WASHINGTON — Companies ranging from Blue Origin to a startup are proposing concepts for missions to visit an asteroid before it makes a very close flyby of Earth in five years.

The asteroid Apophis, about 350 meters across, will pass closer to the Earth than geostationary orbit on April 13, 2029, a flyby that scientists say happens only once every thousand years for an asteroid of that size. There is zero chance that the asteroid will hit Earth either in the 2029 flyby or subsequent flybys into the next century, but the close approach is of scientific interest.

NASA has already agreed to send one mission to Apophis, using the main spacecraft for the OSIRIS-REx asteroid sample return mission. That mission, rechristened OSIRIS-APEX, will rendezvous with Apophis shortly after the asteroid’s 2029 flyby.

Scientists, though, are interested in sending additional missions to Apophis, particularly those that would fly by or orbit the asteroid before the flyby so that researchers can better the understand what impact tidal forces from the flyby might have on the asteroid. Several such mission concepts were discussed during an April 22–23 workshop at a European Space Agency center in The Netherlands.

That includes a proposal by Blue Origin to use its Blue Ring spacecraft to send payloads to Apophis. That vehicle could carry up to 13 payloads, such as individual instruments or deployable spacecraft, to Apophis, arriving at the asteroid before its closest approach to Earth and remaining there through the flyby.

Steve Squyres, chief scientist at Blue Origin, pitched Blue Ring as a cost-effective, low-risk approach to getting instruments or other spacecraft to Apophis. “This allows the cost to be shared among many different payload providers,” he said, but did not state a cost either for the overall mission or individual payloads. He said the Apophis mission would likely be the fifth Blue Ring mission Blue Origin flies, reducing technical risk.

A ”very preliminary and very conservative” mission profile he presented showed the Blue Ring mission launching in October 2027 — ironically on a Falcon 9 and not the company’s own New Glenn vehicle — arriving at Apophis in January 2029 carrying two metric tons of payload. “We haven’t optimized this yet. We can do better,” he said, including using New Glenn to launch the mission.

Another concept presented at the workshop provides new life to a proposal previously studied by the Jet Propulsion Laboratory called the Distributed Radar Observations of Interior Distributions (DROID), which would send a spacecraft to rendezvous with Apophis and deploy two cubesats to perform a “CAT scan” of the asteroid’s interior, said JPL’s Lorraine Fesq.

The DROID team is now working with startup Exploration Labs, or ExLabs, which has plans for its own Apophis mission and long-term ambitions for asteroid mining. “We got very creative and came up with this new business model,” Fesq said.

Caltech, which operates JPL for NASA, is forming a partnership with ExLabs where the company funds a Phase A design study for the mission. Caltech, she said, will work to raise private funding for the later development phases of the mission, whose cost is undisclosed. That would allow the mission to proceed with a launch by May 2028 and arrival at the asteroid in February 2029.

“We saw this opportunity with JPL as a fantastic opportunity for tech transfer and for us to be able to truly understand what it takes to get to an asteroid,” said Tom Cooley, former chief scientist for the Space Vehicles Directorate at the Air Force Research Lab and now senior vice president of ExLabs, in a separate presentation at the workshop.

The mission would use the company’s Space Exploration and Resource Vehicle, or SERV, spacecraft that the company is developing. Cooley said that the spacecraft can accommodate additional payloads from other users beyond DROID.

The workshop featured several other presentations on mission concepts that could visit Apophis before its Earth flyby and thus complement OSIRIS-APEX. One of the most promising is repurposing the Janus spacecraft developed as part of a NASA program to fly by binary asteroids. Delays in the launch of Psyche, on which Janus was a rideshare, meant that Janus could not carry out that original mission and the spacecraft, essentially complete, were put into storage.

The European Space Agency is studying two Apophis mission concepts. One called Rapid Apophis Mission for Space Safety, or RAMSES, would be based on the Hera asteroid mission slated to launch later this year. A second mission, a cubesat called Satis, would be cheaper to develop but carry higher risk.

A common theme for mission concepts discussed at the meeting was funding, or lack thereof. NASA has previously stated its constrained planetary science budget cannot accommodate new missions, even involving a repurposed set of spacecraft like Janus, a point agency officials at the workshop reiterated. A hurdle for RAMSES is that work on the mission, including acquiring key spacecraft components, needs to begin before member states meet for the next major ministerial meeting in late 2025 where they would approve funding for the mission.

Squyres, in a discussion near the end of the two-day meeting, expressed hope that agencies might be able to join forces on an Apophis mission of some kind. “What we hear from one after another after another is that we don’t have the resources available,” to do a mission individually, he said. “I can’t help but hope that the ensemble of those space agencies, together, worldwide, have the resources, if we can find a way to pool the resources of multiple space agencies to pull something off soon. This a doable thing.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...