NASA Posts Revised Janus Asteroid Mission RFI

After a four-week hiatus, NASA has republished a Request for Information (RFI) seeking ideas on how to repurpose a pair of small spacecraft, known as Janus, for an asteroid mission.

The RFI, originally released on August 30, solicited input for a potential mission to visit the asteroid Apophis ahead of its close encounter with Earth in April 2029. However, the updated version, reposted on September 27, removed significant technical details about the spacecraft.

A Call for a Non-NASA-led Mission

The original RFI, published on August 30, was part of NASA's exploration into potential uses for the Janus spacecraft, currently in storage. NASA expressed particular interest in developing a mission to Apophis that would not be led by the agency itself.

“Specifically, NASA is interested in facilitating the development of a non-NASA-led mission to Apophis utilizing the agency’s near-fully developed but still un-flown Janus spacecraft” - NASA

The agency set an October 1 deadline for responses, seeking innovative proposals for the spacecraft. But by the end of that same day, NASA unexpectedly pulled down the document.

"The RFI document has been pulled down so it can be corrected," - NASA

NASA promised to repost the document "as soon as possible."

The Revised RFI: What Changed?

Four weeks later, on September 27, NASA fulfilled its promise, reposting the RFI with a new deadline of October 28. However, the agency did not provide any explanation for what had been corrected.

“The new file does not indicate specific changes. Therefore, all respondents must read the contents of this restored RFI file in their entirety. Please read carefully,” - NASA

A close comparison of the original and revised versions of the RFI reveals that the most significant changes were in the level of technical detail provided about the Janus spacecraft.

In the original version, NASA included tables that detailed mass budgets for the two Janus spacecraft—slightly different from one another—as well as their power margins. These tables were removed from the revised version, as was a diagram showing an internal schematic of one of the spacecraft.

Additionally, the revised RFI provided only general descriptions of spacecraft subsystems, such as propulsion and communications, noting details like the number of thrusters.

The original version, in contrast, listed specific companies and models for these subsystems. For instance, it mentioned that the spacecraft’s propulsion system used IFM Nano electric thrusters from Enpulsion.

NASA has not provided any public explanation for the removal of these details; sespite repeated requests for comment from the media. Furthermore, the agency stated that it would not accept any responses submitted prior to the September 27 revision, despite the initial October 1 deadline that had remained unchanged until the revised document was posted.

Industry Response and Scientific Interest

The sudden changes left industry sources and potential respondents with little guidance. Many reported receiving no clear information from NASA on how to proceed during the gap between the two RFI releases. Some also expressed concern about how the changes might impact their proposed missions.

While NASA's plans for Apophis are already underway—its OSIRIS-APEX spacecraft, part of the OSIRIS-REx asteroid sample return mission, will observe the asteroid after its Earth flyby—scientists have a keen interest in studying Apophis before the encounter. They hope to learn whether the gravitational effects of the close approach to Earth will alter the asteroid in any noticeable way.

Observations made before and after the flyby could provide unprecedented insight into how such encounters impact asteroids.

The Janus spacecraft, originally developed to fly by binary asteroids as secondary payloads on NASA’s Psyche mission, may offer a unique opportunity for pre-flyby observations of Apophis. However, delays in the launch of Psyche meant that the Janus spacecraft missed their original targets. Since then, NASA has placed the spacecraft—nearly complete—into storage.

In February 2024, NASA hosted a workshop to explore "innovative approaches for a low-cost mission" to Apophis, with Janus being one potential option. However, agency officials noted earlier this year that budgetary constraints made it challenging to pursue such a mission without external funding or collaboration.

The Path Forward

As of now, NASA appears committed to facilitating a non-NASA-led mission utilizing Janus, but the technical revisions in the RFI suggest a possible shift in approach. The removal of specific technical details could signal that NASA is seeking a broader range of proposals without prescribing exact parameters for the spacecraft's use.

With a new deadline set for October 28, the window for potential missions to Apophis remains open. Scientists, space industry professionals, and private companies now have a second chance to propose how the Janus spacecraft might make a valuable contribution to our understanding of one of the most intriguing near-Earth objects in the solar system.