SpaceX, Starlink, and the Commercialization of Space

This week, masters student Conor Hayes tackles a thorny issue: how to balance the expansion of private actors in space and the benefits their work can have for those of us on earth with the needs of astronomical research. It's not inconceivable that such an expansion could change the night sky forever, not just for scientists working with sensitive instruments, but also for most of the world's city-bound population for whom a starry sky could be replaced by criss-crossing lights. Must we give up wonder to achieve a better life for each another? Image: 19 Starlink satellites unintentionally imaged by the Blanco Telescope at the Cerro Tololo Inter-American Observatory. (CC BY 4.0, NOIARL/CTIO/AURA/DELVE, https://nationalastro.org/news/starlink-satellites-imaged-from-ctio/)

by Conor Hayes

One of the consequences of the way that our economic systems are structured is an ongoing competition between public and private interests to exploit various resources. This competition rolled through astronomical Twitter like a bowling ball through a set of pins in November 2019, when the image above first made its way onto the internet.

Taken using the Victor M. Blanco 4-metre telescope at the Cerro Tololo Inter-American Observatory in Chile, it shows 19 bright streaks caused by a train of Starlink satellites passing through the telescope’s field of view. Unsurprisingly, this greatly reduced the quality of the data, leading to widespread concern about the long-term impact of Starlink on astronomical observations.

The mere fact that Starlink satellites are visible in telescope imagery isn’t the problem. Outside contamination of CCD images is nearly inevitable with a long-enough exposure time. If you ever get a chance to look at raw data from a telescope, you will probably see similar, though shorter, bright streaks caused by cosmic rays impacting the detector. Furthermore, artificial satellites have been occasionally ruining images for as long as there have been a significant number of them in orbit. So what is the problem then?

Part of what concerns astronomers about the Starlink constellation is the sheer number of satellites involved. SpaceX currently has authorization to launch 12,000 (!) Starlink satellites, and has submitted paperwork to approve another 30,000 (!!). For comparison, the United Nations Office for Outer Space Affairs currently lists about 10,400 objects launched into space since 1957. When the constellation is completed, the number of visible Starlink satellites may even outnumber visible stars in heavily light-polluted areas like Toronto. Given that the constellation is intended to surround the Earth at many different orbital planes, having a small handful of Starlink satellites streak across your telescope’s field of view may become a regular occurrence.

In addition to antagonizing astronomers who work in the optical, the development of Starlink has also worried radio astronomers. Ground-based radio astronomy is already hard enough thanks to the fact that many of our modern-day technological conveniences are constantly blasting radio waves into the environment. Consequently, much like how optical telescopes are located in dark areas away from major population centers, radio telescopes are often surrounded by “radio quiet zones”, large swaths of land where radio emissions are strictly regulated. But when those radio sources are passing overhead, as the Starlink satellites will be, those radio quiet zones may become significantly louder.

If nothing else, the conflict over Starlink shows how vital it will be for the scientific community and private businesses to communicate with each other to find a mutually beneficial way forward. Though SpaceX is now looking into ways to make their satellites less bright, including darker paint, sunshields, and shutting off transmissions when passing over radio quiet zones, these kinds of after-the-fact adjustments are not sustainable in the long term. Though I personally find the commercialization of space somewhat distasteful, I also recognize that as the barrier to entry gets lower, thanks in large part to the innovations championed by companies like SpaceX, it is almost inevitable that commercial interests will want to spread outward. Because astronomers have held a near-total monopoly on space for so long, learning to let other people in will be a difficult process, one that will require sustained, genuine cooperation from all interested parties.

I didn’t start writing this post with the intent to argue for the termination of the Starlink program. It’s a difficult needle for me to thread because on one hand, I am an astronomy grad student whose future career could be hindered by a poorly-managed privatization of space. On the other hand, I recognize that SpaceX’s goal with Starlink is an admirable one. The past year has demonstrated how global access to reliable, high-speed internet is now more of a necessity than a luxury, and demanding that Starlink be shut down just because of the challenges it presents for astronomy would be irresponsible and short-sighted. This goes both ways, of course. It was incredibly disheartening to scroll through some of the replies to the original tweet and see how many people were calling ground-based astronomy little more than a vanity project with no real worth to humanity (Elon’s tweets dismissing astronomers’ concerns out of hand and telling them that they were overreacting certainly didn’t help, either).

Though I don’t have any concrete solutions right now, it seems increasingly likely that, as is the case in so many other areas of our society, the responsibility for dealing with the monumental shifts in the way that the private and public spheres interact with each other beyond Earth will ultimately fall upon the next generation of astronomers currently working their way through their undergraduate and graduate educations. I do believe that we can eventually strike the right balance, but I hope that time comes before unregulated, antagonistic competition severely damages our ability to look up at the sky and wonder what lies beyond our home.

The Pros and Cons of Human Missions to Mars

  

It has been an active time for arrivals at Mars, with several spacecraft from different nations taking up position in orbit and the Perserverance Rover, the first step in sample return, due to land this week. The relationship between human and robotic missions has always been an interesting one. Strictly speaking, the two are managed by different divisions within NASA (The Science Mission Directorate and the Human Exploration Operations Mission Directorate) and it's a popular party topic to discuss the merits of each kind of exploration. MSc student Grace Bischof takes up this conversation in her post this week.
(Image Above: https://commons.wikimedia.org/wiki/File:Concept_Mars_colony.jpg)

by Grace Bischof

With Perseverance set to touch down on the Red Planet in less than 10 days, I’ve been thinking a lot about Mars exploration. In addition to the Mars 2020 mission led by NASA, the Hope Orbiter launched by the United Arab Emirates Space Agency and the Tianwen-1 orbiter, lander, and rover sent by the China National Space Administration will soon be arriving to Mars. In a previous blog post I’ve detailed the family of Martian rovers currently on the planet, but the list continues to grow with these new missions. There are more missions planned moving forward (ExoMars 2022, for example) but a topic that’s on everyone’s mind still remains unanswered: when will humans be sent to Mars?

There are many unique challenges that arise when imagining the idea of human missions to Mars. In this post, I’m going to highlight some of the pros and cons of sending humans to Mars, for both short-term missions and long-term colonization.

Pro #1:

While incredible science and engineering activities have been achieved by landers and rovers, humans may be able fill in some of the gaps left by robotics.  Humans can work faster than the technology currently on Mars, not needing specific commands sent from Earth to complete a task. Additionally, rovers and landers have very specific designs. For example, a rover may only be able to dig 1 meter into the surface because of the length of its robotics arm. Humans would be able to dig further, perhaps making discoveries that a rover could not.

Con #1:

An issue pertaining to both shorter missions and permanent settlement is that Mars could be dangerous. Firstly, the journey to Mars is not a quick trip. The Apollo missions reached lunar orbit nearly 52 hours after launching; Missions to Mars typically take upwards of 200 days. That is a very long time in the space environment, where radiation could have extremely adverse effects on the astronauts. Once humans are on the planet, the intense conditions could pose many problems. Notably, freezing temperature conditions, an unbreathable atmosphere, ultraviolet radiation, and massive dust storms all pose a threat to humans on the surface of the planet.

Pro #2:

The colonization of Mars has been a theme in many science-fiction works throughout the years, and many people are pushing for it to become a reality. Leading the pack on the Mars settlement goal is SpaceX, an American aeronautics company. The major push to move humans to Mars, according to SpaceX’s founder, is an attempt to avoid a future extinction event. It is no secret that human activity has greatly affected the Earth, and by starting a colony on Mars, we may ensure the survival of humankind for thousands or millions of years to come. Additionally, putting humans on Mars is a huge task (as outlined in Con #1), therefore by doing so, we would massively enhance our knowledge of technology, engineering, and science.

Con #2: 

To round out the list, it’s very important to discuss the ethics of human missions to Mars. One of the biggest problems with landing humans on Mars is potential contamination (known as Planetary Protection). This works both ways – there is a risk that humans may bring terrestrial contaminates to Mars’ surface or that scientists might bring Martian contaminates back to Earth. If microbial life does exist on Mars, the possibility of doing damage to that life has grave ethical implications. If Mars were to become the next habitat for humans, the environment would be completely changed, potentially ruining the opportunity for astrobiologists to learn more about the planet. Humans do not have a good track record for treating the Earth kindly. Using Mars as a backup plan for human survival only moves our problems further from the sun. Plus, to live on Mars people have suggested “terraforming” the planet to make it livable. Do we have the right to alter another planet so severely? 

The are no easy answers when it comes to the future of Mars exploration. Humans landing on Mars could lead to discoveries never thought possible using current technology. However, there are many logistical and ethical issues surrounding this idea. For now, all we can do is rewatch “The Martian” again while we wait. 

Update on K2-141b

Above, some art commissioned by NASA to commemorate the mission of the Kepler Space Telescope. Even as the mission encountered technical issues with its reaction wheels near the end of its journey, good science was extracted. The K2 mission allowed the telescope some drift from its original pointing near the constellation of Cygnus. This permitted the telescope to examine a wider range of stars, though each could not be observed for as long as the original set. Still, close-in short orbital period planets like K2-141b could be detected. This week, Giang updates us on his work to model this lava planet.

By Giang Nguyen

As 2021 marches on, I, along with everyone else in the lab, are also chugging along amidst a global pandemic. However, I’m more fortunate than most as my work solely lies in virtual space. As long as I have access to a computer and some internet, my work on K2-141b progresses. Although the internet isn’t necessary to run my models, I always need to have 5 tabs of Google searches on how to python open.

As a refresher, K2-141b is a planet about 200 light years away located in the Aquarius constellation. Its orbit is so close to the star it orbits that its surface temperature can be hot enough to melt and vapourize rocks, creating a thin atmosphere. K2-141b is also tidally locked which means there is a permanent dayside and nightside on the planet. Almost half of the planet is covered by giant magma oceans that can be over 100 km deep.

My work, previously published in the Monthly Notices of the Royal Astronomical Society, assumed an optically thin atmosphere such that all of the star’s light will reach to K2-141b’s surface unhindered. But now, we are restricting that assumption to account for the radiative transfer that occurs in the atmosphere. This involves calculating how much infrared and UV radiation is absorbed by the atmosphere and the subsequent feedback on the surface’s energy budget.

Infrared, or long-wave radiation, accounts for almost half of the stellar radiation but UV accounts for less that 1%. Although IR radiates much more than UV, an SiO atmosphere is better at absorbing UV than IR, 10,000,000 times better. As the atmosphere and the surface themselves also radiate infrared waves, they can warm each other up which complicates things further. Nonetheless, I pressed on with what I had and crunched the numbers.

If you neglect UV absorption, our results wouldn’t differ much from the results of our MNRAS paper. The atmosphere would be a bit warmer for a larger area but eventually drops down to near absolute zero when approaching the night-side; the winds would be about 33% faster. This makes sense as more energy is absorbed initially but, through sensible heat and radiative cooling, the system finds an equilibrium and temperature drops. Next step, add UV radiation.

Although UV absorption is minuscule initially, the atmosphere's thick optical depth at UV wavelengths ensures that 100% of UV stellar radiation is absorbed almost everywhere. While IR absorption and emission drops exponentially, UV absorption stays steady. Just like the tortoise and the hare, slow and steady wins the race. There comes a point when UV heating becomes the dominant radiative term and IR emission is not strong enough to cool the atmosphere. From there on out, the winds get faster and the temperature gets even hotter.

As you approach the night-side, the temperature gets hotter and hotter, upward of over 13,000 K. The winds go up to 7 km/s (400% increase from the classic no radiative transfer scenario). Unlike every other simulation, the results with UV absorption stayed subsonic throughout the entire atmosphere since the temperature rises faster than the wind’s acceleration. These strange results seem counterintuitive physically…but within the mathematical axioms we’ve built for our model everything checks out.

For now, I am further analyzing these results. Atmospheres like the one we have on Earth are also very good at absorbing UV radiation. However, our stratified atmosphere relegates that job to the top, far away from the surface. This leaves Earth with a temperature inversion, and K2-141b should have one too. The adiabatic profile may no longer be accurate when we introduce complex radiative transfer schemes. But if the results are true, then K2-141b’s atmosphere becomes plasma and flies across the surface at 7 km/s speed, like exhaust from a rocket. That’s pretty metal but I don’t know what the results are yet. I’ll keep you updated when I do. Until next time.

Continuing my PhD Life with a Baby

 

Charissa Campbell, one of our PhD students here in PVL, returns to work this week from an extended leave to care for the new addition to her family. She asked to share her experience here in this post, which provides a great bookend to her pre-leave discussion, which can be found here. 

 

by Charissa Campbell

Well January has arrived, and it is time to return to work from maternity leave. It has been a turbulent but amazing past 8 months that I am glad I got to have off. I am proud to introduce my son, Arthur, who has been nothing but a blessing on our life. He came into this world on June 1st with less than 2 hours of labour, which I am very thankful for!

Due to York counting leave by semesters, I was able to take the last month of my pregnancy off which helped me relax as labour was probably the scariest part for me. If you recall in my previous post right before my leave (http://york-pvl.blogspot.com/2020/05/deciding-to-start-family-while-being.html), I mentioned that Arthur was due near the end of May but decided he was too cozy in the belly. By 8 days after my due date, the midwives suggested a stress test to see how the baby was doing as they recommend inducing labour 10 days after your due date. By the time of my stress test, I was ready to meet Arthur and get the scary part out of the way. I was relieved when they told me I was already in labour when I took the stress test and that I wouldn’t be leaving the hospital that day. It was so sudden that it was hard for me to process and get panicked. However, the stress test did reveal that whenever I had a contraction, my stomach would squeeze Arthur to the point where his heart slowed down significantly. This was nerve-wracking in itself. After this was monitored and then found that the umbilical cord was wrapped around his feet, the doctors decided an emergency c-section was necessary as his heart had fully stopped for a moment. My water broke at 2:30 PM and Arthur was born at 4:15 PM. I’ve read that labour can be hours to days for some women so for it to be that quick was relieving for me. Even though I didn’t give birth the “normal” way, it was normal for me or my baby would have died. The stress and emotions on that day are something that I will remember for the rest of my life and I hug Arthur hard every day knowing that.

I was quite blessed that York offered paid maternity leave as these past 8 months were definitely needed to figure out how to live a life with a baby. The worst part of it is probably the first 6-8 weeks when Arthur is trying to figure out how to be a human and you are trying to judge how to handle your newborn. I was also in recovery for 6 full weeks, with the first 2 almost confined to a rocking chair or bed due to my surgery. It was painful to walk anywhere, but I was lucky that my partner was home 24/7 to help. Slowly your entire house gets filled with baby stuff, including things that you either never use or he grows out of so quickly. We barely touched the 3-6 month clothes as Arthur grew tall so fast that by 4 months, he was the height of a 6-7 month old. I am quite short myself, so those genes definitely didn’t come from me! He is currently 8 months on February 1st and still tall and a good weight with blonde hair and blue eyes. He can sit up, loves food and is just an overall happy baby. We are so excited that we decided to take this path and not let my PhD studies get in the way.

Even though I was on leave, there was one important item that needed to get done. Right before I left, I submitted a paper that I co-wrote with a group at Curtin University in Australia about our Machine Learning project. I got an email indicating the first round of revisions were ready. I looked over them quickly and noticed that the majority of the questions were better suited for the Curtin group so I decided to do the revisions while on leave. I asked for an extension as they gave 2 weeks. Unfortunately, Arthur was 4 months at the time and still needed tons of Mom attention. Either way, my partner and I worked out a schedule so I could have time to work and I was able to get my revisions in on time. Just before Christmas I got another email expecting a second round, however, it turns out there were no more revisions needed and it was ready to be published. I am very proud that I was able to write a scientific paper while pregnant and get it published while still on leave. Feel free to check it out here: https://www.sciencedirect.com/science/article/pii/S0094576520307736

Now that I am back at work, I have found that I don’t have the same energy I used to. Some mornings Arthur wakes early so I am more exhausted that day than others. The pandemic has also made it a bit harder to work from home as I can hear Arthur downstairs. Whenever he cries it triggers a reaction that I must pick up my baby. However, by frequently going to see your baby when you are trying to leave them for the day makes it harder on the baby as you are constantly coming and going. I’ve been trying to mediate that by wearing headphones or playing music out loud to drown out the sound downstairs. I am currently in the midst of trying to figure out a good ideal schedule that can balance work and home without getting too overwhelmed. Even then, I am ready and excited to get back into work!

Overall, Arthur has been adjusting well to me being at work and even goes to bed without me on nights that I have to moderate a lab session as part of my Teaching Assistant section of my PhD. As time goes on, both Arthur and I will get used to the new schedule and I will become a full-time working Mom. It is a hard job trying to be a mother and doing PhD studies, but it will be worth it once I get my degree and can provide a good life for my family.