Small satellites are radically remaking space exploration
arstechnica.com
arstechnica.com
The article imagines what we could do with 100 mini Curiosity rovers, but the reality is not much. A rover is a completely different proposition from a cubesat. The instruments Curiosity carried can't just be scaled down 100 times. Similarly if we're going to put a lander on Europa, there's a minimum size such a thing would need to be to work at all, be able to carry useful instruments and have enough power to transmit data back, and it's not tiny.
The fact is you build the probe and mission around the instruments you want to send, and that sets quite high minimum vehicle design parameters for many missions. The MarCO cubesats barely carried any instruments at all, they were mainly communications relays for the InSight probe. On their own they could do practically no science. Yes I know they were mainly a demo mission, but lets keep things in proportion. Add more instruments and you need more power so bigger solar panels, more powerful computers, more capable antennas, bigger batteries, more powerful thrusters, a bigger launcher and all of a sudden it's not a cubesat any more.
So I do apologies for pouring all that cold water. The stuff is really exciting and is genuinely opening up new and exciting opportunities, but let's not kid ourselves that the old way of doing things is over. It really isn't. If these new technologies created the impression that flagship missions are a waste of money and not worth doing, it would be a terrible shame. This isn't an SLS vs Starship type contest where one solution essentially deprecates the other. Micro-missions are a fantastic complement to traditional exploration models, but not a replacement.
I tried to do the math but failed. Pluto's orbital diameter, according to wikipedia, is about 4.4 billion km. That means the main solar system has a circumference of about 27 billion km. Starlink cubesats orbit at about 550km. Relay sats wouldn't need to punch through atmosphere so they could be farther apart.
I pictured a series of circles. The close to the sun the smaller. I'm sure if I'd listened in cal 1 I could use a summation to figure this out.
Losing a few sats periodically isn't a big deal and it won't bring down the whole network.
It might slow signals down to propagate through the mesh but communication is already slow in space. If a probe/ship needs to communicate quickly it can use its own high power dish or laser.
I've got a background in both space engineering and planetary science. One of the most exciting things that I see happening over the coming decade is commoditization of planetary probes. There's so much more of the Solar System that we still have to explore and the traditional flagship missions just don't give us enough access.
The best way to think of how smallsats augment our space science and exploration capability is in terms of the marginal value over traditional missions. For planetary science, the cost per bit of science data can drastically be reduced through the use of Commercial Off-The-Shelf (COTS) components.
There are a number of private companies looking to leveraging smallsats to deliver all-in planetary science missions, like Xplore [1].
As a space engineer, access to suppliers was really a major hurdle towards finding the optimal cost and risk sweet spot. If you're interested, we've published a series of articles shedding light on different products & services available on the market [2]. We've now got 1000s of space engineers every month from all over the world using these articles to drive better sourcing.
Better sourcing will ultimately lead to better missions, and drive the smallsat revolution towards completely remaking the way we think of both space science and exploration.
[2] https://blog.satsearch.co/2019-12-03-space-technology-on-sat....
https://www.kickstarter.com/projects/exodusorbitals/nova-a-c...
Could you expand on this? What are the limitations and regulations on cameras in space for civilian sats?
- For our first mission camera resolution is not a big concern, we are not launching KH-11 grade hardware.
- However, there is list of specific locations that need to be blacklisted for "national security considerations", depending on both of satellite operator jurisdiction and satellite users' nationality as well.
It is going to be messy and complicated, but in the words of our legal consultant: "difficult, but doable".
This is a talk by Satellogic Gerardo Richarte on how they hacked control back of an orbiting satellite after a dev did an rm -rf / on a couple of it's computers https://youtu.be/B88AYaQNlD4 It's in spanish, but it's a great anecdote of "hackers in space"
If Spacex entered the market I think it would be game over but they seem content to ignore it and focus on bigger payloads.
Last time I looked was blown away by the costs for a non-commercial 0.5U tubesat launch. $12,000 including all the hardware:
Why, though? The advantage of small launchers is the ability to put your smallsat into a dedicated orbit, which is not possible with a rideshare.
It's basically the choice of investing in R&D and adding launch mass for an on-sat propulsion system or paying extra for an exclusive ride.
An additional propulsion system not only increases risk, it also adds a substantial amount of cost and may turn a mission into the next bigger class - in terms of mass, overall cost, and development time - which may negate any saving in launch cost.
Edit: you can of course simply wait for an opportunity to launch as a secondary payload into the desired orbit, but that waiting time might be years...
In any case, the expected growth in the smallsat market is significant and the market might exceed the "traditional" satellite market by 2025 [1].
This leaves plenty of room for "boutique" launch services, especially considering that SpaceX will be their own best customer with their StarLink launch campaign.
So while they might be cheaper as far as $/kg is concerned, other factors (launch window, target orbit, payload integration, logistics, ...) have to be considered as well and the bigger the market, the more room for competition.
I'm not saying that no one will use (SpaceX) rideshare services - I'm just pointing out that SpaceX won't be the only reasonable option since $/kg isn't the only relevant metric to consider.
[1] https://www.satellitetoday.com/business/2018/10/22/just-a-sm...