TL;DR
- Catch me if you can!
- Mercury in retrograde
Current events
No I'm not talking about the classic Leonardo DiCaprio movie, I'm talking about Rocket Lab's announcement last week that they too will start trying to recover their rocket boosters! But while such a feat would make Rocket Lab only the second company to pull it off (after SpaceX), there are several nuanced differences between the two companies' motivations and methodologies
It all boils down to rocket size and market positioning. While the Falcon 9 can launch the big expensive satellites only government agencies and big telecom operators can afford, Rocket Lab wants to dominate a different segment - the rapidly growing demand for smallsats and Cubesats (ranging from phone- to refrigerator-sized) that a wider range of customers needing communication and Earth-observation capabilities can afford. Right now these small customers don't have a lot of options, other than waiting to hitch a ride on a larger rocket as a secondary payload. Rocket Lab's cheap, miniature Electron rocket sports a cool $5mm per launch price tag that solves this problem!
Interestingly, for the longest time reusability wasn't a priority for Rocket Lab; with this announcement, CEO Peter Beck said he "ate his hat" in changing his mind. That's because with smaller rockets, there's a point of diminishing return in reusability since manufacturing costs are already lower, and building in booster recovery capability eats away at an already small payload capacity. But pursuing reusability is more about scalability than cost for Rocket Lab; given they're targeting 50 launches/year, they simply don't have enough time to build that many rockets, so reusing them will allow them to serve their customers faster
Planets orbit faster when they're closer to the Sun, so Mercury and Venus move faster than Earth. When one of them overtakes Earth in its respective orbit, our line of sight to the planet appears to start moving backwards due to the circular shapes of our orbits. The same holds true for the planets further than the Sun from us like Mars, only it's the opposite - the outer planets appear to backtrack when we pass them by!
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| Look how much smaller the Electron is versus the SpaceX Falcon 9 |
It all boils down to rocket size and market positioning. While the Falcon 9 can launch the big expensive satellites only government agencies and big telecom operators can afford, Rocket Lab wants to dominate a different segment - the rapidly growing demand for smallsats and Cubesats (ranging from phone- to refrigerator-sized) that a wider range of customers needing communication and Earth-observation capabilities can afford. Right now these small customers don't have a lot of options, other than waiting to hitch a ride on a larger rocket as a secondary payload. Rocket Lab's cheap, miniature Electron rocket sports a cool $5mm per launch price tag that solves this problem!
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| Rocket Lab's first commercial launch on November 11, 2018 from the Mahia Peninsula in New Zealand |
Interestingly, for the longest time reusability wasn't a priority for Rocket Lab; with this announcement, CEO Peter Beck said he "ate his hat" in changing his mind. That's because with smaller rockets, there's a point of diminishing return in reusability since manufacturing costs are already lower, and building in booster recovery capability eats away at an already small payload capacity. But pursuing reusability is more about scalability than cost for Rocket Lab; given they're targeting 50 launches/year, they simply don't have enough time to build that many rockets, so reusing them will allow them to serve their customers faster
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| Whoever flies these rocket-catching helicopters in the future must be an absolute beast |
Finally, Rocket Lab is taking a different approach to booster capture. SpaceX uses propulsive landing, where the rocket reignites its engine to slow down during descent. The Electron will use a balloon braking system to slow down, followed by a parachute that a hook-carrying helicopter will literally catch out of the sky! Talk about choreography and timing! Let's see if it works
Check out their animation of the booster recovery here - it's a must watch!
Today I learned
If you've come here for a horoscope reading or other astrology-related nonsense, you're out of luck - I only dabble in real science! But while you can't blame your workplace chaos or natural disasters on Mercury in retrograde, the concept of apparent retrograde motion is a real thing in astronomy!
The word planet derives from the Ancient Greek word for wanderer (πλανῆται, planetai) because the points of light representing the planets inexplicably wandered relative to the other fixed stars in the night sky. Even more befuddling was how the planets seemed to move in one direction, then suddenly backtrack and start moving in the other direction for a period of time! How could a planet reverse course in its orbit?
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| Retrograde motion of Mars, captured by astrophotographer Tunc Tezel as a composite over 35 different observations | Image credit |
Planets orbit faster when they're closer to the Sun, so Mercury and Venus move faster than Earth. When one of them overtakes Earth in its respective orbit, our line of sight to the planet appears to start moving backwards due to the circular shapes of our orbits. The same holds true for the planets further than the Sun from us like Mars, only it's the opposite - the outer planets appear to backtrack when we pass them by!
Confused? It's actually a simple concept, just one that's way easier to explain visually than verbally, so check out the video above for an awesome explanation!
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