Space Sunday: a legend, TESS and a rocket flight

“Flight”: Christopher C. Kraft Jr. (February 1924 – July 2019), the man who created NASA’s mission control and the role of the flight director. Credit: NASA

During the celebrations marking the 50th anniversary of the Apollo 11 mission in July, came a note of sadness: the passing of Chris Kraft.

This is a name that may not be familiar to some, but Christopher C. Kraft, Jr., was one of the most influential figures of NASA’s pioneering early years of America’s human space flight, who joined the agency from its forebear, the National Advisory Committee for Aeronautics (NACA).

Born in Virginia in February 1924, to Bavarian immigrants, Kraft began his studies at Virginia Polytechnic Institute and State University (Virginia Tech) studying aeronautical engineering. During this time he applied to join the US Navy, but was rejected due to an injury to his right hand that occurred during childhood. He graduated in December 1944 with a Bachelor of Science degree.

On graduation, he applied to both the Chance Vought aircraft company and NACA. On arrival at the former on his first day of work, he was told that he could not be hired without his birth certificate, which he had not brought with him. Annoyed, he returned home and accepted the offer from NACA instead.

At NACA he was assigned to the flight research division, working under Robert Gilruth, who was to become his mentor. Most of Kraft’s work was theoretical – although it did lead him to be the original discoverer of wingtip vortices causing the majority of turbulence behind an aircraft. While he enjoyed it, he also found it taxing to the point of considering leaving, when the NACA was subsumed by NASA.

Kraft (l) and mentor Robert Gilruth (r) celebrate the first orbital rendezvous between two crewed vehicles, Gemini 6 and 7, December 1965. Astronaut L. Gordon Cooper Jr stands behind them, centre, with arms folded. Credit: NASA

Gilruth then invited Kraft to join a new project he was heading – the Space Task Group – charged with putting a man in orbit. As a result, Kraft became one of the original thirty-five engineers to be assigned to Project Mercury. In his new role, he was assigned to the flight operations division at NASA, charged with determining how the Mercury missions would be managed and operated from the ground. He was reporting in to Chuck Matthews, who essentially passed off the division’s requirements to Kraft in a throwaway comment:

Chris, you come up with a basic mission plan. You know, the bottom-line stuff on how we fly a man from a launch pad into space and back again. It would be good if you kept him alive.

Kraft realised that just like test pilots, whom he had supported through the X-1 flight programmes, astronauts would need a system of communications and support back on Earth during critical phases of the mission. He also knew they would also require a ground-based tracking system and instrumentation for the telemetry of data from the spacecraft. Through this, he came up with the idea of a single control centre to monitor and operate missions in real-time; a concept never before tried.

I saw a team of highly skilled engineers, each one an expert on a different piece of the Mercury capsule. We’d have a flow of accurate telemetry data so the experts could monitor their systems, see and even predict problems, and pass along instructions to the astronaut.

– Chris Kraft, Flight: My Life in Mission Control, 2001

Within this structure, Kraft particularly identified the need for a single individual who would have overall control and coordination over the flight centre engineers, and make the real-time decisions about the conduct of the mission. He called that role the Flight Director, and nominated himself as the man for the role.

The first iteration of the mission control concept was the Mercury Control Centre at Cape Canaveral. During this time, Kraft continued to define and refine the role of the flight director, gaining the singular title Flight as a mark of respect, although his own stubbornness that could make him something of a controversial figure in the eyes of management – but not enough to prevent him being awarded the NASA Outstanding Leadership Medal on the recommendation of the NASA Administrator, and awarded by President John F. Kennedy.

During Mercury, Kraft selected and trained three engineers to become the first generation of flight directors with him:  Glynn Lunney, John Hodge and man who also grew into a legend as he followed Kraft, Gene Kranz. As the more intensive Gemini missions took place, Kraft took on a new role: head of mission operations, but remained  entirely hands-on with the flight director programme, continuing to select and train other flight directors and continuing a flight director in his own right.

Kraft, lower right, with his hand-picked team of original NASA flight directors, Gene Krantz (bottom left), Glynn Lunney, (top left) and John Hodge (top right). Credit: NASA

Mid-way through the Gemini programme, Kraft was asked to oversee the design and implementation of the brand-new mission control centre that would form a part of the new Manned Spacecraft Centre, near Houston, Texas (now the Johnson Space Centre), which would become the nerve centre for all of NASA’s human spaceflight operations.

Kraft, Lunney and Kranz worked directly on the requirements for the new mission control centre, located at Building 30 at the new space centre, liaising with contractors and determining the design of the two primary Mission Operations Control Rooms (each referred to as MOCR, or “moe-ker”).

By the mid-1960s, Kraft was made Director of Flight Operations, and closely involved in planning the Apollo programme. He joined with Gilruth, now the head of the Manned Spacecraft Centre and possibly the most powerful man in NASA next to the agency’s administrator, George Low, the manager of the Apollo Spacecraft Programme Office and Donald Kent “Deke” Slayton, the head of the Astronaut Office, to take on an entirely unofficial, but essential role:

The four of us … had become an unofficial committee that got together often in Bob’s [Gilruth’s] office to discuss problems, plans and off-the-wall ideas. Not much happened in Gemini or Apollo that didn’t either originate with us or with our input.

– Chris Kraft, Flight: My Life in Mission Control, 2001

Kraft at the flight director’s console during Gemini IV, June 1965, despite having been promoted to Director of Flight Operations. Credit: NASA

In 1969, Kraft officially became Gilruth’s deputy in running the Manned Spacecraft Centre, and succeeded him as overall facility director in January 1972. He remained in that role past his due retirement in 1980, remaining firmly embedded in the space shuttle programme. However, his stubborn and outspoken nature in matters relating to that programme brought him into conflict with NASA Administrator James M. Beggs and others, and he suddenly announced his belated retirement at the end of 1982.

Kraft indirectly returned to the shuttle programme in 1994, when he was appointed chairman of an independent review committee with the remit to investigate ways in which NASA could make that programme more cost effective. His report, published in February 1995, recommended NASA’s should outsource shuttle operations to a single private contractor.

Christopher J. Kraft Jr., February 1924-July 2019 in his official NASA portrait, 1979. Credit: NASA

More contentiously, it was sharply critical of the post-Challenger accident safety regime at NASA, claiming it was “duplicative and expensive”, while claiming the shuttle had become “a mature and reliable system”.

NASA’s own Aerospace Safety Advisory Panel responded that, “the assumption that the Space Shuttle systems are now ‘mature’ smacks of a complacency which may lead to serious mishaps.” Nonetheless, responsibility for shuttle operations was turned over to United Space Alliance.

In 2003, the investigation into the Columbia accident, directly cited the recommendations made by Kraft’s committee as potentially contributing to that accident, by encouraging NASA to view the shuttle as an operational, rather than experimental vehicle and distracting attention from continuing engineering anomalies. In typical form, Kraft  defended his report, insisting the space shuttle was “the safest space vehicle ever built”.

Kraft received numerous awards throughout his career, and in on April 4th, 2011, he was guest of honour at a ceremony at Johnson Space Centre’s Building 30 Mission Control Centre when it was renamed the Christopher C. Kraft, Jr., Mission Control Centre, in recognition of the facility’s 50 years managing US human space flight, and Kraft’s unique place in both NASA’s and the building’s histories.

Christopher Kraft passed away on July 22nd, 2019 at the age of 95 and leaving his wife of 69 years, Betty Anne, and son and daughter Gordon and Kristi-Anne, and their families.

Continue reading “Space Sunday: a legend, TESS and a rocket flight”

Space Sunday: lunar landers, asteroids and more

A GSLV Mk III lifts-off with the Chandrayaan-2 mission from India’s Satish Dhawan Space Centre, Sriharikota, 09:13 UTC, Monday, July 22nd, 2019. Credit ISRO

The Indian Space Research Organisation (ISRO) successfully launched its Chandrayaan-2 mission to the lunar south pole on Monday, July 22nd, after suffering a week’s day to the schedule. This is an ambitious mission that aims to be the first to land in the Moon’s South Polar region, comprising three parts: an orbiter, a lander and a rover.

Although launched atop India’s most powerful rocket, the GSLV Mk III, the mass of the mission means it cannot take a direct route to Mars, as the upper stage isn’t powerful enough for the mass. Instead, Chandrayaan-2 was placed into an extended 170km x 39,120 km (105 mi x 24,300 mi) elliptical orbit around the earth. For the next month, the orbiter will gradually raise this obit until it reaches a point where lunar gravity becomes dominant, allowing Chandrayaan-2 to transfer into a similarly extended lunar orbit before easing its way down to a 100 km (60 mi) circular polar orbit around the Moon, which it is scheduled to achieve seen days after translating into its initial lunar orbit.

How Chandrayaan-2 will reach the Moon and its operational orbit. Credit: ISRO

During this period, the combined vehicle will carry out multiple surveys of the Moon’s survey, focusing on the South Pole. It will also release the 1.47-tonne Vikram lander (named for Vikram Sarabhai, regarded as the father of the Indian space programme) which will make a soft decent to the lunar surface, which will take several days prior to making a soft landing.

The orbiter vehicle is designed to operate for a year in its polar orbit for one year. It carries a science suite of eight systems, including the Terrain Mapping Camera (TMC), which will produce a 3D map for studying lunar mineralogy and geology, an X-ray spectrometer, solar X-ray monitor, imaging spectrometer and a high-resolution camera.

The Vikram lander, with four science payloads, will communicate both directly with Earth and the orbiter. It will also facilitate communications with the Pragyan rover, which will be deployed within hours of the self-guiding lander touching down. Between them, the lander and rover carry 5 further science experiments and both are expected to operate for around 14 days.

Testing the deployment of the Pragyan rover from the Vikram lander. Credit: ISRO

Craters in the South Polar region lie in permanent shadow and experience some of the coldest temperatures in the solar system and NASA’s Lunar Reconnaissance Orbiter (LRO) has revealed they contain frozen water within them, water likely unchanged since the early days of the Solar System, and thus could hold clues to the history of the Solar System – hence the interest in visiting the region and learning more. The frozen water is also of interest to engineers as it could be extracted to provide water for lunar base; water that could be used for drinking, or growing plants and could also me split to produce oxygen and hydrogen  – essential fuel stocks.

The Chandrayaan-2 mission marks a significant step forward for India’s space ambitions; assuming the Vikram lander is successful, the country will become only the forth nation to land on the Moon after the United States, Russia and China. As a part of its expanding activities in space, the country hopes to fly it first astronauts into space in 2022 and have an operational space station by the end of the 2020s.

2019 OK

No, I’m not making a statement about the year – that’s the name of a chunk of space rock measuring 57 to 130m (187 to 42ft) across that passed by Earth at a distance of around 73,000 km (45,000 mi), putting it “uncomfortably close” to the planet. What’s more, we barely released it was there: 2019 OK was positively identified by the Southern Observatory for Near Earth Asteroids Research (SONEAR), just a couple of days prior to is passage past Earth, and was confirmed by the ASAS-SN telescope network in Ohio, leaving just hours for an announcement of its passage to be made.

Since then, the asteroid’s orbit has been tracked – forward and back (which revealed it had been previously spotted by observatories, but its small size and low magnitude meant its significance wasn’t realised). These observations confirmed 2019 OK is a reactively short-period object, orbiting the Sun every 2.7 years. It passes well beyond Mars before swinging  back in and round the Sun, crossing the Earth’s orbit as it does so. However, while it may pass close to Earth on occasion, it’s highly unlikely it will ever strike us.

Credit: NASA

It does, however, remind us that near-Earth objects (NEOs) are common enough to be of concern; 2,000 were added to the list 2017 alone. The size of 2019 OK reminds us that there are more than enough of them to be of a significant enough size to pose a genuine threat.

In 2013, an asteroid measuring just 20m across entered the atmosphere to be ripped apart  at an altitude of around 30 km above the Russian town of Chelyabinsk. The resultant resulting shock wave shattered glass down below and injured more than 1,000 people. 2019 OK is at a minimum 2.5 times larger than the Chelyabinsk object – and possibly as much as 10 times larger, putting it in the same class of object that caused the Tunguska event of 1908, when 2,000 sq km (770 sq mi) of Siberian forest was flattened by an air blast of 30 megatons as a result of a comet fragment breaking up in the atmosphere.

Hence why observatories such as SONEAR, ASAS-SN telescope network, the Catalina Sky Survey, Pan-STARRS, and ATLAS and others attempt to track and catalogue NEOs. The more of them we can located and establish their orbits, the more clearly we can identify real threats  – and have (hopefully) a lead time long enough to take action against them.

A computer model show the passage of 99942 Apophis on April 13th, 2029. The blue dots represent satellites in orbit around Earth and the pink line the orbit of the International Space Station. Credit: NASA JPL

Oh, and if you thought 2019 OK was big, consider 99942 Apophis. It’s around 400-450m across, and will swing by Earth at a distance of just 31,000 km on  – wait for it – Friday, April 13th, 2029 (so get ready for a lot of apocalyptic predictions in the months leading up to that date!).

Continue reading “Space Sunday: lunar landers, asteroids and more”

Space Sunday special: Apollo 11 at 50 Part 3

NASA’s official Apollo 50th anniversary logo. Credit: NASA

This is the concluding part of a special Space Sunday series, celebrating the 50th anniversary of  Apollo 11 landing on the Moon, and follows on directly from Part 2: “The Eagle Has Landed!”. To follow the full series, please click over to Part 1: Lift-off! We Have lift-off!

Part 3: “Magnificent Desolation” And The Voyage Home

I had asked [Neil] before the mission launch several times what he was going to say on the occasion of this historic moment, setting foot on the lunar surface, and he always replied, “I’m a test pilot, I’ll probably just say how dusty it is or something like that. Don’t worry.” But he came back with his now famous [line]. The media immediately wanted to know if it was one small step for a man, or just man. There was a little bit of static, so it wasn’t entirely clear.

– Astronaut Bruce McCandless, Capsule Communicator (CapCom),
Mission Control Green Team

Whether or not Armstrong had said “a man” in his statement was to become a matter of debate in the decades that followed Apollo 11, almost overshadowing that first step itself. With the indefinite article included, his comment makes sense: he is clearly referring to himself (“one small step for a man”). Without it, “man” becomes more reflective of humanity as a whole, making his comment the equivalent of “That’s one small step for humanity. One giant leap for mankind”.

Such was the level of debate with one analysis of recording suggesting he said “a man”, another suggesting he didn’t, that not long before his death, Armstrong noted a little ruefully – and quite correctly:

I would hope that history would grant me leeway for dropping the syllable and understand that it was certainly intended, even if it wasn’t said – although it might actually have been.

– Neil Armstrong

A ghostly image from the broadcast TV footage – captured by the news agencies by having to re-film live footage received from the Moon and played on a special monitor. Credit: CBS News

But on the Moon, and unaware of the controversy that was even then brewing around his words, Armstrong collected a contingency sample of rock and surface material in case an unexpected issue required the EVA to be curtailed. Then he took the remote-control TV camera mounted on the Lunar Module to take a panoramic shot around the Eagle before setting it on a tripod a short distance from the LM to allow Mission Control to use it to record the EVA.

That  camera is the reason why the Apollo 11 video footage looks ghostly. Its scan rate was incompatible with those used by US TV networks, so the live transmission had to be shown on special monitors with TV cameras set-up in front of them which then re-broadcast the images – with a significant loss of picture quality in the process. (It’s also worth notingthat while NASA recorded the footage onto magnetic tape, it was eventually lost through the agency’s policy of tape re-use.)

Shot from an automated camera aboard the Lunar Module, this shot shows Aldrin standing close to the US flag as Armstrong back away to take a photo of Aldrin saluting the flag. July 20th/21st, 1969. Credit: NASA

Aldrin set foot on the Moon 19 minutes after Armstrong with the words, “Beautiful view. Magnificent desolation.”

There was little time to appreciate it, however. The two men were on a tight schedule: because there was no empirical data on how well the portable life support system (PLSS) in the astronaut’s backpacks would perform on the Moon, it had been decided to limit this first (and only, for Apollo 11, which would spend less than a day on the Moon) EVA to just over 2 hours. Before that time expired, both men had to set-up the US flag, deploy the instruments of the EASEP, the Early Apollo Scientific Experiments Package, survey their location and collect and many rock and soil samples as they could manage.

The shot of Aldrin saluting the flag as taken by Armstrong, July 20th/21st, 1969. Credit: NASA

The flag (purchased from a Sears store) proved a little problematic. Its telescopic pole refused to go deep into the ground, leaving Aldrin fearing it would unceremoniously topple over while on camera. Nevertheless, he dutifully saluted it as a still-commissioned US military officer before taking up position in front of the TV camera to demonstrate various means of locomotion in the low gravity for the benefit of future crews.

While he was doing that we were all wondering what Neil was doing. Well, Neil was collecting this very fine and diverse group of rocks and soil. Not only did he get a very wide distribution, but he also thought the box looked a little empty, so at the last minute he filled it with just the dirt, so to speak, what we call the lunar regolith. That sample turned out to be the best, most comprehensive sample of lunar regolith that was ever taken on any of the Apollo missions.

– Harrison Schmitt, the only geologist-astronaut in the Apollo programme,
who served as both advisor to crews and as the Lunar Module pilot for Apollo 17

Continue reading “Space Sunday special: Apollo 11 at 50 Part 3”

Space Sunday special: Apollo 11 at 50 Part 2

NASA’s official Apollo 50th anniversary logo. Credit: NASA

This is part 2 of a special Space Sunday series, celebrating the 50th anniversary of  Apollo 11 landing on the Moon, and follows on directly from Part 1: “Lift-off! We Have Lift-off!” It was published on Saturday, July 20th, 2019, as a Space Sunday special to mark the actual date of that historic landing.

Part 2: “The Eagle Has landed”

Once the combined Command and Service Module (CSM) and Apollo Lunar Module (CM) were free of the Saturn V’s S-IVB stage, they were in constant sunlight, so to help better regulate their internal and external temperatures, the reaction control system on the CSM was used to set both vehicles spinning very gently along their longitudinal axis in what was called the “Apollo barbecue roll”.

Michael Collins aboard the Apollo Command Module Columbia. Credit: NASA

During this “cruise phase” of the flight, the three men aboard Apollo 11 – Armstrong, Collins and Aldrin – had to perform a range of activities from keeping an eye on their spacecraft through to making broadcasts back to Earth. It was here that their curious relationship came a little to the fore.

While all three men got along very well, they were observed not to bond in the manner of other crews; all three were somewhat quiet men, with Collins and Aldrin particularly coming to refer to their relationships with one to the others as that of “amiable strangers”.

Which is not to say the three men didn’t get along; almost all of the on-board conversations were recorded by NASA, even if they weren’t broadcast, and these “off-air” conversations reveal the three men shared jokes – such as Aldrin and Collins gently teasing Armstrong about his “rookie” status in having clocked the fewest number of hours in space. However, when it came to talking for the benefit of the television audience, Mission Control sometimes had to coax words out of the crew.

The first time we saw the Moon up close, it was a magnificent spectacle. It was huge. The Sun was coming around it, cascading and making a golden halo and filled out entire window. [But] as impressive as the view was of this alien Moon seen up close was, it was nothing compared to the sight of the tiny Earth. The Earth was the main show. The Earth was it.

– Michael Collins, 50th anniversary of the Moon landing

Apollo 11 reached the Moon on July 19th, 1969, after a single mid-course corrections using the single motor of the Service Module (out of 4 planned for the flight).

Edwin Aldrin in the Apollo 11 Lunar Module Eagle, photographed by Neil Armstrong. Credit: NASA

Now Collins again took the controls to gently pivot the vehicles around in their own length, so that single large motor was pointing forward along their line of flight. Then, at 17:21:50 UTC, as they passed around the Moon’s far side, the engine was fired in the first of two orbital insertion burns.

This first engine burn slowed the vehicles so they they were snagged by the Moon’s gravity and placed in an elliptical orbit. A second burn of the engine followed 4 hours and 22 minutes later, circularising the vehicle’s orbit in readiness for Armstrong and Aldrin to make their historic descent.

In all thirty orbits of the Moon were performed as the Lunar Module was prepared for its descent and landing. These orbits frequently passed over the Mare Tranquillitatis, a large basalt plain on the Moon selected as the location for the first manned landing by the United States as it appeared from orbital imaging as being relatively smooth, and had already seen a successful landing by the automated Surveyor 5 mission, which arrived on the Moon on September 11th, 1967.

Shortly after Apollo 11 dropped into orbit around the moon, Frank Borman got a message from the Soviet Union that said, “Congratulations on reaching lunar orbit. We have Luna 15 also in orbit around the moon and its orbital parameters are such and such. If it presents any problem, please advise and we will move it.” We didn’t need Luna 16 moved, but I thought it was a noble gesture in those days of the Cold War.

– Bruce McCandless, Capsule Communicator (CapCom),
Apollo 11 Mission Control Green Team

“The Eagle has wings” – Neil Armstrong’s announcement that the Apollo 11 Lunar Module was operating independently of the Command and Service Module, July 20th, 1969

At 12:52:00 UTC on July 20th, Aldrin and Armstrong entered Eagle, and began the final preparations for lunar descent, Five hours later, all was set and they undocked from the Command Module Columbia. With Michael Collins in the Command Module, Armstrong gently eased Eagle away from the CSM, then used its reaction control system to perform a slow pirouette. This allowed Collins to carry out a visual inspection of the LM, confirm its legs were deployed and that it was generally looked OK to make its decent.

For the first part of the decent, Eagle was effectively “face down” giving Armstrong and Aldrin a view of the Moon. Then the descent engine fired and the vehicle slowly moved to an upright position, and Armstrong voiced a slight concern.

We’re about a minute, maybe 2 minutes, into powered descent, face-down, and Neil says to me, and the Earth, “I think we’re gonna be a little long.” I said to myself, how in the world can he really, at this point, tell that we’re gonna be a little long? But sure enough, we were. I’ve learned that whenever Neil says anything, you’d better pay attention because there’s good meaning to it.

– Buzz Aldrin commenting on the Eagle’s descent to its landing

Continue reading “Space Sunday special: Apollo 11 at 50 Part 2”

Space Sunday special: Apollo 11 at 50

NASA’s official Apollo 50th anniversary logo. Credit: NASA

This week sees the 50th anniversary of the Apollo 11 lunar landing. To mark the event, this Space Sunday article and the next will look at that mission, and the three men who flew it.

Part 1: “Lift-of We Have Lift-off!”

On Wednesday, July 16th, 1969, at 13:31:51 UTC (9:31:51 EDT) five Rocketdyne F-1 at the base of Saturn V SA-506 came to life. Starting with the centre motor, then the opposing outboard pairs, the entire ignition sequence took 600 milliseconds. Held on the pad by four massive clamps, called hold-down arms, the five engines gradually built up thrust to 35,100 kN (7,891,000 lbf).

At precisely 13:32:00 UTC) (9:32:00 EDT) the huge hold-down-arms rocked back in a “soft release”, allowing the rocket, weighing almost 3,274 tons, to start its ascent, its acceleration slowed for the first half-second by a series of 8 pins connecting it to the pad to “reduce transient stresses resulting from abrupt disengagement of a vehicle from its launch stand”. When these pins dropped free from the base of the rocket, Apollo 11 was on its in a historic mission that would seen humans land on the Moon for the first time.

Apollo 11, May 20, 1969, on Flickr
Saturn V SA-506, the Apollo 11 launch vehicle, is rolled out to Pad A at Launch Complex 39 at Kennedy Space Centre, May 20th, 1969

The two men destined to be the first to set foot on Earth’s natural satellite were Neil Alden Armstrong, just shy of his 39th birthday, and  Edwin Eugene “Buzz” Aldrin Jr., who had turned 39 in January 1969, sat atop of the massive Saturn V rocket along with Command Module Pilot, Michael Collins, the youngest of the three (if only by a couple of months). Together, they formed only the second Apollo flight crew where all three men had previously flown in space (the first having been Apollo 10, the “dress rehearsal” mission for the Moon landing).

Armstrong, Aldrin and Collins were also perhaps the most technically competent trio on NASA’s astronaut roster at the time. All had served in the military – Armstrong in the US Navy, Aldrin and Collins in the US Air Force. Both Armstrong and Collins had also built up impressive résumés as test pilots, Armstrong as a civilian and Collins in the US Air Force.

In particular, Armstrong flew with the National Advisory Council for Aeronautics (NACA), NASA’s forebear, prior to being selected for the USAF/ NASA high-altitude X-15 research programme, (he flew the X-15 seven times between late 1960 and mid-1962) whilst simultaneously engaged by the USAF in their X-20 Dyna-Soar space plane project. Collins, meanwhile, took part in high-altitude flights, taking F-104 Starfighter jets to 27.7 km (90,000 ft) in order to experience the “weightless” environment of free-fall at the top of their parabolic flight arcs, helping him to achieve 3,000 hours in the cockpit.

Collins, Aldrin and Armstrong, on Flickr
An unusual portrait in black and white of Michael Collins, Edwin “Buzz” Aldrin and Neil Armstrong. Credit: NASA (this image was later colourised on numerous occasions by various artists)

As well as being aviators, Armstrong and Aldrin were also academics. Armstrong held a BSc in aeronautical engineering and an MSc in aerospace engineering, and Aldrin has a doctorate in astronautics. Aldrin particularly specialised in on-orbit rendezvous, which allowed him to work on Project Gemini as an engineer (and also earned him the nickname “Dr. Rendezvous” , not always meant kindly, by other astronauts).

Despite their qualifications, both Armstrong and Aldrin almost didn’t get selected for NASA’s astronaut programme: neither had the requisite military test pilot qualifications that were initially required. However, in 1962, NASA dropped the “military” element from the test pilot requirement, enabling Armstrong to apply for the Group 2 intake – although he almost missed the cut. his application arrived after the closing date, but fortunately Dick Day, a simulations engineer at NASA who have previously worked with Armstrong saw the application and made sure it was included.

Aldrin’s break came in 1963, when NASA further revised the requirements to test pilot OR 1,000 hours flying jets. This allowed he to re-apply (his first application having been turned-down due to his lack of test pilot experience), and he was invited to join the Group 3 intake alongside Michael Collins.

At 2 minutes 41 seconds into its flight, the S-IC first stage of Apollo 11 separates, four small separation motors pushing the upper stages way from it, prior to the S-II second stage main engines to ignite

A Saturn V launch is perhaps one of the most stunning sights to witness – and Apollo 11 was witnessed by around 1 million people in and around the Kennedy Space Centre. However, for the first part of their flight, the three men were pretty much passengers as the Saturn V rose into the sky.

For all their power, the five F-1 engines took 12 seconds to overcome the 100.6 m tall rocket’s mass and inertia and push it clear of the 120m tall Launch Umbilical Tower (LUT), angling it very slightly away from the tower in the process so to avoid the risk of any wind-driven contact between the two.

Immediately after clearing the tower, the rocket commenced its “roll”, a necessary manoeuvre in which the vehicle rolls around its vertical axis, allowing it to point itself along the line of flight it needs to achieve the required orbit. After that, things started to move quickly.

A minute after launch, the Saturn V was around 6.5 km (3.5 nautical miles) altitude and passing through the sound barrier. Twenty seconds later, it entered “Max Q”, the period of maximum dynamic pressure, placed on this frame as a result of it literally punching its way through the atmosphere.

At this point, the F-1 engines throttled back a little to prevent the vehicle shaking itself apart, but once through “Max Q” – a period of only a handful of seconds, they returned to full thrust, pushing the vehicle up to 62 km (42 mi) above the Earth, and taking only 2 minutes 41 second from launch to do so. At this point, and travelling at 9,960 km/h (6,164 mph), the huge first stage separated, the upper stages of the Saturn 5 pushed clear by a set of four separation motors.

From here, the four motors of the second stage took over. While the massive first stage coasted upwards behind it and then fell back to crash into the Atlantic ocean, the Second stage ran for 6 minutes, accelerating the rocket to 25,000 km/h (15,647 mph) and lifting it to an altitude of 175 km (109 mi).

With its fuel spent, the second stage separated, also to fall back to the Atlantic, while the single, re-usable engines of the all-important S-IVB stage took over. This stage initially ran for about 2.5 minutes, during which time it pushed Apollo 11 to a velocity of 27,900 km/h (17,432 mph), allowing it to assuming a near-circular orbit around the Earth averaging 184 km 98.9 na mi) before shutting down for the first time.

It was at this point that the three crew took a more pro-active role in the flight. For the next  couple of hours, as they completed 1.5 orbits of the Earth, and in tandem with mission control, they confirmed their vehicles were ready to be committed for the flight to the Moon.

Apollo 11, May 20, 1969, on Flickr
A diagram of the Saturn V Apollo launch vehicle.Credit: NASA

Interestingly, while mission commander, Armstrong had actually clocked less time in space than either Collins or Aldrin. However, he had the greatest experience in handling in-flight emergencies, having dealt with the first in-flight failure of a critical system during a US space mission.

Neil Armstrong photographed by Buzz Aldrin as the crew prepare for TLI – trans-lunar injection. Credit: NASA / E.E. Aldrin

This occurred during his flight flight into space on the Gemini 8 mission, alongside David R. Scott. This mission was intended to be the first test of an orbital docking between two vehicles – Gemini 8 and an automated Agena target vehicle. In all, Armstrong and Scott were expected to complete four such docking as a part of the mission objectives.

However, shortly after docking, the Gemini’s Orbit Attitude and Manoeuvring System (OAMS) has suffered a serious failure, and Armstrong ordered Scott to release the docking mechanism before before vehicle broke up. Once free of the Agena (which was later stabilised by ground control allowing it to be used by Gemini 10 with Michael Collins), Armstrong took the took the unorthodox step of shutting down the OAMS and using the Re-entry Control System (RCS) to regain control. While this worked, undoubtedly saving his and Scott’s lives, under mission regulations, they no option but to immediately perform and emergency return to Earth, curtailing the mission.

Back aboard Apollo 11, their checks complete, the crew received the all clear for the critical trans-lunar injection (TLI) burn. This started mid-way through the second orbit of Earth, as the S-IVB motor was restarted and fired for 5 minutes and 47 seconds, accelerating the vehicle to around 40,085 km/h (25,053 mph), and pushing it away from Earth and into an energy-efficient trajectory towards the Moon.

The Apollo 11 LEM, call sign Eagle, on FlickrAs Michael Collins carried out the transposition, docking and extraction manoeuvre, either Aldrin or Armstrong took this image of the Lunar Module (LM) sitting in the top of the Saturn V S-IVB stage, awaiting the Command and Service Module (CSM) to dock with it and gently pull it free of the upper stage. Credit: NASA

Continue reading “Space Sunday special: Apollo 11 at 50”

Space Sunday: rockets, exoplanets and alien oceans

rion AA2, July 2nd 2019The Orion test article lifts-off from Space Launch Complex 46 at Cape Canaveral Air Force Station at the start of Ascent Abort-2, July 2nd 2019. Credit: NASA

NASA’s Orion Multi-Purpose Crew Vehicle passed a significant test on its way to its first crewed launch (due in 2022) on July 2nd, 2019, as it completed a flight test of the capsule’s launch abort system (LAS).

The LAS is a system designed to pull a crewed capsule clear of a malfunctioning rocket during an ascent to orbit, hopefully saving their lives in the process. As such, it is a significant system that must be tested and cleared for use before crewed flights can commence with a new launch vehicle.

For the Space Launch System (SLS), NASA is following its traditional approach, with the LAS designed to “pull” a crew capsule clear of launch vehicle. It does this by placing a special fairing over the capsule that has a tower extending from its top, fitted with three motors. This has always been the traditional approach to US LAS systems – by contrast, Russian LAS systems generally sit below the capsule and are design to “push” it away from a malfunctioning rocket.

The Orion / SLS launch abort system (LAS). Credit: NASA

The July 2nd test – called the Ascent Abort-2 (AA-2) mission – was a critical test flight, designed to test the LAS at the point in an ascent to orbit when the Orion / SLS combination will be subjected to the highest aerodynamic stresses – the so-called period of “Max-Q” – that occurs during a rapid ascent into space.

To achieve this, NASA mounted an Orion structural test article – basically an Orion capsule sans its flight systems – contained within a LAS fairing onto the motor stage of an MX Peacekeeper ICBM, and launched it into the Florida skies in a early morning ascent designed to last some 55 seconds.

In that time, the rocket was expected to reach an altitude of 9.5 kilometres (31,000 ft) and a speed of Mach 1.3, at which point the abort sequence would trigger.

As it turned out, the MX rocket motor ran “hot”, accelerating a little faster than anticipated, so reaching its assigned separation altitude 5 seconds early. Nevertheless, the abort sequence initiated correctly, and the powerful abort motors on the LAS fired, generating 181,400 kg of thrust, hauling the Orion free of the ascent motor unit.

Once a clear separation from the still ascending motor stage had been achieved, the attitude control motors at the very top of the LAS fired, flipping it and Orion over. The middle jettison motor then fired, separating the LAS from the Orion.

During an actual abort sequence, the Orion would then re-orient itself so it would be falling heat shield first, allowing its parachutes to be deployed in preparation for a splashdown. However, for the AA-2 flight, the test article did not carry a parachute system. Instead, and like the LAS, the capsule was allowed to fall back into the Atlantic, hitting it at an estimated 480 km/h (300 mph) and breaking up. Just before it did so, however, it ejected 12 bright orange data recorders not unlike those so-called “black boxes” used by aircraft. These contained critical data recorded during the 3 minute 11 second flight, and which will be assessed post-mission to confirm everything did go an planned.

That was a spectacular test we all witnessed this morning. It was really special for the programme; a really big step forward to us. It was a really great day all around – weather and the vehicle. One of the most important parts of the test was to see how the attitude control motor performed. The internal motor pressure was rock solid, straight line and it had excellent control characteristics. Everything we’ve seen so far looks great.

– Mark Kirasich, NASA’s Orion Programme Manager

Orion AA2, July 2nd 2019The Orion test article climbs into the early morning sky over Cape Canaveral Air Force Station at the start of Ascent Abort-2, July 2nd 2019. Credit: NASA

The US has never has to use the LAS on an actual mission. However, there is no guarantee this will always be the case, and circumstances where a LAS must be used are not unkown – as the Soyuz M-10 mission in October 2018 demonstrated (see Space Sunday: of Soyuz aborts and telescopes). Therefore, passing this test was critical if  Orion and SLS are to achieve the flight goals required for NASA’s programme – Project Artemis – to return humans to the surface of the Moon.

Half-Planet, Half-Star

Discovered in 2012, GJ3470b is a “mini-Neptune” planet orbiting a red dwarf star called Gliese 3470, 100 light years from our Sun. Occupying an orbit some 6 million km (3.7 million mi – roughly one-tenth of the distance between the Sun and Mercury) from its parent, the planet has a mass of around 12.6 Earths.

None of this is particularly unusual; as I’ve noted in past Space Sunday articles, M-type stars are the most common type of star in the galaxy, and mini-Neptune type planets account for around 80% of the exoplanets discovered to date. Nevertheless, recent studies have revealed GJ3470b to be a very unique world.

GJ3470b, its atmospheric composition, and its relative location to its parent star. Credit: NASA, ESA, and L. Hustak (STScI)

The presence of an atmosphere around the planet was detected fairly soon after its discovery and prompted astronomers to take a prolonged look at it. To do this, they combined the Hubble and Spitzer space telescopes to examine the planet’s atmosphere for a total of 20 transits in front of its parent star.

These observations, using the light of the star passing through the planet’s atmosphere during the transits, allowed the astronomers to gather data on the composition of GJ3470b’s atmosphere. What was discovered came as a huge surprise.

It has been expected that the observations would reveal an atmosphere somewhat similar to Neptune’s, but such was the depth to which they could measure, it quickly became clear that GJ3470b has an almost pristine atmosphere of hydrogen and helium surrounding a large solid core.

The presence of hydrogen and helium may not sound too unusual – after all, the four gas giants of our solar system have atmospheres largely made up of those two gases. However, they also have amounts of other, heavier elements – methane, nitrogen, oxygen, ammonia, acetylene, ethane, propane, phosphine, etc., – none of which showed up in any of the spectral analyses performed by Hubble and Spitzer. This makes GJ3470b’s  atmosphere closer in nature to that of the Sun or a star than it does to a planet, leading to it being dubbed “half-planet / half-star” in some quarters, and making it the most unique exoplanet yet discovered.

Continue reading “Space Sunday: rockets, exoplanets and alien oceans”