Crucial Rocket Firing Puts Curiosity on Course for Martian Crater Touchdown


NASA’s car-sized Curiosity Mars Science Lab (MSL) rover is now on course to touch down inside a crater on Mars in August following the completion of the biggest and most crucial firing of her 8.5 month interplanetary journey from Earth to the Red Planet.

Engineers successfully commanded an array of thrusters on MSL’s solar powered cruise stage to carry out a 3 hour long series of more than 200 bursts last night (Jan. 11) that changed the spacecraft’s trajectory by about 25,000 miles (40,000 kilometers) – an absolute necessity that actually put the $2.5 Billion probe on a path to Mars to “Search for Signatures of Life !”

“We’ve completed a big step toward our encounter with Mars,” said Brian Portock of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif., deputy mission manager for the cruise phase of the mission. “The telemetry from the spacecraft and the Doppler data show that the maneuver was completed as planned.”

Mars Science Lab and cruise stage separate from Centaur upper stage just minutes after Nov. 26, 2011 launch. Thrusters on cruise stage performed course correction on Jan. 11, 2012. Up to 6 firings total will put the NASA robot on precision course to Mars.
Credit: NASA TV

This was the first of six possible TCM’s or trajectory correction maneuvers that may be required to fine-tune the voyage to Mars.

Until now, Curiosity was actually on a path to intentionally miss Mars. Since the Nov. 26, 2011 blastoff from Florida, the spacecraft’s trajectory was tracking a course diverted slightly away from the planet in order to prevent the upper stage – trailing behind – from crashing into the Red Planet.

The upper stage was not decontaminated to prevent it from infecting Mars with Earthly microbes. So, it will now sail harmlessly past the planet as Curiosity dives into the Martian atmosphere on August 6, 2012.

The thruster maneuver also served a second purpose, which was to advance the time of the Mars encounter by about 14 hours. The TCM burn increased the velocity by about 12.3 MPH (5.5 meters per second) as the vehicle was spinning at 2 rpm.

“The timing of the encounter is important for arriving at Mars just when the planet’s rotation puts Gale Crater in the right place,” said JPL’s Tomas Martin-Mur, chief navigator for the mission.

Video caption: Rob Manning, Curiosity Mars Science Lab Chief Engineer at NASA JPL describes the Jan. 11, 2012 thruster firing that put the robot on a precise trajectory to Gale Crater on Mars. Credit: NASA/JPL

As of today, Jan. 12, the spacecraft has traveled 81 million miles (131 million kilometers) of its 352-million-mile (567-million-kilometer) flight to Mars. It is moving at about 10,300 mph (16,600 kilometers per hour) relative to Earth, and at about 68,700 mph (110,500 kilometers per hour) relative to the Sun.

The next trajectory correction maneuver is tentatively scheduled for March 26, 2012.

Curiosity rover launches to Mars atop Atlas V rocket on Nov. 26, 2011 from Cape Canaveral, Florida. Credit: Ken Kremer

The goal of the 1 ton Curiosity rover is to investigate whether the layered terrain inside Gale Crater ever offered environmental conditions favorable for supporting Martian microbial life in the past or present and if it preserved clues about whether life ever existed.

Curiosity will search for the ingredients of life, most notably organic molecules – the carbon based molecules which are the building blocks of life as we know it. The robot is packed to the gills with 10 state of the art science instruments including a 7 foot long robotic arm, scoop, drill and laser rock zapper.

Curiosity’s Roadmap through the Solar System-From Earth to Mars
Schematic shows 8.5 month interplanetary trajectory of Curiosity. Credit: NASA/JPL-Caltech

Curiosity Countdown – 205 days to go until Curiosity lands at Gale Crater on Mars !

January 2012 marks the 8th anniversary of the landings of NASA’s Spirit and Opportunity Mars rovers back in January 2004.

Opportunity continues to operate to this day. Read my salute to Spirit here

Read continuing features about Curiosity and Mars rovers by Ken Kremer starting here:
8 Years of Spirit on Mars – Pushing as Hard as We Can and Beyond !
2011: Top Stories from the Best Year Ever for NASA Planetary Science!
Opportunity Discovers Most Powerful Evidence Yet for Martian Liquid Water
Flawlessly On Course Curiosity Cruising to Mars – No Burn Needed Now
NASA Planetary Science Trio Honored as ‘Best of What’s New’ in 2011- Curiosity/Dawn/MESSENGER
Curiosity Mars Rover Launch Gallery – Photos and Videos
Curiosity Majestically Blasts off on ‘Mars Trek’ to ascertain ‘Are We Alone?
Mars Trek – Curiosity Poised to Search for Signs of Life

9 Replies to “Crucial Rocket Firing Puts Curiosity on Course for Martian Crater Touchdown”

  1. This story just reminds me of the kids in the back of the car — “Are we there yet?”

  2. This is just so cool. What a great lander Curiosity is, with amazing capabilities. Good luck to all involved!

  3. The axial and lateral thrusts seem to suggest this orbital correction is nonHohmann transfer.


  4. So what happens to the upper stage? It’ll miss Mars, but does it have sufficient velocity to eventually escape the solar system?

    1. The upper stage of the rocket is travelling at a velocity of about 30.689 km/s, but the Solar System’s escape velocity is 42.1 km/s; therefore, it will not be sufficient to escape the Solar System.

      1. Now I have this mental image of all of these spent rockets drifting through the solar system. I wonder if their orbits are tracked?

      2. Now I have this mental image of all of these spent rockets drifting through the solar system. I wonder if their orbits are tracked?

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