Tag Archives: Landing

Everything you need to know about Curiosity landing on Mars

29 Jul

Panorama of Mars created by the Opportunity Rover between December 2011 and May 2012

The landing of the Mars Science Laboratory (MSL), or Curiosity as it is usually called, is now very much within sight. To get you prepared to watch the landing, here are some things you probably want to know:

#1) What is Curiosity?

In a nutshell, Curiosity is a compact car-sized rover (approx 2.8m x 3m x 2.1m) that left Earth in November 2011 on top of an Atlas-V Rocket. Its 8 month journey to Mars is about to end. It will then start its two-year primary mission to explore a region of Mars inside the Gale Crater, near Mount Sharp, just south of the Martian equator. Curiosity is searching for evidence regarding the past presence of water on Mars and the possibility of past life, amongst various other objectives. The NASA homepage for the mission is: NASA.gov/Mars

If you want to read in detail about the mission you can download the NASA Press Kit PDF by clicking here.

#2) When to watch?

The magic time is 1:31am EDT on August 6 (or 10:31pm PDT on August 5). We will know then whether or not Curiosity has successfully landed. It would probably be a good idea to flip on the TV or the web browser a little bit before this to make sure you don’t miss anything, but truthfully there won’t really be anything to see. There will probably be some interesting discussion from knowledgeable people though if you’re watching on NASA TV. Also, fair warning: don’t expect a live hi-def video feed from Mars. The deep-space communication network does not have that sort of capacity.

NASA TV will start a live feed from their control rooms at 11:30pm EDT (8:30pm PDT) on August 5, which is about two hours prior to touchdown.

Interesting fact: It will be about 3pm “local time” at the landing site on Mars when Curiosity touches down.

Interesting fact #2: only about 40% of missions to Mars are successful. So as you watch, there is a very real possibility that the landing will be unsuccessful.

#3) Where to watch?

NASA TV will be the best place. If you have cable or satellite, check your local listings. You may very well have NASA TV on your dial. Interesting aside: NASA actually doesn’t charge your cable/satellite company anything to carry the channel, so if they don’t carry it they ought to.

In the USA if you have DirecTV go to ch346 or on Dish Network ch212 and you’ll find NASA TV.

In Canada if you have Rogers digital cable you’re in luck: NASA TV is on ch254, or ch579 for the HD feed.

NASA TV is also available live, free, and around the world online right here: Official NASA TV Site

If you have your own satellite dish, click that link to NASA TV as well. You will find instructions on where to point your dish and how to set it up to receive NASA TV. I would also hope that major news networks will pick up the story live, so you can always check in with CNN, FoxNews, SkyNews, BBC World, etc. if you can’t get on with NASA TV.

Sunset on Mars captured by the Spirit rover on May 19, 2005

#4) What about the time-delay because Mars is so far away?

An excellent consideration! However the folks at NASA report times as “Earth Reception” times. So when they say that Curiosity lands on Mars at 1:31am EDT, what they really mean is that we will receive the signal at 1:31am EDT. Curiosity will have actually touched down (or crashed) 13.8 minutes earlier, but because of the distances involved (approx 248 million km) it takes that amount of time for the speed-of-light radio signal to arrive here at Earth from Mars. So if you’re watching at 1:31am EDT, you’ll see it “live” then.

#5) I’ve heard of something called “7 Minutes of Terror” – what’s that about?

The 7 Minutes of Terror refers to the amount of time it takes for Curiosity to land. From when it first touches the top of the atmosphere on Mars to when it’s six wheels are on the ground – is seven minutes. The other part of this to consider is that when we get the first signal that Curiosity has begun the landing process (i.e. it’s hit the top of the atmosphere on Mars) the rover will have actually already been on the surface – alive or dead – for seven minutes (seven minutes to land + seven minutes sitting on the surface = 14 minutes, which is = to the Mars/Earth radio time delay).

To read more about this and watch a truly awesome NASA video about the 7 Minutes of Terror, read this blog post of mine from June 29, 2012.

Mars Landing Sites

#6) Where is Curiosity going to land?

Just south of the equator, inside the Gale Crater, close to Mount Sharp. To be precise: 4.6 degrees south latitude, 137.4 degrees east longitude.

#6) Why did they pick this landing spot?

Geological diversity. NASA researchers believe this spot is likely the bottom on an ancient lake on Mars. There are possibly high concentrations of minerals. It’s near crater impacts and large hills/mountains. If we are going to find evidence of past life on Mars, researchers believe this is the best place to look.

#7) How do we receive communications from Curiosity?

Curiosity is primarily going to make use of three spacecraft that are already in orbit around Mars to relay signals back to Earth: Odyssey, The Mars Reconnaissance Orbiter (MRO), and The Mars Express. Those signals will then be received by the antennae of the Deep Space Network here on Earth. There will be some direct Curiosity-Earth communication though as well.

#8) I heard one of the spacecraft orbiting Mars had a problem that would stop it from relaying signals back to Earth?

The Odyssey Spacecraft did indeed have a problem a couple weeks ago. The craft entered “safe mode” and its orbit was such that it would not have any line-of-sight towards Curiosity during its landing, preventing it from both observing the landing and relaying communications. The fine folks at NASA have taken care of this however. Odyssey has been roused from safe mode and it executed a six-second rocket burn to speed up its orbit by six-minutes, so it will now be in position to observe the landing and relay communications from Curiosity back to Earth in real-time. You can read more about this here.


#9) Why is it so important to have Odyssey in the right spot? There are two other spacecraft in orbit around Mars, and can’t Curiosity just send the signal directly to Earth itself?

Odyssey is the only one of the three orbiters around Mars that is capable of relaying communications in real-time. Both the MRO and Mars Express spacecraft will be in position to observe and record data from Curiosity, however it takes some time for them to transmit the data back to Earth. And Curiosity cannot send the information directly because, from its perspective, Earth will set below the Martian horizon part way through descent – making direct communication impossible. So if we want to know in real-time if Curiosity was successful in landing, Odyssey is the only option.

#10) Why do I care about any of this?

This is a question that always comes up when talking about space exploration, particularly when budgets are tight. It’s a good question, considering that space exploration is an expensive endeavour. The Curiosity mission, for example, is costing about $2.5 billion (USD).

But this sort of exploration is vital. First, it brings people together in cooperative missions. Nations and peoples that used to be bitter enemies are now partners (USA & Russia being the best example in space exploration). It also helps us to understand how our world works. The simple fact is that we cannot explain how everything right here on Earth works, so by better understanding how things work in other places it allows us to figure out stuff here – since the rules of physics and chemistry are the same on Mars as on Earth.

The other part of exploration – and this is the part that is most significant to me – is the romance of it. We simply do not know what we do not know. We don’t even know exactly what questions we need to be asking are. So if we don’t get out there are start poking around, trying to figure things out, we’ll be stuck at the starting line forever.

Don’t get me wrong, we have made amazing discoveries and we have a solid understanding of certain things, but when you get right down to it we’ve truly only been exploring space for 50-odd years (and if you want to be very generous, call it 400 years, from when telescopes first came about) – but however you want to measure it, we are just at the very beginning of our cosmic journey. There are places, things, and discoveries out there that we haven’t even dreamed of yet. And it is our responsibility to carry the journey forward.

Science is awesome.