On 14th July, we witnessed the New Horizons spacecraft finally fly-by Pluto. Indeed, this event is going into the history books. But do you know how this spacecraft, a million miles away, works?
Now, this article contains a lot of science you might not understand, which is fine, but that means you get to learn a lot. Let’s dive into the facts!
1. The spacecraft is over 10 years old. YES. New Horizons was launched on January 19th, 2006, but that means it was built between 2000-2005. We are talking about a time when the internet wasn’t huge. The time when smartphones didn’t really exist. But this spacecraft has some great technology in it: it uses a high performance custom built CPU (Mongoose-V) and a solid state drive to store data. It has a bunch of scientific instruments, which I’ll come to in a moment.
2. The scientific instruments on the spacecraft include three optical instruments, two plasma instruments, a dust sensor and a radio science receiver/radiometer. These instruments are used to scan the surface as well as the atmosphere of the dwarf planet. Read about these instruments here: link. Most pictures we see are taken by LORRI (Long-Range Reconnaissance Imager) that has a 1024x1024 CCD high resolution image sensor.
3. Wondering how a spacecraft that is approximately 4700 million kilometres away (that’s huge, isn’t it?) sends data to centres on earth? Well, that were the NASA Deep Space Network (DSN) comes into picture. New Horizons broadcasts microwaves (in the X-band) that in turn get captured and reflected by all the space objects NASA had sent in the past decades. The data speeds are as low as 1kbit/s because it takes a lot of reflections and amplifications before the images from New Horizons can reach earth. The latency of a one-way trip is about 4.5 hours.
4. The spacecraft is travelling at a speed of… 52,284 km/h (or 14.5 km/s) with respect to the Sun (or about 120,000 km/h w.r.t Earth) (link). That is very fast. And its meant to be. The launch speed (aka escape velocity) given to New Horizons has been the greatest in history, a whopping 16.5 km/s just so that it can escape the Sun’s gravity.
5. The flyby itself is a great achievement. The trajectory of New Horizons needed to be calculated a decade before it would reach Pluto. This is how the trajectory is:
So that’s that. Sending stuff into space is surely no joke, especially when you are talking about numbers that cannot even be imagined. Kudos to NASA for this successful mission.
This is astro science, right here on Technonerds!
Wikipedia: New Horizons
DMuller.net: New Horizons Real-Time Simulation