Category: Space Sunday

Fifty years ago today, January 31st, 2021, America’s Apollo lunar missions resumed – and came perilously close to a second aborted mission.

Originally scheduled to take place in July 1970, Apollo 14 was delayed following the Apollo 13 crisis (see: Space Sunday: Apollo 13, 50 years on), to both allow time for recommendations resulting from the investigations into the Apollo 13 mishap to be implemented. This not only led to a hiatus in lunar landings, it also meant that the Apollo 14 crew of Mercury 7 veteran Alan B. Shepard Jr. (Commander),  Stuart A. Roosa (Command Module Pilot) and Edgar D. Mitchell (Lunar Module Pilot) eventually spent more time training together than any other Apollo crew to that point: a total of 19 months.

In the immediate aftermath of Apollo 13, NASA Administrator Thomas O. Paine indicated the agency would ideally like to launch the mission before the end of 1970; however, the recommendations for changes to be made to the Command and Service Module (CSM) combination meant that the earliest the agency could realistically schedule a launch for the mission was at the end of January 1971 – with much of the work in supervising the necessary changes being loaded directly onto the shoulders of Shepherd and Roosa.

We realised that if our mission failed—if we had to turn back—that was probably the end of the Apollo program. There was no way NASA could stand two failures in a row. We figured there was a heavy mantle on our shoulders to make sure we got it right

– Edgar D. Mitchell, discussing Apollo 14 preparations, speaking in 2011

A  further complication for the mission was that following Apollo 13, the original landing site for the Apollo 14 crew at Littrow crater, in Mare Serenitatis was abandoned in favour of sending the mission to Fra Mauro, the intended landing site for Apollo 13, and which was seen as having greater scientific relevance, requiring Shepherd and Mitchell to revisit their lunar surface and geology training – Littrow had required a high degree of training in volcanic geology; Fra Mauro was an impact crater site.

The key changes to the CSM combination were around the oxygen tanks that had exploded on Apollo 13. These includes a complete redesign of the tanks and the circuitry within them, while a third tank was add on the opposite side of the SM that could act as a back-up in case of issues with the first two. Other changes included incorporating a 5 US gallon tank of “emergency” drinking water and an additional battery to help maintain electrical power to the Command Module in event of the main power buses failing. Alterations were also made to the connections between the Command and Lunar modules for easier and faster transfer of power and control between the two.

Outside of the need to overhaul the CSM combination in the wake of Apollo 13, the Lunar Module for the mission – the last of the “short term” H-class missions – underwent changes that included anti-slosh baffles in the descent engine fuel tanks intended to prevent incorrect low fuel warnings to be triggered – an issue that plagued both Apollo 11 and Apollo 12 – and the installation of additional equipment hard-points for the surface science mission, which would be the most intensive yet for an Apollo lunar mission.

Aside from these changes, the mission was to be the first to fly an altered Saturn V rocket. Whilst ostensibly the same externally as all the previous Saturn Vs that had flown, SA-509 had a series of internal changes made to its fuel system to prevent pogo oscillations – a self-excited vibration in liquid-propellant rocket engines caused by combustion instability that can, if unchecked, result in an engine exploding. On Apollo 13, such oscillations had meant the centre J2 engine of the rocket’s upper stage had to be prematurely shut down.

Of the crew, Shepard was the only one to have previously flown in space as the first American to complete a sub-orbital hop aboard Mercury Freedom 7 in May 1961.

Born in 1923, Shepard attended the US Navy Academy at Annapolis from 1941 to 1944 (the normal 4-year training course having been cut by 12 months due to World War 2). He  initially served aboard the destroyer USS Cogswell – it then being a requirement that Navy aviators serve shipboard time prior to starting flying training -, rising to the rank of Air Gunnery Officer, responsible for the ship’s anti-aircraft guns and crews, a position he held while the Cogswell served critical roles in the Battle of Okinawa and off the coast of Japan.

In November 1945 he transferred to flight training school, and after almost washing out as a pupil, went on to  gain 3,600 flying hours  with more than 1,700 in jets, eventually rising to the position of Aircraft Readiness Officer on the staff of the Commander-in-Chief, Atlantic Fleet.

After his Mercury flight, In 1963 Shepard was grounded due to Ménière’s disease, an inner-ear ailment that caused episodes of extreme dizziness and nausea.This precluded him from flight involvement in the Gemini programme, although from 1963 through 1969 he was NASA’s Chief of the Astronaut Office with overall responsibility for astronaut training and mission selection.

In 1969, Shepard underwent successful surgery to correct his ear issue, and was returned to active flight status. He immediately lobbied his successor as Chief of the Astronaut Office, Donald “Deke” Slayton for a position on Apollo, and was initially earmarked to command Apollo 13. However, his “inexperience” in having missed the entire Gemini programme, and that of his crew as a whole, saw them “bumped” to Apollo 14 to allow them a greater amount of training.

Both Stuart Roosa and Edgar Mitchell were rookies, with Apollo 14 their first and only flight into space. Roosa had previously been a “smokejumper” with the US Forest Service, parachuting into remote area to combat forest fires, prior to transferring to the United States Air Force and training to be both a fighter pilot and an experimental test pilot.  On joining NASA in 1966, he was the capsule communicator (CAPCOM) for the tragic Apollo 1 fire, and also served on the support team for Apollo 9, working closely with Edgar Mitchell.

Mitchell was another Naval aviator, having entered the service in 1952 with a degree in industrial management.  During during his military flying career he gained a second bachelor’s degree in aeronautics and a doctorate in in aeronautics and astronautics. He also clocked an impressive 5,000 flying hours as both a front-line fighter pilot and a test pilot, 2,000 of those hours gained in jets.

Mitchell’s involvement with space activities actually started before he joined NASA, when in  1964 he was assigned to the US Air Force Manned Orbiting Laboratory (MOL), serving as Chief, Project Management Division of the Navy Field Office that was liaising with the Air Force, and also as an instructor in advanced mathematics and navigation theory for MOL astronaut candidates. When MOL was cancelled, he applied to NASA, and was accepted as a part of the fifth astronaut intake alongside Stuart Roosa.

Given it was the first mission to follow Apollo 13, there was a lot of media and political attention on Apollo 14, including pressure for it to launch on schedule. As it was, weather intervened on the launch day, causing the countdown to be paused for some 40 minutes – the first time such a delay had occurred with and Apollo mission. Launch eventually took place at 21:03:02 UTC on January 31st, 1971.

The pre-launch delay wasn’t considered to be a significant issue, as the mission was to take a faster trajectory to the Moon than previous launches, so the delay effectively left it running precisely “on time” compared to earlier missions. Following a require time in Earth orbit, the S-IVB third stage engines were-lit, pushing the mission on its way to the Moon.

Once en-route, the CSM – christened Kitty Hawk by the crew in honour of the Wright Brothers –  had to separate from the S-IVB, then turn through 180º to dock with the now-exposed Lunar Module (called Antares after the star Shepard and Mitchell were due to use as reference point when orienting their craft for its lunar landing) and then gently pull it clear of the rocket stage, which would then gently divert away from the Apollo vehicles flight path.

Roosa, as Command Module Pilot, hoped to set the record for competing this manoeuvre using the least amount of fuel. However, the extended docking mechanism in the nose of the Command Module had other ideas – it refused to latch onto the lunar module firmly enough to trigger the release of the pin holding the LM in place on the S-IVB. Over two hours Roosa repeatedly attempted to make an initial “soft dock” with the LM, but was repeatedly thwarted, leaving the crew and mission control agitated: if the LM could not be extracted by the CM, then the mission was over – and two mission failures in succession, even without any loss of life, would likely spell the end of Apollo.

Continue reading “Space Sunday: Apollo 14, 50 years on” →

After a build-up of excitement around a potential start-of-year flight for SpaceX Starship prototype SN9, things has slowed down somewhat – but the vehicle may now be on the brink of making its 12.5 km ascent to altitude and an attempt to land successfully after an unpowered “skydive” back towards Earth.

As I noted in my January 10th Space Sunday report, SpaceX had managed to accelerate the processing of SN9 in comparison to SN8 to a point where the majority of pre-flight checks for the vehicle – including a static fire test of the engines on January 6th –  had been completed in just a 2-week period following its delivery to the launch stand on December 22nd, compared to 2 months taken for prototype SN8 to reach the same point.

However, as I noted at the time, that static fire test was far shorter than had been expected – just 2 second in length, signifying a possible issue. This appeared to be confirmed when SpaceX attempted further engine tests between January 8th and January 12th, of of which had to be scrubbed for various reasons (including weather), before a further test was made on Wednesday, January 13th – and things took an unexpected turn: after the first brief test, two further tests took place within a 2-hour period for all three tests.

The three firings were apparently “test starts” of the three Raptor motors, rather than a full pre-flight static fire test of all three simultaneously. Following them, and a successful de-tanking of excess fuel, inspections of the motors revealed that two needed slight repairs, causing the company to swap them out for other units.

As part of streamlining starship operations, SpaceX have refined the processes related to engine swap-outs to a point where they can effectively be achieved within days rather than weeks, depending on the availability of replacement motor units – the actual physical removal of an engine can be completed in hours, as can the installation of a replacement. In this case, the work was done over a couple of days, the engines requiring replacement being removed from the vehicle and shipped out of Boca Chica before the replacements were delivered and installed, clearing the way for a final engine test.

This took place on Friday, January 22nd, when all three engines were ignited for several seconds before shutting down.

Outside of SN9, it appears work at Boca Chica has commenced on starship prototypes SN17 and SN18, and on the second Super Heavy booster prototype. Also, in my January 10th Space Sunday update, I noted that work had been discontinued on starship prototypes SN12 through SN14. Work has now commenced in dismantling those parts of SN12 that had been fabricated. This is likely due to the fact that SpaceX are iterating the design and construction of the prototypes so fast, SN12 had become effectively obsolete due to the materials used.

The rapid rate of iteration is also reflected in the move of a new fuel tank section – SN7.2 -, which has been moved to a test stand where it will  be pressurised to destruction in a similar manner to the SN7 and SN7.1, each of which also saw iterations in the basic tank design. SN7.2 in particular is built using 3 mm aluminium rather that the current 4 mm material in an attempt to reduce the overall “dry” mass of the vehicle.

In 2020, Musk raised the idea of launching starship / Super Heavy vehicle from sea platforms, suggesting this could be used for vehicles intended to reach orbit or in passenger-carrying sub-orbital transcontinental flights.. While passenger carrying point-to-point will not happen (for reasons I will explain at some point), evidence has emerged that SpaceX are planning to make sea launches a thing, and is in the process of converting two former offshore drilling platforms for use as floating launch platforms.

Aerospace Photographer Jack Beyer was the first to bring the news to the public eye after exploring the port of Brownsville, Texas, not far from the SpaceX facilities at Boca Chica whilst waiting for the SN9 static fire tests to resume. In particular, he spotted an oil platform apparently called Deimos (“dread”) undergoing extensive refit work. Not long after, a image captured over the port of Galveston, Texas, and dated January 13th revealed another rig with the name Phobos (“fear”), and which was later moved to Pascagoula, Mississippi, between January 17th and 22nd.

Phobos and Deimos are, of course, the names given to the captured moons of Mars, and the discovery of the two rigs sparked speculation that the platforms had been purchased by SpaceX.

Michael Baylor from NASAspaceflight.com started digging into things using further images captured by Jack Beyer, and discovered that the two rigs in question were originally owned by the world’s largest offshore drilling / well drilling company: UK-registered and Texas-based Valaris plc (formerly ENSCO-Rowan).

Originally constructed in Singapore in 2008, the two rigs were originally called ENSCO 8500 (later Valaris 8500 and now Deimos), and ENSCO 8501 (later Valaris 8501 and now Phobos). However, following the company declaring bankruptcy, the company offered the platforms for sale and US 3.5 million apiece. The purchaser was company called Lone Star Mineral Development LLC, which had only formed in June 2020. Further digging revealed that one of the principals for Lone Star Mineral Development is none other than SpaceX Chief Financial Officer (CFO), who is also the head of the company’s Strategic Acquisitions Group, Bret Johnsen.

Both platforms are classified as “semi-submersible”, meaning they float on large pontoons that can be filled with water ballast that both settles them in the water to stabilise them while dynamic positioning water thrusters hold them in a precise location, making them an ideal launch platform, as does their deck loading of around 8,000 tonnes, means that are more than capable of supporting a Super Heavy  / starship combination and their fuel loads.

The work to convert the two platforms to support fuelling, payload integration, launch, and landing operations is extensive. As such neither is likely to be ready for use in 2021. However, once operational, they will effectively double the number of Super Heavy / starship launch facilities – SpaceX is currently building the first Super Heavy platform at Boca Chica, and have plans for a second. Multiple launch facilities will be essential in the future if SpaceX is to start to build towards the planned number of launches for the system..

Continue reading “Space Sunday: rockets, water and spaceplanes” →

Saturday, January 16th saw NASA attempt the Green Run Hot Fire Test of the first Space Launch System (SLS) core stage.

For those who might be unaware of it, the SLS is NASA’s next-generation heavy-lift rocket designed to undertake a range of missions, with the primary focus being the US Artemis programme to return humans to the Moon. Once operational it will be the most powerful launch vehicle commissioned by NASA.

The Hot Fire test formed the final phase of the Green Run test programme, a series of tests vital to clearing the core stage of the rocket ready for it maiden – and only – flight, planned for the end of 2021. The “Green Run” title refers to the fact the test would be the first time all of the components and systems of a core stage would be operated in unison, just as they would in the lead-up to and launch of an SLS rocket.

As such, the Green Run actually comprises a sequence of tests numbered 1 through 8 – each designed to test different aspects of the core stage, gradually bringing everything together as a unified whole and culminating in the hot fire test.

All of the test sequences have been carried out at the historic B-2 Test Stand at NASA’s Stennis Space Centre, Mississippi, and while some issues were encountered along the way, both technical and due to the weather, so  eating into the “reserve time”  available for getting the first SLS vehicle assembled and onto the launch pad, by Saturday January 16th, all of them – including critical fuel loading and unloading (700,000 gallons of liquid hydrogen and liquid oxygen) test – have been completed and signed-off, allowing the hot fire test to go ahead.

Planned for a 8-minute duration – this being the total time the core stage would be expected to operate its engines during a launch – the test commenced at 22:27 GMT, after some last minute minor technical delays put the count-down on a lengthy hold. Ignition saw the four RS-25D engines ignite milliseconds apart from one another in the sequence 1,3,4 and 2, quickly building up to a combined thrust of just under 726,000 kg – somewhat less than the maximum thrust of 900,000 kg they will reach in an actual launch, but sufficient for the purposes of the test.

The long duration of the test had been intended to allow a comprehensive test of things like engine throttling down / up and gimballing (swinging) the motors in a manner that would provide steering in a flight. However, 67.7 seconds into the test something  – at the time of writing, NASA has yet to specify what – triggered the core stage’s automated safety systems, initiating a rapid and safe shut-down of the engines.

The RS-25 is one of the most powerful and advanced rocket engines in the world. Originally built for the shuttle, it is finding new life with SLS – a total of 16 former shuttle variants of the motor will be used to power the first four SLS launches. The four motors for this first core stage already have a distinguished flight career between them, having previously be used on a Hubble Space Telescope servicing missions, the mission that saw John Glenn return to space (STS-95 in 1998), and on the final space shuttle flight, STS-135 featuring the shuttle orbiter vehicle Atlantis (thus offering a direct link between the last flight of the Space Transportation System and the first launch of the Space Launch System). In addition, between them the four engines made six flights to the International Space Station prior to the end of the shuttle programme in 2011.

Once those first 16 motors have been used, SLS will be powered by a new generation of RS-25 motor, built using the very latest technologies including components created using 3D printing which we decrease the complexity of the engines.

Despite the hot fire test lasting less than 68 seconds, managers and engineers monitoring the test were confident that they had gathered sufficient data to classify the run as a success, although it is not yet clear if a further test will be required, or whether the core stage can be dismounted from the test stand – originally built to test the core stage of NASA’s Saturn V rocket – and shipped to Kennedy Space Centre for integration with the rest of the vehicle.

All four RS-25 engines ignited successfully, but the test was stopped early after about a minute. At this point, the test was fully automated. During the firing, the onboard software acted appropriately and initiated a safe shut-down of the engines. During the test, the propellant tanks were pressurised, and this data will be valuable as the team plans the path forward.

In [the] coming days, engineers will continue to analyse data and will inspect the core stage and its four RS-25 engines to determine the next steps.

– NASA statement following the test

Future core stages won’t go through a similar Green Run; these tests were only required for the first core stage to confirm its design and gather vital data on its behaviour during its required operations. Instead, they will generally be fabricated at NASA’s Michoud Assembly Facility, New Orleans and then shipped directly to Kennedy Space Centre for vehicle integration with the rest of their launch elements in the famous cube-like Vehicle Assembly Building, used for the “stacking” of every Saturn  rocket (both the 1B and V) and every shuttle system.

Once integrated with its upper stage, solid rocket boosters and payload, the stage will participate in the Artemis 1 mission to send an uncrewed Orion vehicle to, around, and back from, the Moon at the end of 2021.

Continue reading “Space Sunday: SLS roars, LauncherOne flies and a mole dies” →

Despite the pandemic, 2020 proved to be a busy year for space activities, with a range of significant launches of both government-led / overseen missions and private sector launches. However, as busy and as challenging as it was, 2020 potential pales somewhat in comparison to what we should / will hopefully see in 2021. So, as with last year, I thought I’d kick-off Space Sunday in 2021 with a look ahead to some of the year’s  space missions.

Mars

2021 will see three new arrivals orbiting and landing on Mars.

The first to arrive will be the United Arab Emirates’ Hope spacecraft. Launched on July 20th, 2020 from Tanegashima Space Centre in Japan atop a H-IIA rocket, the mission comprises an orbiter vehicle designed to study the Martian atmosphere and climate.

Built entirely in the UAE, the mission marks the first attempt to operate an interplanetary mission by any West Asian, Arab or Muslim-majority country. It carries a range of science systems provided by the Mohammed bin Rashid Space Centre (MBRSC) and the University of Colorado Boulder with support from Arizona State University (ASU), and the University of California, Berkeley. Hope is due to arrive in an initial orbit around Mars on February 9th, 2021.

China’s Tianwan-1 (“Questions to  Heaven”) mission will be the next to arrive in Mars orbit. The precise date has yet to be confirmed, but orbital insertion should happen between the 11th and 24th February, 2021. It is an incredibly ambitious mission,  comprising a total of 13 science instruments and experiments, split between two distinct mission elements.

The first of these is the orbiter vehicle, which will commence operations almost immediately. It is tasked with producing Martian surface maps, characterising the Martian atmosphere – notably its ionosphere, measuring the Martian magnetic field, examining the composition of the Martian subsurface via radar, and imaging the surface of Mars in high-resolution. As a part of the latter work, the orbiter will carry out extensive surveys of the proposed landing zones for the second part of the mission: a lander / rover.

These will deploy some time around April  23rd. The rover’s mission is to examine the Martian sub-surface to a depth of around 100 metres using ground-penetrating radar and study of Martian weather systems. In particular, both elements of Tianwen-1 will aim to find evidence of current or past life on Mars.

The third mission that will arrive at the Red Planet will be the NASA Mars 2020 mission, comprising the rover Perseverance and the robot helicopter Ingenuity. Unlike the other two missions, Mars 2020 won’t spend any time in orbit: instead, it will proceed directly to atmospheric entry and delivering its payload to the surface on February 18th, 2021.

The primary goal of Perseverance will be to seek signs of habitable conditions on Mars in the ancient past, and will also search for evidence — or biosignatures — of past microbial life and water. As with Curiosity, the rover is powered by a nuclear “battery”, capable of keeping the rover operating for some 14 years. Based on the Mars Science Laboratory (MSL) Curiosity rover, it will be delivered to the surface of Mars in the same manner – using a “skycrane” system.

Ingenuity, the helicopter will arrive on Mars attached to the underside of the rover. Some time in the first few months after arrival, the rover will deposit it on the surface, and it will then complete around 5 flights over a 30-day period. Fully automated, and lasting up to 3 minutes apiece, these flights will each carry Ingenuity up to 10 metres altitude and a distance of up to 600 metres. The primary aim of the mission is to test the ability of an automated aerial vehicle to support ground operations on Mars, in this case, helping to map the best driving route for the rover as it explores Jezero Crater.

The Moon

While America’s Project Artemis is unlikely to achieve its original goal of returning humans to the surface of the Moon by 2024, the coming years should see a number of significant lunar missions take place in the run-up to an eventual human return to our natural satellite.

In April, NASA will launch  CAPSTONE, the Cis-lunar Autonomous Positioning System Technology Experiment via a commercial electron rocket. A cubesat mission, CAPSTONE is intended to test and verify the calculated orbital stability planned for the Lunar Gateway space station.

In July a privately-funded mission in support of Artemis will deliver 14 NASA- funded science missions and 14 private-sector missions to the surface of the Moon, including a trio of rovers – one from the USA, one from Japan, and a novel mini walking robot from the UK called Asagumo. Originally a contender for the lunar X-Prize, the Peregrine mission has been expanded by NASA to test technologies that may be used in support of Artemis. It will be the first operational flight of United Launch Alliance’s Vulcan rocket.

On October 11th (or thereabouts) the Intuitive Machines 1 (IM-1) mission will  similarly deliver a NASA science payload to the surface of the Moon on the company’s NOVA-C lander.

Launched via a SpaceX Falcon 9 rocket, the mission will target a relatively flat area near Vallis Schröteri in the Oceanus Procellarum (Ocean of Storms), where it will operate the package of 5 science systems on behalf of NASA. Overall, NOVA-C is designed to be a highly flexible lander system standing up to 3 metres tall and capable of delivering a wide range of small payloads to the Moon.

The end of the year should also see the first launch of NASA’s massive Space Launch System (SLS) rocket, intended to be the core workhorse for the Artemis programme, as well as offering a potential heavy launch vehicle NASA’s deep space aspirations.

The Artemis-1 mission, currently slated for November 2021, will be the first launch of a the Block 1 variant of the launcher. It will send an uncrewed Orion Multi-Purpose Crew Vehicle (MPCV) to the Moon in a 26-day mission that will include 6 days in which the Orion capsule and its service vehicle will be in a retrograde orbit around the Moon, followed by a return to Earth and splashdown. If successful, the mission will pave the wave for a crewed mission around the Moon in 2023.

October will see Russia make a return to with the launch of the Luna 25 (formerly Luna-Glob) lander combination on October 1st, 2021. Directly to land in the Boguslavsky Crater near the lunar south pole, the mission will characterise the nature of the crater floor, including the presences of any sub-surface water ice, and will attempt to obtain samples for on-board analysis.  The mission was renamed “Luna 25” to mark it as a direct continuance of the old Soviet Luna missions, the last of which – Luna 24 – took place in 1976.

India also intends to expand on its lunar presence in 2021 with the launch of its Chandrayaan 3 mission. A proof-of-concept mission, it is designed to deliver a lander and rover directly to the surface of the Moon (no orbiter vehicle will be used), and is a follow-on to India’s Chandrayaan 2, which successfully placed an orbiter of that name about the Moon (which is still operating), but saw a failure with its Vikram lander and Pragyan rover, lost when a software error resulted in them crashing into the Moon, rather than landing on it.

Continue reading “Space Sunday: previewing missions in 2021” →