Mega-Constellations, Horizontal Launch & Space Traffic Management
With up to 24 more of SpaceX's 'Starlink trains' set to irk astronomers this year and four or more batches of OneWeb satellites set to launch aboard Soyuz form Baikonaur and Vostochny cosmodromes, Earth orbit is set to get busier than ever before in 2020.
SpaceX became the operator of the world's commercial satellite constellation in January 2020 (as reported by SpaceNews here). With the launch of their Starlink #2 mission (watch the launch webcast here) they overtook Planet's 150-satellite constellation to have 182 Starlink satellites in orbit. They've already secured permission from the Federal Communications Commission (FCC) to deploy over 11,000 more and are rumoured to be seeking permission for tens of thousands more on top of this.
The Falcon 9 second stage deployed the satellites into orbit at an altitude of around 300km - it's at these low altitudes that their reflectivity has provided some challenges for ground based astronomers around the world, with the 'trains' leaving light trails, though a dark coating is already being tested on one of the satellites to mitigate the impacts of this. It's believed that as their krypton-powered ion propulsors raise them to their 550km orbit the problems should disappear - time will tell.
London-based OneWeb meanwhile is some way behind their new competitor in the space-based internet game with just six test satellites in a 1,200km orbit, though launch schedules indicate their next batch of 34 are set to launch from Baikonaur some time in February 2020 aboard an Arianespace Soyuz, with at least 3-5 more similar payloads booked in from April onwards. But don't discount them as having lost the mega-constellation race just yet, as they may well be supplementing their vertical launches with a little help from some friends (who also happen to be investors).
Horizontal Launch - Virgin Orbit
Richard Branson invested in OneWeb back in 2015 and this February his own Virgin Orbit's Boeing 747 'Cosmic Girl' is expected to drop and fire their LauncherOne rocket from beneath its port wing for the first time this February as they move towards commercial operations.
747's have long had the capability to carry an extra engine under one of their wings, as demonstrated by Qantas in 2016:
But Cosmic Girl has taken this capability to a whole new level by strapping a two stage orbital booster rocket under the wing of their stripped-out Queen of the Skies, the first drop test of which is shown below:
After climbing to 30-35,000 feet from a conventional runway the aircraft can launch a 300-500kg payload into anything from a low up to sun synchronous orbits. A third stage is being investigated that might allow sub 100kg payloads to be launched to lunar orbit or potentially to Venus or Mars. In theory that means small satellite launch becomes possible from anywhere with a long enough strip of tarmac and the appropriate licensing and regulatory regime in place.
In the short-term launches will be from their operations base at Mojave in California but other options are already being investigated, including from the 'Spaceport Cornwall' based at Newquay Airport in the south west of England. The project has already garnered over £20m of financial support from the British Government's UK Space Agency, £7m of which will go directly to Virgin Orbit UK Ltd (Press Release here) to kick-start horizontal-launch operations from the airport's 2,744m runway.
Crowded (above our) Skies
If Starlink, OneWeb and Virgin Orbit weren't enough, RocketLab will continue a high tempo of small satellite launches in 2020 to add to the 47 satellites the company has already put into orbit.
They'll add the US government to their list of customers this year as they bring Launch Complex 2 online (Press Release here) at Wallops Flight Facility in Virginia.
Both RocketLab and SpaceX offer a 'ride share' concept, and both are chasing the goal of reusable spacecraft (albeit at differing rates) - the cost barrier to getting a payload into orbit is coming down.
All of which serves to remind us that the space around our planet is becoming increasingly crowded. The United Nations Office for Outer Space Affairs (UNOOSA) shows some 9,091 objects having been launched into space since Sputnik (according to their Online Index of Objects Launched into Outer Space) of which c. 2,000 are still functioning - so SpaceX's Starlink constellation alone could see more satellites put into orbit within the next few years than have cumulatively been launched by every other company and nation combined, ever.
As for pilots flying in airspace closer to home, managing traffic and avoiding collisions is an important aspect of responsibly operating a spacecraft - and with constellations of thousands of satellites set to become a feature of our planet's space environment it's certain that a degree of autonomy will be required to ensure we don't see devastating 'space-crashes' and their unintended consequences. Preventing such collisions is at present largely a manual process that simply can't scale to meet the upcoming demands mega-constellations will put on it:
“Today, this negotiation is done through exchanging emails - an archaic process that is no longer viable as increasing numbers of satellites in space mean more space traffic.”
Olger Krag, Head of Space Safety, ESA
Case in point - the European Space Agency's (ESA) Aeolus wind monitoring earth-observation satellite had to fire its thrusters to avoid a collision with SpaceX's Starlink44 satellite in 2019, the first time the agency had ever had to perform such a 'collision avoidance manoeuvre' (Press Release).
As with terrestrial traffic, some places are more crowded than others and it's routine for satellite operators to take action to avoid not just other satellites but the 128 million+ pieces of space debris found in orbit. The data that helps calculate these avoidance manoeuvres is largely provided by the US Space Surveillance Network and a low-earth orbit, high-traffic zone might typically see hundreds of alerts issued every week. The probability of collision usually needs to exceed 1 in 10,000 before avoiding action is deemed necessary.
SpaceX claim that their Starlink satellites feature Automated Collision Avoidance using data from the US Department of Defence - but what's needed is an internationally agreed set of protocols that all operators adhere to, akin to the see-and-avoid principles used in General Aviation perhaps, and work on this is underway. SpaceNews reported in Nov. '19 that some 21 avoiding actions had already been taken by the Starlink network since May of that year.
ESA ran an open competition in Q4 2019 encouraging Machine Learning experts to use sets of training and test data to predict collisions whilst OneWeb are working with their partner Airbus on the OneWeb Responsible Space programme and will incorporate Altius Space Machines' DogTags™ grappling pictures to aid de-orbiting of their spacecraft eg. by nanosat 'tugs'.
One thing is for sure - traffic management and collision avoidance technologies are only going to increase in value across the aerospace industry - in everything from drones and light aircraft through commercial airliners to satellites and spacecraft of all sizes from low earth right up to geostationary orbits.