Long-distance Landing

But the parachute won’t carry InSight all the way to the surface. Less than a minute after the parachute deploys, the probe will first jettison its protective heat shield and extend its three legs. Then, with less than a minute until landing, InSight will separate from the parachute stage entirely and enter a final free fall toward the martian ground with just over half a mile (1 km) to go. The lander’s 12 descent engines will fire, slowing it down and straightening the spacecraft for what engineers hope will be a steady, soft landing in the Elysium Planitia region of Mars , about 373 miles (600 km) north of the Curiosity rover’s initial landing site at Gale Crater. Elysium Planitia was chosen for its flat terrain and equatorial location, which will allow the stationary probe’s solar panels to collect sufficient sunlight to power it all year long.Why all the hype, when this is just another landing on Mars? Because despite all the careful calculations, technological improvements, and system backups, there is still only one chance to get this landing right. Everything, from the angle at which the probe first hits the martian atmosphere, to the exact time its three legs pop free, ready to absorb the shock of landing, must go right — and in the right order. What’s more, the current light travel time between Mars and Earth — the time it takes any signal sent from Mars to reach us here on Earth — is eight minutes seven seconds. That’s longer than the seven-minute landing sequence. The entire landing will have already taken place — and succeeded or failed — before we even know it has begun.Add to that the fact that fewer than half of all attempted Mars landings have ended successfully, and it makes sense that there will definitely be some nervous energy as these events play out on another planet, with engineers blind to the process until it is complete. The only companions InSight will have are its two Mars Cube One (MarCO) CubeSats, and the Mars Reconnaissance Orbiter (MRO). Both MarCO and MRO will communicate with InSight via UHF radio signal, but while both will also send this information back to Earth (via the X band) following landing, only MarCO will be able to do so immediately. MRO cannot receive and transmit data simultaneously, so it is MarCO that will likely inform Earth first of the landing’s outcome. These two tiny CubeSats, each measuring under 15 inches (37 centimeters) along their longest side, will act as InSight’s personal messengers, proving that CubeSats can fill this vital communications gap on future missions to Mars (and other planets). They will also provide additional landing data and telemetry for engineers to analyze after the fact, aimed at improving future missions' shots at successfully touching down on Mars.You can stay up to date on InSight’s status by checking the mission’s Landing Status page, as well as by tuning in to NASA’s live coverage on NASA TV