When it comes to space travel, and space in general, 2018 has been a busy year. It was one marked by remarkable technological firsts, dramatic incidents, and new milestones set. It was a time when commercial spaceflight made great strides, we returned to Mars, headed for Mercury, and probed the farthest reaches of the solar system. Oh, and there was space champagne. So, let's look back on the highlights of the year in space, 2018.
Water on Mars
One of the most exciting bits of space news this year came from Mars, where scientist have found evidence that there's more water on the Red Planet than previously thought. In January, NASA and the United States Geological Survey (USGS) found evidence from the Mars Reconnaissance Orbiter's (MRO) Shallow Radar (SHARAD) instrument of vast ice sheets under the Martian surface – sheets 90 m (295 ft) thick.
If this wasn't enough, ESA's Mars Express Orbiter went one better when its Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) probed the Martian south pole and found a lake of liquid water 4 km (2.5 mi) under the ice that covers a 20-km-wide (12.4-mi) area.
Unfortunately, there was bad news, too, as a new NASA study found that, even at the most optimistic estimates, there isn't enough material on Mars to generate even a minimal atmosphere. This means that terraforming the planet is off the table unless there are several quantum leaps in technology in the future.
Commercial space takes off
Commercial spacefaring was also in the news in 2018 with SpaceX having a busy year. In February, the company's Falcon Heavy made its maiden flight, becoming the world's most powerful operational rocket. In March, the 50th Falcon 9 was launched, and in May, the next-generation variant of SpaceX's mainstay booster flew. Rounding out the year, one Falcon 9 set a new company record by using the same Falcon 9 first stage rocket three times successfully.
Meanwhile, Virgin Galactic continued its slow-but-steady approach to establishing itself as the go-to company for flying tourists on suborbital space flights. The still-experimental SpaceShipTwo spacecraft, VSS Unity, made its first glide tests as well as a series of powered flights, reaching an altitude of 170,800 ft (5,200 m) and a speed of Mach 2.47 (1,832 mph, 2,948 km/h) in July on its third powered test flight. Then, on December 13, it made history as it became the first commercial, passenger-carrying-capable spacecraft to reach the edge of space at an altitude of 51.4 mi (82.7 km).
In January, New Zealand became a spacefaring nation as Rocket Lab's Electron rocket lifted off on the first successful commercial space launch in the Southern Hemisphere. The composite-bodied, two-stage rocket launched from Rocket Lab's Launch Complex 1 on the tip of the Māhia Peninsula on the east coast of the North Island of New Zealand with a payload of mini satellites. It also carried a surprise payload in the form of a passive geodesic sphere called Humanity Star – an orbiting mirror ball designed to reflect the Sun's rays and be visible to everyone on Earth as a way to create a "shared experience for all humanity."
And then there's Jeff Bezos' Blue Origin company, which made the eighth and ninth successful test flights of its New Shepard rocket. Blue Origin has yet to field an operational booster, but it seems that the US Air Force was impressed enough to give the company US$500 million to develop Blue Origin's New Glenn rocket.
New Horizons
NASA's New Horizons deep space probe may have reached Pluto in 2015, but there's life in the old nuclear-powered robotic explorer yet. On June 16, the spacecraft was woken by mission control from a 165-day hibernation as it prepares to make its historic encounter with the Kuiper Belt object Ultima Thule. It's now locked on target and will make its fleeting rendezvous on New Year's Day.
Voyager 2
Of course, New Horizons isn't the farthest spacecraft from Earth, though it is four billion miles (6.4 billion km) away. That honor goes to the Voyager spacecraft launched in the 1970s. The venerable pair may have been launched over four decades ago, but they're still operational and have a few years of life left in them. Voyager 1 already entered interstellar space in 2013, and in December Voyager 2 joined that very exclusive club as, at a distance of 11 billion (18 billion km) miles, it passed beyond the influence of the Sun's magnetosphere.
Juno
A little closer to home, NASA's Juno orbiter continues to circle Jupiter, completing 16 of 32 planned science orbits as it gathers data about the giant planet's structure, atmosphere, and magnetic and radiation fields. Because it's trapped in a larger than intended orbit due to a thruster malfunction, the space agency granted the mission a 41-month extension so it can complete it objectives.
InSight
The first mission to land on Mars in six years lifted off from Vandenberg Air Force Base on May 5 to become the first interplanetary mission to launch from the West Coast of the United States. Designed to study the deep interior and dynamics of the Red Planet, the InSight mission made a dramatic rocket-powered landing on November 26. Since then, its deployed it solar panels, set a record for generating electricity on Mars, flexed its robotic arm, taken a full-body selfie, and eavesdropped on the Martian winds.
What it does when it actually starts its actual work next year should be some encore.
Hayabusa 2
Another 2018 arrival was JAXA's Hayabusa 2, which went into orbit around the asteroid Ryugu after a three-and-a-half-year voyage. It isn't the first spacecraft to reach an asteroid, but this one deployed a pair of bouncing robots to make a close-up, low-gravity reconnoiter of the surface. These were soon followed by a larger sibling robot, the Mobile Asteroid Surface Scout (MASCOT) for a more detailed examination.
OSIRIS-REx
NASA had its own asteroid mission reach its destination on December 3 as the OSIRIS-Rex spacecraft made it to the Bennu asteroid. The main purpose of the mission is to make more accurate estimates of Bennu's shape, mass and rotation, as well as to identify the best sites for the probe to make a close approach to gather 2 oz (60 g) of surface samples toward the end of its stay. That's still in the works, but the probe has already confirmed that Bennu contains water, which is a bit surprising.
BepiColombo
On October 19, ESA's first mission to the planet Mercury took off from Kourou, French Guiana. BepiColombo is actually two orbiters built by ESA and JAXA, which are mounted on a common cruise stage until they arrive at the solar system's smallest planet. It will take seven years to reach its destination, but it will get there with the help of four state-of-the-art ion thrusters that have already passed their first in-flight tests.
Parker Solar
Perhaps the most dramatic mission of this year is NASA's Parker Solar Probe, which lifted off on August 12. As the name implies, its goal is to study the Sun, but instead of standing off and relying on long-distance sensors, the spacecraft is set on a series of ever-tightening orbits that will see it touch the Sun's outer atmosphere. It's already come closer to our parent star than any other spacecraft in history, and has come out relatively unscathed after approaching to within 15 million miles (24 million km) of the Sun's surface on November 5.
ISS
Another spot of unintentional drama was the International Space Station (ISS), and the station's crew could have done without either of the incidents experienced this year. On August 29, one of the Soyuz spacecraft docked with the ISS sprang an air leak, which was tracked down and repaired. At first, this was thought to be caused by a micrometeorite, but later investigations indicated that it was a drill hole that may or may not have been accidental.
The other incident was on October 11, when the launch of a manned Soyuz rocket automatically aborted, sending the crew's capsule to touch down on the plains of Kazakhstan. All Soyuz flights to the ISS were subsequently grounded until an investigation by Russian authorities determined that the cause was a sensor pin in one of the boosters that was bent during assembly. Launches have since resumed with an unmanned cargo mission sent up on November 16 and a manned mission on December 3.
Endings
The year in space was also a time of sadness as a number of missions came to an end. On April 1, China's Tiangong-1 space laboratory made an uncontrolled reentry into the Earth's atmosphere over the South Pacific. This was met with general sighs of relief because the derelict station had suffered a major malfunction, causing it to shut down and raising fears that it could come down over a populated area.
NASA's Kepler mission also reached its end. After nine years of hunting for planets beyond our solar system, the space telescope ran out of propellant and could no longer maintain its attitude control. In October, the space agency took the decision to conclude the mission and on November 16 the signals were sent ordering the spacecraft to shut down its systems. However, having already discovered thousands of exoplanets, scientists will be kept busy for many years analyzing its data.
Also in November, NASA's Dawn asteroid mission of 11 years came to an end. In orbit around the dwarf planet Ceres 257 million mi (414 million km) away, mission control lost all contact with the spacecraft on October 31 and on November 1 concluded that it had run out of hydrazine fuel, so it could no longer keep its antenna pointed at Earth.
But the most poignant ending is probably NASA's Opportunity Mars rover. That's because it's less an ending than a question of missing in action. In February, the mission, which was originally only to last 90 days, marked 5,000 Martian days on the Red Planet. This was certainly worth celebrating, but it seems that this year luck ran out for the robotic explorer.
In May the planet was gripped in a global dust storm that was so dense that it turned noon into the blackest night. With its solar panels unable to recharge, Opportunity soon lost power as its batteries drained and it went into shutdown mode. All radio contact was lost on June 10 and, despite numerous attempts by mission control, communications remain dead.
The storm has abated, Opportunity has even been sighted from orbit, and the rover still seems lost, but NASA hasn't given up yet. The agency says that it will continue to send signals and keep listening through at least January 2019.
On the lighter side of space
The year in space also had its lighter side. When SpaceX sent its Falcon Heavy into space for the first time, the upper stage went into a solar orbit that sent it out as far as the orbit of Mars. Normally, such a test launch would have swapped out an operational payload for a concrete block of ballast, but company founder Elon Musk, being the consummate showman he is, decided to send up his personal Tesla Roadster instead – complete with a spacesuit-clad mannequin called "Starman" in the driver's seat.
The cosmic convertible sent back live videos for as long as it was in range of Earth and even carried a copy of Isaac Asimov's sci fi epic, The Foundation Trilogy, laser etched on a quartz disc called an "Arch library," which is designed to survive intact for billions of years. Unfortunately, we also found out that the Roadster is probably the dirtiest man-made object in space and that it won't keep its cherry condition for long in the hostile environment of space.
However, there is good news for future space travelers. Vostok has not only come up with a beer for imbibing in zero gravity, but a bottle to go with it. Not to be outdone, Mumm has developed its Grand Cordon Stellar – a champagne for the sophisticated astronaut that isn't so much drunk as inhaled in the form of a flavorsome froth.
Looking forward to 2019 it looks set to be a busy year of launches, exploration, and research both in the solar system and beyond, but if 2018 was anything to go by, there will undoubtedly be many surprises as well – let's just hope they're welcome ones.
