Mars’s First Rocket Launch Will begin In Midair
To return samples from the Red Planet to Earth, NASA’s Mars Ascent Vehicle will attempt a wildly unconventional launch.
The rover will pick up rock samples left by a previous mission on Mars within a decade. The rocket will be mounted on a flat piece of Earth’s surface and loaded with the explorers. After the rocket’s hatch shuts, the platform will then throw it upward on its side, similar to how a football is thrown. Upon ignition, the engine will propel the rocket toward Mars’ orbit, where a spacecraft will catch the rocket’s samples so they can be ferried back to Earth and studied by researchers looking for signs of past life on Mars. The Mars Sample Return might sound like the wildest interplanetary shuffle ever created, but scientists simply call it the most epic game of catch ever invented.
According to lead engineer Christopher Chatellier of NASA’s Jet Propulsion Laboratory (JPL), “it’s never been done before.” But it has been envisioned and planned for decades.
NASA’s Perseverance rover landed one year ago in Jezero Crater to explore the delta of an aeons-old river, which is being searched as a potential site for life remnants from when the planet was a wetter, warmer place. Perseverance has been collecting samples from inside the crater using its extendable arm and drill. The samples are likely to be billions of years old. Thomas Zurbuchen, director of NASA’s science missions, says the samples will provide crucial clues as to whether life once flourished on Mars’ surface. A total of dozens of samples will be placed in small cigar-like tubes to be cached on the surface awaiting collection later.
There is already some clarity about how this collection will proceed, but key details remain to be determined. Could you please tell me, for example, where the samples will be cached, and how many locations? The European Space Agency (ESA) is building the “fetch rover” that will collect the rocks. How will it look? How are the samples going to be returned to Earth successfully after rocketing off Mars’ surface? Zurbuchen says the launch from another planet will be history-making. This brings us answers to questions about our neighbouring planet that cannot be answered otherwise.”
We have now made great progress in the details of that crucial last question. A potential $194-million NASA contract was awarded to Lockheed Martin last month for the construction of the Mars Ascent Vehicle (MAV), a relatively small rocket intended to launch Perseverance’s samples into orbit. As engineers design components for the MAV, they must solve a number of unique challenges for this first-of-its-kind mission. Although its gravity is just one-third that of Earth’s, the Red Planet must be overcome. Mars’s tenuous atmosphere, 100 times that of Earth’s, will make the launch unlike anything tried on Earth, or from a moon or an asteroid, where successful samples have been returned previously. In addition, the MAV must launch autonomously and flawlessly, from millions of kilometres away.
In 2026 or later, NASA plans to launch the MAV to Mars, but some people are expecting it to arrive in 2028. In the same manner, as NASA’s InSight lander, the lander will be housed in a landing platform. 2018 was the year that InSight successfully landed on Mars after performing a propulsion landing rather than making use of the Sky Crane system common for Perseverance and Curiosity. It will take 28 months to get the MAV to Mars so that it lands either in or near Jezero during local summertime. According to Lockheed Martin’s business development lead for deep space exploration, Dave Murrow, the spacecraft needs to arrive at Mars during the right season in order to avoid dust storms.
In order to facilitate an easy subsequent liftoff, the lander will aim to land in a benign part of the crater after safely navigating the atmosphere. It’s important to find a landing site that’s flat and devoid of rocks,” Murrow says. “We will choose the landing site in the coming years.” Without scientific instrumentation, the lander will serve primarily for protecting the MAV on the surface, deploying ESA’s fetch rover, and finally launching the sample-filled MAV back to orbit.
It will be challenging to prevent the aluminium-based fuel used by the MAV’s propulsion systems from freezing, which is supplied by Northrop Grumman. Often, the surface of Mars has temperatures as low as –60 degrees Celsius, so the lander will use solar-powered electric heaters installed in an insulated container aptly called an igloo to warm the MAV. According to engineers, this approach could allow the MAV to remain on the surface for approximately one Earth year, which should provide the fetch rover with enough time to collect samples from Perseverance’s cache.
The fun really starts then. Chatellier and his team at JPL have been tackling the difficult problem of launching small rockets from Mars for several years. According to Chatellier, the basic idea was to point the MAV on a rail and launch it from the platform. The rail would have to be heavy and nearly as long as the lander itself. Angela Jackman, project manager of NASA’s Marshall Space Flight Center’s MAV program, says that there are not a lot of things holding the lander in place. It would be possible to kick the entire platform up into the air to strike the rocket without the counterweight of a heavy rail. It would also be very challenging to test such a system on Earth in conditions corresponding to those on Mars.
Therefore, the team decided on a different approach: What if the rocket could be tossed a few meters above the surface, providing more clearance for blastoff? Even though it may seem counterintuitive to launch an unlit rocket, Chatellier says it simplifies the testing and design process quite a bit. Cold launch systems are not new: the U.S. army’s Peacekeeper missiles were lofted from silos with steam pressure before they were ignited between 1987 and 2005. MAVs are launched off the ground, just like standard missiles from a fighter jet, Chatellier explains.
A vertically ejected controlled tip-off release was developed, dubbed VECTOR, or Vertically Ejected Controlled Tip-Off Release. Two years ago, the JPL team accomplished 23 “throws” using VECTOR, with cables catching the rocket mid-air during testing. VECTOR is designed to raise the MAV from Mars using a force similar to a strong human punch at a speed of about five meters per second. (The system in its entirety, including the rocket ignition, will be launched for the first time from Mars.) The VECTOR will also aid in aiming the MAV once its engine is ignited, by causing the spacecraft to rotate by 45 degrees, lifting it up so its two-stage rocket can send the basketball-size sample capsule into orbit 400 kilometres above the planet after it ignites its engine. As long as Perseverance remains operational, everyone on Earth will be able to watch the launch from a safe distance.
Following this rendezvous, a European-built spacecraft will take the sample capsule from Martian orbit, stowing it for its return to Earth. With its durable samples intact, the capsule will intentionally crash land in the Utah desert in the early 2030s after leaving Mars.
As audacious as it may seem, VECTOR appears to be the best option for returning the half-kilograms worth of samples collected by Perseverance on Earth. Chatellier says that everyone thought Sky Crane was crazy. He and his team think they will have finished about 50 tests of the system by the end of the decade so that it can be launched to Mars in 2028. The physics of how the rocket will be hurled aloft, as well as other details still need to be worked out, but the aim is to have a system that can handle whatever conditions Mars throws at it. We cannot afford to make mistakes. Chatellier says, “We want to make sure the system is designed to work even under the harshest conditions on Mars.”.
The dream of returning samples from Mars to Earth could be a reality in a decade. A small rocket can land on Mars, be thrown into the thin, cold air and be launched back into space. This will still be a historic event even if the materials it eventually helps return aren’t alive. Jackman says he and his friends geek out on the topic a lot. “It’s just incredible.”