JPL
Careers
Education
Science & Technology
JPL Logo
JPL Logo
Solar System
.

InSight Steers Toward Mars

May 23, 2018
NASA's InSight spacecraft is currently cruising to Mars. Yesterday, it performed its first course correction guiding it to the Red Planet.
Credit: NASA/JPL-Caltech

The spacecraft has completed its first trajectory correction maneuver.

NASA's InSight lander has made its first course correction toward Mars.

InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, is the first mission dedicated to exploring the deep interior of Mars.

The lander is currently encapsulated in a protective aeroshell, which launched on top of an Atlas V 401 rocket on May 5 from Vandenberg Air Force Base in Central California. Yesterday, the spacecraft fired its thrusters for the first time to change its flight path. This activity, called a trajectory correction maneuver, will happen a maximum of six times to guide the lander to Mars.

Every launch starts with a rocket. That's necessary to get a spacecraft out past Earth's gravity -- but rockets don't complete the journey to other planets. Before launch, every piece of hardware headed to Mars is cleaned, limiting the number of Earth microbes that might travel on the spacecraft. However, the rocket and its upper stage, called a Centaur, don't get the same special treatment.

As a result, Mars launches involve aiming the rocket just off-target so that it flies off into space. Separately, the spacecraft performs a series of trajectory correction maneuvers guiding it to the Red Planet. This makes sure that only the clean spacecraft lands on the planet, while the upper stage does not come close.

Precise calculations are required for InSight to arrive at exactly the right spot in Mars' atmosphere at exactly the right time, resulting in a landing on Nov. 26. Every step of the way, a team of navigators estimates the position and velocity of the spacecraft. Then they design maneuvers to deliver it to an entry point at Mars. That navigation team is based at NASA's Jet Propulsion Laboratory in Pasadena, California, which leads the InSight mission.

"This first maneuver is the largest we'll conduct," said Fernando Abilleira of JPL, InSight's Deputy Mission Design and Navigation Manager. "The thrusters will fire for about 40 seconds to impart a velocity change of 3.8 meters per second [8.5 mph] to the spacecraft. That will put us in the right ballpark as we aim for Mars."

Especially at the beginning of that cruise, navigators rely on NASA's Deep Space Network (DSN) to track the spacecraft. The DSN is a system of antennas located at three sites around the Earth. As the planet rotates, each of these sites comes into range of NASA's spacecraft, pinging them with radio signals to track their positions. The antennas also send and receive data this way.

The DSN can give very accurate measurements about spacecraft position and velocity. But predicting where InSight will be after it fires its thrusters requires lots of modeling, Abilleira said. As the cruise to Mars progresses, navigators have more information about the forces acting on a spacecraft. That lets them further refine their models. Combined with DSN tracking measurements, these models allow them to precisely drive the spacecraft to the desired entry point.

"Navigation is all about statistics, probability and uncertainty," Abilleira said. "As we gather more information on the forces acting on the spacecraft, we can better predict how it's moving and how future maneuvers will affect its path."

Yesterday's 40-second burn relies on four of eight thrusters on the spacecraft. A separate group of four is autonomously fired on a daily basis to keep the spacecraft's solar panels trained on the Sun and its antennas pointed at Earth. While necessary to maintain orientation, these small, daily firings also introduce errors that navigators have to account for and counterbalance.

"Everyone has been working hard since launch to assess what these small forces have done to the trajectory," said Allen Halsell of JPL, InSight's navigation team chief. "People have worked lots of hours to look at that. For engineers, it's a very interesting problem, and fun to try to figure out."

When the spacecraft is just a few hours from Mars, the planet's gravitational pull, or gravity well, will begin to reel the spacecraft in. At that point, InSight's team will prepare for the next milestone after cruise: entering Mars' atmosphere, descending to the surface and sticking InSight's landing.

JPL, a division of Caltech in Pasadena, California, manages InSight for NASA's Science Mission Directorate in Washington. InSight is part of NASA's Discovery Program, managed by the agency's Marshall Space Flight Center in Huntsville, Alabama. The InSight spacecraft, including cruise stage and lander, was built and tested by Lockheed Martin Space in Denver.

Find more information about InSight at:

https://mars.nasa.gov/insight/

Follow InSight's path to Mars by visiting NASA's Eyes on the Solar System:

https://go.nasa.gov/2FSWReg

http://mars.nasa.gov

News Media Contact

Andrew Good

Jet Propulsion Laboratory, Pasadena, Calif.

818-393-2433

andrew.c.good@jpl.nasa.gov

2018-114

Related News

Mars .

NASA to Host Virtual Briefing on February Perseverance Mars Rover Landing

Mars .

NASA InSight’s ‘Mole’ Ends Its Journey on Mars

Mars .

Mars 2020 Perseverance Rover to Capture Sounds From the Red Planet

Solar System .

NASA’s Juno Mission Expands Into the Future

Mars .

NASA’s Curiosity Rover Reaches Its 3,000th Day on Mars

Mars .

NASA Extends Exploration for Two Planetary Science Missions

Mars .

Celebrate the Perseverance Rover Landing With NASA's Student Challenge

Mars .

7 Things to Know About the NASA Rover About to Land on Mars

Mars .

A Martian Roundtrip: NASA's Perseverance Rover Sample Tubes

Mars .

NASA Moves Forward With Campaign to Return Mars Samples to Earth

Explore More

Image .

Juno's Mission Goes On

Topic .

Solar System

Image .

A Hot Spot on Jupiter

Image .

Jupiter's Storm Oval BA As Viewed By An Artist

Image .

Two Views of Jupiter Hot Spot

Image .

A Jupiter Circumpolar Cyclone

Image .

Jupiter North Pole Detail

Video .

What's Up - January 2021

Image .

All Eight Northern Circumpolar Cyclones in 2020

Image .

Tracking Clouds on Jupiter

About JPL
Who We Are
Executive Council
Directors of JPL
JPL History
Documentary Series
Virtual Tour
Annual Reports
Missions
All
Current
Past
Future
News
All
Earth
Mars
Solar System
Universe
Technology
Galleries
Images
Videos
Audio
Podcasts
Infographics
Engage
JPL and the Community
Lecture Series
Public Tours
Events
Team Competitions
JPL Speakers Bureau
Topics
Solar System
Mars
Earth
Climate Change
Stars and Galaxies
Exoplanets
Technology
JPL Life
For Media
Contacts and Information
Press Kits
More
Asteroid Watch
Robotics at JPL
Subscribe to Newsletter
Social Media
Get the Latest from JPL
Follow Us

JPL is a federally funded research and development center managed for NASA by Caltech.

More from JPL
Careers Education Science & Technology Acquisitions JPL Store
Careers
Education
Science & Technology
Acquisitions
JPL Store
Related NASA Sites
Basics of Spaceflight
Climate Kids
Earth / Global Climate Change
Exoplanet Exploration
Mars Exploration
Solar System Exploration
Space Place
NASA's Eyes Visualization Project
Voyager Interstellar Mission
NASA
Caltech
Privacy
Image Policy
FAQ
Feedback
Site Manager: Veronica McGregor
Site Editors: Tony Greicius, Randal Jackson, Naomi Hartono