On July 25th, NASA released a statement on a recent find made by the Mars 2020 rover Perseverance as it continues to explore an ancient river outflow delta within Jezero Crater on Mars.
The statement relates to a rather unusual arrowhead-like rock NASA has dubbed “Cheyava Falls” which attracted interest both due to its general shape and the fact its surface has white veins of calcium sulphate—minerals that precipitate out of water – running across it. More particularly, between the veins, Perseverance imaged tiny mineral “leopard spots”, whitish splotches ringed by black material.
On Earth, such spotting can form when organic molecules react with hematite, or rusted iron. These reactions, in turn, can fuel microbial life. “Cheyava Falls” is the first time they’ve been seen on Mars, and so it is understandably a cause for interest and some excitement, and marked the rock – measuring around a metre in length and half a metre across at its widest, – and a target for more detailed study.
This commenced with analyses of various parts of the rock using instruments mounted on the turret at the end of the rover’s robotic arm, notably SHERLOC, PIXL and WATSON.
SHERLOC – the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals – revealed the compounds both within the white veins and on the surface of the rock as a whole, are consistent with those known to be involved in the advent of life. Meanwhile, WATSON, the Wide Angle Topographic Sensor for Operations and eNgineering imager associated with SHERLOC was able to provide detailed images of the “leopard spots” and the calcium sulphate veins, revealing multiple other minerals to be present, some of which contain elements which might assist in the formation of life; whilst the Planetary Instrument for X-Ray Lithochemistry (PIXL) instrument confirmed the “leopard spots” themselves contain both iron and phosphate, and so might possibly have once powered organic processes.
This is the first time that a combination of all three of these types of deposit have been found in a single location on Mars, thus raising even more interest in “Cheyava Falls” and potentially making it the strongest contender yet for indicating basic microbial life may have at one time existed on the planet. However, as the science team has noted, the situation is far from clear.
On Earth, whilst they are noted for their association with microbial life, “leopard spots” are initially the result of an abiotic chemical reaction. So even if the same processes were at work on Mars and may have eventually gone on to feed Martian microbe which may have come about courtesy of the other processes at work in the rock, it is also possible other factors intervened which halted any microbes getting a kick-start with life. In this, matters are complicated by the presence of olivine mineral fragments in the rock.
Olivine is a product of magma – and magma is not friend to organics, as such, their presence in the rock suggest they and the phosphates may have been deposited at temperatures too great to allow organic material to survive, but the phosphates were deposited into veins and pits in the rock after it had been initially laid down as sedimentary mud and compressed into rock, thus giving rise to the veins and spots.
To understand how the rock may have formed, the rover was instructed to take a core sample of “Cheyava Falls” on July 21st, and only the 22nd rock sample to be taken by the rover since it arrived on Mars in February 2021 – the being due to drilling operations having been cut back as a result of a series of issues with the drill mechanism and a desire to avoid it failing prematurely as a result of wear and tear.
Some of this sample will be analysed by the rover itself using its on-board lab. Unfortunately, while this may reveal more of the rock’s history, its unlikely to definitive answer the question of whether microbes might have once nommed on the minerals in the rock; there are simply too many variables involved for the rover’s limited capabilities to reach such a definitive conclusion on its own.
As such, the material gathered in the sample would need to be returned to Earth. For this to happen NASA need to sort out how it is going to managed getting the sample – and others Perseverance has gathered (and in some cases already cached on the Martian surface). The problem here being that, as I’ve noted in previous Space Sunday updates, is that NASA has no clear idea as to how such a sample return mission might be completed; its original planes for far too complicated and way too costly – estimates by the agency’s own Office of Inspector General (OIG) pushing the mission upwards of US $9 billion – making it impractical and prompted NASA to re-think the whole thing.
Given this, the mystery of “Cheyava Falls” is liable to remain long after Perseverance has moved on in its exploration.
Boeing Starliner: “Hot Fire” Test Success, But No Return Date
In my previous Space Sunday update, I provided an update on the Boeing CST-100 Starliner Crew Flight Test (CFT) mission to the International Space Station (ISS), but things were hanging in the balance, as there were tests taking place at the time which could determine the vehicle’s readiness to make a return to Earth.
At the risk of repeating myself, Starliner vehicles use two propulsion systems: four larger orbital manoeuvring and attitude control (OMAC) system, used for making significant manoeuvres, and 28 smaller reaction control system (RCS) thrusters used to carry out precise manoeuvring and also to help stabilise and fine tune the vehicle’s pitch, yaw and roll during and after use of the OMACs. Four sets of thrusters, each comprising an OMAC unit and seven RCS units, are equidistantly places around the Starliner’s service module in external units called “doghouses”. During the flight up to the ISS, the RCS thrusters in particular suffered a series of issues and helium purge line leaks.
Since then, NASA and Boeing has been working through matters, delaying the return to Earth for both the vehicle and its crew of Barry “Butch” Wilmore and Sunita “Suni” Williams. Most recently, comparative testing between “doghouse” units on Earth and those on the Starliner in orbit revealed large temperature spikes occurring within latter’s doghouses when pulse-firing the RCS thrusters immediately after the used of the OMACs – and these spikes are believed to be the cause of leaks detected in the RCS helium purge lines and cause the failure of one of the RCS thrusters.
To combat this, Boeing and NASA have been developing an alternate procedure for the use of the RCS systems in an attempt to eliminate the noted temperature spikes in the “doghouses”, and the tests carried out on July 27th aboard Calypso were designed to test these new procedures. Following an initial review of the test data, NASA issued a statement noting:
The test involved firing 27 of the spacecraft’s 28 jets for short bursts, moving through them one at a time to check thruster performance and helium leak rates. Preliminary results show all the tested thrusters are back to preflight levels based on thrust and chamber pressure.
As part of the test configuration, all helium manifolds, which control and direct the flow of helium, were opened allowing engineers to continue evaluation of Starliner’s helium supply and leak rates. The teams verified Starliner continues to show the margin needed to support a return trip from the station.
– NASA Hot Fire Test statement, July 30th, 2024
In other words, there is currently a high confidence within NASA and Boeing that Starliner is fit for purpose in being able to bring Wilmore and Williams back to Earth.
However, prior to a final decision being made in this regards, a formal return readiness review meeting must be held. This is a necessary step to certifying a vehicle which has experienced issues is believed to be fit for a return to Earth, and which usually sees a target date for its return is identified.
Prior to the hot-fire test, NASA indicated this meeting might take place during the week immediately after the test; but on August 2nd, NASA indicated it would not occur any earlier than the week commence August 5th, so as to allow further review and vetting of the test results. This resulted (again) in a lot of social media driven speculation NASA were about to “abandon” Starliner.
This speculation appears based on unlinking a number of suppositions: that: a) NASA’s delay with the readiness review meeting shows “something is wrong”; b) as NASA is still prepping the four-person Crew 9 for launch to the ISS on August 18th, but doesn’t have room for it to dock (there are only two docking ports on the ISS which can be used by Crew Dragon, one of which is occupied by the vehicle used by the 4-person Crew 8, and the other by Starliner); ergo, c) NASA “must” be considering sending Starliner back to Earth uncrewed, in order to make way for the Crew 9 flight.
While it is true that that data may yet surface that warrants NASA to consider returning Calypso to Earth uncrewed and looking to other means to bring Wilmore and Williams home, there is absolutely no evidence for this being the case at this point in time. Further, it’s actually not the only contingency NASA has at its disposal.
If the confidence in Starliner remains high, but the return cannot be completed until after August 18th (and assuming Crew 9’s launch is not itself delayed), the agency could opt to bring Crew 8 back to earth ahead of the launch of Crew 9. Doing things in this order would not be optimal – but it is possible. However, as it stands, and as Steve Stich, NASA’s Commercial Crew Programme Manager, has made it clear where NASA’s focus for Starliner lies.
I think we’re starting to close in on those final pieces of the flight rationale to make sure that we can come home safely, and that’s our primary focus right now. We have contingency options; NASA always has contingency options … But right now we’re really focused on bringing Butch and Suni home on Starliner.
– NASA Commercial Crew Programme Manager Steve Stich
Outside of this, and following the July 27th tests, Boeing issued its own statement noting that return preparations are underway, and has held an “integrated simulation” – essentially a full dress rehearsal of Starliner and Calypso’s departure from the ISS and return to Earth, involving ground controllers and Wilmore and Williams in readiness for readying for “potential returns throughout August”.
In addition the ISS crew used the station’s CanadArm 2 robotic arm to complete a visual inspection of Starliner’s exterior – both the Calypso capsule and the service module. Such inspections are a normal part of preparing for a vehicle’s departure from the ISS. All of which seems to underline Boeing and NASA are fully expecting Williams and Wilmore to return to Earth aboard the vehicle.
In the meantime, and in news unlikely to sit well with Boeing shareholders, the continuing issues with the Crew Flight Test have resulted in Boeing taking a further US $125 million charge from NASA. This brings the total amount charged to Boeing as a result of the delays across the entire Starliner programme to US $1.6 billion against NASA payments to Boeing for Starliner development totalling US $5.1 billion.
Inara Pey: Living in a Modemworld 