Space Sunday: Martian clouds, lunar missions and a space station

NASA’s Curiosity Mars rover captured these clouds during the twilight period on March 19, 2021, the 3,063rd Martian day, or sol, of the rover’s mission. The image is made up of 21 individual images stitched together and colour corrected so that the scene appears as it would to the human eye. The clouds are drifting over “Mont Mercou,” a cliff face that Curiosity has been studying on “Mount Sharp”. Credit: NASA/JPL

Clouds are rare on Mars, but they can form, being typically found at the planet’s equator in the coldest time of year, when Mars is the farthest from the Sun in its oval-shaped orbit. However, in 2019 – a year ago in Martian terms – the Mars Science Laboratory team managing NASA’s Curiosity rover in Gale Crater noticed the clouds there forming earlier than expected.

With the onset of winter in the region earlier in 2021, the MSL team wanted to be ready in case the same thing happened, training the rovers cameras on the sky around “Mount Sharp” to catch any evening cloud formations that might appear as the tenuous atmosphere cooled towards night-time temperatures.

Clouds moving over Mount Sharp, as captured by Curiosity on March 19th, 2021. Credit: NASA/JPL

What resulted are images of wispy puffs filled with ice crystals that scattered light from the setting Sun, some of them shimmering with colour. Visible through both the black-and-white lenses of the rover’s navigation cameras and the high-resolution lenses of the Mastcam system, the pictures captured by Curiosity might easily be mistaken for high-altitude clouds here on Earth.

And high altitude is precisely the term to use for this clouds. Most clouds on Mars largely comprise water vapour and water ice. They tend to occur some 60 km above the planet, although they can occur much lower – the massive shield volcano of Olympus Mons, for example, has oft been images with cloud formations around its  flanks, the product of differing atmospheric temperature regimes on the slopes.

However, the clouds seen by Curiosity are believed to be far higher than 60 km in the Martian atmosphere, and are thought to be largely composed of frozen carbon dioxide (dry ice). They occur during the twilight hours – although the mechanism that gives rise to them is not fully understood; but they are thin enough for sunlight to pass through them, catching the ice crystals and causing them to shimmer for a time before the Sun drops below their altitude, causing them to darken. This effect gives them their name: noctilucent  (“night shining”) clouds.

These clouds are best seen in the black and white images captured by the rover’s Navcams, as shown here. However, there is a second form of clouds best seen via Curiosity’s Mastcam colour images. These are iridescent, or “mother of pearl” clouds, rich in pastel colours.

Mother of Pearl clouds spotted by Curiosity in March 2021. Credit: NASA/JPL

They are the result of the cloud particles all being nearly identical in size, something that tends to happen just after the clouds have formed and have grown at the same rate. The colours are so clear, were you able to stand on Mars and look at the clouds, you’d see the shades with your naked eye, and they are another part of the beauty of Mars.

Ingenuity Hiccups During Sixth Flight

NASA’s Mars helicopter Ingenuity encountered some trouble on its sixth flight – the first flight of its extended mission  – on May 22nd.

The flight should have seen the helicopter climb to a height of 10 metres, then fly some 150 metres south-west of its starting point to reach a point of interest where it would travel south for 15 metres, imaging the terrain around and below it for study by scientists on Earth, before making a return to a point close to where it lifted-off.

This image was taken from the height of 10 metres by NASA’s Ingenuity Mars helicopter during its sixth flight on May 22, 2021. Credit: NASA/JPL

The flight was designed to be the first specifically targeted at testing the helicopter’s ability to be used in support of ground operations on Mars, offering the mission team the chance to determine if the area images might be worth a future foray by the Mars 2020 Perseverance rover.

However, 54 seconds into the flight, Ingenuity suffered a glitch that interrupted the flow of images from its navigation camera to its onboard computer. This meant that each time the navigation algorithm performed a correction based on a navigation image, it was operating on the basis of incorrect information about when the image was taken, leading to incorrect assumptions about where it was and what it should be doing.

This lead to Ingenuity pitching and rolling more than 20 degrees at some points during the flight as it struggled to return to its landing zone, post-flight telemetry revealed the helicopter experienced some significant power consumption spikes. However, it maintained its flight and  executed a safe landing just 5 metres from the intended touch-down point.

In a very real sense, Ingenuity muscled through the situation, and while the flight uncovered a timing vulnerability that will now have to be addressed, it also confirmed the robustness of the system in multiple ways. While we did not intentionally plan such a stressful flight, NASA now has flight data probing the outer reaches of the helicopter’s performance envelope That data will be carefully analysed in the time ahead, expanding our reservoir of knowledge about flying helicopters on Mars.

Håvard Grip, Ingenuity’s chief pilot.

Making the Moon a Busy Place

It’s starting to look like the Moon is going to be a terribly busy place. NASA’s Artemis programme is gathering pace in several areas – despite a degree of in-fighting among the principal US contractors – Russia and China have signed an accord that is liable to see them operating in the lunar south pole regions alongside the US-led mission (although the two will remain separate mission entities), whilst Canada and Japan have announced missions to the Moon as a part of the overall Artemis framework, and NASA is seeking ideas from lunar rover vehicles.

The in-fighting revolves around NASA’s April announcement that SpaceX will be granted a sole contract to develop the HLS – Human Landing System – the vehicle that will place humans on the surface of the Moon and return them to orbit. It was a contentious decision; the US agency had previously indicated that two contracts for HLS would be granted, with three players involved: a team led by Jeff Bezos’ Blue Origin, a team led by Dynetics, and the late-comer to the party, SpaceX.

The three proposals for NASA’s Human Landing System vehicles that had been under consideration for the Artemis programme. Left: the Dynetics lander / ascent vehicle; centre: the modified SpaceX Starship NASA has opted for; right: the National Team’s descent / ascent modules. Credit: NASA

There were several leading reasons for the decision – including the matter of cost. However, both Dynetics (potentially with the most flexible approach to HLS) and Blue Origin raised objections with the Government Accountability Office (GAO), which ordered NASA to cease any financial support to SpaceX (worth a total of US $2.9 billion) to the SpaceX effort until it has completed an investigation.

The US Senate has also weighed-in on the subject, with Senator Maria Cantwell (D-Wash.), chair of the Senate Commerce, Science and Transportation Committee, adding an amendment to the Endless Frontier Act which forms the backbone for financing the Artemis programme, requiring NASA put a further US $10 billion into HLS – whilst Senator Bernie Sanders (D-Vermont) went the other way by calling for the cancellation of the entire HLS programme, wrongly characterising it as the “Bezos Bailout”, and so doing what he does best; creating further division and confusion.

As it is, the GAO will release its findings on the matter in August, and while it is hard to ascertain the impact of the delay, it would likely further diminish NASA’s chances of achieving the original goal of a return to the Moon by the end of 2024.

NASA’s Nancy Grace Roman Space Telescope has been targeted for continued financial support by the Biden administration, potentially ending ill-conceived attempts by the previous administration to axe the project.  Credit: NASA Goddard Space Flight Centre / CI Lab

In the meantime, the Biden administration has given a boost to NASA’s hopes, putting forward a proposed US $6 trillion federal budget for 2022 that includes US $24.8 billion for the space agency. This includes US $7.9 billion specifically for NASA science programmes – an increase of 9% over the Trump years, with a further 5% to be directed in to NASA’s deep-space exploration ambitions that include Artemis, including a further $1.2 billion for HLS.

A  major part of the science expenditure will be Earth observation, including climate observations – working to alleviate climate change (which actually is a threat to the planet, despite the naysayers) being a priority for the Democrats. In addition, the proposal includes funding for the Nancy Grace Roman Space Telescope (formally WFIRST) and the PACE and CLARREO Pathfinder Earth science missions, which the Trump administration repeatedly attempted to cancel – although the budget will likely see the SOFIA airborne telescope cancelled – the agency viewing the US $85 million annual operating cost far outweighing the telescope’s science returns.

If approved, the Biden administration’s 2022 federal budget will bring to a close the Stratospheric Observatory for Infrared Astronomy (SOFIA), a joint US / German airborne observatory, Credit: NASA

Elsewhere, South Korea has become the latest country to join the Artemis programme, signing the Artemis Accords on May 24th.

A set of principles laying out the responsible exploration of the Moon that use the US programme’s name, the accords set of how signatory countries can undertake their own or joint missions to the Moon in mutual agreement and co-operation with all other signatories. In signing the accords, South Korea re-iterated its determination to become a space capable nation, using its own launch system to deliver a robotic mission to the Moon by 2030.

In  signing the accords, South Korea joins the United States, Australia, Canada, Italy, Japan, Luxembourg, Ukraine, the United Kingdom and the United Arab Emirates, with Brazil and New Zealand expected to follow suit.

Canada plans to land a robotic rover on the Moon in 2026. Working in cooperation with NASA, the Canadian Space Agency (CSA). It  will carrying at least two science instruments, Canadian and American. The mission will aim to gather imagery and measurements and data of the surface of the moon, as well as to have the rover survive an entire lunar night (14 terrestrial days) whilst operating the Moon’s south polar regions.

The vehicle represents a further significant step for Canada in is support for Artemis: the country has already committed to providing a robotic arm similar to those used on the International Space Station for the moon-orbiting Gateway station, and  in 2022 CSA is due to fly three commercial technologies to the Moon as a part of a joint mission with Japan, as a part of the AKUTO-R lander mission, which will carry a range of science packages, technology demonstrators and a small rover vehicle built by the United Arab Emirates, keen to further flex its space science muscles after the on-going success of the Hope Mars orbiter.

The UAE’s Rashid mini-rover will be one of a number of packages flown to the Moon aboard a Japanese robot lander

Also getting in on all things lunar are Lockheed Martin and General Motors, who are teaming up to respond to a NASA RFI on the next generation of lunar rover vehicles that will ferry astronauts around when on the surface of the Moon.

Rovers were first used during the Apollo programme, but were limited by battery life and range. For Artemis, NASA wants vehicles that are far more capable – and more flexible in their use. LM and GM think they have the answer.

The two companies are proposing unpressurised rover vehicles capable of transporting 2 or 4 people plus their surface equipment, or which can be set-up as autonomous rover vehicles able to operate via their on-board computers assisted by astronauts at the lunar base, and carry out long-range surveys and remote research far beyond the limits imposed by space suit life support systems. Fully capable of automated battery charging via solar power and also of surviving the 14-day lunar night, the se rovers would be used for a wide range of activities in and around the south polar base.

It’s not clear if the proposal will be accepted, or whether other companies in the US will pitch ideas to NASA, but for Lockheed Martin, acceptance of the proposed rover(s) could overcome disappointment should they and their partners remain locked out of the initial HLS contract.

 China Launches Tianzhou-2 Re-Supply Mission

As prefaced in my previous Space Sunday update, China launched it’s Tianzhou-2 cargo spacecraft to rendezvous the the core module of its new Tianhe space station. Carrying around 6.5 tonnes of supplies and station consumables, the 13-tonne automated re-supply vehicle was carried into orbit by a long March 7 medium lift launch vehicle, after lifting off from the Wenchang  Space Centre at 12:55 UTC on  May 29th.

May 29th, 2021: a Chinese Long March 7 rocket launches the Tianzhou-2 cargo ship on its way to rendezvous with the Tianhe core module of the country’s new space station. Credit: China Manned Space Engineering Office

Following its separation from the booster’s upper stage, the Tianzhou-2 vehicle deployed its solar arrays at 13:17 UTC and performed an automated docking procedure with the Tianhe module less than eight hours after launch.

The arrival of the vehicle – which marks the second official launch in China’s new space station programme, paves the way for the first crewed mission to the station.

This is due to commence in June, with the launch of a three-man crew board the Shenzhou-12 vehicle from the Jiuquan base in China’s northwest. The crew will spend around 3 months at Tianhe. Their primary mission will be to ready the station for initial operations during the construction phase – which will see it expanded with two more modules in 2022 – and to check-out various operating procedures on the station, one of which may be initial EVAs – space walks -when two of the crew will venture outside.

The automated rendezvous and docking of Tianzhou-2 with Tinahe was shown live on China’s state television

While the initial crew will be all male, Chinese officials have indicated women will be a part of future crews, as will international astronauts – like the ISS, China sees the space station as a means for international science cooperation. However, the United States will not be a part of this (China is banned for participation in any US-led space endeavours), as the US authorities remain sceptical about China’s space ambitions due to its close ties with the People’s liberation Army.

No date has been give for the Shenzhou-12 launch;  it is entirely possible no date will be supplied in advance of the roll-out of the launch vehicle to the pad, which tends to happen a week or two prior to lift-off.