Space Sunday: crunches, telescopes and ambitions

Starship SN3 tank section sits as a crumpled mess after the pressurisation test failure. Credit: SpaceX

I’ve covered the development and plans SpaceX have for their mighty Starship vehicle – designed to be capable of lifting up to 100 tonnes of cargo, or 100 people to the Moon or Mars – and its equally massive reusable booster on numerous occasions. For the last 12+ months, the company has been engaged in fabricating a series of prototype / test versions of the Starship vehicle, some of which are (or were) intended for actual flight testing. But it has been far from plain sailing for the company.

The first vehicle in the series, called simply “Starship Mark 1”, and built at the company’s Boca Chica test facilities in southern Texas, underwent a series of tank pressurisation tests that were initially positive, at least up until a full pressure test – mimicking the pressure the vehicle’s tanks would be under when fully fuelled and awaiting launch – on November 20th, 2019. SpaceX CEO Elon Musk anticipated this test might end in failure – and it did, the fuel tank bulkheads suffering a catastrophic failure.

Sections of the Starship SN3 unveiled on March 26th, 2020. Note the black cylinders of the deployable landing legs on the section on the right. Credit: SpaceX

A second prototype, Starship SN1, had a series of refinements built into the tank bulkheads and was subjected to a similar test on February 28th, 2020. This time, the bulkheads survived, but a failure occurred with a “thrust puck” at the base of the tank that takes the load from the vehicle’s Raptor engines, again resulting in the loss of the vehicle. As a result, the third prototype, SN2 was modified and then stripped back just to its tanks so that a further test of the “thrust puck” weld on March 3rd – which it passed successfully.

The adjustments were then made to the next prototype: SN3, a vehicle intended to start flight tests. The sections of SN3 were revealed on March 26th, 2020, after which the main tank section was moved to a test stand where it would also undergo a series of pressurisation tests, culminating a full pressurisation using liquid nitrogen to simulate a fuel load at typical launch temperatures. This took place on April 2nd (CST) / April 3rd (UK / CET), and once again ended in failure and the loss of the tank section.

Video recorded by NASASpaceflight.com (not an official NASA site) shows the tank under pressure and venting gas (as expected) before the upper portion initially buckles before completely collapsing.

Immediately following the test, Musk indicated via Twitter the the loss of the section may have been a result of the test being incorrectly configured, rather than a failure with the vehicle itself – although analysis of the data is continuing.

A significant difference between the SN3 vehicle and the prototypes that came before it was the inclusion of deployable landing legs, included in the vehicle to allow it to undertake the system’s first, low-altitude “hops”. SpaceX had already applied to the Federal Aviation Administration (FAA) for permission to complete a static fire of the vehicle’s raptor engine – a required precursor for any test flights – and the FAA had in turn issued a notification to airmen to remain clear of the airspace around the Boca Chica test area between April 6th to 8th, a move consistent with an engine static fire test, which the failed pressurisation test was in turn something of a precursor.

Artist impressions of Starship. On the left, the crewed and cargo variants, on the right a typical large payload deployment. Credit: SpaceX Starship User Guide

It’s not clear how the incident with SN3 affects Starship testing; a further test vehicle, Starship SN4 is under construction specifically to complete higher-altitude flight tests before SN5 undertakes flights in excess of 20km altitude. Whether this SN4 will now be used for the low altitude hops and SN5 and SN6 for the higher flights, or the range of flights for SN4 is extended to cover both low and intermediate altitude tests remains to be seen. All the company has indicated is that the failures encountered so far shouldn’t deflect them too much in their aspirational goals of a lunar vicinity flight in 2022 and a Mars flight in 2024. In respect of these, in March 2020, SpaceX issued payload and crew guidelines for customer wishing to launch cargoes to orbit – a further option for the Starship / Super Heavy booster combination being cargo flights and payload deployments, replacing the company’s Falcon 9 and Falcon Heavy boosters.

James Web Unfurls its Telescope for the First Time

NASA’s next great observatory, the James Webb Space Telescope, has fully deployed its primary mirror under test conditions for the first time, marking another milestone on its journey to space.

The giant mirror, 6.5 metres across, is so large, it must be folded and stowed during launch, requiring it to be carefully deployed while on-route to its final L2 halo orbit beyond the Moon – which will take it around 14 days to initially reach, and another 14 to settle into.

Prior to the SARS-CoV-2 situation caused NASA to suspend work on the telescope, it was hooked-up to a gravity / mass compensating rig – needed to support the weight of the two deployable “sides” of the mirror as well as the mass of the central section – allowing the mirror’s deployment motors to be spun up and the entire mirror assembly put through its actual deployment routine.

JWST deployment. Credit: NASA

The test was one of the final large-scale crucial test of JWST’s key systems. Integration testing of the telescope’s systems and those of it’s “bus” that includes the sun shield were completed in early 2019, while a test deployment of the complex and delicate sun shield “sandwich” – vital to keeping the telescope cool and allowing it to “see” in the glare of the sun – was successfully in October 2019.

Even so, the project has several more hurdles to clear before its actual launch date can be confirmed without risk of further significant delays, and such confirmation will not be given until after the coronavirus situation is no longer impacting the project, and a further review of its overall status completed.

Space Sunday: Al Worden remembered

Al Worden, Apollo 15, July 1971. Credit: NASA

The years 2019 through 2022 mark the 50th anniversaries of the Apollo lunar landings of the 1960s. At a time when those ambitious, pioneering mission, undertaken at what was still the early dawn of human space flight, serve as a background against the current US Artemis endeavour, it is sad to report on the passing of another of one of the 24 men who flew to the Moon as a part of those trailblazing missions has passed away.

Alfred Merrill “Al” Worden was one of those Apollo pioneers who is perhaps less well-known than others, as he was one of Command Module Pilots. These were the mean who remained in lunar orbit piloting the Apollo Command and Service Module (CSM) whilst their fellow crew members made the actual descent and landing on the Moon, and so – with perhaps the exceptions of Michael Collins (Apollo 11) and John Leonard (“Jack”) Swigert Jr. (Apollo13) – did not garner the same degree of media attention during their missions and their surface exploring crew mates.

Worden’s lunar flight aboard Apollo 15 (July 26th, 1971 through August 7th, 1971) was his only flight into space, thanks to actions he and his fellow crew, David R. Scott and James Irwin, took before, during and after the mission which saw all three removed from active flight status for the remainder of their careers at NASA.

Born in 1932, in Jackson, Michigan, Worden was the second of six children and the oldest of the four boys born into a low-income farming family. A keen learner, he opted to try to continue his education beyond high school by obtaining an scholarship, initially to the University of Michigan. But unable to secure funding for more than a year, he turned his attention to the military in order to continue his learning. Applying to both United States Military Academy at West Point (US Army) and the United States Naval Academy at Annapolis, he found himself accepted by both, and after some deliberation, opted to go to West Point, enrolling there in 1951.

Al Worden at an Apollo 11 50th anniversary event. Credit: NASA

Whilst he enjoyed the army discipline at West Point, Worden found himself being encouraged by instructors to pursue a career in the nascent United States Air Force (formed out of the United States Army Air Force in 1947). At that time, the USAF was so young as an independent branch of the US military, it did not have its own training academy, so Worden was able to take advantage of an arrangement that allowed West Point and Annapolis graduates to transfer to the USAF for training, regardless of any possible lack of experience in flying.

As it turned out, Worden proved to be a natural flyer, moving swiftly from the propeller-driven T34 trainer to the jet-powered Lockheed T33. On completing his Air Defense Command training, he was posted to the 95th Fighter Interceptor Squadron, based at  Andrews Air Force Base near Washington D.C. , where he mostly flew the USAF’s first supersonic, swept-wing fighter, the F-102 Delta Dagger. Staying with the squadron as a pilot and armaments officer through until May 1961, Worden applied for, and received, permission to study aerospace engineering at the University of Michigan, graduating in 1963 with Master of Science degrees in astronautical/aeronautical engineering and instrumentation engineering.

Returning to flight service, Worden increased his logged flying time to over 4,000 hours, 2,500 of which was flying jets. During this time he graduated from both the Instrument Pilots Instructor School in the US, and the Empire Test Pilots’ School, UK, one of the most high-regarded test pilots schools in the world. He then served as an instructor at the Aerospace Research Pilots School, then attended the USAF’s advanced flight training school for experimental aircraft, as both a pilot and as an instructor.

In 1966, he joined NASA as a part of the 19-strong Group 5 astronaut intake, alongside of his eventual crew mate, (“Jim”) Irwin. In 1968, they were selected to be the Apollo 12 back-up under the command of veteran astronaut David R. Scott, one of the most experienced Apollo astronauts, whoo had already flown on Gemini 8 and, more particularly, Apollo 9, the proving flight for all of the Apollo hardware – Saturn V rocket, Apollo Command and Service Modules, and the Lunar Module.

Apollo 15 crew: David Scott (l), James Irwin (r) and Al Worden (c). Credit: NASA

The crew were appointed as the prime crew for Apollo 15 at the start of 1970. From the start, Scott, as the mission commander, was determined that they would by the crew that gathered the most scientific data on and about the Moon – spurred in on part back the Apollo 15 back-up crew included Harrison Schmitt, the only actual scientist to participate in a lunar flight (Apollo 17). A first reason for wanting to be the best science crew on Apollo was that thanks to NASA cancelling two of the planned missions, Apollo 15 was raised to a “J-mission”, becoming the first such mission to feature an enhanced Lunar Module, capable of carrying more to the surface of the Moon, including the now famous lunar rover vehicle.

The J mission status of the flight also meant that Worden would have far more to do in lunar orbit than previous CM pilots, as the service module for the mission was the first to include a dedicated Scientific Instrument Module (SIM) bay. This was an equipment bay shielded by a protective panel during launch (and jettisoned once en route to the Moon), and carrying a range of science equipment – a high-resolution contained a panoramic camera, a gamma ray spectrometer, a mapping camera, a laser altimeter and mass spectrometer, all of which Worden had to manage and monitor. In addition, the bay contained a sub-satellite he was tasked with deploying before Apollo 15 left lunar orbit to return to Earth, and designed to study the plasma, particle, and magnetic field environment of the Moon and map the lunar gravity field.

A shot of the Apollo 15 Command Module Endeavour and its Service Module, as seen by from the Lunar Module Falcon, showing the exposed SIM bay and instruments, the cover having been jettisoned en route to the Moon. Credit: NASA

Worden’s sojourn about the Command Module Endeavour began after the Lunar Module carrying Scott and Irwin detached from his vehicle on July 30th, 1971 at an attitude of just 10.7 km above the lunar surface. Following separation, Worden fired the main engine on the Service Module to raise his orbit to 120.8 km x 101.5 km in order to commence his science work.

Over the next 4 days, he worked steadily on his assigned science duties, actually exceeding in some of them. Among his activities, he used the spy satellite quality camera system in the SIM bay to capture 1,529 usable high-resolution images of the lunar surface, and also carried out a regime of exercises using a bungee cord for research into muscle behaviour in micro-gravity environments. These exercises were supposed to mirror similar exercises performed by Scott and Irwin under the greater influence of lunar gravity, so that comparative data could be obtained between them. However, Worden was so enthusiastic about his work, he completed twice the amount of exercise he was required to do!

During those days on his own, Worden gained a citation from Guinness World Records as “the most isolated human being”, because as times during his flights around the Moon he would by up to 3,597 km away from the Lunar Module Falcon and Scott and Irwin – further than any human being had been from anyone else up until that point in time.

After the mission and when asked if he ever felt alone during this time, he would always reply in the negative, saying it suited his jet fighter pilot mentality, and he particularly enjoyed his times on the far side of the Moon when he’d be totally out of contact with any living soul, and would have something special to look forward to.

Every time I came around the Moon I went to a window and watched the Earth rise and that was pretty unique.

The thing that was most interesting to me was taking photographs of very faint objects with a special camera that I had on board. These objects reflect sunlight, but it’s very, very weak and you can’t see it from [Earth]. There are several places between the Earth and the moon that are stable equilibrium points. And if that’s the case, there has to be a dust cloud there. I got pictures of that.

– Al Worden discussing his time alone as the Apollo 15 Command Module Pilot

Following the rendezvous with, and recovery of, the Lunar Module ascent stage, Worden had another record-setting duty to complete: whilst en-route back to Earth, he had to perform an EVA – extra-vehiclular activity -, leaving the Apollo Command Module to make his way back to the SIM bay of the service module to collect the 25 kg cassette of images he’d captured during his time orbiting the Moon.

Worden during his historic deep space EVA, the round drum of the film cassette hanging from his harness. Credit: NASA

The space walk was completed with Jim Irwin standing in the Command Module’s hatch ready to provide assistance if needed, a camera watching over his shoulder. At the time, Apollo 15 was approximately 317,000 km from Earth, marking Worden’s space walk has the first “deep space” EVA in history. As of 2020, it remains one of only three such EVAs, all performed during  the last three Apollo lunar missions.

Despite the overwhelming success of Apollo 15 and the achievements made – first J-class mission, first use of the SIM bay, first use of the lunar rover vehicle, etc., – following the astronaut’s return to Earth, the mission would become the subject of the controversy that would see Scott, Irwin and Worden grounded by NASA for the rest of their careers.

Prior to the flight – and against NASA policy – all three men entered into a financial arrangement with a West German stamp dealer to fly 400 postal covers to the surface of the Moon and back.

Postmarked on the day of the launch at the Kennedy Space Centre post office and smuggled onto the Command Module, the covers flew to the Moon and then to the lunar surface with Scott and Irwin. On their return to Earth, the three men managed to get 398 of the covers – two were accidentally destroyed – cancelled and date-stamped on the day of their splash down at the post office aboard the recovery ship, USS Okinawa. Once back in the USA, the astronauts annotated and signed them, before sending 100 to the dealer, Hermann Sieger, whilst splitting the rest between themselves. The arrangement was for Sieger to pay the three men $7,000 each (approximately US $45,196 in today’s terms), and then give them a percentage each of the 100 in his possession, which he sold to dealers at $1,500 a cover.

Space Sunday: hot ice, capsules and dealing with a virus

The north polar region of Mercury showing the disposition of water ice in permanently-shadowed craters. Credit: NASA / Georgia Tech

Mercury, the closest planet in our solar system to the Sun, is hardly the kind of place where you’d expect to find water ice. With surface temperatures reaching 400º C (750º F) on its sunlit side, the planet is fairly constantly broiled by the Sun. And yet NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission did actually confirm ice on Mercury in 2012.

As with ice on the Moon, this water ice is located in deep craters around Mercury’s poles where the Sun never shines. What’s more, it appears to be created through a similar process and the lunar water ice; however, and in what may seem to be a counter-intuitive fact, the greater heat Mercury endures means it has far more ice located in its polar craters than the Moon.

It goes like this, electrically charged particles from the Sun’s solar wind interact with the oxygen present in some dust grains on the surface to produce hydroxyl  (OH – a single hydrogen atom and a single oxygen atom). This hydroxyl bonds in groups within Mercury’s surface material, just as they do on the Moon.

On both the Moon and Mercury, heat from the Sun both frees these hydroxyl groups and energises them, causing collisions that that produce free hydrogen and water molecules. Some of these water molecules are broken down by sunlight and dissipate. But others descend into deep, dark polar craters that are shielded from the Sun. Here they freeze to become a part of the growing, permanent glacial ice housed in the shadows.

However, because Mercury is so much closer to the Sun, the greater exposure to the solar wind and  – more importantly – greater heat means that the production and release of hydroxyl means that the production of hydrogen and water molecules is much greater – and some is the volume of those molecules falling into polar craters. Thus, the production of water ice on Mercury is much more pronounced – so pronounced that it is estimated some 10,000,000,000,000 kg (11,023,110,000 tons) of ice is generated over the course of 3 million years, cumulatively enough to account for around 10% on the total ice found on and under the surface of Mercury – the rest having being delivered via asteroid bombardment in the planet’s early history.

The process of the ice falling into the craters is a little like the song Hotel California. The water molecules can check in to the shadows, but they can never leave.

– Thom Orlando, Georgia Tech, a co-author of a new study into water ice on Mercury

Starliner: 61 Changes Required

On Friday, December 20th, 2019, NASA and Boeing, together with launch partner United Launch Alliance (ULA), attempted to undertake the first flight of the Boeing CST-100 Starliner commercial crew transportation system to the International Space Station (ISS).

The mission – called Orbital Flight Test-1 (OFT-1) should have seen the uncrewed Starliner craft achieve orbit and then rendezvous with the ISS, where it would dock and spend several days there before making a return to Earth and a parachute landing in the Mojave desert.

While, as I reported in Starliner’s first orbital flight, the majority of the mission was a success – the vehicle achieved orbit and was able to carry out as series of orbital tests before returning safely to a soft landing, issues with the craft meant the capsule incorrectly initiated a series of firings of the vehicle’s attitude control system (ACS) when they were not required. By the time the errors were corrected, the vehicle had insufficient fuel reserves left in the ACS system tanks to achieve a safe docking with the station, thus causing the rendezvous to be abandoned.

The CST-100 Starliner system. Credit: Boeing

Since then, NASA and Boeing have been investigating the root cause of the ACS timing misfiring. The results of these investigations identified both technical and organisational issues within Boeing’s management of the CST-100 programme. At the same time, a NASA internal review identified several areas where the agency could make improvements with regard to its participation in the production and testing of Orion capsules.

In all, some 61 corrective actions have been identified by NASA that Boeing need to make to both the processing of Orion vehicles and in their flight management organisation. These include gaps in processes that prevented ground-based mission controllers identifying what had gone wrong with OFT-1 in order to initiate corrective action that might have allowed the vehicle to go forward with its rendezvous with the ISS.

Boeing has accepted all 61 recommendations from NASA, and has started to implement them. At the same time, it has indicated it is to overhaul all of its testing, review, and approval processes for CST-100 hardware and software, and institute changes with its engineering board authority. NASA also plans to perform an Organisation Safety Assessment (OSA) of the workplace culture at Boeing prior to any future CST-100 flights.

The OFT-1 Starliner following its successful return to Earth, December 22nd, 2019

While there was no crew aboard the test vehicle, NASA has nevertheless designated the flight a “high visibility close call” in accordance with their own procedural requirements. This means that while it is unlikely they would have threatened a crew had they been aboard (in fact, a crew would likely have been able to immediately respond to the ACS issue and correct it) the anomalies during the flight were simply too big to ignore, and could have led to serious consequences under different circumstances.

No date has yet been confirmed for the second orbital flight for a Starliner vehicle. This is due to deliver a crew of three NASA astronauts (Nicole Mann, Mike Fincke and Christopher Ferguson) to what might yet be an extended stay at the ISS in what is regarded as the final test flight for the CST-100.

The first “operational” flight for Orion will comprise NASA personnel: mission commander Sunita Williams and Josh Cassada, ESA astronaut Thomas Pesquet and cosmonaut Andrei Borisenko. This flight will see the vehicle used in OFT-1 re-used as part of NASA’s plans to fly each CST-100 a number of times. Commander Williams was on hand to witness the vehicle’s return to Earth at the end of OFT-1, and she named the vehicle Calypso.

Space Sunday: inside Apollo, rover delays & LOP-G changes

Apollo in Real Time. Credit: NASA
2019 through 2022 mark the fiftieth anniversaries of the Apollo Moon landings, and I’ve previously covered the flights of Apollo 11 (in three parts: part 1, part 2 and part 3) and the flight of Apollo 12. This year marks the 50th anniversary of the only Apollo mission to take place in 1970, and perhaps the second most famous of them all: the flight of Apollo 13.

On Friday, March 13th, in the run-up to marking the 50th anniversary of that dramatic mission (which I’ll be covering nearer the time), NASA has released Apollo 13: The Third Lunar Landing Attempt, the third in its web-based Apollo in Real Time.

Developed and produced by NASA software engineer and historian Ben Feist, Apollo in Real Time is a series of in-depth on-line resources that allow people to relive Apollo missions 11, 17 and now 13 by presenting all of the space-to-ground and on board audio from the missions; all of the mission control film footage, news pool television transmissions and press conferences audio; and all of the flight photography synced to a timeline for each mission covering when every word was spoken, scene was filmed and image was taken. Together they represent the most complete records of the three missions.

Putting these sites together has been a labour of love and a technical challenge for Feist. While almost all of the original audio recordings for the missions had been archived, they had been made using a tape format for which only one playback machine remained, requiring they be re-recorded digitally.

Apollo 13 In Real Time showing (top l) the moment of engine ignition; (bottom l) mission milestone / transcript / commentary options; (r top) adjustable audio tracks for entire mission and current period; (bottom r) options for displaying additional information / images. Credit: NASA

For Apollo 13, however, there was a particular problem: the five most important tapes from the mission – those recording the events leading up to, during and immediately following the explosion that crippled both the Service and Command modules – were missing, having been removed to be used in the post-accident investigations. These took time to locate, and proved to be in as poor condition as the rest.

Fortunately, Feist was able to enlist the help of Jeremy Cooper, a software audio specialist, who wrote an algorithm that allowed the distortions in all of the tapes to be eliminated during the re-recording process, providing a complete, high-quality audio record of all three missions.

Most poignantly, perhaps with the Apollo 13 mission, are not the exchanges between mission team members or with mission control and the spacecraft (many of which run concurrently with one another, hence the sheer volume of audio available), but the recordings of telephone conversations between the wives of the astronauts aboard the stricken space craft, and astronaut Ken Mattingly (who had been due to fly the mission, before he was exposed to a risk of contracting German measles and was replaced by Jack Swigert) at mission control.

My kids aren’t up yet and they don’t even know what is going on. They went to sleep before all this came up last night. And I was wondering what I could tell them as far as… um, um, in other words, are we really pretty safe right now?   

– Marilyn Lovell, wife of Apollo 13 commander James Lovell, on the phone to mission CapCom
Ken Mattingly
in the early hours of April 14th, 1970, following the explosion aboard the
spacecraft.

These exchanges, filled with angst and concern, yet delivered in an eerie calmness, really bring home the situation faced by all involved in the unfolding situation.

Apollo 13 in Real Time includes photography by the crew. In these images, captured by Fred Haise, (l) the Lunar Module can be seen stowed in the upper section of the Saturn V S-IVB stage as Lovell guides the command and Service Module towards a docking with the round port in the top of the LM, ready to withdraw it from the spent stage. (r) The S-IVB stage as it drifts and diverges away from the mated CSM and LM post-extraction. The nozzles in the lower left corner are a group of attitude control thrusters on the LM. Credits: F. Haise / NASA

As well as recovering the audio from the missions, Feist and his team had to also painstakingly match it to footage recorded within Mission control throughout each mission – much of it without sound. All of this took considerable time and effort by Feist and his small team; in the case of Apollo 13, a total of eight months of continuous work went into putting together a complete history of the mission’s exact timeline of event from launch to splashdown.

Currently, you can join Apollo 13 in the moments leading up to launch or while it is “in progress.” However, from April 10th, and for the period of the mission from pre-flight through to recovery, you’ll be able to join in “right now” exactly to the hour in the mission, 50 years later and witness it unfolding.

Apollo 13 in Real Time: the Lunar module Aquarius, which served as the crew’s lifeboat (l) and the Command and Service Module (CSM), showing the area of the explosion and damage. Credit: NASA

Apollo 13 In Real Time, together with Apollo 11 and Apollo 17, provides a remarkable insight into these historic flights of exploration and discovery.

ESA Delays Rosalind Franklin’s Flight to Mars

Rosalind Franklin, the European Space Agency’s ExoMars rover, together with its Russian-built lander, has had its July launch date pushed back by two years. The British-built rover, which has had far more than its fair share of woes over the 10+ years of its development (including having to be entirely re-designed after NASA welched on an agreement to launch the rover), will now not launch until the August / September 2022 opposition launch opportunity.

The primary reason for the launch delay is related to the mission’s complex parachute system intended to slow the combined lander / rover as they pass through the Martian atmosphere and to a soft landing on the planet’s surface.

In all, the mission utilises three parachute systems: a high-altitude pilot parachute, designed to steady the vehicles after entry into the Martian atmosphere; an initial “first stage” supersonic parachute, designed to act as a speed brake and slow the lander and rover to subsonic speeds; and finally a much larger “second stage” parachute designed to manage the descent through the atmosphere. As late as August 2019, both of these latter parachutes were failing test deployments in simulated Martian conditions.

The ExoMars parachute systems. Credit: ESA

With the assistance of expertise from NASA – who have the greatest experience in the use of parachute landing systems on Mars – the cause of the failures was eventually traced to the containment bags for the parachutes, which were damaging both on their deployment. This forced a complete redesign of the bags, which was due to be tested at a high-altitude test range in Oregon, USA this month to confirm their readiness for use. However, the spread of the COVID-19 coronavirus strain means that the testing is not now possible. Nor is the testing the only aspect of the mission impacted by the virus: the primary control and management centre for the rover mission is located in Turn, Italy, and is under lock-down, severely hampering mission management and coordination work.

However, it was the inability to carry out the parachute deployment tests that prompted the decision to postpone the mission’s launch date.

We agreed together it’s better to go for success than just to go for launch at this time. Although we are close to launch readiness we cannot cut corners. Launching this year would mean sacrificing essential remaining tests. We want to make ourselves 100% sure of a successful mission. We cannot allow ourselves any margin of error. More verification activities will ensure a safe trip and the best scientific results on Mars.

– ESA Director General Jan Wörner, announcing the ExoMars mission delay

Space Sunday: Mars rovers, molecules & 1.8 billion pixels

NASA’s Mars 2020 rover. Credit: NASA/JPL

It might look like the Mars Science Laboratory (MSL) rover Curiosity, but the vehicle seen above (in an artist’s impression) is in fact the Mars 2020 rover that is due to be launched on its way to the red planet in July of this year to arrive in early 2021.

Based on the chassis, body and power plant used by Curiosity, the 2020 rover is a very different vehicle that is tasked with very different roles. And now the 2020 rover has a name as well: Perseverance.

The name was selected following a US national competition in which K-12 students (kindergarten through to 17-19 years of age) were invited to suggest a name for the rover in essay form ( a practice NASA has taken with a number of missions to Mars, including the MER rovers Spirit and Opportunity and with Curiosity). From the initial entries received, NASA narrowed the choice down to nine possible names, with the public asked to cast their vote for their favourite – although the final decision on any name remained with NASA management. Those nine names were: Clarity, Courage, Endurance, Fortitude, Ingenuity, Perseverance, Promise, Tenacity and Vision, with each name identified by a single essay selected by NASA as best representing the goals of the pace agency.

The final choice of name, based on a combination of votes for the nine and an internal decision at NASA, was made by the agency’s associate administrator for science missions, Thomas Zurbuchen, who selected the name Perseverance based on an essay by 13-year-old Alexander Mather of Virginia. The formal announcement of the name was made by Zurbuchen at a special event at Alexander’s school on Friday, March 5th.

In making the announcement, Zurbuchen made note of the fact that Curiosity actually started its journey to Mars when Alexander and many of the other competition entrants were babies – or had yet to be born – citing their involvement in the competition as an example of the innate curiosity that draws us to want to explore the planets and stars around us. He also noted why he felt Perseverance was a particularly apt name for the new rover.

Yes, it’s curiosity that pulls us out there, but it’s perseverance that does not let us give up. There’s no exploration without perseverance.

Alex’s entry captured the spirit of exploration. Like every exploration mission before, our rover is going to face challenges, and it’s going to make amazing discoveries. It’s already surmounted many obstacles to get us to the point where we are today – processing for launch. Alex and his classmates are the Artemis generation, and they’re going to be taking the next steps into space that lead to Mars. That inspiring work will always require perseverance. We can’t wait to see that nameplate on Mars.

– Thomas Zurbuchen, NASA’s associate administrator for science missions

As noted above, Perseverance may look like Curiosity, but it is a very different vehicle in terms of mission and capabilities.

An artist’s illustration of the Mars 2020 rover Perseverance, showing the “turret” of science instruments at the end of the rover’s robot arm. Credit: NASA/JPL

In terms of overall science mission, Curiosity was tasked with identifying conditions and finding evidence that show that Mars may have once been capable of supporting life on its surface – a primary mission it actually achieved within three months of arriving on Mars. However, it was not actually capable of identifying whether any of that life – and we’re talking microbial life here – may still be present, or of what it might have been. Perseverance will take the next logical step in the process:  it will look for actual signs of past life, or biosignatures, capturing samples of rocks and soil that could be retrieved by future missions and returned to Earth for in-depth study.

To achieve this, Perseverance will carry a host of new science instruments and more advanced versions of some of the systems found on Curiosity, together with additional enhancements born of lessons learned in operating the MSL rover on Mars for the past 8 years.

This means that the rover is slightly larger than Curiosity somewhat heavier, massing just over a metric tonne compared to Curiosity’s 899 kg. Part of this extra weight is accounted for by the systems that allow it to obtain samples of sub-surface material and seal them in containers for possible later retrieval by sample return missions. These include a larger, more robust drilling system mounted on the “turret” at the end of the rover’s robot arm, which also in part accounts for the increase in weight of that unit from 30 kg to 45 kg.

Perseverance rover: instruments and systems

Also, while Curiosity is equipped with 17 camera systems, with only four of them colour imagers. Perseverance has 23 cameras, the majority of which are colour imaging systems. These include a suite of 7 cameras that will provide unique views of the rover’s descent and landing, including views of the parachute deployment and views of it being winched to the ground by its hovering “skyhook” platform It also has a pair of “ears” – microphones that, if they work (NASA’s past attempts to operate microphones on Mars haven’t been successful), will allow us to hear the Red Planet for the first time.

Two further key differences between the two rovers are that Perseverance has a different set of wheels that are larger and designed to better handle Martian terrain, which has taken its toll on Curiosity’s six wheels. Perseverance’s steering  has been updated to give it better manoeuvring capabilities, while the second major difference is that Perseverance has a massively updated self-driving capability. These updates mean that Perseverance will be able to map its route far better than Curiosity, calculating route options five times faster than the older rover. This will eventually seen the time required to map and plan each stage in the rover’s drive route reduced from around a day to about 5 hours. In turn, this means that while Perseverance will travel at the same speed as Curiosity, it will be able to cover more ground in the same time periods, and gather more samples over the course of its prime mission.

Continue reading “Space Sunday: Mars rovers, molecules & 1.8 billion pixels”

Space Sunday: the mathematician of NASA

Tribute to Katherine Johnson. Credit: Breen, San Diego Union-Tribune

So often, when we think of the early years of US space flight, we think of steely-eyed, square-jawed test pilots supported in their missions by male, bespectacled and white-shirted scientists and flight controllers, their breast pockets lined with pens of various colours, all with similar haircuts and staring earnestly at computer screens, headsets allowing them to talk in clipped, precise terms with one another in acronym-laden sentences.

While both were very much the public persona for NASA, even becoming something of a cliché in television and film, they were only in fact the tip of the iceberg of the multitude of talents that formed NASA and made its missions possible. In particular, the image of the “nerds” of mission control has tended to very much overshadow the role played by many women in getting America both into orbit and to the Moon.

One of the foremost of these women was Creola Katherine Coleman, better known as Katherine Johnson, who sadly passed away on February 24th, 2020 at the age of 101. As a mathematician who spent 35 years working for NASA and its precursor, her calculations of orbital mechanics were critical to the success of the first US flights into space during the Mercury programme, and her work also encompassed the Apollo programme and the space shuttle.

Katherine Johnson, circa 1960. Credit NASA

Katherine Johnson was born on August 26, 1918, in White Sulphur Springs, West Virginia, the youngest of four children born to Joylette Coleman, a teacher, and her husband Joshua Coleman, a lumberman, farmer, and handyman. She showed a natural ability with mathematics from an early age. However, as her home county of Greenbrier did not offer public schooling for African-American students past the eighth grade (13-14 years of age), her parents enrolled her, at the age of 10, at the high school on the campus of West Virginia State College.

Following her graduation at 14, she attended West Virginia State, where she took every course in mathematics offered by the college and studied under chemist and mathematician Angie Turner King, and William Schieffelin Claytor, the third African-American to receive a Ph.D. in mathematics In fact, Claytor was so impressed with Johnson, he added new courses just for Katherine. Graduating summa cum laude in 1937 at the age of 18 and with degrees in mathematics and French, Johnson took on a teaching job at a black public school in Marion, Virginia.

She returned to studying mathematics after marrying her first husband, James Goble in 1939, becoming the first African-American woman to attend graduate school at West Virginia University.

Johnson’s association with aerospace commenced in 1953 when she joined the National Advisory Committee for Aeronautics (NACA), joining the Guidance and Navigation Department at the Langley Memorial Aeronautical Laboratory, Virginia. Here, she initially worked in a team of women supervised by mathematician Dorothy Vaughan, carrying out a range of mathematical analyses of aircraft flight dynamics, wind handling and more. She was then reassigned to the Guidance and Control Division of Langley’s Flight Research Division.

At first she [Johnson] worked in a pool of women performing maths calculations. Katherine has referred to the women in the pool as virtual “computers who wore skirts”. Their main job was to read the data from the black boxes of planes and carry out other precise mathematical tasks. Then one day, Katherine (and a colleague) were temporarily assigned to help the all-male flight research team. Katherine’s knowledge of analytic geometry helped make quick allies of male bosses and colleagues to the extent that, “they forgot to return me to the pool”. While the racial and gender barriers were always there, Katherine says she ignored them. Katherine was assertive, asking to be included in editorial meetings (where no women had gone before). She simply told people she had done the work and that she belonged.

– Oral history archive at by the US National Visionary Leadership Project

Katherine G. Johnson Computational Research Facility, Langley Research Centre, Virginia, inaugurated in 2019 and named in honour of Katherine Johnson. Credit: NASA

With the formation of NASA, Johnson worked as an aerospace technologist, moving to the agency’s Spacecraft Controls Branch, a department in which she continued to work through until her retirement from the agency in 1986. Her first major project was calculating the launch window and flight trajectory for Freedom 7, the sub-orbital flight that made Alan Shepard the first American in space on May 5th, 1961. In particular, her trajectory calculations – manually produced – ensured the recovery teams were on hand when Shepherd splashed down. In addition, to her calculation for flights, Johnson plotted backup navigation charts for the astronauts in case of electronic failures aboard their craft.

Such was her reputation and prowess, Johnson was key to ensuring NASA could transition from human computers to electronic computers. In this role, when John Glenn was preparing to make NASA’s first orbital flight around the Earth, he refused to fly unless and until Johnson had personally verified all of the electronic flight calculations for the mission. Despite the greater complexity in orbital flight calculations, Johnson did so by comparing the electronically-produced calculations  with her own manual calculations that she produced over the course of a day and a half – a feat that passed almost unnoticed in the pages of history.

In this respect, Johnson – although living in a state where segregation on the basis of colour was still very real (despite NASA’s somewhat more relaxed view of things) – would later state that she found sexism in the workplace the bigger problem (Glenn, for example, called for her to review the data relating to his flight simply as “the girl”).

We needed to be assertive as women in those days – assertive and aggressive – and the degree to which we had to be that way depended on where you were. I had to be. In the early days of NASA women were not allowed to put their names on the reports – no woman in my division had had her name on a report. I was working with Ted Skopinski and he wanted to leave and go to Houston … but Henry Pearson, our supervisor – he was not a fan of women – kept pushing him to finish the report we were working on. Finally, Ted told him, “Katherine should finish the report, she’s done most of the work anyway.” So Ted left Pearson with no choice; I finished the report and my name went on it, and that was the first time a woman in our division had her name on something.

– Katherine Johnson quoted in Black Women Scientists in the United States, 1999.

President Barack Obama awards the Presidential Medal of Freedom to Katherine Johnson in 2015. Credit: UPI

As NASA shifted gears to achieve President Kennedy’s goal of “landing a man on the Moon and returning him safely to the Earth”, Johnson threw herself into the task of making sure it could happen. She would arrive at the office early in the morning, work through until late in the afternoon, then go home to look after her three daughters – born to her late first husband, and living with her and her second husband, James Johnson – then returning to NASA after the children were in bed, maintaining a schedule of 14- to 16-hour days.

These hours enabled her to carry out a critical role in calculating Apollo 11’s flight to the Moon and back and – most crucially of all – she calculated the exact time that the lunar module ascent stage needed to lift-off from the lunar surface in order to successfully rendezvous with the Command and Service Module, a feat she would come to regard as her proudest accomplishment.

During this time, she also embarked on co-authoring a series of papers specifically for the Apollo programme (as part of some 26 science and mathematics papers she wrote while at the agency). These were intended to guide mission teams and astronauts alike through scenarios in which various computer systems on the spacecraft might fail. One of these papers, produced in 1967 with Al Hamer, detailed alternative methods of celestial navigation in the event of a failure with Apollo’s on-board navigation systems, and was pulled into use in the Apollo13 rescue in April 1970.

Everybody [in the Apollo programme] was concerned about them getting there. We were concerned about them getting back.

– Katherine Johnson, 2010, discussing her co-authored approach to one-star navigation,
tested by Jim Lovell during Apollo 8 (1968), and which formed a part of the Apollo 13 recovery efforts (1970)

Following Apollo, Johnson moved to the space shuttle programme, again playing a key role in preparations for the 1981 first flight of the original space-capable orbiter vehicle, Columbia, and worked on orbital requirements for the Earth Resources Technology Satellite (ERTS) project, which would later be renamed Landsat. Additionally, in leading up to her retirement in 1986, she turned her mind to plans for missions to Mars.

Following her official retirement, Johnson spent her later years encouraging students to enter the fields of science, technology, engineering, and mathematics (STEM), talking about her work at NASA and remaining a strong advocate of human space flight. In 2015, she was awarded the Presidential Medal of Freedom by President Barack Obama, while in 2016 her work, and that of her fellow African-American women at NASA was charted in the 2016 biographical movie Hidden Figures. In that same year NASA dedicated a purpose-built unit, the Katherine G. Johnson Computational Research Facility at the Langley Research Centre, in her honour. A second facility, also in Virginia, was renamed in her honour in 2019. The is responsible for developing and verifying software crucial to NASA missions. Both are fitting tributes to one of NASA’s pathfinders.

Katherine Johnson at 97. Credit: unknown

I found what I was looking for at Langley. This was what a research mathematician did. I went to work every day for 33 years happy. Never did I get up and say, “I don’t want to go to work.”

– Katherine Johnson, commenting on her time at NASA

Katherine Johnson died at a retirement home in Newport News on February 24, 2020, at age 101, she is survived by her three daughters, six grandchildren and 11 great-grandchildren. Her legacy is one that has carried humans into space and to the Moon, and paved the way for modern human space flight.