In just one week NASA will launch the $1 billion Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) in the hopes of having it return in 2023 with some asteroid dust that scientists can study to try to understand whether an asteroid hitting Earth may be responsible for the origin of life on this planet.
It began 12 years ago for one meteorite scientist
Dante Lauretta, at the University of Arizona – Tucson was certain that he and his team were on to something over a decade ago. They were looking at meteorites and were near certain that they found triphosphate in a handful of meteorite specimens. Triphosphate is the TP in ATP, and well, ATP is responsible for life. Unfortunately, the team couldn’t be certain owing to potential contamination that would have come from the meteorites hitting the Earth.
Needing a specimen free of contamination is of paramount importance to Lauretta and in about seven years he may finally get his wish as the Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) is hoping to bring back at least a scoop of asteroid dust when it doesn’t so much as land as pogo on the “B-type” asteroid Bennu. Bennu is all sorts of carbon-rich to the point of being near jet black in its appearance.
Bennu is roughly a half-kilometer wide and when its orbit is closest to Earth it’s roughly the same distance from us as the moon. If the launch goes off without a hitch next Thursday the explorer will land on Bennu in August of 2018. For the first part of its mission,the spacecraft will match Bennu’s orbit and survey it from roughly 250 meters above its surface and look to study the Yarkovsky effect. By studying it like this, NASA and other researchers involve hope to date the asteroid that many believe goes back hundreds of millions of years ago.
Additionally, the spacecraft will look to identify 12 sampling sites for the last part of the spacecraft’s mission. Where they choose to sample will involve fierce debate from scientists based on what each is looking for..a core sample or simply a scoop of surface dust.
Ultimately, Lauretta and NASA will make that decision together with the former saying, “It’s the billion-dollar decision.”
Once the decision is made…..the OSIRIS-REx will touch down on the asteroid for 3 to 5 seconds and vacuum the surface to collect a sample of somewhere between 50 and 300 grams. Hap McSween who will be charged with the curation of the samples that will remain at the Johnson Space Center for both scientists involved in the project but also future scientists to test their yet unwritten hypothesises says, “ [The sample] won’t be much, but NASA scientists have become masters at working with practically nothing.”
The sampling, according to Christina Richey, a deputy program scientist at NASA headquarters in Washington, D.C., will be like a “safe, smooth, slow high-five of that surface.”
This won’t make everyone happy
Alan Rubin, a meteorite scientist at the University of California, Los Angeles, doesn’t want a surface sample but would like the spacecraft to “Go some millimeters below the fusion crust” of a meteorite and that stuff is still pristine.”
While clearly a lot of care is being put into the “pogo site” it’s also imperative that the samples remain untouched and uncontaminated on the trip back to Earth. We are talking about a billion dollars for something that could weigh only 50 grams. The spacecraft will not be landing on Earth when it returns but rather jettisoning a capsule with its cargo for a planned landing in Utah’s West Desert in 2023.
When the Japanese collected a sample a handful of years back, the Hayabusa 1’s return capsule had an O-ring leak that led to terrestrial contamination on landing.