Nasa’s billion-dollar asteroid mission thwarted by two pesky screws
‘Houston, we have a problem’ – scientists cannot get the lid off the asteroid Bennu sample capsule.
Nasa’s OSIRIS-REx mission may have carried its precious scientific cargo of space dust 200 million miles, but not having the right tool is thwarting efforts to access it.
The space agency reported: ‘After multiple attempts at removal, the team discovered two of the 35 fasteners on the TAGSAM [Touch-and-Go Sample Acquisition Mechanism] head could not be removed with the current tools approved for use in the OSIRIS-REx glovebox.’
All curation work on the sample – and the TAGSAM head – is performed in a specialised glovebox under a flow of nitrogen to keep it from being exposed to Earth’s atmosphere, preserving the sample’s pristine state for subsequent scientific analysis.
Researchers at Nasa’s Johnson Space Center in Houston are now scratching their heads over how to get at the priceless rocks and dust contained within using tools approved for use in the glovebox.
‘The team has been working to develop and implement new approaches to extract the material inside the head, while continuing to keep the sample safe and pristine,’ Nasa explained.
The tools for any proposed solution to extract the remaining material from the head must be able to fit inside the glovebox and not compromise the scientific integrity of the collection, and any procedures must be consistent with the clean room’s standards.
The curation team processing the Bennu sample has already removed and collected 70.3g of rocks and dust from the sampler hardware – surpassing the agency’s goal of bringing at least 60g to Earth.
Referring to the trapped sample, they said: ‘And the good news is, there’s still more of Nasa’s OSIRIS-REx [Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer] sample to collect.’
Asteroid Bennu: friend or foe?
The seven-year mission to visit asteroid Bennu and bring back a sample of its surface has been followed with bated breath by space fans across the globe.
Now, as the sample prepares for analysis, there is yet more excitement ahead.
Look a bit further to the future however, say about 150 years, and Earthlings may not be quite so keen on Bennu.
On Tuesday, September 24, 2182, the asteroid has a 1 in 2,700 chance of colliding with Earth.
The odds of it hitting sometime between now and 2300 are even lower at about 1 in 1,750.
In 2135 the asteroid will make a close approach, which scientists who haven’t yet been born will use to understand Bennu’s exact trajectory and how Earth’s gravity will alter the asteroid’s path – affecting the chances of hitting the planet on another orbit.
But for those of us living now, Bennu can continue to be a source of wonder – rather than an existential threat.
The sample processed so far includes the rocks and dust found on the outside of the sampler head, as well as a portion of the bulk sample from inside the head, which was accessed through the head’s mylar flap.
Additional material remaining inside the sampler head, or TAGSAM, is set for removal when the fastener issue is resolved, adding to the mass total.
As a first step, the team successfully accessed some of the material by holding down the head’s mylar [polyester film] flap and removing the sample inside with tweezers or a scoop, depending on material size.
The collection and containment of material through this method, combined with the earlier collection of material located outside the head, yielded a total mass exceeding the 60g required.
The team will spend the next few weeks developing and practicing a new procedure to remove the remaining asteroid sample from the TAGSAM sampler head while simultaneously processing the material that was collected this week.
The OSIRIS-REx science team will also proceed with its plan to characterise the extracted material and begin analysis of the bulk sample obtained so far.
While the procedure to access the final portion of the material is being developed, the team has removed the TAGSAM head from the active flow of nitrogen in the glovebox and stored it in its transfer container, sealed with an O-ring and surrounded by a sealed Teflon bag to make sure the sample is kept safe in a stable, nitrogen-rich, environment.
The OSIRIS-REx mission collected rocks and dust, called regolith, from Bennu’s surface in 2020.
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