It’s one of nature’s topsy-turvy tricks that the deep interior of the Earth is as hot as the Sun’s surface. The sphere of iron that resides there is also under extreme pressure: about 360 million times more pressure than we experience on the Earth’s surface. But how can scientists study what happens to the iron at the center of the Earth when it’s largely unobservable?
One of the reasons the ISS is still alive and kicking is that it offers a unique environment for testing that is available nowhere, either on the Earth or off of it. Plenty of science experiments want to take advantage of that uniqueness. This week, a fresh crop of experiments was delivered to the ISS aboard a Northrop Grumman Cygnus resupply craft. They range from 3D printers to a high school science experiment with mold, and now they each have the opportunity to make use of the ISS’s microgravity environment.
Radishes are a very divisive food – most people either love them or hate them. However, they are very easy to grow, and have now been grown in one of the most inhospitable environments of all – the International Space Station.
Astronauts have long reported the experience of seeing flashes while they are in space, even when their eyes are closed. Neil Armstrong and Buzz Aldrin both reported these flashes during the Apollo 11 mission, and similar reports during the Apollo 12 and 13 missions led to subsequent Apollo missions including experiments specifically looking at this strange phenomenon. These experiments involved blindfolding crewmembers and recording their comments during designated observation sessions, and later missions had a special device, the Apollo Light Flash Moving Emulsion Detector (ALFMED), which was worn by the astronauts during dark periods to record of incidents of cosmic ray hits.
It was determined the astronauts were ‘seeing’ cosmic rays zipping through their eyeballs. Cosmic rays are high-energy charged subatomic particles whose origins are not yet known. Fortunately, cosmic rays passing through Earth are usually absorbed by our atmosphere. But astronauts outside the atmosphere can find themselves “seeing things that aren’t there,” wrote current International Space Station astronaut Don Pettit, who told about his experience of seeing these flashes on his blog:
“In space I see things that are not there. Flashes in my eyes, like luminous dancing fairies, give a subtle display of light that is easy to overlook when I’m consumed by normal tasks. But in the dark confines of my sleep station, with the droopy eyelids of pending sleep, I see the flashing fairies. As I drift off, I wonder how many can dance on the head of an orbital pin.”
In a report on the Apollo experiment, astronauts described the types of flashes they saw in three ways: the ‘spot’, the ‘streak’, and the ‘cloud’; and all but one described the flashes as ‘white’ or ‘colorless.’ One crewmember, Apollo 15 Commander David Scott, described one flash as “blue with a white cast, like a blue diamond.”
Pettit described the physics/biology of what takes place:
“When a cosmic ray happens to pass through the retina it causes the rods and cones to fire, and you perceive a flash of light that is really not there. The triggered cells are localized around the spot where the cosmic ray passes, so the flash has some structure. A perpendicular ray appears as a fuzzy dot. A ray at an angle appears as a segmented line. Sometimes the tracks have side branches, giving the impression of an electric spark. The retina functions as a miniature Wilson cloud chamber where the recording of a cosmic ray is displayed by a trail left in its wake.”
Pettit said that the rate or frequency at which these flashes are seen varies with orbital position.
“There is a radiation hot spot in orbit, a place where the flux of cosmic rays is 10 to 100 times greater than the rest of the orbital path. Situated southeast of Argentina, this region (called the South Atlantic Anomaly) extends about halfway across the Atlantic Ocean. As we pass through this region, eye flashes will increase from one or two every 10 minutes to several per minute.
During the Apollo missions, astronauts saw these flashes after their eyes had become dark-adapted. When it was dark, they reported a flash every 2.9 minutes on average. Only one Apollo crewmember involved in the experiments did not report seeing the phenomenon, Apollo 16’s Command Module Pilot Ken Mattingly, who stated that he had poor night vision.
These cosmic rays don’t just hit people, but things in space, too, and sometimes cause problems. Pettit wrote:
“Free from the protection offered by the atmosphere, cosmic rays bombard us within Space Station, penetrating the hull almost as if it was not there. They zap everything inside, causing such mischief as locking up our laptop computers and knocking pixels out of whack in our cameras. The computers recover with a reboot; the cameras suffer permanent damage. After about a year, the images they produce look like they are covered with electronic snow. Cosmic rays contribute most of the radiation dose received by Space Station crews. We have defined lifetime limits, after which you fly a desk for the rest of your career. No one has reached that dose level yet.”
There are experiments on board the ISS to monitor how much radiation the crew is receiving. One experiment is the Phantom Torso, a mummy-looking mock-up of the human body which determines the distribution of radiation doses inside the human body at various tissues and organs.
There’s also the Alpha Magnetic Spectrometer experiment, a particle physics experiment module that is mounted on the ISS. It is designed to search for various types of unusual matter by measuring cosmic rays, and hopefully will also tell us more about the origins of both those crazy flashes seen in space, and also the origins of the Universe.
Star Lab, the next-generation vehicle for suborbital experiments developed by the Florida-based 4Frontiers Corporation, is well on its way toward its first successful flight — and it’s looking for payloads.
First reported on Universe Today by Jason Rhian in November of last year, Star Lab consists of stacked and subdivided cylindrical sections customized to hold scientific experiments. Contained within a rocket vehicle affixed to the wing of a Starfighters, Inc. F-104 supersonic aircraft, Star Lab will be launched during flight to attain an altitude of about 100 km, going suborbital and achieving 3 1/2 minutes of microgravity before descending.
“If Star Lab proves itself viable this could open the door to a great many scientific institutions conducting their research by using the Star Lab vehicle,” Mark Homnick, CEO of 4Frontiers Corporation, told Universe Today in November.
A high-purity environment within the Star Lab compartments will ensure no contamination from the outside can interfere with payloads contained within, making Star Lab suitable for both non-organic and bio-med experiments.
Alternatively, the payload compartments can be made accessible to the external environment, allowing for atmospheric sampling.
After descent, Star Lab will splash down into the Atlantic and be retrieved by ship. Clients can expect to have their payloads returned within a 24-hour period — a quick turnaround especially essential for biological experiments.
In addition, Star Lab payloads can be accessed up to 24 hours before launch, allowing for any last-minute adjustments, minor installations or fine tuning.
Currently Star Lab is moving into its flight test phase of development, when the F-104s will go through a series of incremental tests up to and including an actual launch of the vehicle. This will determine how well it handles the stresses of flight and how to best — and most safely — perform the actual launch, slated for September 2012.
A maneuver only ever executed in military operations, Star Lab will become the first commercial vehicle to be launched from an aircraft.
Star Lab has 14 contracts signed for payloads at this time, and is right now working on a partnership with the payload-specialist company Kentucky Space to co-develop a successful market for bio-med experiments.
“We are looking for payloads… we’re real, we’re viable, and we have the best deal that I know of in respect to costs and what we provide,” Homnick said during an interview on March 15, 2012. “We’ll have the lowest cost and the highest launch rate, anywhere.”
At this point, signups with Star Lab require only a signature… no payment is required until the vehicle is proven.
“There’s even a contingency in there… we have to show with our prototypes that we are launching in the summer that they actually perform,” Homnick added. “One, they have to reach the altitude — over 80 kilometers — and two, we have to return the payloads for our prototype. And then, after all that, they would actually pay us… half up front, and half after launch.”
And if that’s not a good enough deal, the state of Florida is helping pick up some of the bill.
Under NASA’s Florida Space Grant, commercial ventures taking place in Florida are subject to a rebate program. Once a payload is launched, Space Lab customers can receive a refund from Space Florida of 1/3 of their cost.
Starting at $4,000 (after the Space Florida rebate), including integration and return costs, getting an experiment suborbital has never been so cost-effective.
“The whole concept is to make it really inexpensive and convenient to fly a lot of payloads,” Homnick said. “With ten launches a year, and up to thirteen payloads per launch, there’s a high launch rate.”
And with such convenience, Star Lab will help get the future of space research off the ground — literally.
“We’re real, we’re viable, and we have the best deal that I know of… we’ll have the lowest cost and the highest launch rate, anywhere.”
– Mark Homnick, CEO of 4Frontiers Corporation
4Frontiers will be at the Space Flight Payloads Workshop on Friday, March 23 at the Florida Solar Energy Center from 10 am to 5 pm. See more about Star Lab and what’s coming next from 4Frontiers here.
4Frontiers Corporation, the principal developer of Star Lab, was founded in 2005 in Florida, USA. 4Frontiers is an emerging space commerce company focused on developing fundamental space-related capabilities and resources essential for a long-term human presence in space. 4Frontiers will address the potential of the four most promising space frontiers: Earth orbit, the Moon, Mars and asteroids.
The scientific method is the important process by which all scientific knowledge is acquired. It is a tried and tested method that has been refined over the centuries leading to ever greater discoveries and a better understanding of the universe around us.
The scientific method began with the rules of logic established by the Greek philosopher Aristotle. Over time other philosophers and scientists improved on his work refining the process of inquiry and proving of theories and hypotheses. The current version of the method is 6 to 8 steps depending on whether you are looking to explain an observed phenomenon, coming up with new methods, or integrating old information.
The first step is to define the question. You look at the problem you are trying solve or the phenomena you are trying to understand and formulate a question that can get a solution. This step is the most important as asking the right question is more likely to lead you to the right answer.
The next step is to collect data and observe. This is the part where you either study previous bodies of knowledge or observe the phenomena for the first set of clues needed to find the answer to your question. Observation when done properly will draw your attention to information you may miss at the first glance.
The proceeding step is to form a hypothesis. This is your preliminary explanation of the answer to your question. If you are answering the question of whether an atom is divisible you would look at data of previous scientist observe an atom and make an initial hypothesis. You can say that given the data that the unique characteristics of different atoms must mean that atoms are made up of smaller particles that determine its differing properties.
After the hypothesis are experimentation and more data collection. You find a premise or test to prove or disprove your hypothesis. In the case of whether an atom is made up of smaller particles we can use the example of Rutherford Hayes polonium experiment. He used a radioactive material in the form of cathode rays to bombard a material to see if it was altered.
Data Analysis immediately follows your experiment. You look at the data to see if you found new clues. Depending on the data you may find evidence that proves or disproves your hypothesis.
You finally draw a conclusion and see if the data supports your hypothesis or if you need to remodel it. This step often has scientists restarting the process so they can better refine their hypothesis or try a new approach.
The final two steps involve publishing your findings and retesting where other scientists as well as yourself retest and experiment to see if the hypothesis holds up in all cases. Many times this can lead to the discovery of exception on theories and natural laws.
We have written many articles about scientific methods for Universe Today. Here’s a podcast about The Scientific Method, and here are some Science Fair Ideas.
It’s no secret that astronomers claim that most of our universe is made of dark matter that cannot be readily detected. From Fritz Zwicky’s observations of the Coma clusters in the 1920’s which suggested that additional mass would be necessary to hold the cluster together, to the flat rotation curves of galaxies, to lensing in such places as the Bullet Cluster, all signs point to matter that neither emits nor absorbs any form of light we can detect. One possible solution was that this missing matter was ordinary, but cold matter floating around the universe. This form was called Massive astrophysical compact halo objects, or MACHOs, but studies to look for these came up relatively empty. The other option was that this dark matter was not so garden variety. It posed the idea of hypothetical particles which were very massive, but would only rarely interact. These particles were nicknamed WIMPs (for weakly interacting massive particles). But if these particles were so weakly interacting, detecting them would be a challenge.
An ambitious project, known as the Cryogenic Dark Matter Search, has been attempting to detect one of these particles since 2003. Today, they made a major announcement.
The experiment is located a half-mile underground in the Soudan mine in northern Minnesota. The detector is kept here to shield it from cosmic rays. The detectors are made from germanium and silicon which, if struck by a potential WIMP, will become ionized and resonate. The combination of these two features allow for the team to gain some insight as to what sort of particle it was that triggered the event. To further weed out false detections, the detectors are all cooled to just above absolute zero which prevents most of the “noise” caused by the random jittering of atoms thanks to their temperature.
Although the detector had not previously found signs for any dark matter they have provided understanding of the background levels to the degree that the team felt confident that they would be able to begin distinguishing true events. Despite this, false positives from neutron collisions have required the team to “throw out roughly 2/3 of the data that might contain WIMPs, because these data would contain too many background events.”
The most recent review of the data covered the 2007-2008 set. After carefully cleaning the data of as many false events and as much background noise as possible the team discovered that two detection events remained. The significance of these two detections was the result of today’s conference.
Although the presence of these two detections from 8/5 and 10/27 2007, could not be ruled out as genuine dark matter detections, the presence of only two detections was not statistically significant enough to be able to truly stand out from the background noise. As the summary of results from the team described it, “Typically there must be less than one chance in a thousand of the signal being due to background. In this case, a signal of about 5 events would have met those criteria.” As such, there is only a 1:4 probability that this was a true case of a detection of WIMPs.
Astronomer turned writer, Phil Plait put it slightly more succinctly in a tweet; “The CDMS dark matter talk indicates two signals, but they are not statistically strong enough to say “here be dark matter”. Damn.”