When space missions achieve significant milestones a glimpse inside the control room often shows an outpouring of emotion from the talented people who have devoted their lives to the mission. It’s interesting to remember that those people on the ground are making it possible for magnificent, unmanned machines to traverse space and make incredible new discoveries.

The list of active space missions without crews is as long as your arm and growing longer by the season. It’s becoming difficult to stay up to date as new spacecraft are launched, milestones surpassed, and missions extended.

The types of missions are many and varied. There are space telescopes that observe distant galaxies or closer star systems; lunar and planetary landers, orbiters, and rovers (one with an experimental helicopter in tow); ambitious sample return missions, observatories dedicated to the study of the Sun or its corona – the list goes on.

Unexpected discoveries are not uncommon as some craft serendipitously observe phenomena that they weren’t looking for and weren’t primarily designed for.

With many agencies and countries actively contributing, space is no longer the exclusive domain of the traditional big players either. We live in exciting times!

This blog highlights just some of the incredible unmanned missions going where no human has gone before.

Sample Returns

By the end of 2020, China, Japan, and the U.S. will all have sample return missions in flight.

China’s Chang’e 5 is slated for a December launch. Destination: the Moon. Why the Moon? Didn’t the Apollo astronauts retrieve nearly 400kg of rock and regolith? Well, yes, they did, and with improving techniques, scientists to this day, are gaining new insights as they continue studying this material. Interestingly in 2019, NASA scientists opened a sample that had remained sealed since leaving the Moon in 1972! As cool as all this is, the Apollo samples are not representative of the whole Moon so the study of samples from diverse regions will be of incredible value.

At the time of writing JAXA’s Hayabusa2 is carrying home a precious cargo of material from the near-Earth asteroid Ryugu. Its sample-return capsule will detach from the mother craft for re-entry then make landfall in Australia on 6 December 2020. Fingers crossed for a successful descent to mark a great conclusion to a six-year primary mission! As the capsule descends, Hyabusa2, will slingshot away from Earth towards new targets.

Meanwhile NASA’s OSIRIS-Rex has been orbiting asteroid Bennu since 2018. On August 11 2020 it completed its second sample collection rehearsal by descending close to the surface. Its actual asteroid touchdown is scheduled for October 20th.

Perserverance, NASA’s rover, is now well on its way to Mars carrying its experimental helicopter named Ingenuity. One of Perseverance’ objectives is to collect diverse soil samples, sealing them in tubes, then eventually depositing them at a retrieval point. Two future missions will work together to collect and transport them to Earth by 2031. This has long been a dream of planetary scientists. Watch that space!

Find out more here.

Caption: Japan’s Hayabusa2 just seconds before touching down on asteroid Ryugu to collect samples.

Credit: JAXA


Hard to get to places

On a different kind of mission, Europe and Japan’s Mercury-bound BepiColombo returned stunning images of us as it flew by Earth in April. It is scheduled for the first of two Venus flybys on 16 October 2020.

Despite its relative proximity to Earth, Mercury is deceptively difficult to get to – so much so that it took until 1985 for anyone to figure out how to get there! BepiColombo will require no fewer than nine planetary flybys (six of Mercury itself) in order to position itself precisely at Mercury.

This mission’s predecessor, MESSENGER, uncovered a world of contradictions which raised many new questions. The new mission, consisting of two individual orbiters, is seeking to address these questions and is scheduled to arrive at the mysterious little world in 2025.

Learn more here.

Caption: BepiColombo takes last snaps of Earth en route to Mercury

Credit: ESA

Hot Stuff

The Solar Orbiter (SolO) is a joint project of NASA and the European Space Agency ESA. Launched on 10 February 2020, it made the news in July when it returned images of the Sun taken from just 77 million kilometres – the closest ever acquired by cameras. SolO’s images revealed mini flares (dubbed ‘campfires’) that had never been noticed before. Mere millionths or billionths of the size of the solar flares more regularly observed, it is possible there are millions of them.

Higher resolution images of the Sun had previously been acquired by Earth-based telescopes but SolO is carrying a suite of six different instruments that will help untangle the Sun’s mysteries in unprecedented fashion.

SolO is one of two complementary spacecraft studying the Sun at close quarters.

The other, NASA’s Parker Solar Probe (PSP), was launched in April 2018 on a seven-year mission described as ‘humanity’s first visit to a star’.

This plucky little craft soon broke all the records for close approaches to the Sun. On 11 July 2020, PSP rounded Venus on the third of seven flybys designed to keep shrinking its orbit.

Eventually it will be swooping to a little over six million kilometres above the seething surface (nearly ten times closer than Mercury). On these close approaches PSP will actually be flying inside of and sampling the Sun’s superheated outer atmosphere or Corona – targeting the area of space where the Solar Wind originates. PSP has a suite of five instruments, one of which (WISPR), returned a beautiful image of the recent comet NEOWISE.

One of the Sun’s key mysteries that has bothered researchers for decades is why the corona is so much hotter than the visible surface. Better understanding of this near-Sun environment will have far-reaching implications – two standouts being the reduction of risk to modern technologies on Earth and to fragile humans in space.

If you want to learn more about these hot missions, check out these links:

SolO Parker Teamwork

Solar Orbiter

Parker Solar Probe

All Solar Missions

Caption: SolO has taken images of our Sun from the closest vantage point ever – note the campfire and Earth scale.

Credit: ESA

Far Out

On 4 July 2020, NASA’s planet hunter TESS completed its primary mission of discovery.

TESS stands for the ‘Transiting Exoplanet Survey Satellite’ – another great space-nerd acronym! As its name suggests, TESS looks for transits; the tell-tale dimming of stars caused by orbiting planets that pass in front of their stars from our point of view here on Earth. This ‘transit’ method of exoplanet detection is just one of the methods employed over the past two decades, but it has been by far the most successful.

Launched in April 2018, TESS commenced regular science operations in July of that year, and over the ensuing two years imaged about 75% of the sky! Contrast this with its wildly successful predecessor Kepler, which surveyed just 0.25% of the sky during its primary mission – that’s right – just ¼ of one percent! The K2 mission built on this, but the combined area of sky was minuscule compared to the TESS coverage.

Nevertheless, Kepler uncovered thousands of exoplanets, confirming that planets are plentiful, and notably revealing that Earth-to-Neptune-sized planets (conspicuously absent in our Solar System) are, in fact, common.

Still, the Kepler field, and therefore the bulk of its discoveries, lie at great distances making it difficult to obtain ground-based follow-up observations.

By contrast, TESS’s mission is to discover planets that transit stars close enough to facilitate more useful follow-up observations – allowing for more refined measurements of planet masses, sizes, densities, and even atmospheric compositions. Follow up studies will be carried out by ground-based observatories and space platforms such as CHEOPS  (launched in 2019), and the long-awaited James Webb Space Telescope JWST.

TESS has now entered its extended mission, repeating its observations with improvements. So far, 66 new exoplanets have been found as well as nearly 2,100 candidates that astronomers are working to confirm. The new datasets will keep researchers busy for years.

In addition, TESS has also observed a comet outburst in our Solar System, a planet orbiting two stars, a newly formed planet, an Earth-like one, exploding stars, a planet experiencing seasons caused by its star, and witnessed a black hole devouring a Sun-like star, to name but a few of their observations!

What new revelations await? Read more and view the video here.

Image caption: TESS has discovered thousands of exoplanets candidates thus far.

Credit: NASA

Really far out – ESA’s Galactic Census

Last, but not least, don’t forget ESA’s GAIA mission. Gaia was launched in 2013 and has since been quietly gathering information on every celestial object it sees. Repeated observations have been allowing astronomers to calculate distances and velocities, thus enabling 3D mapping of incredible detail and helping them to piece together our Galaxy’s history.

Gaia’s objective is to map about one percent of the Milky Way. Doesn’t sound like much? When we put a number to it we gain a better perspective – that’s more than a billion stars!

More on GAIA here.

Caption: Artistic impression of GAIA against the backdrop of the Milky Way

Credit: NASA

And there we have it! Just a small selection of significant missions taking place right now. It’s great how incredible technologies driven by dedicated people continue to open our eyes to the great beyond. And we get to sit back and enjoy it.


John Rowe

Astronomy Educator