Yes, several organizations are developing proposals for possible missions. None of those proposals are concrete, but that could change in the near future. Here’s an overview:
NASA’s Journey to Mars
NASA’s strategy for a manned Mars expedition is probably the most promising, given that the agency has actually landed robotic craft on the planet’s surface. The administration envisions a multi-stage approach in which the moon serves as a stepping stone to Mars.
Currently, NASA is working on sending new technology to the moon in preparation for human missions there. In the next five years, NASA plans to launch a spaceship to stay in orbit around the moon, offering opportunities to "test new tools, instruments and equipment that could be used on Mars, including human habitats, life support systems, and technologies and practices that could help [them] build self-sustaining outposts away from Earth."
NASA’s goal is to land crewed missions on Mars in the 2030s.
"If we bring together the capabilities and resources of our international and commercial partners to take us forward to the Moon and on to Mars, we will demonstrate to people around the world the power of a unified purpose," the administration wrote on its website. "It will serve as an unparalleled and inspiring example of what humanity can do when it comes together to achieve a common goal for the common good."
Mars Base Camp
A proposed component of the NASA plan, Mars Base Camp was developed by Lockheed Martin. It would consist of a space station orbiting Mars capable of supporting crews on 1,000-day missions. It could generate hydrogen and oxygen from water, and craft sent from Base Camp would be reusable.
"With these additional developments, the Mars Base Camp concept can be seen as a core system that pivots humanity into a viable, sustainable long-term Mars exploration program," Lockheed Martin scientists wrote in a technical paper released by the company.
SpaceX’s Mars Missions
Private space exploration company SpaceX wants to beat NASA to Mars, and a first cargo mission is planned for 2022.
"The objectives for the first mission will be to confirm water resources, identify hazards, and put in place initial power, mining, and life support infrastructure," SpaceX’s website reads. "A second mission, with both cargo and crew, is targeted for 2024, with primary objectives of building a propellant depot and preparing for future crew flights. The ships from these initial missions will also serve as the beginnings of the first Mars base, from which we can build a thriving city and eventually a self-sustaining civilization on Mars."
Over the last few decades, a number of private companies and government organizations have aborted missions to the planet.
For example, in 2012, a Dutch company called Mars One envisioned a mission that would put the components of a base on Mars by 2023. However, that company went bankrupt in January 2019.
So, will we really land on Mars by 2024, or even 2030? It’s possible, though unlikely. Before humanity heads to Mars, we’ll need to figure out an incredible number of technical issues, and that’s not cheap—NASA plans on capping costs at $220 billion. However, engineers at both SpaceX and NASA insist that the mission will eventually happen, and they’ve set aspirational deadlines for the goal in order to maintain public interest.
"To many engineers, students and others, if you tell someone that something is going to happen in twenty years, twenty years is never," Josh Brost, a SpaceX executive, said at the 2018 Humans to Mars Summit. "Fifteen years is hard to be motivated. You have to be something that’s sub-a decade to get large masses of people excited about what you’re trying to accomplish."