s a very good chance that there are methanogens present because no known non-biological process would be able to explain the low hydrogen levels. The data has already been collected, all that remains is separating the hydrogen levels out of the rest of the data from when the probe descended to Titan’s surface. If analyzing the hydrogen levels proves too difficult, the team might try to measure the acetylene levels instead, because they too would show a fall off towards the surface:
One hope for testing their idea rests with the data from an instrument on Huygens called the GCMS, which recorded Titan’s chemical make-up as the probe descended. It will take time to analyse the raw data, partly because hydrogen’s signal will have to be separated from those of other molecules. “Eventually, I hope, we will have numbers for at least upper limits for hydrogen,” says Hasso Niemann of Goddard Space Flight Center in Maryland, principal investigator of the GCMS.
Acetylene could be easier to analyse, McKay says, and it too might betray life. “I would guess that there would be a similar fall-off of acetylene if the microbes are eating it.”
The new Earth model
NASA has combined several models of the Earth to create a new picture of how our climate operates. The new system combines models of the atmosphere, ocean, land surface, and sea ice into one framework that promises to improve predictive capabilities for both short-term forecasts like one sees on TV to long-term climate models spanning a century or more.
Under a partnership, groups from NASA, the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA), the Department of Energy (DOE), the Department of Defense and research universities are using ESMF as the standard for coupling their weather and climate models to achieve a realistic representation of the Earth as a system of interacting parts, unifying much of the modeling community. ESMF makes it easier to share and compare alternative scientific approaches from multiple sources, uses remote sensing data more efficiently and eliminates the need for individual agencies to develop their own coupling software.
ESMF allows researchers to combine their efforts to create one comprehensive picture of the Earth. Whereas before, isolated groups worked on one part of the model, ESMF allows them to combine all of the pieces together, which would have been too large an undertaking for any one group to do.
The article goes into detail on how the pieces are layered together to create a cohesive whole.
Meteor showers, Mars satellites, and shuttle launches
A smattering of space and astonomy news tonight…
After scrubbing the scheduled Discovery launch, NASA plans to go ahead with the launch on Tuesday, assuming there are no problems.
Shuttle program manager Bill Parsons said the only way to thoroughly check the system is to fuel Discovery and have all its equipment running.
“We believe the best way to go through this is to do a countdown,” he said. “If the sensors (gauges) work exactly like we think they will, then we’ll launch on that day. If anything goes not per the plan that we’ve laid out in front of us, then we’ll have a scrub and we’ll have to talk about it.”
This will be the first shuttle mission in two years, since the Columbia tragedy.
The Mars Reconnaissance Orbiter (MRO) is scheduled to embark on its six-month journey on August 10, blasting off from Cape Canaveral. The MRO is special for a few reasons:
- It’s huge: 4 stories by 2 stories; 2180Kg.
- It will glide 20% closer to the planet, at an average height of 305Km from the surface.
- It will take pictures over an area 10x larger than previous surveys.
- It will be able to transmit 10x the amount of information per minute than any other Mars probe. (I wonder what the actual data rate will be?)
There are six instruments on board:
- The High Resolution Imaging Science Experiment which will snap pictures that can resolve objects as small as an office desk* over 1% of the entire Martian surface.
- The Context Camera which takes wide-angle images
- The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) which will be able to identify minerals over an area as small as a swimming pool.**
- The Shallow Radar (SHARAD) will measure the atmosphere’s water vapor, dust, and temperature with twice the sensitivity of previous probes
- The Mars Color Imager will track daily weather changes***
- Another (unnamed) instrument to make future landings safer by finding Mars’s two moons (Phobos and Deimos) based on their predicted missions so future landers can use their gravity to land closer to their targets
Click for a larger image of the MRO (4.22MB).
* 1 office desk is a new SI unit recently developed by NASA. It is equal to 1/20th of a swimming pool.
**1 swimming pool is another SI unit developed by NASA. It is equal to 20 office desks.
***No word on whether weathermen on Mars will suck too.
Mars will join the Perseid Meteor Shower on August 12 before sunrise.