Human Mars missions are still stuck in sci-fi for many reasons, one being that the right propulsion technology hasn’t yet launched. Now deep space propulsion is about to take off.
The Space Subcommittee of the House Committee on Space, Science and Technology recently held a hearing with several experts who are also part of the Next Space Technologies for Exploration Partnerships (NextSTEP) taking a stand for advancing travel through the final frontier. Technological breakthroughs brought before Congress included ways to amp up speed, payloads and propulsion. There was one in particular that surprised even the cynics.
NASA’s Asteroid Redirect Mission (ARM) program was all but extinct until leaders in the space industry highlighted the propulsion advances brought about by developments for the program meant to prepare astronauts for Mars by robotically redirecting an asteroid to orbit the Moon. They would then explore this asteroid and use it to test out tech prototypes as a precursor to putting boots on the Red Planet. Even with the current administration’s planned funding cuts that threaten to be its last gasp, ARM is spawning another arm.
NextSTEP connects the public and private sector in space exploration by joining forces with NASA and using commercial developments (whose funding can’t be blasted by the government) to probe new possibilities for extended missions to Mars and beyond. ARM had made some serious leaps forward in solar electric propulsion (SEP) aka ion propulsion. This is a more efficient alternative to the chemical rockets and thrusters on most spacecraft, which rely on heavy fuel. Solar panels use radiation to power the ionizing—electrically charging—of a gas, which creates enough thrust to propel the craft while minimizing weight.
SEP is the same type of technology that sustains the Dawn mission which has been exploring the asteroid belt for a decade, and thruster advancements intended for ARM have tripled its power, increased its efficiency by half and drastically reduced the amount of required propellant. It could someday send off payloads that will give rise to a human colony on Mars.
“High power solar electric propulsion capabilities, scalable to handle power and thrust levels needed for deep space human exploration missions, are considered essential to efficiently and affordably perform human exploration missions to distant destinations such as Mars,” stated Bill Gerstenmaier, NASA associate administrator for the Human Exploration and Operations Directorate, at the hearing.
The only con in the galaxy of pros SEP brings to space exploration is that such engines is that, unlike chemical rockets, they are unable to accelerate fast enough to defy Earth’s gravity and launch a spacecraft off the surface. That all changes once it’s shot into space. Outside our atmosphere, SEP can fire for years on end. Superpowered electric propulsion will operate at levels that start at hundreds of kilowatts, eventually switching out solar electric power for nuclear electric power the further away future missions take us from the sun. NASA foresees sending Earthlings to Mars by using SLS (Space Launch System), the shiny new rocket it’s currently developing, together with SEP to propel immense payloads towards the planet before the first human footsteps land in its red dust. But first, we actually have to blast something running on one of these engines into space.
“A key goal is to demonstrate these new capabilities in the next few years and infuse them into human missions in the next decade,” said Gerstenmaier. Watch out, Mars.